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diff --git a/doc/src/declarative/anchor-layout.qdoc b/doc/src/declarative/anchor-layout.qdoc index 0655fdb..4dd5eb9 100644 --- a/doc/src/declarative/anchor-layout.qdoc +++ b/doc/src/declarative/anchor-layout.qdoc @@ -28,15 +28,16 @@ /*! \page qml-anchor-layout.html \target anchor-layout -\title Anchor-Based Layout in QML - -\section1 Overview +\contentspage QML Features +\previouspage {Using QML Positioner and Repeater Items}{Component Layouts} +\nextpage {QML Mouse Events}{Mouse Events} +\title Anchor-based Layout in QML In addition to the more traditional \l Grid, \l Row, and \l Column, QML also provides a way to layout items using the concept of \e anchors. Each item can be thought of as having a set of 7 invisible "anchor lines": \l {Item::anchors.left}{left}, \l {Item::anchors.horizontalCenter}{horizontalCenter}, -\l {Item::anchors.right}{right}, \l {Item::anchors.top}{top}, +\l {Item::anchors.right}{right}, \l {Item::anchors.top}{top}, \l {Item::anchors.verticalCenter}{verticalCenter}, \l {Item::anchors.baseline}{baseline}, and \l {Item::anchors.bottom}{bottom}. diff --git a/doc/src/declarative/animation.qdoc b/doc/src/declarative/animation.qdoc index 59bf8f6..129fa34 100644 --- a/doc/src/declarative/animation.qdoc +++ b/doc/src/declarative/animation.qdoc @@ -27,308 +27,214 @@ /*! \page qdeclarativeanimation.html -\title QML Animation +\ingroup qml-features +\contentspage QML Features +\previouspage {QML States}{States} +\nextpage {QML Data Models}{Structuring Data with Models} +\title QML Animation and Transitions + +\keyword qml-animation-elements +\section1 Animation and Transitions Elements +\list +\o \l {Transition} - Animates transitions during state changes +\o \l {SequentialAnimation} - Runs animations sequentially +\o \l {ParallelAnimation} - Runs animations in parallel +\o \l {Behavior} - Specifies a default animation for property changes +\o \l {PropertyAction} - Sets immediate property changes during animation +\o \l {PauseAnimation} - Introduces a pause in an animation +\o \l {SmoothedAnimation} - Allows a property to smoothly track a value +\o \l {SpringAnimation} - Allows a property to track a value in a spring-like motion +\o \l {ScriptAction} - Runs scripts during an animation +\endlist +\keyword qml-property-animation-elements +Elements that animate properties based on data types +\list +\o \l {PropertyAnimation} - Animates property changes +\o \l {NumberAnimation} - Animates properties of type qreal +\o \l {Vector3dAnimation} - Animates properties of type QVector3d +\o \l {ColorAnimation} - Animates color changes +\o \l {RotationAnimation} - Animates rotations +\o \l {ParentAnimation} - Animates parent changes +\o \l {AnchorAnimation} - Animates anchor changes +\endlist -In QML, animations are created by applying animation objects to object property -values to gradually change them over time. Animation objects are created from -the built-in set of animation elements, which can be used to animate various -types of property values. In addition, animation objects can be applied in -different ways depending on the context in which they are required. +In QML, animations are created by applying animation elements to property +values. Animation elements will interpolate property values to create smooth +transitions. As well, state transitions may assign animations to state changes. To create an animation, use an appropriate animation element for the type of the property that is to be animated, and apply the animation depending on the -type of behavior that is required. This page describes the \l {Types of -Animations} that can be created and the \l {Animation Elements} that are used -to create these animations. - - -\section1 Types of Animations - -An animation is created in different ways depending on the context in which it -is required. Suppose a \l Rectangle's movement - that is, changes in its \c x -or \c y property values - should be animated. The semantics of the animation -differ depending on whether you want to create: - -\list -\o An animation that moves the \l Rectangle as soon as it is created, to a -known position -\o An animation that only triggers when the \l Rectangle is moved by external -sources - for example, when the mouse is clicked, animate the movement to the -mouse position -\o An animation that triggers when a particular signal is received -\o A standalone animation that is not bound to the \l Rectangle's movement, but -instead can be started and stopped from script as required -\o An animation that only triggers during \l{QML States}{state changes} -\endlist +type of behavior that is required. -To support these different types of animation methods, QML provides several -methods for defining an animation. These are: +\keyword qml-triggering-animations +\section1 Triggering Animations -\list -\o Creating an \l{Animations as Property Value Sources}{animation using -property value sources}, to immediately animate a specific property -\o Using \l{Behavioral Animations}{behavioral animations}, which are triggered -when a property changes value -\o \l{Animations in a Signal Handler}{Within a signal handler}, to be triggered -when a signal is received -\o As a \l{Standalone Animation}{standalone animation}, that can be -started/stopped from script and can be rebound to different objects -\o Using \l{Transitions}{transitions}, to provide animations between \l{QML -States}{state changes} -\endlist +There are several ways of setting animation to an object. -These methods are demonstrated below. Notice these examples use -PropertyAnimation, which is one of several QML elements that can be used to -create an animation. See the \l {Animation Elements} section further below for -details. +\keyword qml-direct-animation +\section2 Direct Property Animation +To create an immediate movement or animated movement, set the property value +directly. This may be done in signal handlers or attached properties. +\snippet doc/src/snippets/declarative/animation.qml direct property change -\section2 Animations as Property Value Sources +However, to create more control, \e {property animations} apply smooth movements +by interpolating values between property value changes. Property animations +provide timing controls and allows different interpolations through +\l{qml-easing-animation}{easing curves}. -An animation is applied as a \l{QDeclarativePropertyValueSource}{property value -source} using the \e Animation \bold on \e Property syntax. Here is a \l -Rectangle whose movement is animated using this method: +\snippet doc/src/snippets/declarative/animation.qml property animation -\snippet doc/src/snippets/declarative/animation-propertyvaluesource.qml 0 - -This applies a PropertyAnimation to the \l Rectangle's \c x and \c y properties -to animate from their current values (i.e. zero) to 50, over 1000 milliseconds. -The animation starts as soon as the \l Rectangle is loaded. To animate from -specific values rather than the current \c x and \c y values, set the -PropertyAnimation's \l {PropertyAnimation::}{from} property. - -Specifying an animation as a property value source is useful for animating a -property to a particular value as soon as the object is loaded. - - -\section2 Behavioral Animations - -Often an animation should be applied whenever a particular property value -changes. In these cases, a \l Behavior can be used to specify a default -animation for a property change. Here is an example: - -\snippet doc/src/snippets/declarative/animation-behavioral.qml 0 - -This \l Rectangle has \l Behavior objects applied to its \c x and \c y -properties. Whenever these properties change (in this case, when the mouse is -clicked within the parent \l Item), the PropertyAnimation objects defined -within the behaviors will be applied to these properties, thus animating the \l -Rectangle's movement to its new position. Unlike the method of \l {Animations -as Property Value Sources}{defining an animation as a property value source}, -which creates a one-time animation that animates a property to a known value, a -behavioral animation is an animation that is triggered \e {in response to} a -value change. - -Any changes to these properties will trigger their animations. If \c x or \c y -were bound to other properties, and those properties changed, the animation -would be triggered. The \l{Behavior::}{enabled} property can be used to force a -\l Behavior to only apply under certain circumstances. - -Notice that unlike for property value source animations, the -PropertyAnimation's \l {PropertyAnimation::}{from} and \l -{PropertyAnimation::}{to} properties do not need to be defined because these -values are already provided, respectively, by the \l Rectangle's current values -and the new values set in the \c onClicked handler. If these properties were -defined anyway, they would override the default values. +Specialized \l{qml-property-animation-elements}{property animation elements} +have more efficient implementations than the \l{PropertyAnimation} element. They +are for setting animations to different QML types such as \c int, \c color, and +rotations. Similarly, the \l{ParentAnimation} can animate parent changes. -See the \l {declarative/animation/behaviors}{Behaviors example} for a -demonstration of behavioral animations. +See the \l {qml-controlling-animations}{Controlling Animations} section for more +information about the different animation properties. +\keyword qml-transition-animations +\section2 Transitions during State Changes -\section2 Animations in a Signal Handler +\l{QML States}{States} are property configurations where a property may have different values to reflect different states. State changes introduce +abrupt property changes; animations smooth transitions to produce visually +appealing state changes. -An animation can be created within a signal handler to be triggered when the -signal is received. For example: - -\snippet doc/src/snippets/declarative/animation-signalhandler.qml 0 +The \l{Transition} element can contain +\l{qml-animation-elements}{animation elements} to interpolate property changes +caused by state changes. To assign the transition to an object, bind it to the +\c transitions property. -The PropertyAnimation is triggered when the MouseArea is clicked, animating the -\c x and \c y properties to a value of 50 over 1000 milliseconds. Since the -animation is not bound to a particular object or property, it must define the -\l {PropertyAnimation::}{target} and \l {PropertyAnimation::}{property} (or \l -{PropertyAnimation::}{targets} and \l{PropertyAnimation::}{properties}) values. -The \l {PropertyAnimation::}{to} property is also required to specify the new -\c x and \c y values. +A button might have two states, the \c pressed state when the user clicks on the +button and a \c released state when the user releases the button. We can assign +different property configurations for each state. A transition would animate the +change from the \c pressed state to the \c released state. Likewise, there would +be an animation during the change from the \c released state to the \c pressed +state. +\snippet doc/src/snippets/declarative/animation.qml transition animation -\section2 Standalone Animations +Binding the \c to and \c from properties to the state's name will assign that +particular transition to the state change. For simple or symmetric transitions, +setting the to \c to property to the wild card symbol, "\c{*}", denotes +that the transition applies to any state change. -Animations can also be created as ordinary QML objects that are not bound to -any particular objects and properties. Here is an example, using a -PropertyAnimation object. The animation is explicitly started when the -\l Rectangle is clicked: +\snippet doc/src/snippets/declarative/animation.qml wildcard animation -\snippet doc/src/snippets/declarative/animation-standalone.qml 0 +\section2 Default Animation as Behaviors -A standalone animation object is not running by default and must be started explicitly -using the \l {Animation::}{running} property or \l {Animation::}{start()} and -\l {Animation::}{stop()} methods. Since the animation is not bound to a -particular object or property, it must define the \l -{PropertyAnimation::}{target} and \l {PropertyAnimation::}{property} (or \l -{PropertyAnimation::}{targets} and \l{PropertyAnimation::}{properties}) values. -The \l {PropertyAnimation::}{to} property is also required to specify the new -\c x and \c y values. (The \l {PropertyAnimation::}{from} value can optionally -be provided.) +Default property animations are set using \e {behavior animations}. Animations +declared in \l {Behavior} elements apply to the property and animates any +property value changes. However, Behavior elements have an +\c enabled property to purposely enable or disable the behavior animations. -Standalone animations are useful when an animation is not targeted towards a -single object property and the animation should be explicitly started and -stopped. +A ball component might have a behavior animation assigned to its \c x, \c y, and +\c color properties. The behavior animation could be set up to simulate an +elastic effect. In effect, this behavior animation would apply the elastic +effect to the properties whenever the ball moves. +\snippet doc/src/snippets/declarative/animation.qml behavior animation -\section2 Transitions +There are several methods of assigning behavior animations to properties. The +\c{Behavior on <property>} declaration is a convenient way of assigning a +behavior animation onto a property. -Transitions are used to describe the animations to be applied when a \l {QML -States}{state change} occurs. To create a transition, define a \l Transition -object and add it to an item's \l {Item::}{transitions} property. An example: +See the \l {declarative/animation/behaviors}{Behaviors example} for a +demonstration of behavioral animations. -\snippet doc/src/snippets/declarative/animation-transitions.qml 0 +\section1 Playing Animations in Parallel or in Sequence -The PropertyChanges object in the \e moved state defines that when the -\l Rectangle is in this state, its position should be changed -to (50, 50). When the \l Rectangle changes to the \e moved state, the -\l Transition will be triggered, and the transition's \l PropertyAnimation will -animate the changes in the \c x and \c y properties to their new values. -The animation will not be applied at any time other than during the state -change. +Animations can run \e {in parallel} or \e {in sequence}. Parallel animations +will play a group of animations at the same time while sequential animations +play a group of animations in order: one after the other. Grouping animations in +\l{SequentialAnimation} and \l{ParallelAnimation} will play the animations in +sequence or in parallel. -Notice the example does not set any \l {PropertyAnimation::}{from} and \l -{PropertyAnimation::}{to} values for the PropertyAnimation. As a convenience, -these properties are automatically set to the values of \c x and \c y before -and after the state change, respectively. However, they can be explicitly set -if these values should be overrided. +A banner component may have several icons or slogans to display, one after the +other. The \c opacity property could transform to \c 1.0 denoting an opaque +object. Using the \l{SequentialAnimation} element, the opacity animations will +play after the preceding animation finishes. The \l{ParallelAnimation} element +will play the animations at the same time. -Also notice the PropertyAnimation does not need to specify a \l -{PropertyAnimation::}{target} object; any \c x or \c y value of any object that -has changed during the state change will be animated. However, the target can -be set if the animation should be restricted to certain objects. +\snippet doc/src/snippets/declarative/animation.qml sequential animation -The top-level animations in a \l Transition are run in parallel. To run them -one after the other, use a SequentialAnimation, as shown below in \l {Grouping -Animations}. +Once individual animations are placed into a SequentialAnimation or +ParallelAnimation, they can no longer be started and stopped independently. The +sequential or parallel animation must be started and stopped as a group. -See the \l Transition documentation for more information. +The \l SequentialAnimation element is also useful for playing +\l{qml-transition-animations}{transition animations} because animations are +played in parallel inside transitions. +See the \l {declarative/animation/basics}{Animation basics example} for a +demonstration of creating and combining multiple animations in QML. -\section1 Animation Elements +\keyword qml-controlling-animations +\section1 Controlling Animations -To create an animation, choose from one of the built-in QML animation elements. -While the above examples are demonstrated using PropertyAnimation, they could -have used other elements depending on the type of the property to be animated -and whether a single or multiple animations are required. +There are different methods to control animations. -All animation elements inherit from the \l Animation element. It is not +\section2 Animation Playback +All \l{qml-animation-elements}{animation elements} inherit from the \l Animation element. It is not possible to create \l Animation objects; instead, this element provides the -essential properties and methods for animation elements. For example, it allows -animations to be started and stopped through the \l {Animation::}{running} -property and the \l{Animation::}{start()} and \l{Animation::}{stop()} methods. -It can also define the number of \l {Animation::}{loops} for an animation. +essential properties and methods for animation elements. Animation elements have +\c{start()}, \c{stop()}, \c{resume()}, \c{pause()}, \c {restart()}, and +\c{complete()} -- all of these methods control the execution of animations. +\keyword qml-easing-animation +\section2 Easing -\section2 Property Animation Elements +Easing curves define how the animation will interpolate between the start value +and the end value. Different easing curves might go beyond the defined range of +interpolation. The easing curves simplify the creation of animation effects such +as bounce effects, acceleration, deceleration, and cyclical animations. -PropertyAnimation is the most basic animation element for animating a property. -It can be used to animate \c real, \c int, \c color, \c rect, \c point, \c size, and -\c vector3d properties. It is inherited by NumberAnimation, ColorAnimation, -RotationAnimation and Vector3dAnimation: NumberAnimation provides a more -efficient implementation for animating \c real and \c int properties, and -Vector3dAnimation does the same for \c vector3d properties. ColorAnimation -and RotationAnimation provide more specific attributes for animating color -and rotation changes. +A QML object may have different easing curve for each property animation. There +are also different parameters to control the curve, some of which are exclusive +to a particular curve. For more information about the easing curves, visit the +\l {PropertyAnimation::easing.type}{easing} documentation. -A ColorAnimation allows color values for the \l {ColorAnimation::}{from} -and \l {ColorAnimation::}{to} properties. The -following animates the rectangle's \l {Rectangle::}{color} property: - -\snippet doc/src/snippets/declarative/animation-elements.qml color +The \l{declarative/animation/easing}{easing example} visually demonstrates each +of the different easing types. -RotationAnimation allows a rotation's direction to be specified. The following -animates the rectangle's \l {Item::rotation} property: +\section2 Other Animation Elements -\snippet doc/src/snippets/declarative/animation-elements.qml rotation +In addition, QML provides several other elements useful for animation: -In addition, the following specialized animation elements are available: +\list +\o PauseAnimation: enables pauses during animations +\o ScriptAction: allows JavaScript to be executed during an animation, and can +be used together with StateChangeScript to reused existing scripts +\o PropertyAction: changes a property \e immediately during an animation, +without animating the property change +\endlist +These are specialized animation elements that animate different property types \list -\o SmoothedAnimation: a specialized NumberAnimation that provides smooth +\o SmoothedAnimation: a specialized NumberAnimation that provides smooth changes in animation when the target value changes -\o SpringAnimation: provides a spring-like animation with specialized -attributes such as \l {SpringAnimation::}{mass}, +\o SpringAnimation: provides a spring-like animation with specialized +attributes such as \l {SpringAnimation::}{mass}, \l{SpringAnimation::}{damping} and \l{SpringAnimation::}{epsilon} \o ParentAnimation: used for animating a parent change (see ParentChange) \o AnchorAnimation: used for animating an anchor change (see AnchorChanges) \endlist -See their respective documentation pages for more details. - - -\section3 Easing - -Any PropertyAnimation-based animations can specify \l -{PropertyAnimation::easing.type}{easing attributes} to control the -easing curve applied when a property value is animated. These control the -effect of the animation on the property value, to provide visual effects like -bounce, acceleration and deceleration. - -For example, this modified version of an \l {Animations as Property Value -Sources}{earlier example} uses \c Easing.OutBounce to create a bouncing effect -when the animation reaches its target value: - -\snippet doc/src/snippets/declarative/animation-easing.qml 0 - -The \l{declarative/animation/easing}{easing example} visually demonstrates each -of the different easing types. +*/ -\section2 Grouping Animations -Multiple animations can be combined into a single animation using one of the -animation group elements: ParallelAnimation or SequentialAnimation. As their -names suggest, animations in a ParallelAnimation are run at the same time, -while animations in a SequentialAnimation are run one after the other. -To run multiple animations, define the animations within an animation group. -The following example creates a SequentialAnimation that runs three animations -one after the other: a NumberAnimation, a PauseAnimation and another -NumberAnimation. The SequentialAnimation is applied as a \l{Animations as -Property Value Sources}{property value source animation} on the image's \c y -property, so that the animation starts as soon as the image is loaded, moving -the image up and down: +\snippet doc/src/snippets/declarative/animation-elements.qml color +\snippet doc/src/snippets/declarative/animation-propertyvaluesource.qml 0 +\snippet doc/src/snippets/declarative/animation-signalhandler.qml 0 +\snippet doc/src/snippets/declarative/animation-standalone.qml 0 +\snippet doc/src/snippets/declarative/animation-transitions.qml 0 \snippet doc/src/snippets/declarative/animation-groups.qml 0 -\image propanim.gif - -Since the SequentialAnimation is applied to the \c y property, the individual -animations within the group are automatically applied to the \c y property as -well; it is not required to set their \l{PropertyAnimation::}{properties} -values to a particular property. - -Animation groups can be nested. Here is a rather complex animation making use -of both sequential and parallel animations: \snippet doc/src/snippets/declarative/animation-groups.qml 1 +\snippet doc/src/snippets/declarative/animation-groups.qml 0 +\image propanim.gif -Once individual animations are placed into a SequentialAnimation or -ParallelAnimation, they can no longer be started and stopped independently. The -sequential or parallel animation must be started and stopped as a group. - -See the \l {declarative/animation/basics}{Animation basics example} for a -demonstration of creating and combining multiple animations in QML. - - - -\section2 Other Animation Elements - -In addition, QML provides several other elements useful for animation: - -\list -\o PauseAnimation: enables pauses during animations -\o ScriptAction: allows JavaScript to be executed during an animation, and can -be used together with StateChangeScript to reused existing scripts -\o PropertyAction: changes a property \e immediately during an animation, -without animating the property change -\endlist - -See their respective documentation pages for more details. - -*/ diff --git a/doc/src/declarative/basicelements.qdoc b/doc/src/declarative/basicelements.qdoc new file mode 100644 index 0000000..0146591 --- /dev/null +++ b/doc/src/declarative/basicelements.qdoc @@ -0,0 +1,114 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of this +** file. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! +\page qmlbasicelements.html +\ingroup qml-features +\contentspage QML Features +\previouspage QML Features +\nextpage {QML Basic Types}{Data Types} + +\title QML Basic Elements + +QML's basic elements allow the easy inclusion of objects into the +scene. + +\section1 Basic Elements +This is a list of some of the elements readily available for users. +\list +\o \l {Item} +\o \l {Rectangle} +\o \l {Image} +\o \l {Text} +\o \l {TextInput} +\o \l {TextEdit} +\o \l {FocusScope} +\o \l {Component} +\o \l {MouseArea} +\endlist + +For a complete list of QML elements, please visit the \l {QML Elements} page. + +\section1 Properties and Qt Declarative Module + +When using QML elements, keep in mind that elements may possess properties that +other elements also possess. This is because QML and its underlying engine is +implemented in C++ using Qt. More importantly, the chain of property inheritance +is directly due to QML's use of the \l {Qt Declarative Module} and Qt's +\l {Meta-Object System}{meta-object} and \l {The Property System}{property} systems. For example, visual elements that have C++ implementation are sublcasses of +\l {QDeclarativeItem}. As a result, elements such as \l {Rectangle} and +\l {Text} elements inherit properties such as \c clip and \c smooth. + +\section1 Item Element + +Many QML elements inherit \l Item properties. \c Item possesses important properties +such as \c focus, \c children, and dimension properties such as \c width and +\c height. Although \c Item has physical properties, it is not a visual element. +Using \c Item as the top-level QML element (as the screen) will not produce a +visual result, use the \l {Rectangle} element instead. Use the \c Item to create +opacity effects, such as when creating an invisible container to hold other +components. + +\section1 Rectangle Element + +The \l Rectangle element is the basic visual element, for displaying different +types of items onto the screen. The \c Rectangle is customizable and utilizes +other elements such as \l Gradient and \l BorderImage for displaying advanced +customized graphics. + +\section1 Image Element + +To insert an image into a QML scene, merely declare an \l Image element. The +\c Image element can load images in formats supported by Qt. + +\section1 Text Elements + +The \l Text and \l TextEdit elements display formatted text onto the screen. +\c TextEdit features multi-line editing while the \l TextInput element is for +single line text input. + +\keyword qml-top-level-component +\section1 Using Elements as the Top-Level Component + +For creating components (or displaying a simple scene), there are different +elements that could be used as the top-level component. To display a simple scene, +a \l Rectangle as the top-level component may suffice. \l Rectangle, +\l FocusScope, \l Component, \l {QML:QtObject} {QtObject}, \l Item, are some of +the commonly used elements as the top-level component. + +When importing components, the top-level component is important because the +top-level component's properties are the only properties exposed to the parent. + +For example, a \c Button component may be implemented using different elements as +its top-level component. When this component is loaded into another QML scene, +the component will retain the top-level component's properties. If a non-visual +component is the top-level component, the visual properties should be aliased to +the top-level to display the component properly. + +For more information on how to build upon QML elements, see the +\l{Importing Reusable Components} document. +*/ diff --git a/doc/src/declarative/basictypes.qdoc b/doc/src/declarative/basictypes.qdoc index f43e22e..cd10e2b 100644 --- a/doc/src/declarative/basictypes.qdoc +++ b/doc/src/declarative/basictypes.qdoc @@ -27,23 +27,26 @@ /*! \page qdeclarativebasictypes.html + \ingroup qml-features + \contentspage QML Features + \previouspage {QML Basic Elements} + \nextpage Property Binding \title QML Basic Types QML has a set of primitive types, as listed below, that are used throughout the \l {QML Elements}. - Some of these types can also be used for defining - \c property values in QML. See \l{Writing QML Components: Properties, Methods and Signals} for the - list of types that can be used for \c property values. - \annotatedlist qmlbasictypes + + To create additional types, such as data types created in C++, read the + \l{Extending QML Functionalities using C++} article. */ /*! \qmlbasictype int \ingroup qmlbasictypes - \brief An integer is a whole number, e.g. 0, 10, or -20. + \brief An integer is a whole number, e.g. 0, 10, or -20. An integer is a whole number, e.g. 0, 10, or -20. The possible \c int values range from around -2000000000 to around 2000000000, @@ -137,7 +140,7 @@ \qmlbasictype url \ingroup qmlbasictypes - \brief A URL is a resource locator, like a file name. + \brief A URL is a resource locator, like a file name. A URL is a resource locator, like a file name. It can be either absolute, e.g. "http://qt.nokia.com", or relative, e.g. @@ -150,9 +153,6 @@ Image { source: "pics/logo.png" } \endqml - \raw HTML - \endraw - \sa {QML Basic Types} */ @@ -215,7 +215,7 @@ /*! \qmlbasictype size \ingroup qmlbasictypes - + \brief A size type has width and height attributes A \c size type has \c width and \c height attributes. @@ -254,7 +254,7 @@ For example, to read the \l {Item::childrenRect.x}{Item::childrenRect} \c rect property: \qml - Rectangle { + Rectangle { width: childrenRect.width height: childrenRect.height @@ -290,7 +290,7 @@ MyDatePicker { minDate: "2000-01-01"; maxDate: "2020-12-31" } \endqml - To read a date value returned from a C++ extension class, use + To read a date value returned from a C++ extension class, use \l{QML:Qt::formatDate()}{Qt.formatDate()} and \l{QML:Qt::formatDateTime()}{Qt.formatDateTime()}. \sa {QML Basic Types} @@ -309,7 +309,7 @@ MyTimePicker { time: "14:22:15" } \endqml - To read a time value returned from a C++ extension class, use + To read a time value returned from a C++ extension class, use \l{QML:Qt::formatTime()}{Qt.formatTime()} and \l{QML:Qt::formatDateTime()}{Qt.formatDateTime()}. \sa {QML Basic Types} @@ -399,8 +399,9 @@ \c child1, \c child2 and \c child3 will be added to the children list in the order in which they appear. - List \l {Adding Properties}{properties} can be declared as \c list<Type> - type, where \c Type is the type of the object in the list: + List \l {Property Binding}{properties} can be created as a + \c variant type, or as a \c list<Type> type, where \c Type is the + type of the object in the list: \qml Item { @@ -570,7 +571,7 @@ \qml Text { horizontalAlignment: "AlignRight" } \endqml - + or as \c {<Element>.<value>}: \qml Text { horizontalAlignment: Text.AlignRight } diff --git a/doc/src/declarative/declarativeui.qdoc b/doc/src/declarative/declarativeui.qdoc index aa9ed18..ff38ac6 100644 --- a/doc/src/declarative/declarativeui.qdoc +++ b/doc/src/declarative/declarativeui.qdoc @@ -31,12 +31,10 @@ \ingroup qt-gui-concepts \brief Qt Quick provides a declarative framework for building highly -dynamic, custom user interfaces. - -\section1 Introduction +dynamic user interfaces. Qt Quick is a collection of technologies that are designed to help -developers create the kind of intuitive, modern-looking, fluid user +developers create the kind of intuitive, modern, fluid user interfaces that are increasingly used on mobile phones, media players, set-top boxes and other portable devices. @@ -45,114 +43,101 @@ language for describing user interfaces and a language runtime. A collection of C++ APIs is used to integrate these high level features with classic Qt applications. -\section2 QML, Elements and the Qt Declarative Module - -User interfaces and their behavior are described using QML, an extension to -\l{About JavaScript}{JavaScript} that lets developers and designers -use a declarative syntax to specify each user interface in terms of -\l{QML Elements}{QML elements}. These elements are a sophisticated set of -graphical and behavioral building blocks that can be combined together in -\l{QML Documents}{QML documents} to build components ranging in complexity -from simple buttons and sliders, to complete Internet-enabled applications. - -QML improves the integration between JavaScript and Qt's existing -QObject-based type system, adds support for automatic -\l{Property Binding}{property bindings} and provides -\l{Network Transparency}{network transparency} at the language level. - -The Qt Declarative module implements the interface between the QML language -and the elements available to it. It also provides a C++ API that can be -used to load and interact with QML files from within Qt applications. - -Qt Quick builds on \l{QML for Qt programmers}{Qt's existing strengths}. -QML can be be used to incrementally extend an existing application or -to build completely new applications. QML is fully -\l{Extending QML in C++}{extensible from C++} through the Qt Declarative -Module. - \section1 Getting Started \list -\o \l{What's new in Qt Quick} -\o \l{Introduction to the QML language} -\o \l{QML for Qt Programmers} +\o \l{Intro to Qt Quick}{Introduction to Qt Quick} +\o \l{QML for Qt Programmers}{QML Programming for Qt Programmers} \o \l{Getting Started Programming with QML} -\o \l{Intro to Qt Quick} -\endlist -\list -\o \l{QML Tutorial}{Tutorial: "Hello World"} -\o \l{QML Advanced Tutorial}{Tutorial: "Same Game"} +\o \l{What's new in Qt Quick}{What's New in the Qt Quick Release} \o \l{QML Examples and Demos} \endlist -\section1 QML Concepts +\section1 QML Features \list -\o \l{QML Documents} +\o \l{QML Basic Elements}{Basic Elements} +\o \l{QML Basic Types}{Data Types} \o \l{Property Binding} -\o \l{Anchor-Based Layout in QML} -\o \l{Writing QML Components: Properties, Methods and Signals} -\o \l{QML Scope} -\o \l{QML Modules} +\o \l{Using QML Positioner and Repeater Items}{Component Layouts} +\o \l{Anchor-based Layout in QML}{Layouts using Anchors} +\o \l{QML Mouse Events}{Mouse Events} +\o \l{QML Text Handling and Validators}{Text Handling and Validators} +\o \l{Keyboard Focus in QML}{Keyboard Focus} +\o \l{QML Signal and Handler Event System}{Signal and Handler Event System} +\o \l{Importing Reusable Components} +\o \l{QML States}{States} +\o \l{QML Animation and Transitions}{Animation and Transitions} +\o \l{QML Data Models}{Structuring Data with Models} +\o \l{Presenting Data with Views} +\o \l{Extending QML Functionalities using C++} +\o \l{Using QML Bindings in C++ Applications} +\o \l{Integrating QML Code with Existing Qt UI Code} +\o \l{Dynamic Object Management in QML}{Dynamic Object Management} +\o \l{Network Transparency}{Loading Resources in QML} +\o \l{QML Internationalization}{Internationalization} \endlist -\section1 User Interaction +\section1 QML Add-Ons \list -\o \l{Keyboard Focus in QML} -\o \l{QML States} -\o \l{QML Animation} +\o \l{QtWebKit QML Module} +\o \l{http://doc.qt.nokia.com/qtmobility-1.1.0/qml-plugins.html}{Mobility QML Plugins} \endlist -\section1 Handling Data +\section1 Qt Quick Tools \list -\o \l{QML Basic Types}{QML Basic Data Types} -\o \l{Using QML Positioner and Repeater Items} -\o \l{QML Data Models} -\o \l{Presenting Data with QML} -\o \l{Network Transparency} +\o \l{Debugging QML} +\o \l{Developing Qt Quick Applications with Creator}{Developing with Qt Creator} +\o \l{QML Viewer} \endlist -\section1 Architecture +\section1 Reference \list -\o \l{Qt Declarative UI Runtime} -\o \l{Integrating JavaScript} -\o \l{Dynamic Object Management in QML} +\o \l{Introduction to the QML language}{QML Syntax} +\o \l{QML Elements} +\o \l{Qt Declarative Module} +\o \l{QML Basic Types}{QML Data Types} +\o \l{QML Coding Conventions} +\o \l{Qt Creator Manual} +\o \l{Programming with Qt} +\o \l{http://doc.qt.nokia.com/qtmobility-1.1.0/index.html}{Qt Mobility Documentation} \endlist -\section1 Using QML with C++ +\section1 Architecture \list \o \l{Qt Declarative UI Runtime} -\o \l{Using QML in C++ Applications} -\o \l{Integrating QML with existing Qt UI code} -\o \l{Tutorial: Writing QML extensions with C++} -\o \l{Extending QML in C++} -\endlist - -\section1 Reference - -\list -\o \l{QML Elements} -\o \l{QML Basic Types} +\o \l{Integrating JavaScript} +\o \l{QML Scope} +\o \l{QML Modules} +\o \l{QML Documents} \o \l{QML Global Object} -\o \l{QML Internationalization} \o \l{QML Security} \o \l{Qt Declarative Module} -\o \l{Debugging QML} -\o \l{QML Viewer} -\o \l{QML Performance} -\o \l{QML Coding Conventions} \endlist -\section1 Online Examples +\section1 Examples \list +\o \l{QML Tutorial}{"Hello World" Tutorial} +\o \l{Getting Started Programming with QML} +\o \l{QML Advanced Tutorial}{Tutorial: "Same Game"} +\o \l{Tutorial: Writing QML extensions with C++} +\o \l{QML Examples and Demos} + \o Forum Nokia: \l{http://wiki.forum.nokia.com/index.php/Qt_Quick_examples_for_porting}{Qt Quick examples for porting} \endlist + +\section1 Best Practices + +\list +\o \l{QML Best Practices: Coding Conventions}{Coding Tips} +\o \l{QML Performance}{Performance Tips} +\endlist */ diff --git a/doc/src/declarative/dynamicobjects.qdoc b/doc/src/declarative/dynamicobjects.qdoc index 316fe6b..7c10760 100644 --- a/doc/src/declarative/dynamicobjects.qdoc +++ b/doc/src/declarative/dynamicobjects.qdoc @@ -27,13 +27,17 @@ /*! \page qdeclarativedynamicobjects.html +\ingroup qml-features +\contentspage {QML Features} +\previouspage {Integrating QML Code with Existing Qt UI Code} +\nextpage {Network Transparency}{Loading Resources in QML} \title Dynamic Object Management in QML -QML provides a number of ways to dynamically create and manage QML objects. +QML provides a number of ways to dynamically create and manage QML objects. The \l{Loader}, \l{Repeater}, \l{ListView}, \l{GridView} and \l{PathView} elements -all support dynamic object management. Objects can also be created and managed +all support dynamic object management. Objects can also be created and managed from C++, and this is the preferred method for hybrid QML/C++ applications -(see \l{Using QML in C++ Applications}). +(see \l{Using QML Bindings in C++ Applications}). QML also supports the dynamic creation of objects from within JavaScript code. This is useful if the existing QML elements do not fit the needs of your @@ -45,31 +49,31 @@ of the concepts discussed on this page. \section1 Creating Objects Dynamically -There are two ways to create objects dynamically from JavaScript. You can either call +There are two ways to create objects dynamically from JavaScript. You can either call \l {QML:Qt::createComponent()}{Qt.createComponent()} to dynamically create a \l Component object, or use \l{QML:Qt::createQmlObject()}{Qt.createQmlObject()} to create an item from a string of QML. -Creating a component is better if you have an existing component defined in a \c .qml +Creating a component is better if you have an existing component defined in a \c .qml file, and you want to dynamically create instances of that component. Otherwise, -creating an item from a string of QML is useful when the item QML itself is generated +creating an item from a string of QML is useful when the item QML itself is generated at runtime. -\section2 Creating a Component dynamically +\section2 Creating a Component Dynamically -To dynamically load a component defined in a QML file, call the -\l {QML:Qt::createComponent()}{Qt.createComponent()} function on the \l{QML Global Object}. +To dynamically load a component defined in a QML file, call the +\l {QML:Qt::createComponent()}{Qt.createComponent()} function on the \l{QML Global Object}. This function takes the URL of the QML file as its only argument and creates a \l Component object from this URL. -Once you have a \l Component, you can call its \l {Component::createObject()}{createObject()} method to create an instance of +Once you have a \l Component, you can call its \l {Component::createObject()}{createObject()} method to create an instance of the component. This function can take one or two arguments: \list -\o The first is the parent for the new item. Since graphical items will not appear on the scene without a parent, it is - recommended that you set the parent this way. However, if you wish to set the parent later you can safely pass \c null to - this function. -\o The second is optional and is a script which assigns values to the item's properties during creation. This avoids warnings - when certain properties have been bound to before they have been set by the code. Additionally, there are small performance +\o The first is the parent for the new item. Since graphical items will not appear on the scene without a parent, it is + recommended that you set the parent this way. However, if you wish to set the parent later you can safely pass \c null to + this function. +\o The second is optional and is a script which assigns values to the item's properties during creation. This avoids warnings + when certain properties have been bound to before they have been set by the code. Additionally, there are small performance benefits when instantiating objects in this way. \endlist @@ -94,25 +98,27 @@ in case the QML file is loaded over a network and thus is not ready immediately. \codeline \snippet doc/src/snippets/declarative/componentCreation.js finishCreation -If you are certain the QML file to be loaded is a local file, you could omit the \c finishCreation() +If you are certain the QML file to be loaded is a local file, you could omit the \c finishCreation() function and call \l {Component::createObject()}{createObject()} immediately: \snippet doc/src/snippets/declarative/componentCreation.js func \snippet doc/src/snippets/declarative/componentCreation.js local \snippet doc/src/snippets/declarative/componentCreation.js func-end -Notice in both instances, \l {Component::createObject()}{createObject()} is called with +Notice in both instances, \l {Component::createObject()}{createObject()} is called with \c appWindow passed as an argument so that the created object will become a child of the \c appWindow item in \c main.qml. Otherwise, the new item will not appear in the scene. When using files with relative paths, the path should be relative to the file where \l {QML:Qt::createComponent()}{Qt.createComponent()} is executed. -To connect signals to (or receive signals from) dynamically created objects, use the signal -\c connect() method. See \l {Connecting signals to methods and other signals} for more information. +To connect signals to (or receive signals from) dynamically created objects, +use the signal \c connect() method. See +\l{QML Signal and Handler Event System#Connecting Signals to Methods and Signals} +{Connecting Signals to Methods and Signals} for more information. -\section2 Creating an object from a string of QML +\section2 Creating an Object from a String of QML If the QML is not defined until runtime, you can create a QML item from a string of QML using the \l{QML:Qt::createQmlObject()}{Qt.createQmlObject()} function, as in the following example: @@ -162,7 +168,7 @@ items that you did not dynamically create yourself. Items can be deleted using the \c destroy() method. This method has an optional argument (which defaults to 0) that specifies the approximate delay in milliseconds -before the object is to be destroyed. +before the object is to be destroyed. Here is an example. The \c application.qml creates five instances of the \c SelfDestroyingRect.qml component. Each instance runs a NumberAnimation, and when the animation has finished, calls @@ -196,7 +202,7 @@ Item { } \endqml -This would result in an error, since items can only be dynamically +This would result in an error, since items can only be dynamically destroyed if they were dynamically created. Objects created with \l{QML:Qt::createQmlObject()}{Qt.createQmlObject()} @@ -204,6 +210,4 @@ can similarly be destroyed using \c destroy(): \snippet doc/src/snippets/declarative/createQmlObject.qml 0 \snippet doc/src/snippets/declarative/createQmlObject.qml destroy - */ - diff --git a/doc/src/declarative/elements.qdoc b/doc/src/declarative/elements.qdoc index 466b940..873d0de 100644 --- a/doc/src/declarative/elements.qdoc +++ b/doc/src/declarative/elements.qdoc @@ -31,7 +31,8 @@ \title QML Elements \brief A listing of standard QML elements. -These are the functionally grouped lists of QML elements. +These are the functionally grouped lists of QML elements as part of +\l{Qt Quick}. Elements are declared with the their name and two curly braces. Elements may be nested in elements, thereby creating a parent-child relationship between the @@ -44,7 +45,7 @@ To see the QML elements listed by functional area, see the \list \o \l {Item} - Basic item element inherited by QML elements \o \l {Component} - Encapsulates QML elements during importing -\o \l {QML:QtObject} {QtObject} - Basic element containing only the objectName property +\o \l {QML:QtObject} {QtObject} - Basic element containing only the \c {objectName} property \endlist \section1 Graphics @@ -54,7 +55,7 @@ To see the QML elements listed by functional area, see the \o \l {BorderImage} - Allows the use of images as borders \o \l {AnimatedImage} - For playing animations stored in a series of frames \o \l {Gradient} - For defining a color gradient -\o \l {GradientStop}Â - Used to define a color within a \l {Gradient} +\o \l {GradientStop} - Used to define a color within a \l {Gradient} \o \l {SystemPalette} - Provides access to the Qt palettes \endlist @@ -74,9 +75,8 @@ To see the QML elements listed by functional area, see the \o \l {MouseArea} - Sets up an area for mouse interaction \o \l {Keys} - Provides components with attached properties to handle key input. \o \l {FocusScope} - Element that mediate keyboard focus changes -\o \l {Flickable}Â - Provides a surface that can be "flicked" +\o \l {Flickable} - Provides a surface that can be "flicked" \o \l {Flipable} - Provides a surface that produces "flipping" effects -\o \l {GestureArea} - Enables simple gesture handling \endlist \section1 Positioners and Repeater diff --git a/doc/src/declarative/example-slideswitch.qdoc b/doc/src/declarative/example-slideswitch.qdoc index 9f84ee6..482a292 100644 --- a/doc/src/declarative/example-slideswitch.qdoc +++ b/doc/src/declarative/example-slideswitch.qdoc @@ -33,8 +33,6 @@ This example shows how to create a reusable switch component in QML. The code for this example can be found in the \c $QTDIR/examples/declarative/ui-components/slideswitch directory. -\section1 Overview - The elements that composed the switch are: \list @@ -123,7 +121,7 @@ For more information on scripts see \l{Integrating JavaScript}. At this point, when the switch toggles between the two states the knob will instantly change its \c x position between 1 and 78. In order for the the knob to move smoothly we add a transition that will animate the \c x property with an easing curve for a duration of 200ms. -For more information on transitions see \l{qdeclarativeanimation.html#transitions}{QML Transitions}. +For more information on transitions see \l{QML Animation and Transitions}. \section1 Usage The switch can be used in a QML file, like this: diff --git a/doc/src/declarative/examples.qdoc b/doc/src/declarative/examples.qdoc index be2d0c7..06bd819 100644 --- a/doc/src/declarative/examples.qdoc +++ b/doc/src/declarative/examples.qdoc @@ -147,7 +147,6 @@ The examples can be found in Qt's \c examples/declarative directory. \section2 Touch Interaction \list -\o \l{declarative/touchinteraction/gestures}{Gestures} \o \l{declarative/touchinteraction/mousearea}{MouseArea} \endlist diff --git a/doc/src/declarative/extending-tutorial.qdoc b/doc/src/declarative/extending-tutorial.qdoc index 4caa631..0ddc430 100644 --- a/doc/src/declarative/extending-tutorial.qdoc +++ b/doc/src/declarative/extending-tutorial.qdoc @@ -27,13 +27,13 @@ /*! \page qml-extending-tutorial-index.html -\title Tutorial: Writing QML extensions with C++ +\title Tutorial: Writing QML Extensions with C++ The Qt Declarative module provides a set of APIs for extending QML through C++ extensions. You can write extensions to add your own QML types, extend existing Qt types, or call C/C++ functions that are not accessible from ordinary QML code. -This tutorial shows how to write a QML extension using C++ that includes +This tutorial shows how to write a QML extension using C++ that includes core QML features, including properties, signals and bindings. It also shows how extensions can be deployed through plugins. @@ -45,7 +45,7 @@ Tutorial chapters: \list 1 \o \l{declarative/tutorials/extending/chapter1-basics}{Creating a New Type} \o \l{declarative/tutorials/extending/chapter2-methods}{Connecting to C++ Methods and Signals} -\o \l{declarative/tutorials/extending/chapter3-bindings}{Adding Property Bindings} +\o \l{declarative/tutorials/extending/chapter3-bindings}{Property Binding} \o \l{declarative/tutorials/extending/chapter4-customPropertyTypes}{Using Custom Property Types} \o \l{declarative/tutorials/extending/chapter5-listproperties}{Using List Property Types} \o \l{declarative/tutorials/extending/chapter6-plugins}{Writing an Extension Plugin} @@ -67,18 +67,18 @@ like network programming that are not accessible through built-in QML features. In this tutorial, we will show how to use the C++ classes in the Qt Declarative module to extend QML. The end result will be a simple Pie Chart display implemented by -several custom QML types connected together through QML features like bindings and +several custom QML types connected together through QML features like bindings and signals, and made available to the QML runtime through a plugin. To begin with, let's create a new QML type called "PieChart" that has two properties: a name and a color. We will make it available in a \l {Modules}{module} called "Charts", with -a module version of 1.0. +a module version of 1.0. We want this \c PieChart type to be usable from QML like this: \code import Charts 1.0 - + PieChart { width: 100; height: 100 name: "A simple pie chart" @@ -99,16 +99,16 @@ Here is our \c PieChart class, defined in \c piechart.h: \snippet declarative/tutorials/extending/chapter1-basics/piechart.h 0 -The class inherits from QDeclarativeItem because we want to override +The class inherits from QDeclarativeItem because we want to override QDeclarativeItem::paint() in order to draw. If the class just represented some data type and was not an item that actually needed to be displayed, it could simply inherit -from QObject. Or, if we want to extend the functionality of an existing QObject-based +from QObject. Or, if we want to extend the functionality of an existing QObject-based class, it could inherit from that class instead. The \c PieChart class defines the two properties, \c name and \c color, with the Q_PROPERTY macro, -and overrides QDeclarativeItem::paint(). The class implementation in \c piechart.cpp -simply sets and returns the \c m_name and \c m_color values as appropriate, and -implements \c paint() to draw a simple pie chart. It also turns off the +and overrides QDeclarativeItem::paint(). The class implementation in \c piechart.cpp +simply sets and returns the \c m_name and \c m_color values as appropriate, and +implements \c paint() to draw a simple pie chart. It also turns off the QGraphicsItem::ItemHasNoContents flag to enable painting: \snippet declarative/tutorials/extending/chapter1-basics/piechart.cpp 0 @@ -150,19 +150,19 @@ Try it yourself with the code in Qt's \c examples/tutorials/extending/chapter1-b At the moment, the \c app.qml is run from within a C++ application. This may seem odd if you're used to running QML files with the \l {QML Viewer}. -Later on, we'll show how to create a plugin so that you can run \c app.qml using the +Later on, we'll show how to create a plugin so that you can run \c app.qml using the \l {QML Viewer} instead. */ /*! -\title Chapter 2: Connecting to C++ Methods and Signals +\title Chapter 2: Connecting to C++ Methods and Signals \example declarative/tutorials/extending/chapter2-methods Suppose we want \c PieChart to have a "clearChart()" method that erases the -chart and then emits a "chartCleared" signal. Our \c app.qml would be able +chart and then emits a "chartCleared" signal. Our \c app.qml would be able to call \c clearChart() and receive \c chartCleared() signals like this: \snippet declarative/tutorials/extending/chapter2-methods/app.qml 0 @@ -210,7 +210,7 @@ Property bindings is a powerful feature of QML that allows values of different elements to be synchronized automatically. It uses signals to notify and update other elements' values when property values are changed. -Let's enable property bindings for the \c color property. That means +Let's enable property bindings for the \c color property. That means if we have code like this: \snippet declarative/tutorials/extending/chapter3-bindings/app.qml 0 @@ -224,7 +224,7 @@ updates to the same value. When the window is clicked, the \c onClicked handler in the MouseArea changes the color of \c chartA, thereby changing both charts to the color blue. -It's easy to enable property binding for the \c color property. +It's easy to enable property binding for the \c color property. We add a \l{Qt's Property System}{NOTIFY} feature to its Q_PROPERTY() declaration to indicate that a "colorChanged" signal is emitted whenever the value changes. @@ -244,7 +244,7 @@ It's important for \c setColor() to check that the color value has actually chan before emitting \c colorChanged(). This ensures the signal is not emitted unnecessarily and also prevents loops when other elements respond to the value change. -The use of bindings is essential to QML. You should always add NOTIFY +The use of bindings is essential to QML. You should always add NOTIFY signals for properties if they are able to be implemented, so that your properties can be used in bindings. Properties that cannot be bound cannot be automatically updated and cannot be used as flexibly in QML. Also, since @@ -286,7 +286,7 @@ int-type property to store an identifier for each chart: \endcode We can also use various other property types. QML has built-in support for the types -listed in the \l{Adding Properties} documentation, which includes the following: +listed in the \l{QML Basic Types} documentation, which includes the following: \list \o bool, unsigned int, int, float, double, qreal @@ -299,7 +299,7 @@ listed in the \l{Adding Properties} documentation, which includes the following: If we want to create a property whose type is not supported by QML by default, we need to register the type with QML. -For example, let's replace the use of the \c property with a type called +For example, let's replace the use of the \c property with a type called "PieSlice" that has a \c color property. Instead of assigning a color, we assign an \c PieSlice value which itself contains a \c color: @@ -358,10 +358,10 @@ have a \c slices property that accepts a list of \c PieSlice items: \image extending-tutorial-chapter5.png To do this, we replace the \c pieSlice property in \c PieChart with a \c slices property, -declared as a QDeclarativeListProperty type. The QDeclarativeListProperty class enables the +declared as a QDeclarativeListProperty type. The QDeclarativeListProperty class enables the creation of list properties in QML extensions. We replace the \c pieSlice() -function with a \c slices() function that returns a list of slices, and add -an internal \c append_slice() function (discussed below). We also use a QList to +function with a \c slices() function that returns a list of slices, and add +an internal \c append_slice() function (discussed below). We also use a QList to store the internal list of slices as \c m_slices: \snippet declarative/tutorials/extending/chapter5-listproperties/piechart.h 0 @@ -409,7 +409,7 @@ To create a plugin library, we need: \list \o A plugin class that registers our QML types -\o A project file that describes the plugin +\o A project file that describes the plugin \o A \l{Writing a qmldir file}{qmldir} file that tells the QML engine to load the plugin \endlist @@ -468,8 +468,9 @@ In this tutorial, we've shown the basic steps for creating a QML extension: \endlist -The \l {Extending QML in C++} reference documentation shows other useful features that can be added to -QML extensions. For example, we could use \l{Default Property}{default properties} to allow +The \l {Extending QML Functionalities using C++} reference documentation shows +other useful features that can be added to QML extensions. For example, we +could use \l{Default Property}{default properties} to allow slices to be added without using the \c slices property: \code @@ -489,7 +490,8 @@ Or randomly add and remove slices from time to time using \l{Property Value Sour \endcode -See the \l{Extending QML in C++}{reference documentation} for more information. +See the \l{Extending QML Functionalities using C++} reference documentation +for more information. */ diff --git a/doc/src/declarative/extending.qdoc b/doc/src/declarative/extending.qdoc index 4b4e05e..019f04a 100644 --- a/doc/src/declarative/extending.qdoc +++ b/doc/src/declarative/extending.qdoc @@ -27,7 +27,11 @@ /*! \page qml-extending.html -\title Extending QML in C++ +\ingroup qml-features +\contentspage QML Features +\previouspage {Presenting Data with Views} +\nextpage {Using QML Bindings in C++ Applications} +\title Extending QML Functionalities using C++ The QML syntax declaratively describes how to construct an in-memory object tree. In Qt, QML is mainly used to describe a visual scene graph, but it is @@ -82,7 +86,7 @@ Types can be registered by libraries, application code, or by plugins Once registered, all \l {Qt's Property System}{properties} of the supported types are available in QML. QML has intrinsic support for -properties of the types listed in the \l{Adding Properties} +properties of the types listed in the \l{QML Basic Types} document, which includes the following: \list @@ -429,28 +433,28 @@ pointers to invalid objects. QML makes the following guarentees: \list \o An object assigned to a QObject (or QObject-derived) pointer property will be -valid at the time of assignment. +valid at the time of assignment. -Following assignment, it is the responsibility of the class to subsequently guard +Following assignment, it is the responsibility of the class to subsequently guard this pointer, either through a class specific method or the generic QPointer class. -\o An object assigned to a QVariant will be valid at the time of assignment. +\o An object assigned to a QVariant will be valid at the time of assignment. -When assigning an object to a QVariant property, QML will always use a QMetaType::QObjectStar -typed QVariant. It is the responsibility of the class to guard the pointer. A -general rule when writing a class that uses QVariant properties is to check the -type of the QVariant when it is set and if the type is not handled by your class, +When assigning an object to a QVariant property, QML will always use a QMetaType::QObjectStar +typed QVariant. It is the responsibility of the class to guard the pointer. A +general rule when writing a class that uses QVariant properties is to check the +type of the QVariant when it is set and if the type is not handled by your class, reset it to an invalid variant. -\o An object assigned to a QObject (or QObject-derived) list property will be -valid at the time of assignment. +\o An object assigned to a QObject (or QObject-derived) list property will be +valid at the time of assignment. -Following assignment, it is the responsibility of the class to subsequently guard +Following assignment, it is the responsibility of the class to subsequently guard this pointer, either through a class specific method or the generic QPointer class. \endlist Elements should assume that any QML assigned object can be deleted at any time, and -respond accordingly. If documented as such an element need not continue to work in +respond accordingly. If documented as such an element need not continue to work in this situation, but it must not crash. \section1 Signal Support @@ -477,7 +481,7 @@ but different parameters cannot be distinguished. Signal parameters become accessible by name to the assigned script. An unnamed parameter cannot be accessed, so care should be taken to name all the signal parameters in the C++ class declaration. The intrinsic types -listed in \l {Adding Types}, as well registered object types are permitted as +listed in \l{Adding Types}, as well registered object types are permitted as signal parameter types. Using other types is not an error, but the parameter value will not be accessible from script. @@ -498,7 +502,7 @@ on<Property-name>Changed, regardless of the name used for the NOTIFY signal in C++. We recommend using <property-name>Changed() for the NOTIFY signal in C++. -See also \l {Writing QML Components: Properties, Methods and Signals} +See also \l {Importing Reusable Components} \section1 Methods @@ -701,478 +705,4 @@ public: } }; \endcode - -*/ - -/*! -\page qml-extending-types.html -\title Writing QML Components: Properties, Methods and Signals - -One of the key concepts in QML is the ability to define your own QML components that suit -the purposes of your application. The standard \l {QML Elements} provide the essential components -for creating a QML application; beyond these, you can write your own custom components that can -be created and reused, without the use of C++. - -Components are the building blocks of a QML project. When writing a QML application, whether -large or small, it is best to separate QML code into smaller components that perform specific -sets of operations, instead of creating mammoth QML files with large, combined functionality -that is more difficult to manage and may contain duplicated code. - - -\section1 Defining New Components - -A component is a reusable type with a well-defined interface, built entirely in QML. -Any snippet of QML code can become a component, by placing the code in a file "<Name>.qml" where -<Name> is the new component name, beginning with an uppercase letter. These QML files automatically -become available as new QML element types to other QML components and applications in the same directory. - -For example, one of the simplest and most common components you can build in QML is a -button-type component. Below, we implement this component as a \l Rectangle with a clickable -\l MouseArea, in a file named \c Button.qml: - -\snippet doc/src/snippets/declarative/qml-extending-types/components/Button.qml 0 - -Now this component can be reused by another file within the same directory. Since the file is -named \c Button.qml, the component is referred to as \c Button: - -\table -\row -\o \snippet doc/src/snippets/declarative/qml-extending-types/components/application.qml 0 -\o \image qml-extending-types.png -\endtable - -The root object in \c Button.qml defines the attributes that are available to users of the -\c Button component. In this case, the root object is a \l Rectangle, so any properties, methods -and signals of \l Rectangle are made available, allowing \c application.qml to -customize the \c width, \c height, \c radius and \c color properties of \c Button objects. - - -If \c Button.qml was not in the same directory, \c application.qml would need to load it as a -\l {Modules}{module} from a specific filesystem path or \l{QDeclarativeExtensionPlugin}{plugin}. -Also, note the letter case of the component file name is significant on some (notably UNIX) -filesystems. It is recommended the file name case matches the case of the QML component name -exactly - for example, \c Box.qml and not \c BoX.qml - regardless of the platform to which the -QML component will be deployed. - -To write a useful component, it is generally necessary to provide it with custom attributes that store and -communicate specific data. This is achieved by adding the following attributes to your components: - -\list -\o \bold Properties that can be accessed externally to modify an object (for example, \l Item has - \l {Item::}{width} and \l {Item::}{height} properties) and used in \l {Property Binding} -\o \bold Methods of JavaScript code can be invoked internally or externally (for example, - \l Animation has a \l {Animation::}{start()} method) -\o \bold Signals to notify other objects when an event has occurred (for example, MouseArea has a - \c clicked signal) -\endlist - -The following sections show how these attributes can be added to QML components. - - -\section1 Adding Properties - -A property is a value of a QML component that can be read and modified by other objects. For -example, a \l Rectangle component has \l {Item::}{width}, \l {Item::}{height} and \l -{Rectangle::}{color} properties. Significantly, properties be used with \l {Property Binding}, where -a property value is automatically updated using the value of another property. - -The syntax for defining a new property is: - -\code -[default] property <type> <name>[: defaultValue] -\endcode - -A \c property declaration can appear anywhere within a QML component definition, but it is customary -to place it at the top. A component cannot declare more than one property with the same name. (It is -possible to have a property name that is the same as an existing property in a type, but this is not -recommended as the existing property becomes hidden and inaccessible.) - -Below is an example. The \c ImageViewer component has defined a \c string type property named -\c currentImage, and its initial value is "default-image.png". This property is used to set the image -displayed in the child \l Image object. Another file, \c application.qml, can create -an \c ImageViewer object and read or modify the \c currentImage value: - -\table -\row -\o \snippet doc/src/snippets/declarative/qml-extending-types/properties/ImageViewer.qml 0 -\o \snippet doc/src/snippets/declarative/qml-extending-types/properties/application.qml 0 -\endtable - -It is optional for a property to have a default value. The default value is a convenient shortcut, and is -behaviorally identical to doing it in two steps, like this: - -\qml -Item { - // Use default value - property int myProperty: 10 - - // Longer, but behaviorally identical - property int myProperty - myProperty: 10 -} -\endqml - - -\section2 Supported property types - -All QML properties are typed. The examples above show properties with \c int and \c string types; -notice that the type of the property must be declared. The type is used to determine the property -behavior, and how the property is defined in C++. - -A number of property types are supported by default. These are listed in the table below, -with their default values and the corresponding C++ type: - -\table -\header \o QML Type Name \o Default value \o C++ Type Name -\row \o \l int \o 0 \o int -\row \o \l bool \o \c false \o bool -\row \o \l double \o 0.0 \o double -\row \o \l real \o 0.0 \o double -\row \o \l string \o "" (empty string) \o QString -\row \o \l url \o "" (empty url) \o QUrl -\row \o \l color \o #000000 (black) \o QColor -\row \o \l date \o \c undefined \o QDateTime -\row \o \l variant \o \c undefined \o QVariant -\endtable - -QML object types can also be used as property types. This includes -\l {Defining new QML elements}{custom QML types} implemented in C++. Such properties are -defined like this: - -\qml -Item { - property Item itemProperty - property QtObject objectProperty - property MyCustomType customProperty -} -\endqml - -Such object-type properties default to an \c undefined value. - -It is also possible to store a copy of a JavaScript object using the \c variant -property type. This creates some restrictions on how the property should be used; -see the \l {variant}{variant type documentation} for details. - -\l{list}{List properties} are created with the \c list<Type> syntax, and default to an empty -list: - -\qml -Item { - property list<Item> listOfItems -} -\endqml - -Note that list properties cannot be modified like ordinary JavaScript -arrays. See the \l {list}{list type documentation} for details. - - -\section2 Property change signals - -Adding a \c property to an item automatically adds a \e {value changed} -signal handler to the item. To connect to this signal, use a \l {Signal Handlers}{signal handler} -named with the \c on<Property>Changed syntax, using upper case for the first letter of the -property name. - -For example, the following \c onMyNumberChanged signal handler is automatically called whenever the -\c myNumber property changes: - -\snippet doc/src/snippets/declarative/qml-extending-types/properties/property-signals.qml 0 - - -\section2 Default properties - -The optional \c default attribute for a property marks it as the \e {default property} -for a type. This allows other items to specify the default property's value -as child elements. For example, the \l Item element's default property is its -\l{Item::children}{children} property. This allows the children of an \l Item -to be set like this: - -\qml -Item { - Rectangle {} - Rectangle {} -} -\endqml - -If the \l{Item::children}{children} property was not the default property for -\l Item, its value would have to be set like this instead: - -\qml -Item { - children: [ - Rectangle {}, - Rectangle {} - ] -} -\endqml - -See the \l{declarative/ui-components/tabwidget}{TabWidget} example for a -demonstration of using default properties. - -Specifying a default property overrides any existing default property (for -example, any default property inherited from a parent item). Using the -\c default attribute twice in the same type block is an error. - - -\section2 Property aliases - -Property aliases are a more advanced form of property declaration. Unlike a -property definition, which allocates a new, unique storage space for the -property, a property alias connects the newly declared property (called the -aliasing property) as a direct reference to an existing property (the aliased property). Read -operations on the aliasing property act as read operations on the aliased -property, and write operations on the aliasing property as write operations on -the aliased property. - -A property alias declaration looks a lot like an ordinary property definition: -\code - [default] property alias <name>: <alias reference> -\endcode - -As the aliasing property has the same type as the aliased property, an explicit -type is omitted, and the special "alias" keyword is used. Instead of a default -value, a property alias includes a compulsory alias reference. The alias -reference is used to locate the aliased property. While similar to a property -binding, the alias reference syntax is highly restricted. - -An alias reference takes one of the following forms: -\code - <id>.<property> - <id> -\endcode - -where <id> must refer to an object id within the same component as the type -declaring the alias, and, optionally, <property> refers to a property on that object. - -For example, below is a \c Button.qml component with a \c buttonText aliased property which is -connected to the child Text object's \c text property: - -\snippet doc/src/snippets/declarative/qml-extending-types/properties/alias.qml 0 - -The following code would create a \c Button with a defined text string for the -child \l Text object: - -\qml -Button { buttonText: "This is a button" } -\endqml - -Here, modifying \c buttonText directly modifies the \c textItem.text value; it does not -change some other value that then updates \c textItem.text. - -In this case, the use of aliased properties is essential. If \c buttonText was not an alias, -changing its value would not actually change the displayed text at all, as -\l {Property Binding}{property bindings} are not bi-directional: the \c buttonText value would -change when \c textItem.text changes, but not the other way around. - -Aliased properties are also useful for allowing external objects to directly modify and -access child objects in a component. For example, here is a modified version of the \c ImageViewer -component shown \l {Adding Properties}{earlier} on this page. The \c currentImage property has -been changed to an alias to the child \l Image object: - -\table -\row -\o \snippet doc/src/snippets/declarative/qml-extending-types/properties/alias/ImageViewer.qml 0 -\o \snippet doc/src/snippets/declarative/qml-extending-types/properties/alias/application.qml 0 -\endtable - -Instead of being limited to setting the \l Image source, \c application.qml can now directly -access and modify the child \l Image object and its properties. - -Obviously, exposing child objects in this manner should be done with care, as it allows external -objects to modify them freely. However, this use of aliased properties can be quite useful in -particular situations, such as for the \l {declarative/ui-components/tabwidget}{TabWidget} -example, where new tab items are actually parented to a child object that displays the current tab. - - -\section3 Considerations for property aliases - -Aliases are only activated once the component specifying them is completed. The -most obvious consequence of this is that the component itself cannot generally -use the aliased property directly during creation. For example, this will not work: - -\code - // Does NOT work - property alias buttonText: textItem.text - buttonText: "Some text" // buttonText is not yet defined when this value is set -\endcode - -A second, much less significant, consequence of the delayed activation of -aliases is that an alias reference cannot refer to another aliasing property -declared within the same component. This will not work: - -\code - // Does NOT work - id: root - property alias buttonText: textItem.text - property alias buttonText2: root.buttonText -\endcode - -At the time the component is created, the \c buttonText value has not yet been assigned, -so \c root.buttonText would refer to an undefined value. (From outside the component, -however, aliasing properties appear as regular Qt properties and consequently can be -used in alias references.) - -It is possible for an aliased property to have the same name as an existing property. For example, -the following component has a \c color alias property, named the same as the built-in -\l {Rectangle::color} property: - -\snippet doc/src/snippets/declarative/qml-extending-types/properties/alias-override.qml 0 - -Any objects that use this component and refer to its \c color property will be -referring to the alias rather than the ordinary \l {Rectangle::color} property. Internally, -however, the rectangle can correctly set this property to "red" and refer to the actual defined -property rather than the alias. - - -\section1 Adding Methods - -A QML component can define methods of JavaScript code. These methods can be invoked -either internally or by other objects. - -The syntax for defining a method is: - -\code -function <name>([<parameter name>[, ...]]) { <body> } -\endcode - -This declaration may appear anywhere within a type body, but it is customary to -include it at the top. Attempting to declare two methods or signals with the -same name in the same type block is an error. However, a new method may reuse -the name of an existing method on the type. (This should be done with caution, -as the existing method may be hidden and become inaccessible.) - -Unlike \l{Adding Signals}{signals}, method parameter types do not have to be declared as they -default to the \c variant type. The body of the method is written in JavaScript and may access -the parameters by name. - -Here is an example of a component with a \c say() method that accepts a single \c text argument: - -\snippet doc/src/snippets/declarative/qml-extending-types/methods/app.qml 0 - -A method can be connected to a signal so that it is automatically invoked whenever the signal -is emitted. See \l {Connecting signals to methods and other signals} below. - -Also see \l {Integrating JavaScript} for more information on using JavaScript with QML. - - -\section1 Adding Signals - -Signals provide a way to notify other objects when an event has occurred. For example, the MouseArea -\c clicked signal notifies other objects that the mouse has been clicked within the area. - -The syntax for defining a new signal is: - -\code -signal <name>[([<type> <parameter name>[, ...]])] -\endcode - -This declaration may appear anywhere within a type body, but it is customary to -include it at the top. Attempting to declare two signals or methods with the -same name in the same type block is an error. However, a new signal may reuse -the name of an existing signal on the type. (This should be done with caution, -as the existing signal may be hidden and become inaccessible.) - -Here are three examples of signal declarations: - -\code -Item { - signal clicked - signal hovered() - signal performAction(string action, variant actionArgument) -} -\endcode - -If the signal has no parameters, the "()" brackets are optional. If parameters are used, the -parameter types must be declared, as for the \c string and \c variant arguments for the \c -performAction signal above; the allowed parameter types are the same as those listed in the \l -{Adding Properties} section on this page. - -Adding a signal to an item automatically adds a \l {Signal Handlers}{signal handler} as well. -The signal hander is named \c on<SignalName>, with the first letter of the signal being upper -cased. The above example item would now have the following signal handlers: - -\list -\o onClicked -\o onHovered -\o onPerformAction -\endlist - -To emit a signal, simply invoke it in the same way as a method. Below left, when the \l MouseArea is -clicked, it emits the parent \c buttonClicked signal by invoking \c rect.buttonClicked(). The -signal is received by \c application.qml through an \c onButtonClicked signal handler: - -\table -\row -\o \snippet doc/src/snippets/declarative/qml-extending-types/signals/basic.qml 0 -\o \snippet doc/src/snippets/declarative/qml-extending-types/signals/no-parameters.qml 0 -\endtable - -If the signal has parameters, they are accessible by parameter name in the signal handler. -In the example below, \c buttonClicked is emitted with \c xPos and \c yPos parameters instead: - -\table -\row -\o \snippet doc/src/snippets/declarative/qml-extending-types/signals/Button.qml 0 -\o \snippet doc/src/snippets/declarative/qml-extending-types/signals/parameters.qml 0 -\endtable - - -\section2 Connecting signals to methods and other signals - -Signal objects have a \c connect() method that can be used to a connect a signal to a method or -another signal. When a signal is connected to a method, the method is automatically invoked -whenever the signal is emitted. (In Qt terminology, the method is a \e slot that is connected -to the \e signal; all methods defined in QML are created as Qt slots.) This enables a signal -to be received by a method instead of a \l {Signal Handlers}{signal handler}. - -For example, the \c application.qml above could be rewritten as: - -\snippet doc/src/snippets/declarative/qml-extending-types/signals/connectslots.qml 0 - -The \c myMethod() method will be called whenever the \c buttonClicked signal is received. - -In many cases it is sufficient to receive signals through signal handlers rather than using -the \c connect() function; the above example does not provide any improvements over using a -simple \c onButtonClicked handler. However, if you are \l{Dynamic Object Management in QML}{creating objects dynamically}, -or \l {Integrating JavaScript}{integrating JavaScript code}, then you will find the -\c connect() method useful. For example, the component below creates three \c Button -objects dynamically, and connects the \c buttonClicked signal of each object to the -\c myMethod() function: - -\snippet doc/src/snippets/declarative/qml-extending-types/signals/connectdynamic.qml 0 - -In the same way, you could connect a signal to methods defined in a dynamically -created object, or \l {Receiving QML Signals in JavaScript}{connect a signal to a JavaScript method}. - -There is also a corresponding \c disconnect() method for removing connected signals. The following -code removes the connection created in \c application.qml above: - -\qml -// application.qml -Item { - // ... - - function removeSignal() { - button.clicked.disconnect(item.myMethod) - } -} -\endqml - - -\section3 Forwarding signals - -The \c connect() method can also connect a signal to other signals. This has the effect -of "forwarding" a signal: it is automatically emitted whenever the relevant signal is emitted. For -example, the MouseArea \c onClicked handler in \c Button.qml above could have been replaced with -a call to \c connect(): - -\qml -MouseArea { - anchors.fill: parent - Component.onCompleted: clicked.connect(item.buttonClicked) -} -\endqml - -Whenever the \l MouseArea \c clicked signal is emitted, the \c rect.buttonClicked signal will -automatically be emitted as well. */ diff --git a/doc/src/declarative/focus.qdoc b/doc/src/declarative/focus.qdoc index 599d63c..940f864 100644 --- a/doc/src/declarative/focus.qdoc +++ b/doc/src/declarative/focus.qdoc @@ -28,11 +28,16 @@ /*! \target qmlfocus \page qdeclarativefocus.html +\ingroup qml-features +\contentspage QML Features +\previouspage {QML Text Handling and Validators}{Text Handling and Validators} +\nextpage {QML Signal and Handler Event System}{Signal and Handler Event System} + \title Keyboard Focus in QML When a key is pressed or released, a key event is generated and delivered to the focused QML \l Item. To facilitate the construction of reusable components -and to address some of the cases unique to fluid user interfaces, the QML items add a +and to address some of the cases unique to fluid user interfaces, the QML items add aged \e scope based extension to Qt's traditional keyboard focus model. \tableofcontents diff --git a/doc/src/declarative/integrating.qdoc b/doc/src/declarative/integrating.qdoc index f0d3a37..c2f55f5 100644 --- a/doc/src/declarative/integrating.qdoc +++ b/doc/src/declarative/integrating.qdoc @@ -27,7 +27,11 @@ /*! \page qml-integration.html -\title Integrating QML with existing Qt UI code +\ingroup qml-features +\previouspage {Using QML Bindings in C++ Applications} +\nextpage {Dynamic Object Management in QML}{Dynamic Object Management} +\contentspage QML Features +\title Integrating QML Code with Existing Qt UI Code There are a number of ways to integrate QML into QWidget-based UI applications, depending on the characteristics of your existing UI code. @@ -37,8 +41,8 @@ depending on the characteristics of your existing UI code. If you have an existing QWidget-based UI, QML widgets can be integrated into it using QDeclarativeView. QDeclarativeView is a subclass of QWidget so you -can add it to your user interface like any other QWidget. Use -QDeclarativeView::setSource() to load a QML file into the view, then add the +can add it to your user interface like any other QWidget. Use +QDeclarativeView::setSource() to load a QML file into the view, then add the view to your UI: \code @@ -52,7 +56,7 @@ layout->addWidget(qmlView); The one drawback to this approach is that QDeclarativeView is slower to initialize and uses more memory than a QWidget, and creating large numbers of QDeclarativeView -objects may lead to performance degradation. If this is the case, it may be +objects may lead to performance degradation. If this is the case, it may be better to rewrite your widgets in QML, and load the widgets from a main QML widget instead of using QDeclarativeView. @@ -70,7 +74,7 @@ of simple and dynamic elements. If you have an existing UI based on the \l{Graphics View Framework}, you can integrate QML widgets directly into your QGraphicsScene. Use QDeclarativeComponent to create a QGraphicsObject from a QML file, and -place the graphics object into your scene using \l{QGraphicsScene::addItem()}, or +place the graphics object into your scene using \l{QGraphicsScene::addItem()}, or reparent it to an item already in the \l{QGraphicsScene}. For example: @@ -95,12 +99,13 @@ of QML UIs: \section2 Loading QGraphicsWidget objects in QML -An alternative approach is to expose your existing QGraphicsWidget objects to +An alternative approach is to expose your existing QGraphicsWidget objects to QML and construct your scene in QML instead. See the \l {declarative-cppextensions-qgraphicslayouts.html}{graphics layouts example} which shows how to expose Qt's graphics layout classes to QML in order to use QGraphicsWidget with classes like QGraphicsLinearLayout and QGraphicsGridLayout. To expose your existing QGraphicsWidget classes to QML, use \l {qmlRegisterType()}. -See \l{Extending QML in C++} for further information on using C++ types in QML. +See \l{Extending QML Functionalities using C++} for further information on +how to use C++ types in QML. */ diff --git a/doc/src/declarative/javascriptblocks.qdoc b/doc/src/declarative/javascriptblocks.qdoc index 65877f9..7ef7f9a 100644 --- a/doc/src/declarative/javascriptblocks.qdoc +++ b/doc/src/declarative/javascriptblocks.qdoc @@ -224,7 +224,8 @@ in \c script.js: The \c jsFunction() will now be called whenever MouseArea's \c clicked signal is emitted. -See \l {Connecting signals to methods and other signals} for more information. +See \l{QML Signal and Handler Event System#Connecting Signals to Methods and Signals} +{Connecting Signals to Methods and Signals} for more information. \section1 QML JavaScript Restrictions diff --git a/doc/src/declarative/mouseevents.qdoc b/doc/src/declarative/mouseevents.qdoc new file mode 100644 index 0000000..ade6760 --- /dev/null +++ b/doc/src/declarative/mouseevents.qdoc @@ -0,0 +1,120 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of this +** file. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! +\page mouseevents.html +\title QML Mouse Events +\ingroup QML Features +\previouspage {Anchor-based Layout in QML}{Layouts using Anchors} +\nextpage {QML Text Handling and Validators}{Text Handling and Validators} +\contentspage QML Features + +\tableofcontents + +\section1 Mouse Elements + +\list +\o \l{MouseArea} Element +\o \l{MouseEvent} Object +\endlist + +\section1 Mouse Event Handling + +QML uses \l{QML Signal and Handler Event System}{signals and handlers} to +deliver mouse interactions. Specifically, the \l MouseArea and \l MouseEvent +elements provide QML components with signal handlers to accept mouse events +within a defined area. + +\section1 Defining a Mouse Area + +The \l MouseArea element receives events within a defined area. One quick way +to define this area is to anchor the \c MouseArea to its parent's area using the +\c anchors.fill property. If the parent is a \l Rectangle (or any \l Item +component), then the MouseArea will fill the area defined by the parent's +dimensions. Alternatively, an area smaller or larger than the parent is +definable. +\snippet doc/src/snippets/declarative/mousearea/mousearea-snippet.qml anchor fill + +\section1 Receiving Events + +The MouseArea element provides +\l{QML Signal and Handler Event System}{signals and handlers} to detect different +mouse events. The \l MouseArea element documentation describes these +gestures in greater detail: + +\list +\o canceled +\o clicked +\o doubleClicked +\o entered +\o exited +\o positionChanged +\o pressAndHold +\o pressed +\o released +\endlist + +These signals have signal handlers that are invoked when the signals are emitted. +\snippet doc/src/snippets/declarative/mousearea/mousearea-snippet.qml mouse handlers + +\section1 Enabling Gestures +Some mouse gestures and button clicks need to be enabled before they send or +receive events. Certain \l MouseArea and \l MouseEvent properties enable these +gestures. + +To listen to (or explicitly ignore) a certain mouse button, set the appropriate +mouse button to the \l {MouseArea::acceptedButtons}{acceptedButtons} property. + +Naturally, the mouse events, such as button presses and mouse positions, are +sent during a mouse click. For example, the \c containsMouse property will only +retrieve its correct value during a mouse press. The +\l {MouseArea::hoverEnabled}{hoverEnabled} will enable mouse events and +positioning even when there are no mouse button presses. Setting the +\c hoverEnabled property to \c true, in turn will enable the \c entered, +\c exited, and \c positionChanged signal and their respective signal handlers. + +\snippet doc/src/snippets/declarative/mousearea/mousearea-snippet.qml enable handlers +Additionally, to disable the whole mouse area, set the \c MouseArea +element's \c enabled property to \c false. + +\section1 MouseEvent Object + +Signals and their handlers receive a \l MouseEvent object as a parameter. The +\c mouse object contain information about the mouse event. For example, the +mouse button that started the event is queried through the +\l {MouseEvent::button}{mouse.button} property. + +The \c MouseEvent object can also ignore a mouse event using its \c accepted +property. + +\section2 Accepting Further Signals +Many of the signals are sent multiple times to reflect various mouse events +such as double clicking. To facilitate the classification of mouse clicks, the +MouseEvent object has an \c accepted property to disable the event propagation. + +To learn more about QML's event system, please read the \l {QML Signal and Handler Event System} document. +*/ diff --git a/doc/src/declarative/network.qdoc b/doc/src/declarative/network.qdoc index 675a0aa..1b2934a 100644 --- a/doc/src/declarative/network.qdoc +++ b/doc/src/declarative/network.qdoc @@ -27,6 +27,10 @@ /*! \page qdeclarativenetwork.html +\ingroup qml-features +\previouspage {Dynamic Object Management in QML}{Dynamic Object Management} +\nextpage {QML Internationalization}{Internationalization} +\contentspage QML Features \title Network Transparency QML supports network transparency by using URLs (rather than file names) for all @@ -57,7 +61,7 @@ Network transparency is supported throughout QML, for example: Even QML types themselves can be on the network - if the \l {QML Viewer} is used to load \tt http://example.com/mystuff/Hello.qml and that content refers to a type "World", the engine will load \tt http://example.com/mystuff/qmldir and resolve the type just as it would for a local file. -For example if the qmldir file contains the line "World World.qml", it will load +For example if the qmldir file contains the line "World World.qml", it will load \tt http://example.com/mystuff/World.qml Any other resources that \tt Hello.qml referred to, usually by a relative URL, would similarly be loaded from the network. diff --git a/doc/src/declarative/positioners.qdoc b/doc/src/declarative/positioners.qdoc index 5493d4a..763bc88 100644 --- a/doc/src/declarative/positioners.qdoc +++ b/doc/src/declarative/positioners.qdoc @@ -27,9 +27,12 @@ /*! \page qml-positioners.html +\ingroup qml-features +\previouspage Property Binding +\nextpage Anchor-based Layout in QML +\contentspage QML Features \title Using QML Positioner and Repeater Items -\section1 Introduction Positioner items are container items that manage the positions and sizes of items in a declarative user interface. Positioners behave in a similar way to @@ -53,7 +56,7 @@ graphical elements: \section2 Column -\div{float-right} +\div {class="float-right"} \inlineimage qml-column.png \enddiv @@ -70,7 +73,7 @@ must be added to a parent Rectangle, if desired. \section2 Row -\div{float-right} +\div {class="float-right"} \inlineimage qml-row.png \enddiv @@ -87,7 +90,7 @@ left around the edges of the horizontally centered Row item. \section2 Grid -\div{float-right} +\div {class="float-right"} \inlineimage qml-grid-spacing.png \enddiv @@ -97,7 +100,7 @@ in a 2-by-2 grid. As with the other positioners, the spacing between items can be specified using the \l{Grid::spacing}{spacing} property. \clearfloat -\snippet doc/src/snippets/declarative/grid/grid-spacing.qml document +\snippet doc/src/snippets/declarative/grid-spacing.qml document There is no difference between horizontal and vertical spacing inserted between items, so any additional space must be added within the items @@ -108,7 +111,7 @@ at the appropriate places in the Grid definition. \section2 Flow -\div{float-right} +\div {class="float-right"} \inlineimage qml-flow-text1.png \inlineimage qml-flow-text2.png \enddiv @@ -137,7 +140,7 @@ control of spacing between items and between lines of items. \section1 Repeaters -\div{float-right} +\div {class="float-right"} \inlineimage qml-repeater-grid-index.png \enddiv diff --git a/doc/src/declarative/propertybinding.qdoc b/doc/src/declarative/propertybinding.qdoc index 379a4ec..afbbe4f 100644 --- a/doc/src/declarative/propertybinding.qdoc +++ b/doc/src/declarative/propertybinding.qdoc @@ -27,192 +27,297 @@ /*! \page propertybinding.html +\ingroup qml-features +\contentspage QML Features +\previouspage {QML Basic Types}{Data Types} +\nextpage {Using QML Positioner and Repeater Items}{Component Layouts} \title Property Binding -Property binding is a declarative way of specifying the value of a property. Binding allows -a property's value to be expressed as an JavaScript expression that defines the value relative -to other property values or data accessible in the application. The property value is -automatically kept up to date if the other properties or data values change. +\section1 Properties -Property bindings are created implicitly in QML whenever a property is assigned an JavaScript -expression. The following QML uses two property bindings to connect the size of the rectangle -to that of \c otherItem. +QML components have \e properties that can be read and modified by other objects. +In QML, properties serve many purposes but their main function is to bind to +values. Values may be a \l{QML Basic Types}{basic type}, or other QML elements. -\code -Rectangle { - width: otherItem.width - height: otherItem.height -} -\endcode +The syntax for properties is: -QML extends a standards compliant JavaScript engine, so any valid JavaScript expression can be -used as a property binding. Bindings can access object properties, make function calls and even -use builtin JavaScript objects like \e {Date} and \e {Math}. Assigning a constant value to a -property can even be thought of as a binding - after all, a constant is a valid JavaScript -expression! Here are some examples of more complex bindings: - -\code -Rectangle { - function calculateMyHeight() { - return Math.max(otherItem.height, thirdItem.height); - } - - anchors.centerIn: parent - width: Math.min(otherItem.width, 10) - height: calculateMyHeight() - color: { if (width > 10) "blue"; else "red" } -} -\endcode +\tt{[default] property <type> <name>[: defaultValue]} -While syntactically bindings can be of arbitrary complexity, if a binding starts to become -overly complex - such as involving multiple lines, or imperative loops - it may be better -to refactor the component entirely, or at least factor the binding out into a separate -function. +Elements already possess useful properties but, to create custom properties, +precede the property name with the keyword \c property. -\section1 Changing Bindings - -The \l PropertyChanges element can be used within a state change to modify the bindings on -properties. - -This example modifies the \l Rectangle's width property binding to be \c {otherItem.height} -when in the "square" state. When it returns to its default state, width's original property -binding will have been restored. - -\code -Rectangle { - id: rectangle - width: otherItem.width - height: otherItem.height - - states: State { - name: "square" - PropertyChanges { - target: rectangle - width: otherItem.height - } - } -} -\endcode +\snippet doc/src/snippets/declarative/properties.qml parent begin +\snippet doc/src/snippets/declarative/properties.qml inherited properties +\snippet doc/src/snippets/declarative/properties.qml custom properties +\snippet doc/src/snippets/declarative/properties.qml parent end +QML property rules coincide with many of JavaScript's property rules, for example, +property names must begin with a lowercase letter. +\l {JavaScript Reserved Words}{JavaScript reserved words} are not valid property +names. -\section1 Binding Properties from JavaScript +\section1 Property Binding -When working with both QML and JavaScript, it is important to differentiate between -\l {Property Binding} syntax in QML and simple \e {property assignment} in JavaScript. Take -the example below, which uses property binding to ensure the item's \c height is always twice -its \c width: - -\qml -Item { - width: 100 - height: width * 2 -} -\endqml - -On the other hand, take the following JavaScript code snippet, which \e assigns, rather -than \e binds, the value of the \c height property: - -\code -Item { - width: 100 - - Component.onCompleted: { - height = width * 2 // if width changes later, height is not updated! - } -} -\endcode +Property binding is a declarative way of specifying the value of a property. Binding allows +a property's value to be expressed as an JavaScript expression that defines the value relative +to other property values or data accessible in the application. The property value is +automatically kept up to date if the other properties or data values change. -Instead of creating a property binding, this simply sets the \c height property to the correct -value \e {at the time that} the JavaScript code is invoked. Unlike the first example, the -\c height will never change if \c width changes. +Property bindings are created in QML using the colon "\c {:}" before the value: +\snippet doc/src/snippets/declarative/properties.qml property binding +The property binding causes the width of the \c Rectangle to update whenever the +\c {parent}'s width changes. -The \e {property : value} syntax for property binding is QML-specific and cannot be used in -JavaScript. Instead, to bind a property from JavaScript, assign a \e function to the property -that returns the required value. The following code correctly sets the property binding -created in the first example, but creates the binding in JavaScript rather than QML: +QML extends a standards compliant JavaScript engine, so any valid JavaScript expression can be +used as a property binding. Bindings can access object properties, make function calls and even +use built-in JavaScript objects such as \c {Date} and \c {Math}. +\snippet doc/src/snippets/declarative/properties.qml JavaScript sample -\qml -Item { - width: 100 +While syntactically bindings can be of arbitrary complexity, if a binding starts to become +overly complex - such as involving multiple lines, or imperative loops - it may be better +to refactor the component entirely, or at least factor the binding out into a separate +function. - Component.onCompleted: { - height = (function() { return width * 2 }) - } -} -\endqml +\section1 Property Assignment versus Property Binding +When working with both QML and JavaScript, it is important to differentiate between +QML property binding and JavaScript value assignment. In QML, a property +binding is created using the colon "\c {:}". +\snippet doc/src/snippets/declarative/properties.qml property binding +The property binding causes the width of the \c Rectangle to update whenever the +\c {parent}'s width changes. -\section2 Using \c this to create a binding +Assigning a property value (using the equals sign "\c {=}") does not create a +property binding. +\snippet doc/src/snippets/declarative/properties.qml property assignment -When creating a property binding from JavaScript, QML allows the use of the \c this keyword to -refer to the object to which the property binding will be assigned. This allows one to -explicitly refer to a property within an object when there may be ambiguity about the exact -property that should be used for the binding. +Instead of creating a property binding, the assignment simply sets the \c Rectangle +\c width value to a number when the \c Component.onCompleted code is invoked. -For example, the \c Component.onCompleted handler below is defined within the scope of the -\l Item, and references to \c width within this scope would refer to the \l Item's width, rather -than that of the \l Rectangle. To bind the \l Rectangle's \c height to its own \c width, the -function needs to explicitly refer to \c this.width rather than just \c width. Otherwise, the -height of the \l Rectangle would be bound to the width of the \l Item and not the \l Rectangle. +Assigning a value to a property that is already bound will remove the previous binding. +A property can only have one value at a time (a list of property is one value), +and if any code explicitly re-sets this value, the property binding is removed. -\qml -Item { - width: 500 - height: 500 +There is no way to create a property binding directly from imperative JavaScript code, +although it is possible to use the \l {Using the Binding Element}{Binding} element. - Rectangle { - id: rect - width: 100 - color: "yellow" - } +\section1 Types of Properties - Component.onCompleted: { - rect.height = (function() { return this.width * 2 }) - } -} -\endqml +Properties may bind to different types, but they are are \e type-safe. That is, +properties only allow you to assign a value that matches the property type. For +example, if a property is a real, and if you try to assign a string to it you +will get an error. -(In this case, the function could also have referred to \c rect.width rather than \c this.width.) +\badcode +property real volume: "four" //generates an error +\endcode -Note that the value of \c this is not defined outside of its use in property binding. -See \l {QML JavaScript Restrictions} for details. +Certain properties bind to more complex types such as other elements and objects. + +\keyword qml-basic-property-types +\section2 Basic Property Types +Basic types such as \l int, \l real, and other Qt structures may be bound to +properties. For a list of types, visit the \l {QML Basic Types} document. -\section2 Effects of property assignment +\keyword qml-id-property +\section2 The \c id Property + +Each QML object may be given a special unique property called an \c id. +No other object within the same QML component (see \l{QML Documents}) can have +the same \c id value. QML objects may then access an object using the \c id +property. +\snippet doc/src/snippets/declarative/properties.qml id property +A component may readily access its parent's properties by using the \c parent +property. -Note that assigning a value to a property that is currently bound will remove the binding. -A property can only have one value at a time, and if any code explicitly sets this value, the -binding is removed. In the following example, although \c width has been bound to \c height, -the binding is removed by the JavaScript code that assigns \c width to 50: +Note that an \c id must begin with a lower-case letter or an underscore. The +\c id cannot contain characters other than letters, numbers, underscores, and +\l {JavaScript Reserved Words}{JavaScript reserved words}. + +\section2 Elements and Objects as Property Values -\code -Item { - width: height * 2 - height: 100 +Many properties bind to objects. For example, the \l Item element has a +\c states property that can bind to \l State elements. This type of property +binding allows elements to carry additional non-children elements. \c Item's +\c transitions property behaves in a similar way; it can bind to \l Transition +elements. + +Care must be taken when referring to the parent of an object property binding. +Elements and components that are bound to properties are not necessarily set +as children of the properties' component. + +\snippet doc/src/snippets/declarative/properties.qml object binding +The code snippet has a \l Gradient element that attempts to print its parent's +\c width value. However, the \c Gradient element is bound to the \c gradient +property, not the \c children property of the \c Rectangle. As a result, the +\c Gradient does not have the \c Rectangle as its parent. Printing the value +of \c{parent.width} generates an error. Printing the \c Rectangle object's +first child's \c name will print \c {childrectangle} because the second +\c Rectangle is bound to the \c children property. + +For more information about the \c children property, please read the +\l {Default Properties} section. + +\keyword attached-properties +\section2 Attached Properties + +Certain objects provide additional properties by \e attaching properties to other +objects. For example, the \l Keys element have properties that can \e attach to other QML +objects to provide keyboard handling. + +\snippet doc/src/snippets/declarative/properties.qml list attached property +The element \l ListView provides the delegate, \c listdelegate, the property +\c isCurrentItem as an attached property. The \c ListView.isCurrentItem +\e{attached property} provides highlight information to the delegate. +Effectively, the \l ListView element attaches the \c ListView.isCurrentItem +property to each delegate it creates. + +\keyword attached-signalhandlers +\section2 Attached Signal Handlers + +\e {Attached signal handlers} are similar +to \l{Attached Properties}{attached properties} in that they attach to objects +to provide additional functionality to objects. Two prominent elements, +\l Component and \l Keys element provide +\l{QML Signal and Handler Event System}{signal handlers} as attached signal +handlers. +\snippet doc/src/snippets/declarative/properties.qml attached signal handler + +Read the \l{QML Signal and Handler Event System} and the \l{Keyboard Focus in QML} +articles for more information. + +\section2 List properties + +Some properties may accept a binding to a list property, where more than one +component can bind to the property. List properties allow multiple +\l {State}{States}, \l {Gradient}{Gradients}, and other components to bind to a +single property. +\snippet doc/src/snippets/declarative/properties.qml list property +The list is enclosed in square brackets, with a comma separating the +list elements. In cases where you are only assigning a single item to a +list, you may omit the square brackets. +\snippet doc/src/snippets/declarative/properties.qml single property + +To access the list, use the \c index property. +\snippet doc/src/snippets/declarative/properties.qml print list property +The snippet code simply prints the name of the first state, \c FETCH. + + See the \l{list}{list type} documentation +for more details about list properties and their available operations. + +\keyword qml-grouped-properties +\section2 Grouped Properties + +In some cases properties form a logical group and use either the \e dot notation +or \e group notation. + +Grouped properties may be written both ways: +\snippet doc/src/snippets/declarative/properties.qml grouped properties + +In the element documentation grouped properties are shown using the dot notation. + +\section2 Property Aliases + +Unlike a property definition, which allocates a new, unique storage space for +the property, a property alias connects the newly declared property, called the +\e{aliasing property} as a direct reference to an existing property, the +\e{aliased property}. Read or write operations on the aliasing property results +in a read or write operations on the aliased property, respectively. + +A property alias declaration is similar to an ordinary property definition: + +\tt{[default] property alias <name>: <alias reference>} + +As the aliasing property has the same type as the aliased property, an explicit +type is omitted, and the special \c alias keyword is before the property name. +Instead of a default value, a property alias has a compulsory alias reference. +Accessing the aliasing property is similar to accessing a regular property. In +addition, the optional \c default keyword indicates that the aliasing property +is a \l{Default Properties}{default property}. + +\snippet doc/src/snippets/declarative/Button.qml property alias +When importing the component as a \c Button, the \c buttonlabel is directly +accessible through the \c label property. +\snippet doc/src/snippets/declarative/properties.qml alias usage +In addition, the \c id property may also be aliased and referred outside the +component. +\snippet doc/src/snippets/declarative/Button.qml parent begin +\snippet doc/src/snippets/declarative/Button.qml id alias +\snippet doc/src/snippets/declarative/Button.qml parent end +The \c imagebutton component has the ability to modify the child \l Image object + and its properties. +\snippet doc/src/snippets/declarative/properties.qml image alias + +Using aliases, properties may be exposed to the +\l{qml-top-level-component}{top level component}. Exposing properties to the +top-level component allows components to have interfaces similar to Qt widgets. + +\section3 Considerations for property aliases + +Aliases are only activated once the component +\l{Component::onCompleted}{completes} its initialization. An error is generated +when an uninitialized alias is referenced. Likewise, aliasing an aliasing +property will also result in an error. + +\snippet doc/src/snippets/declarative/properties.qml alias complete + +When importing the component, however, aliasing properties appear as regular Qt +properties and consequently can be used in alias references. + +It is possible for an aliasing property to have the same name as an existing +property, effectively overwriting the existing property. For example, +the following component has a \c color alias property, named the same as the built-in +\l {Rectangle::color} property: + +\snippet doc/src/snippets/declarative/properties.qml alias overwrite + +Any object that use this component and refer to its \c color property will be +referring to the alias rather than the ordinary \l {Rectangle::color} property. +Internally, however, the \c coloredrectangle can correctly set its \c color +property and refer to the actual defined property rather than the alias. + +The \l{declarative/ui-components/tabwidget}{TabWidget} example uses +aliases to reassign children to the \l ListView, creating a tab effect. + +\keyword default-properties +\section2 Default Properties - Component.onCompleted: { - width = 50; - } -} -\endcode +When imported, QML components will bind declared children to their designated +\e{default properties}. The optional \c default attribute specifies a property +as the \e {default property}. For example, the State element's default property +is its \l{State::changes}{changes} property. \l PropertyChanges elements +may simply be placed as the \c{State}'s children and they will be bound to the +\c changes property. +\snippet doc/src/snippets/declarative/properties.qml state default + +Similarly, the \l Item element's default property is its +\l{Item::data}{data} property. The \c data property manages Item's +\c children and \c resources properties. This way, different data types may be +placed as direct children of the \c Item. +\snippet doc/src/snippets/declarative/properties.qml default property +Reassigning a default property is useful when a component is reused. For +example, the \l{declarative/ui-components/tabwidget}{TabWidget} example uses +the \c default attribute to reassign children to the \l ListView, creating +a tab effect. -\section1 The Binding Element +\section1 Using the Binding Element -The implicit binding syntax shown previously is easy to use and works perfectly for most uses -of bindings. In some advanced cases, it is necessary to create bindings explicitly using the -\l Binding element. +In some advanced cases, it may be necessary to create bindings explicitly with +the\l Binding element. -For example, to bind a property exposed from C++ (\c system.brightness) to a value -coming from QML (\c slider.value), you could use the Binding element as follows: -\qml -Binding { - target: system - property: "brightness" - value: slider.value -} -\endqml +For example, to bind a property exposed from C++ (\c system.brightness) to a +value written in QML (\c slider.value), you could use the \l Binding element as +follows: +\snippet doc/src/snippets/declarative/properties.qml binding element +\section1 Changing Property Values in States +The \l PropertyChanges element is for setting property bindings within a +\l State element to set a property binding. + +\snippet doc/src/snippets/declarative/properties.qml PropertyChanges element +The rectangle's \c color property will bind to the \c warning component's +\c color property when its \c state is set to the \c WARNING state. */ - diff --git a/doc/src/declarative/qdeclarativedocument.qdoc b/doc/src/declarative/qdeclarativedocument.qdoc index b94e32e..423d77c 100644 --- a/doc/src/declarative/qdeclarativedocument.qdoc +++ b/doc/src/declarative/qdeclarativedocument.qdoc @@ -30,8 +30,6 @@ \title QML Documents \brief A description of QML documents and the kind of content they contain. -\section1 Introduction - A QML document is a block of QML source code. QML documents generally correspond to files stored on a disk or at a location on a network, but they can also be constructed directly from text data. @@ -42,17 +40,17 @@ Here is a simple QML document: QML documents are always encoded in UTF-8 format. -A QML document always begins with one or more import statements. To prevent elements -introduced in later versions from affecting existing QML programs, the element types -available within a document are controlled by the imported QML \l {Modules}. That is, +A QML document always begins with one or more import statements. To prevent elements +introduced in later versions from affecting existing QML programs, the element types +available within a document are controlled by the imported QML \l {Modules}. That is, QML is a \e versioned language. -Syntactically a QML document is self contained; QML does \e not have a preprocessor that -modifies the document prior to presentation to the QML runtime. \c import statements -do not "include" code in the document, but instead instruct the QML runtime on how to -resolve type references found in the document. Any type reference present in a QML -document - such as \c Rectangle and \c ListView - including those made within an -\l {Inline JavaScript}{JavaScript block} or \l {Property Binding}s, are \e resolved based exclusively on the +Syntactically a QML document is self contained; QML does \e not have a preprocessor that +modifies the document prior to presentation to the QML runtime. \c import statements +do not "include" code in the document, but instead instruct the QML runtime on how to +resolve type references found in the document. Any type reference present in a QML +document - such as \c Rectangle and \c ListView - including those made within an +\l {Inline JavaScript}{JavaScript block} or \l {Property Binding}s, are \e resolved based exclusively on the import statements. QML does not import any modules by default, so at least one \c import statement must be present or no elements will be available! @@ -63,12 +61,12 @@ resolved according to the document scope. \section1 Documents as Component Definitions -A QML document defines a single, top-level \l {QDeclarativeComponent}{QML component}. A QML component -is a template that is interpreted by the QML runtime to create an object with some predefined -behaviour. As it is a template, a single QML component can be "run" multiple times to -produce several objects, each of which are said to be \e instances of the component. +A QML document defines a single, top-level \l {QDeclarativeComponent}{QML component}. A QML component +is a template that is interpreted by the QML runtime to create an object with some predefined +behaviour. As it is a template, a single QML component can be "run" multiple times to +produce several objects, each of which are said to be \e instances of the component. -Once created, instances are not dependent on the component that created them, so they can +Once created, instances are not dependent on the component that created them, so they can operate on independent data. Here is an example of a simple "Button" component (defined in a \c Button.qml file) that is instantiated four times by \c application.qml. Each instance is created with a different value for its \c text property: @@ -80,7 +78,7 @@ Each instance is created with a different value for its \c text property: \row \o \snippet doc/src/snippets/declarative/qml-documents/qmldocuments.qml document -\o +\o \qml import QtQuick 1.0 @@ -112,23 +110,23 @@ to other QML components and applications in the same directory. \section1 Inline Components In addition to the top-level component that all QML documents define, and any reusable -components placed in separate files, documents may also -include \e inline components. Inline components are declared using the -\l Component element, as can be seen in the first example above. Inline components share +components placed in separate files, documents may also +include \e inline components. Inline components are declared using the +\l Component element, as can be seen in the first example above. Inline components share all the characteristics of regular top-level components and use the same \c import list as their -containing QML document. Components are one of the most basic building blocks in QML, and are +containing QML document. Components are one of the most basic building blocks in QML, and are frequently used as "factories" by other elements. For example, the \l ListView element uses the \c delegate component as the template for instantiating list items - each list item is just a new instance of the component with the item specific data set appropriately. -Like other \l {QML Elements}, the \l Component element is an object and must be assigned to a +Like other \l {QML Elements}, the \l Component element is an object and must be assigned to a property. \l Component objects may also have an object id. In the first example on this page, -the inline component is added to the \l Rectangle's \c resources list, and then -\l {Property Binding} is used to assign the \l Component to the \l ListView's \c delegate +the inline component is added to the \l Rectangle's \c resources list, and then +\l {Property Binding} is used to assign the \l Component to the \l ListView's \c delegate property. While using property binding allows the \l Component object to be shared (for example, -if the QML document contained multiple \l ListView's with the same delegate), in this case the -\l Component could have been assigned directly to the \l ListView's \c delegate. The QML -language even contains a syntactic optimization when assigning directly to a component property +if the QML document contained multiple \l ListView's with the same delegate), in this case the +\l Component could have been assigned directly to the \l ListView's \c delegate. The QML +language even contains a syntactic optimization when assigning directly to a component property for this case where it will automatically insert the \l Component tag. These final two examples are behaviorally identical to the original document. diff --git a/doc/src/declarative/qdeclarativei18n.qdoc b/doc/src/declarative/qdeclarativei18n.qdoc index 9ca8938..bbee37c 100644 --- a/doc/src/declarative/qdeclarativei18n.qdoc +++ b/doc/src/declarative/qdeclarativei18n.qdoc @@ -27,9 +27,12 @@ /*! \page qdeclarativei18n.html +\ingroup qml-features +\contentspage QML Features +\previouspage {Network Transparency}{Loading Resources in QML} +\nextpage {QML Features} \title QML Internationalization -\section1 Overview Strings in QML can be marked for translation using the qsTr(), qsTranslate(), QT_TR_NOOP(), and QT_TRANSLATE_NOOP() functions. diff --git a/doc/src/declarative/qdeclarativemodels.qdoc b/doc/src/declarative/qdeclarativemodels.qdoc index 9409eaf..23dd390 100644 --- a/doc/src/declarative/qdeclarativemodels.qdoc +++ b/doc/src/declarative/qdeclarativemodels.qdoc @@ -27,10 +27,14 @@ /*! \page qdeclarativemodels.html +\ingroup qml-features +\contentspage QML Features +\previouspage {QML Animation and Transitions}{Animation and Transitions} +\nextpage {Presenting Data with Views} \target qmlmodels \title QML Data Models -QML items such as ListView, GridView and \l Repeater require Data Models +QML items such as ListView, GridView and \l Repeater require Data Models that provide the data to be displayed. These items typically require a \e delegate component that creates an instance for each item in the model. Models may be static, or @@ -38,7 +42,7 @@ have items modified, inserted, removed or moved dynamically. Data is provided to the delegate via named data roles which the delegate may bind to. Here is a ListModel with two roles, \e type and \e age, -and a ListView with a delegate that binds to these roles to display their +and a ListView with a delegate that binds to these roles to display their values: \snippet doc/src/snippets/declarative/qml-data-models/listmodel-listview.qml document @@ -48,7 +52,7 @@ properties, the roles can be accessed with the qualified \e model name instead. For example, if a \l Text element had \e type or \e age properties, the text in the above example would display those property values instead of the \e type and \e age values from the model item. In this case, the properties could have been referenced as -\c model.type and \c model.age instead to ensure the delegate displays the +\c model.type and \c model.age instead to ensure the delegate displays the property values from the model item. A special \e index role containing the index of the item in the model @@ -68,11 +72,13 @@ QML provides several types of data models among the built-in set of QML elements. In addition, models can be created with C++ and then made available to QML components. -The views used to access data models are described in \l{Presenting Data with QML}. +The views used to access data models are described in the +\l{Presenting Data with Views} overview. The use of positioner items to arrange items from a model is covered in \l{Using QML Positioner and Repeater Items}. +\keyword qml-data-models \section1 QML Data Models \section2 ListModel @@ -108,7 +114,7 @@ XmlListModel allows construction of a model from an XML data source. The roles are specified via the \l XmlRole element. The following model has three roles, \e title, \e link and \e description: -\code +\qml XmlListModel { id: feedModel source: "http://rss.news.yahoo.com/rss/oceania" @@ -117,7 +123,7 @@ XmlListModel { XmlRole { name: "link"; query: "link/string()" } XmlRole { name: "description"; query: "description/string()" } } -\endcode +\endqml The \l{demos/declarative/rssnews}{RSS News demo} shows how XmlListModel can be used to display an RSS feed. @@ -125,31 +131,19 @@ be used to display an RSS feed. \section2 VisualItemModel -VisualItemModel allows QML items to be provided as a model. +VisualItemModel allows QML items to be provided as a model. This model contains both the data and delegate; the child items of a -VisualItemModel provide the contents of the delegate. The model +VisualItemModel provide the contents of the delegate. The model does not provide any roles. -\code - VisualItemModel { - id: itemModel - Rectangle { height: 30; width: 80; color: "red" } - Rectangle { height: 30; width: 80; color: "green" } - Rectangle { height: 30; width: 80; color: "blue" } - } - - ListView { - anchors.fill: parent - model: itemModel - } -\endcode +\snippet doc/src/snippets/declarative/models/visual-model-and-view.qml visual model and view Note that in the above example there is no delegate required. The items of the model itself provide the visual elements that will be positioned by the view. - +\keyword qml-c++-models \section1 C++ Data Models Models can be defined in C++ and then made available to QML. This is useful @@ -165,7 +159,7 @@ models. A model may be a simple QStringList, which provides the contents of the list via the \e modelData role. -Here is a ListView with a delegate that references its model item's +Here is a ListView with a delegate that references its model item's value using the \c modelData role: \snippet examples/declarative/modelviews/stringlistmodel/view.qml 0 @@ -184,7 +178,7 @@ the model by calling QDeclarativeContext::setContextProperty() again. \section2 QObjectList-based model -A list of QObject* values can also be used as a model. A QList<QObject*> provides +A list of QObject* values can also be used as a model. A QList<QObject*> provides the properties of the objects in the list as roles. The following application creates a \c DataObject class that with @@ -205,7 +199,7 @@ the ListView delegate: \snippet examples/declarative/modelviews/objectlistmodel/view.qml 0 -Note the use of the fully qualified access to the \c color property. +Note the use of the fully qualified access to the \c color property. The properties of the object are not replicated in the \c model object, since they are easily available via the \c modelData object. @@ -221,10 +215,10 @@ the model by calling QDeclarativeContext::setContextProperty() again. A model can be defined by subclassing QAbstractItemModel. This is the best approach if you have a more complex model that cannot be supported -by the other approaches. A QAbstractItemModel can also automatically +by the other approaches. A QAbstractItemModel can also automatically notify a QML view when the model data has changed. -The roles of a QAbstractItemModel subclass can be exposed to QML by calling +The roles of a QAbstractItemModel subclass can be exposed to QML by calling QAbstractItemModel::setRoleNames(). The default role names set by Qt are: \table @@ -244,9 +238,9 @@ that has \e type and \e size roles. It calls QAbstractItemModel::setRoleNames() role names for accessing the properties via QML: \snippet examples/declarative/modelviews/abstractitemmodel/model.h 0 -\dots +\dots \snippet examples/declarative/modelviews/abstractitemmodel/model.h 1 -\dots +\dots \snippet examples/declarative/modelviews/abstractitemmodel/model.h 2 \codeline \snippet examples/declarative/modelviews/abstractitemmodel/model.cpp 0 @@ -261,14 +255,14 @@ roles: QML views are automatically updated when the model changes. Remember the model must follow the standard rules for model changes and notify the view when -the model has changed by using QAbstractItemModel::dataChanged(), +the model has changed by using QAbstractItemModel::dataChanged(), QAbstractItemModel::beginInsertRows(), etc. See the \l {Model subclassing reference} for more information. The complete example is available in Qt's \l {declarative/modelviews/abstractitemmodel}{examples/declarative/modelviews/abstractitemmodel} directory. QAbstractItemModel presents a hierarchy of tables, but the views currently provided by QML -can only display list data. +can only display list data. In order to display child lists of a hierarchical model the VisualDataModel element provides several properties and functions for use with models of type QAbstractItemModel: @@ -283,14 +277,14 @@ with models of type QAbstractItemModel: \section2 Exposing C++ Data Models to QML -The above examples use QDeclarativeContext::setContextProperty() to set -model values directly in QML components. An alternative to this is to -register the C++ model class as a QML type from a QML C++ plugin using -QDeclarativeExtensionPlugin. This would allow the model classes to be +The above examples use QDeclarativeContext::setContextProperty() to set +model values directly in QML components. An alternative to this is to +register the C++ model class as a QML type from a QML C++ plugin using +QDeclarativeExtensionPlugin. This would allow the model classes to be created directly as elements within QML: \table -\row +\row \o \code @@ -299,7 +293,7 @@ class MyModelPlugin : public QDeclarativeExtensionPlugin public: void registerTypes(const char *uri) { - qmlRegisterType<MyModel>(uri, 1, 0, + qmlRegisterType<MyModel>(uri, 1, 0, "MyModel"); } } @@ -339,7 +333,7 @@ An integer can be used to specify a model that contains a certain number of elements. In this case, the model does not have any data roles. The following example creates a ListView with five elements: -\code +\qml Item { width: 200; height: 250 @@ -355,7 +349,7 @@ Item { } } -\endcode +\endqml \section2 An Object Instance @@ -367,7 +361,7 @@ The example below creates a list with one item, showing the color of the \e myText text. Note the use of the fully qualified \e model.color property to avoid clashing with \e color property of the Text element in the delegate. -\code +\qml Rectangle { width: 200; height: 250 @@ -389,7 +383,7 @@ Rectangle { delegate: myDelegate } } -\endcode +\endqml \section1 Accessing Views and Models from Delegates @@ -408,44 +402,7 @@ In the following example, the delegate shows the property \e{language} of the model, and the color of one of the fields depends on the property \e{fruit_color} of the view. -\code -Rectangle { - width: 200; height: 200 - - ListModel { - id: fruitModel - property string language: "en" - ListElement { - name: "Apple" - cost: 2.45 - } - ListElement { - name: "Orange" - cost: 3.25 - } - ListElement { - name: "Banana" - cost: 1.95 - } - } - - Component { - id: fruitDelegate - Row { - Text { text: " Fruit: " + name; color: ListView.view.fruit_color } - Text { text: " Cost: $" + cost } - Text { text: " Language: " + ListView.view.model.language } - } - } - - ListView { - property color fruit_color: "green" - model: fruitModel - delegate: fruitDelegate - anchors.fill: parent - } -} -\endcode +\snippet doc/src/snippets/declarative/models/views-models-delegates.qml rectangle Another important case is when some action (e.g. mouse click) in the delegate should update data in the model. In this case you can define @@ -457,92 +414,11 @@ a function in the model, e.g.: ...and call it from the delegate using: -\code +\js ListView.view.model.setData(index, field, value) -\endcode +\endjs ...assuming that \e{field} holds the name of the field which should be updated, and that \e{value} holds the new value. */ - -/*! -\page qml-presenting-data.html -\title Presenting Data with QML - -\section1 Introduction - -Qt Quick contains a set of standard items that can be used to present data in a -number of different ways. For simple user interfaces, -\l{Using QML Positioner and Repeater Items#Repeaters}{Repeaters} can be used -in combination with -\l{Using QML Positioner and Repeater Items#Positioners}{Positioners} -to obtain pieces of data and arrange them in a user interface. However, when -large quantities of data are involved, it is often better to use models with -the standard views since these contain many built-in display and navigation -features. - -\section1 Views - -Views are scrolling containers for collections of items. They are feature-rich, -supporting many of the use cases found in typical applications, and can be -customized to meet requirements on style and behavior. - -A set of standard views are provided in the basic set of Qt Quick -graphical elements: - -\list -\o \l{#ListView}{ListView} arranges items in a horizontal or vertical list -\o \l{#GridView}{GridView} arranges items in a grid within the available space -\o \l{#PathView}{PathView} arranges items on a path -\endlist - -Unlike these items, \l WebView is not a fully-featured view item, and needs -to be combined with a \l Flickable item to create a view that performs like -a Web browser. - -\section2 ListView - -\l ListView shows a classic list of items with horizontal or vertical placing -of items. - -\div{float-right} -\inlineimage qml-listview-snippet.png -\enddiv - -The following example shows a minimal ListView displaying a sequence of -numbers (using an \l{QML Data Models#An Integer}{integer as a model}). -A simple delegate is used to define an items for each piece of data in the -model. - -\clearfloat -\snippet doc/src/snippets/declarative/listview/listview-snippet.qml document - - - -\section2 GridView - -\l GridView displays items in a grid like an file manager's icon view. - -\section2 PathView - -\l PathView displays items on a path, where the selection remains in -the same place and the items move around it. - -\section1 Decorating Views - -\section2 Headers and Footers - -\section2 Sections - -\section2 Navigation - -In traditional user interfaces, views can be scrolled using standard -controls, such as scroll bars and arrow buttons. In some situations, it -is also possible to drag the view directly by pressing and holding a -mouse button while moving the cursor. In touch-based user interfaces, -this dragging action is often complemented with a flicking action, where -scrolling continues after the user has stopped touching the view. - -\section1 Further Reading -*/ diff --git a/doc/src/declarative/qdeclarativestates.qdoc b/doc/src/declarative/qdeclarativestates.qdoc index 6d5aebc..655b647 100644 --- a/doc/src/declarative/qdeclarativestates.qdoc +++ b/doc/src/declarative/qdeclarativestates.qdoc @@ -27,197 +27,110 @@ /*! \page qdeclarativestates.html +\ingroup qml-features +\contentspage QML Features +\previouspage {Importing Reusable Components} +\nextpage {QML Animation and Transitions}{Animation and Transitions} \target qmlstates \title QML States -\section1 Overview - -User interfaces are designed to present different interface configurations in -different scenarios, or to modify their appearances in response to user -interaction. Often, there are a set of changes that are made concurrently, such -that the interface could be seen to be internally changing from one \e state to -another. +\section1 States Elements +\list +\o \l State +\o \l PropertyChanges +\o \l StateGroup +\o \l StateChangeScript +\o \l ParentChange +\o \l AnchorChanges +\endlist -This applies generally to interface elements regardless of their complexity. -A photo viewer may initially present images in a grid, and when an image is -clicked, change to a "detailed" state where the individual image is expanded -and the interface is changed to present new options for image editing. On the -other end of the scale, when a simple button is pressed, it may change to a -"pressed" state in which its color and position is modified to give a pressed -appearance. +Many user interface designs are \e state driven; interfaces have configurations +that differ depending on the current state. For example, a traffic signal will +configure its flags or lights depending on its state. While in the signal's +\c stop state, a red light will turn on while the yellow and the green lights +will turn off. In the \c caution state, the yellow light is on while the other +lights are turned off. -In QML, any object can change between different \e states to apply sets of -changes that modify the properties of relevant items. Each \e state could -present a different configuration that could, for example: +In QML, \e states are a set of property configurations defined in a \l State +element. Different configurations could, for example: \list \o Show some UI elements and hide others \o Present different available actions to the user -\o Start, stop or pause animations +\o Start, stop, or pause animations \o Execute some script required in the new state \o Change a property value for a particular item -\o Show a different view or "screen" +\o Show a different view or screen \endlist -Changes between states can be animated using \l {Transitions}{transitions}, as -discussed further below. - -All \l {Item}-based objects have a \e {default state}, and can specify additional -states by adding new \l State objects to the item's \l {Item::}{states} -property. Each state has a \e name that is unique for all states within that -item; the default state's name is an empty string. To change the current state +All \l {Item}-based objects have a \c state property, and can specify additional +states by adding new \c State objects to the item's \l {Item::}{states} +property. Each state within a component has a unique \c name, an empty string +being the default. To change the current state of an item, set the \l {Item::}{state} property to the name of the state. -Non-Item objects can use states through the StateGroup element. - +Non-Item objects may use states through the \l StateGroup element. \section1 Creating States To create a state, add a \l State object to the item's \l {Item::}{states} property, which holds a list of states for that item. -Following is an example. Here, the \l Rectangle is initially placed in the -default (0, 0) position. It has defined an additional state named "moved", in -which a PropertyChanges object repositions the rectangle to (50, 50). Clicking -within the MouseArea changes the state to the "moved" state, thus moving the \l -Rectangle. - -\snippet doc/src/snippets/declarative/states.qml 0 - -The \l State item defines all the changes to be made in the new state. It -could specify additional properties to be changed, or create additional -PropertyChanges for other objects. It can also modify the properties of other -objects, not just the object that owns the state. For example: - -\qml -Rectangle { - // ... - states: [ - State { - name: "moved" - PropertyChanges { target: myRect; x: 50; y: 50; color: "blue" } - PropertyChanges { target: someOtherItem; width: 1000 } - } - ] -} -\endqml - -As a convenience, if an item only has one state, its \l {Item::}{states} -property can be defined as a single \l State, without the square-brace list -syntax: - -\snippet doc/src/snippets/declarative/propertyanimation.qml single state - -A \l State is not limited to performing modifications on property values. It -can also: - +A warning \c signal component may have two states, the \c NORMAL and the +\c CRITICAL state. Suppose that in the \c NORMAL state, the \c color of the +signal should be \c green and the warning \c flag is down. Meanwhile, in the +\c CRITICAL state, the \c color should be \c red and the flag is \c up. We may +model the states using the \c State element and the color and flag +configurations with the \c PropertyChanges element. +\snippet doc/src/snippets/declarative/states.qml signal states +The \l PropertyChanges element will change the values of object properties. +Objects are referenced through their \l {qml-id-property}{id}. Objects outside +the component are also referenced using the \c id property, exemplified by the +property change to the external \c flag object. + +Further, the state may change by assigning the \c state property with the +appropriate signal state. A state switch could be in a \l MouseArea element, +assigning a different state whenever the signal receives a mouse click. +\snippet doc/src/snippets/declarative/states.qml switch states + +The State element is not limited to performing modifications on property values. +It can also: \list -\o Run some script using StateChangeScript -\o Override an existing signal handler for an object using PropertyChanges -\o Re-parent an \l Item using ParentChanges -\o Modify anchor values using AnchorChanges +\o Run some script using \l StateChangeScript +\o Override an existing signal handler for an object using \l PropertyChanges +\o Re-parent an \l Item using \l ParentChange +\o Modify anchor values using \l AnchorChanges \endlist -The \l {declarative/animation/states}{States and Transitions example} -demonstrates how to declare a basic set of states and apply animated -transitions between them. - - \section1 The Default State -Of course, the \l Rectangle in the example above could have simply been moved -by setting its position to (50, 50) in the mouse area's \c onClicked handler. -However, aside from enabling batched property changes, one of the features of -QML states is the ability of an item to revert to its \e {default state}. -The default state contains all of an item's initial property values before -they were modified in a state change. - -For example, suppose the \l Rectangle should move to (50,50) when the mouse is -pressed, and then move back to its original position when the mouse is -released. This can be achieved by using the \l {State::}{when} property, -like this: - -\qml -Rectangle { - // ... - - MouseArea { - id: mouseArea - anchors.fill: parent - } - - states: State { - name: "moved" - when: mouseArea.pressed - // ... - } -} -\endqml - -The \l {State::}{when} property is set to an expression that evaluates to -\c true when the item should be set to that state. When the mouse is pressed, -the state is changed to \e moved. When it is released, the item reverts to its -\e default state, which defines all of the item's original property values. - -Alternatively, an item can be explicitly set to its default state by setting its -\l {Item::}{state} property to an empty string (""). For example, instead of -using the \l {State::}{when} property, the above code could be changed to: - -\qml -Rectangle { - // ... - - MouseArea { - anchors.fill: parent - onPressed: myRect.state = 'moved'; - onReleased: myRect.state = ''; - } - - states: State { - name: "moved" - // ... - } -} -\endqml - -Obviously it makes sense to use the \l {State::}{when} property when possible -as it provides a simpler (and a better, more declarative) solution than -assigning the state from signal handlers. - - -\section1 Animating State Changes +Every \l Item based component has a \c state property and a \e{default state}. +The default state is the empty string (\c{""}) and contains all of an item's +initial property values. The default state is useful for managing property +values before state changes. Setting the \c state property to an empty string +will load the default state. +\section1 The \c when Property -State changes can be easily animated through \l {Transitions}{transitions}. A -\l Transition defines the animations that should be applied when an item -changes from one state to another. +For convenience, the \l State element has a \c when property that can bind to +expressions to change the state whenever the bound expression evaluates to +\c true. The \c when property will revert the state back to the +\l {The Default State}{default state} when the expression evaluates to false. -If the above example was modified to include the following \l Transition, the -movement of the \l Rectangle would be animated: +\snippet doc/src/snippets/declarative/states.qml when property +The \c bell component will change to the \c RINGING state whenever the +\c signal.state is \c CRITICAL. -\qml -Rectangle { - // ... - - MouseArea { - // Handle mouse events... - } +\section1 Animating State Changes - states: [ - // States are defined here... - ] - - transitions: [ - Transition { - NumberAnimation { properties: "x,y"; duration: 500 } - } - ] - } -\endqml +State changes induce abrupt value changes. The \l Transition element allow +smoother changes during state changes. In transitions, animations and +interpolation behaviors are definable. The +\l {QML Animation and Transitions}{Animation and Transitions} article has more +information about creating state animations. -This \l Transition defines that if any \c x or \c y properties have changed -during a state change within this item, their values should be animated over 500 -milliseconds. +The \l {declarative/animation/states}{States and Transitions example} +demonstrates how to declare a basic set of states and apply animated +transitions between them. -See the \l Transitions documentation for more information. */ diff --git a/doc/src/declarative/qml-intro.qdoc b/doc/src/declarative/qml-intro.qdoc deleted file mode 100644 index 3f3e0e4..0000000 --- a/doc/src/declarative/qml-intro.qdoc +++ /dev/null @@ -1,616 +0,0 @@ -/**************************************************************************** -** -** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). -** All rights reserved. -** Contact: Nokia Corporation (qt-info@nokia.com) -** -** This file is part of the documentation of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:FDL$ -** No Commercial Usage -** This file contains pre-release code and may not be distributed. -** You may use this file in accordance with the terms and conditions -** contained in the Technology Preview License Agreement accompanying -** this package. -** -** GNU Free Documentation License -** Alternatively, this file may be used under the terms of the GNU Free -** Documentation License version 1.3 as published by the Free Software -** Foundation and appearing in the file included in the packaging of this -** file. -** -** If you have questions regarding the use of this file, please contact -** Nokia at qt-info@nokia.com. -** $QT_END_LICENSE$ -** -****************************************************************************/ - - - -/*! -\page qml-intro.html -\title Intro to Qt Quick - -\section1 Overview - -QML is a high level, scripted language. Its commands, more correctly \e elements, -leverage the power and efficiency of the Qt libraries to make easy to use -commands that perform intuitive functions. Draw a rectangle, display an image at -a position and so on. Behind these elements are complex C++ libraries that -efficiently perform the action. As with any graphical application, always -consider that this ability to easily build graphically rich applications means -that some care may be needed to prevent performance problems. - -The language also allows more flexibility of these commands by using -Javascript rather than C++ to add new layers of logic to your application. -Javascript is easier to learn than C++ and can be embedded into the QML -files or imported from a separate file. - -\bold{In QML the types of various 'objects' are referred to as \l {QML -Elements}{elements}}. - -An element usually has various \e properties that help define the element. For -example, if we created an element called Circle then the radius of the circle -would be a property. - - -\section1 A First Look - -The basic syntax of an \l{QML Elements}{element} is - -\qml -SomeElement { - id: myObject - // ... some other things here ... -} -\endqml - -Here we are defining a new object. We specify its 'type' first as SomeElement. -Then within matching braces { ... } we specify the various parts of our -element. - -The \c id is a unique identifier for the element, it must start with a lower -case letter and only contain letters, numbers and underscores. It is this -particular object's name. If this SomeElement \l {QML Elements}{element} was -a Rectangle instead and it was one of many then the \e optional unique id -would allow us to manipulate each element individually. - -Each visual element is ultimately based on, or inherits from, an element -called \l Item. \l Item has certain properties and actions that may be -useful. The properties have default values so you need only specify the -ones you will need. - -Take a simple element such as a \l Rectangle. It has an \c id, we will call -it \e myRectangle, it has a \c width and a \c height. Imagine that we -want a rectangle that is 500 pixels by 400 pixels in the x and y directions -(horizontal by vertical). - -We can implement this \l Rectangle with these properties this way - -\snippet doc/src/snippets/declarative/qml-intro/rectangle.qml document - -This is a valid QML script. To run it, copy it and save it to a file, say -myexample.qml, and on the command line run the following command: - -\code -qmlviewer myexample.qml -\endcode - -On Mac OS X, open the "QMLViewer" application instead and open the -\c myexample.qml file, or run it from the command line: - -\code -QMLViewer.app/Contents/MacOS/QMLViewer myexample.qml -\endcode - -It will create a very boring rectangle in its own window. - - -\section1 Hello World! - -We can now add some color and text to make a Hello World QML program. - -\l Rectangle has the property \l{Rectangle::color}{color} to produce a -background color. - -Text is handled by a different element called \l Text. We need to create a -\l Text object inside the \l Rectangle and set its \l{Text::}{text} -property to "Hello World!". So to set the text to "Hello world" and the -background colour to light gray, - -\snippet doc/src/snippets/declarative/qml-intro/hello-world1.qml document - - -\section1 Hello World Again - -From now on we will not always show the import statement for Qt but it -should still be there when you create your QML scripts. - -To make our Hello World example a little nicer set the position of the text -to be at pixel position x = 100, y = 100 within the displayed window. This -position belongs to the \l Text element so we set the position inside its -definition. Note that we separate different QML statements on the same line -with a semi-colon, or we could have simply put each statement on a new line - -\snippet doc/src/snippets/declarative/qml-intro/hello-world2.qml updated text - -Not only did we reposition the text, but the text was altered by adding -HTML tags to change the font size. The text color was also changed from the -default black to dark green by using a standard string for the color's SVG -name. - -We could also have used a hexadecimal string for the RGB (red-green-blue, as -#rrggbb) values of the color similar to the method used in HTML. For -example, mostly blue with a green tint, - -\snippet doc/src/snippets/declarative/qml-intro/hello-world3.qml updated text - -All of these changes occurred within the \l Text object which is the scope -of these property changes. - -Other objects may use the information but it belongs to the element where -the property has been defined. - - -\section1 Images - -To add an image to our little application we use the \l Image element. An -\l Image uses a path to an image file, and has properties to control -the aspect ratio, the image size, to tile the area amongst others. The -source of the image, the path to the file, is a URL. Therefore the file can -be local: \e {mydir/myimage1.png}. Or it can be remote: -\e {"http://www.example.com/images/myimage1.png"}. - -\snippet doc/src/snippets/declarative/qml-intro/hello-world4.qml added an image - -This displays the image, as we would expect, at the top left of the window. -The position of the default x = 0, y = 0 coordinate. The example here uses -a PNG file, but it could have been one of various supported formats, -including JPG and GIF. - -Let us reposition the image and enlarge it. Place it at the same 'x' offset -as the "Hello world again" text, but put it another 50 pixels below the -text, also make it 150 by 150 pixels in size, - -\snippet doc/src/snippets/declarative/qml-intro/hello-world5.qml positioning the image - -Adding the Hello World example, with the text and the image example we can -write a simple piece of QML that starts to look a bit better. - -\snippet doc/src/snippets/declarative/qml-intro/hello-world5.qml document - -The result is still quite simple - -\image qml-intro-helloa.png - - -\section1 Anchors: Aligning Elements - -Using absolute positioning, such as saying x = 100 and y = 150, works well -until the user or developer stretches or increases the size of the window. -Then the positions need to be recalculated. What would be nice would be a -relative means of positioning of objects in a window or rectangle. For -example, we want to place an image at the bottom of a rectangle, we would -like to specify the image's location as the 'bottom of the window', not a -specific coordinate. We can do this with the anchors property, which -objects inherit from Item. - -The anchors property is really a property group. It is a collection of -related properties. It has properties within it which can be used by means -of the dot notation. - -The dot notation uses object \c{id}s and property names to use a particular -object or property. Say I have a rectangle r1, which contains a rectangle -r2, which contains an Item item1, which has an 'x' property I want to -change. I just use the dot notation to identify it: r1.r2.item1.x - -If we want to position an image at the bottom of the rectangle it is -inside. I have to specify that the bottom of the image is also at the -bottom of the rectangle - -\snippet doc/src/snippets/declarative/qml-intro/anchors1.qml document - -This places the logo at the bottom left of the window. - -\image qml-intro-anchors1.png "A simple anchor" - -We would like it centered and not touching the bottom of the window, for -aesthetic reasons. For the centering we use the horizontalCenter property, -and to prevent the touching of the image to the bottom of the rectangle, -the bottomMargin property is used. So the new actions for the script are - - \list - \o set the bottom of the image (anchors.bottom) to be the bottom of the window - \o move the image to be in the horizontal center of the window - \o set a margin of 10 pixels so that the image does not touch the bottom window border - \endlist - -Encoded into QML the script becomes - -\snippet doc/src/snippets/declarative/qml-intro/anchors2.qml document - -Run this and resize the window. You will see that now the position of the -image adjusts during the resize. - -\image qml-intro-anchors2.png "Image Centered at the Bottom" - -You can also add another object say a block of descriptive text and place -it above or below the image or to the side. This code places some text just -above the image - -\snippet doc/src/snippets/declarative/qml-intro/anchors3.qml adding some text - -\image qml-intro-anchors3.png - -\note \e anchors is a property group, to be used within the object. When -referencing these properties from another object we use the property -directly, instead of saying: - -\qml -Item { - anchors.bottom: myRectangle.anchors.top // Wrong -} -\endqml - -we use - -\qml -Item { - anchors.bottom: myRectangle.top // Correct -} -\endqml - - -\section1 Transformations - -We can transform a graphical object to get additional effects. Rotate a -piece of text by 180 degrees to display upside-down text. Rotate an image -by 90 degrees to lay it on its side. These transformations require -additional information. - -For rotation, the additional information includes: the origin relative to -the object being rotated, the axis of rotation, and the angle in degrees to -rotate the image through in a clockwise direction. The axis does not have -to be the z-axis, the line between your eyes and the image, it could be -along the vertical y-axis or the horizontal x-axis. We have three -dimensions to play with. For simplicity in this example we will rotate -about the z-axis by 90 degrees in a negative direction, anti-clockwise. - -Rotation of text was also suggested. It could also be useful to scale the -text. We can do both. The \l {Item::transform}{transform} property is a -\e list of \l Transform elements, so using the list syntax -\c{myList: [ listElement1, listElement2, ... } ]} -we can produce a list of transformations. - -The text will be rotated by 45 degrees anti-clockwise and scaled -vertically by a factor of 1.5 and by 1.2 horizontally. - -Using the example above as the basis for this we have, - -\snippet doc/src/snippets/declarative/qml-intro/transformations1.qml document - -The code block in \c image1 starting with \c transform specifies that the -\l {Item::transform}{transform} property will be a Rotation through -90 -degrees, which is anti-clockwise, about the z-axis running through the -center of the image at (75,75), since the image is 150 x 150 pixels. - -The other transformation available is \l Translate. This produces a change -in position of the item. - -\note In a list of transformations the order of the transformations is -important. In the above example try swapping around the Scale transform with -the Rotation transform, remember to remove or add the comma. The results are -acceptable for our little test but not the same. - - -\section1 Animations - -Animation in QML is done by animating properties of objects. Properties -that are numbers, colors, Rectangles, points and directions. In QML these -are \l {QML Basic Types} named as real, int, color, rect, point, size, and -vector3d. There are a number of different ways to do animation. Here we -will look at a few of them. - -\section2 Number Animation - -Previously we have used a rotation transformation to change the orientation -of an image. We could easily animate this rotation so that instead of a -straight rotation counter-clockwise of 90 degrees we could rotate the image -through a full 360 degrees in an animation. The axis of rotation wont -change, the position of the center of the image will not change, only the -angle will change. Therefore, a NumberAnimation of a rotation's angle should -be enough for the task. If we wish for a simple rotation about the center -of the image then we can use the \c rotation property that is inherited -from \l Item. The rotation property is a real number that specifies the -angle in a clockwise direction for the rotation of the object. Here is the -code for our animated rotating image. - -\snippet doc/src/snippets/declarative/qml-intro/number-animation1.qml document - -The \c {transformOrigin: Item.Center} is redundant since this is the default -axis of rotation anyway. But if you change \c Center to \c BottomRight you -will see an interesting variation. - -Also if instead the \l Rotation transformation had been used then we would have -more control over the various parameters. We could vary the axis, to be not -just a different offset from the z-axis but along the y-axis, x-axis or -combination. For example, if the task had been to animate the rotation -about the y-axis passing through the center of the image then the following -code would do it. - -\snippet doc/src/snippets/declarative/qml-intro/number-animation2.qml document - -Here there is a rectangle 600 by 400 pixels. Placed within that rectangle -is an image 100 by 100 pixels. It is rotated about the center of the image -about the y-axis so that it looks as if it is rotating about an invisible -vertical string holding it up. The time it takes to complete the rotation is 3 -seconds (3,000 milliseconds). The NumberAnimation is applied to the angle -taking it from 0 (no change) to 360 degrees, back where it started. -Strictly speaking it isn't necessary to go from 0 to 360 since the same -location is duplicated, but it makes it easier to read in this example and -it has no visible effect on the animation. The number of loops that the -animation will execute is set to \c {Animation.Infinite} which means that the -animation is in an endless loop. - -To see an interesting variation. Change the axis to \c {axis { x:1; y:1; z:1 -}}. This is a line coming from the center of the image downwards to the -right and out of the screen. Although the change is simple the rotation -seems complex. - -\section2 Sequential Animation - -For a more complex animation we will need two images. The first image will -be placed at the center of a window (Rectangle) and the second image will -be at the upper left of the window. The animation will move the second -image from the top left of the window to the bottom right. In doing so we -will be animating the position and the size of the image. - -First create two images - -\snippet doc/src/snippets/declarative/qml-intro/sequential-animation1.qml document - -We will add to 'image1' a SequentialAnimation from x = 20 to the target of -x = 450. The 'from' values will be used because we will be repeating the -animation, so the object needs to know where the original position is, both -x and y. The SequentialAnimation of x will set it to repeat by indicating -that the number of animation loops is infinite, meaning that the 'loop' -counter will be set to a value Animation.Infinite that indicates an endless -cycle. Also there will be a NumberAnimation to vary the numeric property -between the x values and over a given duration. After the NumberAnimation -there will be a PauseAnimation that will pause the animation for 500 -milliseconds (half a second) simply for the visual effect. - -\snippet doc/src/snippets/declarative/qml-intro/sequential-animation2.qml adding a sequential animation - -A similar block of code is written for the animation of the 'y' value of -the position. - -We will also animate the scale of the object, so as it goes from top left -to bottom right of the window it will become smaller until about midway, -and then become larger. To complete the animation we will set the 'z' -values of the images. 'z' is the stacking order, the z-axis effectively -points out from the screen to your eyes with the default value of 'z' being -0. So if we set the Rectangle to have z with value zero, just to be sure, -and image1 to 1 and image2 to 2 then image2 will be in the foreground and -image1 in the background. When image1 passes image2 it will pass behind it. -The completed code looks like - -\snippet doc/src/snippets/declarative/qml-intro/sequential-animation3.qml document - -The \c {easing.type} has many options, expressed as a string. It specifies the -kind of equation that describes the acceleration of the property value, not -necessarily position, over time. - -For example, \e InOutQuad means that at the start and the end of the animation the -'velocity' is low but the acceleration or deceleration is high. Much like a car -accelerating from stop, and decelerating to stop at the end of a journey, -with the maximum speed being in the middle. Examine the \l {PropertyAnimation::easing.type} -{easing} documentation and the various graphs that show the effect. The horizontal -axis, 'progress', can be thought of as time. The vertical axis is the value -of the particular property. - -In discussing animation we need to describe three objects: State, MouseArea -and Signals. Although independent of the animation elements, animation -delivers some of the best examples that illustrate these new elements. - - - -\section2 Animation Summary - -\table - \header - \o Name - \o Description - \row - \o PropertyAnimation - \o a property value on a target object is varied to a specified value over a given time. - - \row - \o NumberAnimation - \o animate a numeric property from one value to another over a given time. - - \row - \o PauseAnimation - \o results in the task waiting for the specified duration, in milliseconds. - - \row - \o SequentialAnimation - \o allows us to list in order the animation events we want to occur, first A then B then C and so on. - - \row - \o ParallelAnimation - \o enables us to run different animations at the same time instead of sequentially. - -\endtable - - -\section1 Using States - -A state is a defined set of values in the configuration of an object and -often depends on the previous state. For example, a glass could be in a -state we call 'HalfFull' if it is being filled with a liquid and has -reached half of its total capacity. We could also have a state called -HalfEmpty which is the state that occurs when the amount of liquid drops to -half of the glass's capacity. Both states represent the same amount of -liquid, but we consider them different. Likewise, states in a program -represent not just values but may include how the current values were -reached. - -When a state changes a \e transition occurs. This is an opportunity to make -changes or take actions that depend on the movement to the new state. For -example, if we had a scene in the country where the state variable has two -states "daylight" and "night". Then when the state changes to "night" at -this transition the sky would be made dark, stars would be shown, the -countryside would be darkened. And when the state changes to "daylight" the -opposite changes would be made: the sky is now blue, the scenery is green, -there is a sun in the sky. - -Here is a simple QML program that shows the change of state in the above -example. We have two rectangles, the top one is the 'sky' and the bottom -one is the 'ground'. We will animate the change from daylight to night. -There will be two states, but we only need to define one since 'daylight' -will be the default state. We will just go to 'night' by clicking and -holding the left mouse button down, releasing the mouse button will reverse -the process - -\snippet doc/src/snippets/declarative/qml-intro/states1.qml document - -Several new things appear in this sample. Firstly, we use a \l MouseArea -element to detect mouse clicks in the \e mainRectangle. Secondly, we use -the list notation [ thing1 , thing2, ... ] to build a list of states and a -list of transitions. - -\l MouseArea defines a region that will respond to mouse clicks. In this case -we are only concerned with when the mouse is pressed or not pressed, not -the particular button or other details. The area of the MouseArea is the -entire main window, mainRectangle, so that clicking anywhere in this region -will start the animation. Since we are using the 'pressed' mouse state, -then the animation will move from 'daylight' to 'night' only while the mouse -button remains pressed. - -When the button is released the 'daylight' state is entered and the -transition from 'night' to 'daylight' is triggered causing the animation to -run. The transition specifies the duration in milliseconds of the -ColorAnimation, while the state specifies the color of the new state. - -The PropertyChanges command is the way that we nominate which properties -will change in a change of state, and what new value the property will -take. Since, for example, we want the 'sky' region to turn to dark blue and -the 'ground' region to turn to black for the 'night' state, then the -rectangles for those regions are the 'target' and the property in the target -is 'color'. - - -\section1 Signals - -Signals are simply events that can be hooked up to actions we want performed. -In QML they are usually preceded by the word 'on', for example in the animation -using a MouseArea the signal was \l {MouseArea::onPressed}{onPressed}. If -you look at the C++ documentation you will see a lot of talk about -\l {Signals & Slots}{Signals and Slots}. Signals are connected to Slots. The -signal represents an event and the Slot is the function that does something -based on that event. You can also have Signals connected to other Signals, so -that one Signal (event) triggers another Signal (event), and so forth. It is -nice to know this is what happens beneath the QML layer but not essential for -using QML. - -Most elements do not have Signals associated with them. However, a few like -the \l Audio element have many signals. Some of the \l Audio signals are -used to represent events such as when the audio is stopped, play is pressed, -paused, and reaching the end of the media. They allow the developer to connect, - for example, the press of a user interface button (perhaps a MouseArea) to - some QML that will handle this event. - - -\section1 Analyzing An Example: Dial Control - -In the Qt \e {examples/declarative/ui-components} folder you will find a folder -\e {dialcontrol} which contains the \e dialcontrol example. - -\image qml-dial.png "QML Dial example with Slider" - -In essence this small application has a sliding bar that you can slide using -a mouse, and a graphical dial that responds to the position of the slider. - -The code for the example is in two parts: Dial.qml and dialcontrol.qml. - -\e {Dial.qml} can be found in the \e content sub-directory. It defines a \c Dial -component similar to an odometer. Eventually, the example will hook up a slider -component so that moving the slider will change the position of a needle on the -dial. - -The code for the \c Dial, identified by the name of the file, contains four images -in overlapping order: the background (numbers and divisions), the shadow of the -needle, the needle itself, and finally the 'glass' overlay (containing -transparent layers). - -The \c needle_shadow.png image has a \l Rotation assigned to the \e transform -attribute of the \l Image. The rotation is set to match the angle of the needle -image angle value \e {needleRotation.angle}. Both the needle and the -needle_shadow have the same default \e x and \e y values but the rotation origin -for the needle is slightly different so that a shadow will be evident as the -needle moves. - -\snippet examples/declarative/ui-components/dialcontrol/content/Dial.qml needle_shadow - -And the needle - -\snippet examples/declarative/ui-components/dialcontrol/content/Dial.qml needle - -The final image is the overlay which simply has a position defined. - -\snippet examples/declarative/ui-components/dialcontrol/content/Dial.qml overlay - -\e {dialcontrol.qml} in the \e {examples/declarative/ui-components/dialcontrol} directory is the -main file of the example. It defines the visual environment that the Dial -will fit into. Because the \e Dial component and the images live in the \e -content sub-directory we will have to import this into \e dialcontrol.qml. So the -start of the file looks like - -\snippet examples/declarative/ui-components/dialcontrol/dialcontrol.qml imports - -The visual space is bound by a 300 by 300 pixel \l Rectangle which is given -a gray color. Inside this rectangle is our component \e Dial and a \l Rectangle. -Inside the rectangle called 'container' is another rectangle with the -interesting name 'slider'. - -\snippet examples/declarative/ui-components/dialcontrol/dialcontrol.qml 0 - -The Dial component, named 'dial, is \e anchored to the center of the main -rectangle. The \c value attribute of 'dial' is set to a value based on the -'slider' horizontal position and the 'container' width. So changes to the -'slider' position will change the Dial \c value which is used in Dial to compute -the rotation of the needle image. Notice this piece of code in Dial where -the change in \c value modifies the position of the needle. - -\snippet examples/declarative/ui-components/dialcontrol/content/Dial.qml needle angle - -This is part of the \c needleRotation that rotates the needle and causes the -rotation of its shadow. \l SpringAnimation is an element that modifies the value -of that rotation \e angle and mimics the oscillatory behavior of a spring, -with the appropriate \e spring constant to control the acceleration and the \e -damping to control how quickly the effect dies away. - -The 'container' is light gray with a color gradient defined using -\l GradientStop. The gradient is applied vertically. If you need a horizontal -gradient then you could apply the vertical gradient and then rotate the item -by 90 degrees. - -The 'slider' is dark gray and also has a vertical color gradient. The most -important thing about the 'slider' is that it has a MouseArea defined, which -specifies a \c {drag.target} on itself along the X-axis. With minimum -and maximum values on the X-axis defined. So we can click on the 'slider' and -drag it left and right within the confines of the 'container'. The motion of -the 'slider' will then change the \c value attribute in \e Dial as discussed -already. - -Also notice the use of a \c radius value for a rectangle. This produces rounded -corners. That is how the 'container' and 'slider' are displayed with a -pleasant rounded look. - - - -*/ - - - diff --git a/doc/src/declarative/qmlevents.qdoc b/doc/src/declarative/qmlevents.qdoc new file mode 100644 index 0000000..566f71c --- /dev/null +++ b/doc/src/declarative/qmlevents.qdoc @@ -0,0 +1,127 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of this +** file. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! +\page qmlevents.html +\ingroup qml-features +\contentspage QML Features +\previouspage {Keyboard Focus in QML}{Keyboard Focus} +\nextpage Importing Reusable Components + +\title QML Signal and Handler Event System + +QML utilizes Qt's \l{The Meta-Object System}{meta-object} and +\l{Signals & Slots}{signals} systems. Signals and slots created using Qt in C++ +are inheritely valid in QML. + +\keyword qml-signals-and-handlers +\section1 Signals and Handlers + +Signals provide a way to notify other objects when an event has occurred. For +example, the MouseArea \c clicked signal notifies other objects that the mouse +has been clicked within the area. + +The syntax for defining a new signal is: + +\tt{signal <name>[([<type> <parameter name>[, ...]])]} + +Attempting to declare two signals or methods with the same name in the same type +block generates an error. However, a new signal may reuse the name of an existing signal on the type. (This should be done with caution, as the existing signal may be hidden and become inaccessible.) + +Here are various examples of signal declarations: +\snippet doc/src/snippets/declarative/events.qml parent begin +\snippet doc/src/snippets/declarative/events.qml signal declaration +\snippet doc/src/snippets/declarative/events.qml parent end + +If the signal has no parameters, the "\c{()}" brackets are optional. If +parameters are used, the parameter types must be declared, as for the \c string +and \c variant arguments of the \c perform signal. + +Adding a signal to an item automatically adds a \e{signal handler} as well. The +signal hander is named \c on<SignalName>, with the first letter of the signal in +uppercase. The previous signals have the following signal handlers: +\snippet doc/src/snippets/declarative/events.qml signal handler declaration + +Further, each QML properties have a \c{<property_name>Changed} signal and its +corresponding \c{on<property_name>Changed} signal handler. As a result, property +changes may notify other components for any changes. +\snippet doc/src/snippets/declarative/events.qml automatic signals + +To emit a signal, invoke it as a method. The signal handler binding is similar +to a property binding and it is invoked when the signal is emitted. Use the +defined argument names to access the respective arguments. +\snippet doc/src/snippets/declarative/events.qml signal emit +Note that the \c Component.onCompleted is an +\l{attached-signalhandlers}{attached signal handler}; it is invoked when the +\l Component initialization is complete. + +\keyword qml-connect-signals-to-method +\section2 Connecting Signals to Methods and Signals + +Signal objects have a \c connect() method to a connect a signal either to a +method or another signal. When a signal is connected to a method, the method is +automatically invoked whenever the signal is emitted. (In Qt terminology, the +method is a \e slot that is connected to the \e signal; all methods defined in +QML are created as \l{Signals & Slots}{Qt slots}.) This enables a signal +to be received by a method instead of a \l {Signal Handlers}{signal handler}. + +\snippet doc/src/snippets/declarative/events.qml connect method +The \c {connect()} method is appropriate when connecting a JavaScript method to +a signal. + +There is a corresponding \c disconnect() method for removing connected +signals. + +\section3 Signal to Signal Connect + +By connecting signals to other signals, the \c connect() method can form different +signal chains. +\snippet doc/src/snippets/declarative/events.qml forward signal + + +Whenever the \l MouseArea \c clicked signal is emitted, the \c send +signal will automatically be emitted as well. + +\code +output: + MouseArea clicked + Send clicked +\endcode + +\section1 C++ Additions + +Because QML uses Qt, a signal defined in C++ also works as a QML signal. The +signal may be emitted in QML code or called as a method. In addition, the QML +runtime automatically creates signal handlers for the C++ signals. For more +signal control, the \c connect() method and the \l Connections element may connect +a C++ signal to another signal or method. + +For complete information on how to call C++ functions in QML, read the +\l{Extending QML - Signal Support Example}. + + +*/ diff --git a/doc/src/declarative/qmlreusablecomponents.qdoc b/doc/src/declarative/qmlreusablecomponents.qdoc new file mode 100644 index 0000000..ee360eb --- /dev/null +++ b/doc/src/declarative/qmlreusablecomponents.qdoc @@ -0,0 +1,143 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of this +** file. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! +\page qmlreusablecomponents.html +\ingroup qml-features +\previouspage {QML Signal and Handler Event System}{Signal and Handler Event System} +\nextpage {QML States}{States} +\contentspage QML Features + +\title Importing Reusable Components + +A \e component is an instantiable QML definition, typically contained in a +\c .qml file. For instance, a Button \e component may be defined in +\c Button.qml. The QML runtime may instantiate this Button component to create +Button \e objects. Alternatively, a component may be defined inside a +\l Component element. + +Moreover, the Button definition may also contain other components. A Button +component could use a Text element for its label and other components to +implement its functions. Compounding components to form new components +(and effectively new interfaces) is the emphasis in QML. + +\keyword qml-define-components +\section1 Defining New Components + +Any snippet of QML code may become a component, by placing the code in a QML +file (extension is \c .qml). A complete Button component that responds to user +input may be in a Button.qml file. +\snippet doc/src/snippets/declarative/reusablecomponents/Button.qml document + +Alternatively, a \l Component element may encapsulate a QML object to form a +component. +\snippet doc/src/snippets/declarative/reusablecomponents/component.qml parent begin +\snippet doc/src/snippets/declarative/reusablecomponents/component.qml define inline component +\snippet doc/src/snippets/declarative/reusablecomponents/component.qml parent end + +\keyword qml-loading-components +\section1 Loading a Component + +The initialization of inline components is different from loading a component +from a \c .qml file. + +\section2 Importing a Component + +A component defined in a \c .qml file is directly usable by declaring the name +of the component. For example, a button defined in \c Button.qml is created by +declaring a \c Button. The button is defined in the +\l {qml-define-components}{Defining New Components} section. +\snippet doc/src/snippets/declarative/reusablecomponents/application.qml document + +Note that the component name, \c Button, matches the QML filename, \c Button.qml. +Also, the first character is in upper case. Matching the names allow +components in the same directory to be in the direct import path of the +application. + +For flexibility, a \c qmldir file is for dictating which additional components, +plugins, or directories should be imported. By using a \c qmldir file, +component names do not need to match the filenames. The \c qmldir file should, +however, be in an imported path. +\snippet doc/src/snippets/declarative/reusablecomponents/qmldir document + +\section2 Loading an Inline Component + +A consequence of inline components is that initialization may be deferred or +delayed. A component may be created during a MouseArea event or by using a +\l Loader element. The component can create an object, which is addressable in a +similar way as an \l {qml-id-property}{id property}. Thus, the created object may +have its bindings set and read like a normal QML object. +\snippet doc/src/snippets/declarative/reusablecomponents/component.qml define inline component +\snippet doc/src/snippets/declarative/reusablecomponents/component.qml create inline component + +\keyword qml-component-properties +\section1 Component Properties + +Initializing a component, either from a .qml file or initializing an inline +component, have several properties to facilitate component execution. +Specifically, there are \l{attached-properties}{attached properties} and +\l{attached-signalhandlers}{attached signal handlers} for setting properties +during the lifetime of a component. + +The \c{Component.onCompleted} attached signal handler is called when the +component completes initialization. It is useful for executing any commands +after component initialization. Similarly, the \c{Component.onDestruction} +signal handler executes when the component finishes destruction. + +\keyword qml-top-level +\section1 Top-Level Component + +Choosing the \e{top-level} or the \e{root} object of components is an important +design aspect because the top-level object dictates which properties are +accessible outside the component. Some elements are not visual elements and +will not have visual properties exposed outside the component. Likewise, some +elements add functionality that are not available to visual elements. + +Consider the Button component from the +\l{qml-define-components}{Defining New Components} section; it's top-level +object is a \l Rectangle. When imported, the Button component will possess the +Rectangle's properties, methods, signals, and any custom properties. + +\snippet doc/src/snippets/declarative/reusablecomponents/Button.qml parent begin +\snippet doc/src/snippets/declarative/reusablecomponents/Button.qml ellipses +\snippet doc/src/snippets/declarative/reusablecomponents/Button.qml properties +\snippet doc/src/snippets/declarative/reusablecomponents/Button.qml ellipses +\snippet doc/src/snippets/declarative/reusablecomponents/Button.qml parent end + +The Button's \c text alias is accessible from outside the component as well as +the Rectangle's visual properties and signals such as \c x, \c y, \c anchors, +and \c states. + +Alternatively, we may choose a \l {Keyboard Focus in QML}{FocusScope} as our +top-level object. The \l FocusScope element manage keyboard focus for its +children which is beneficial for certain types of interfaces. However, since +\c FocusScopes are not visual elements, the visual properties of its child need +to be exposed. + +\snippet doc/src/snippets/declarative/reusablecomponents/focusbutton.qml document +*/ + diff --git a/doc/src/declarative/qmlruntime.qdoc b/doc/src/declarative/qmlruntime.qdoc index f6604fb..a1f3f96 100644 --- a/doc/src/declarative/qmlruntime.qdoc +++ b/doc/src/declarative/qmlruntime.qdoc @@ -29,13 +29,13 @@ \page qmlruntime.html \title Qt Declarative UI Runtime -QML documents are loaded and executed by the QML runtime. This includes the +QML documents are loaded and executed by the QML runtime. This includes the Declarative UI engine along with the built-in QML elements and plugin modules, and it also provides access to third-party QML elements and modules. -Applications that use QML need to invoke the QML runtime in order to -execute QML documents. This can be done by creating a QDeclarativeView -or a QDeclarativeEngine, as described below. In addition, the Declarative UI +Applications that use QML need to invoke the QML runtime in order to +execute QML documents. This can be done by creating a QDeclarativeView +or a QDeclarativeEngine, as described below. In addition, the Declarative UI package includes the \QQV tool, which loads \c .qml files. This tool is useful for developing and testing QML code without the need to write a C++ application to load the QML runtime. @@ -44,7 +44,7 @@ a C++ application to load the QML runtime. \section1 Deploying QML-based applications -To deploy an application that uses QML, the QML runtime must be invoked by +To deploy an application that uses QML, the QML runtime must be invoked by the application. This is done by writing a Qt C++ application that loads the QDeclarativeEngine by either: @@ -61,12 +61,12 @@ For example, if there is a QML file, \c application.qml, like this: \qml import QtQuick 1.0 - + Rectangle { width: 100; height: 100; color: "red" } \endqml It can be loaded in a Qt application's \c main.cpp file like this: - + \code #include <QApplication> #include <QDeclarativeView> @@ -82,10 +82,10 @@ It can be loaded in a Qt application's \c main.cpp file like this: return app.exec(); } \endcode - -This creates a QWidget-based view that displays the contents of + +This creates a QWidget-based view that displays the contents of \c application.qml. - + The application's \c .pro \l{qmake Project Files}{project file} must specify the \c declarative module for the \c QT variable. For example: @@ -97,36 +97,36 @@ the \c declarative module for the \c QT variable. For example: \section2 Creating a QDeclarativeEngine directly - -If \c application.qml does not have any graphical components, or if it is + +If \c application.qml does not have any graphical components, or if it is preferred to avoid QDeclarativeView for other reasons, the QDeclarativeEngine can be constructed directly instead. In this case, \c application.qml is loaded as a QDeclarativeComponent instance rather than placed into a view: \code #include <QApplication> - #include <QDeclarativeEngine> + #include <QDeclarativeEngine> #include <QDeclarativeContext> #include <QDeclarativeComponent> int main(int argc, char *argv[]) { QApplication app(argc, argv); - + QDeclarativeEngine engine; QDeclarativeContext *objectContext = new QDeclarativeContext(engine.rootContext()); - + QDeclarativeComponent component(&engine, "application.qml"); QObject *object = component.create(objectContext); - + // ... delete object and objectContext when necessary - + return app.exec(); } \endcode -See \l {Using QML in C++ Applications} for more information about using -QDeclarativeEngine, QDeclarativeContext and QDeclarativeComponent, as well +See \l {Using QML Bindings in C++ Applications} for more information about using +QDeclarativeEngine, QDeclarativeContext and QDeclarativeComponent, as well as details on including QML files through \l{The Qt Resource System}{Qt's Resource system}. @@ -135,8 +135,8 @@ as details on including QML files through \l{The Qt Resource System}{Qt's Resour The Declarative UI package includes a QML runtime tool, the \QQV, which loads and displays QML documents. This is useful during the application development -phase for prototyping QML-based applications without writing your own C++ -applications to invoke the QML runtime. +phase for prototyping QML-based applications without writing your own C++ +applications to invoke the QML runtime. See the \l{QML Viewer} documentation for more details. diff --git a/doc/src/declarative/qmlsyntax.qdoc b/doc/src/declarative/qmlsyntax.qdoc new file mode 100644 index 0000000..fc25bce --- /dev/null +++ b/doc/src/declarative/qmlsyntax.qdoc @@ -0,0 +1,155 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of this +** file. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! +\page qmlsyntax.html +\title QML Syntax +\ingroup QML Reference +\contentspage QML Reference + +\tableofcontents + +QML is a declarative language designed to describe the user interface of a +program: both what it looks like, and how it behaves. In QML, a user +interface is specified as a tree of objects with properties. + +JavaScript is used as a scripting language in QML, so you may want +to learn a bit more about it (\l{Javascript Guide}) before diving +deeper into QML. + +\section1 Basic QML Syntax + +QML looks like this: + +\code +import QtQuick 1.0 + +Rectangle { + width: 200 + height: 200 + color: "blue" + + Image { + source: "pics/logo.png" + anchors.centerIn: parent + } +} +\endcode + +Objects are specified by their type, followed by a pair of braces. Object +types always begin with a capital letter. In the above example, there are +two objects, a \l Rectangle, and an \l Image. Between the braces, we can specify +information about the object, such as its properties. + +Properties are specified as \c {propertyname: value}. In the above example, we +can see the Image has a property named \c source, which has been assigned the +value \c "pics/logo.png". The property and its value are separated by a colon. + +Properties can be specified one-per-line: + +\code +Rectangle { + width: 100 + height: 100 +} +\endcode + +or you can put multiple properties on a single line: + +\code +Rectangle { width: 100; height: 100 } +\endcode + +When multiple property/value pairs are specified on a single line, they +must be separated by a semicolon. + +The \c import statement imports the \c Qt \l{QML Modules}{module}, which contains all of the +standard \l {QML Elements}. Without this import statement, the \l Rectangle +and \l Image elements would not be available. + +\section1 Expressions + +In addition to assigning values to properties, you can also assign +expressions written in JavaScript. + +\code +Rotation { + angle: 360 * 3 +} +\endcode + +These expressions can include references to other objects and properties, in which case +a \e binding is established: when the value of the expression changes, the property the +expression has been assigned to is automatically updated to that value. + +\code +Item { + Text { + id: text1 + text: "Hello World" + } + Text { + id: text2 + text: text1.text + } +} +\endcode + +In the example above, the \c text2 object will display the same text as \c text1. If \c text1 is changed, +\c text2 is automatically changed to the same value. + +Note that to refer to other objects, we use their \e id values. (See below for more +information on the \e id property.) + +\section1 QML Comments + +Commenting in QML is similar to JavaScript. +\list +\o Single line comments start with // and finish at the end of the line. +\o Multiline comments start with /* and finish with *\/ +\endlist + +\snippet doc/src/snippets/declarative/comments.qml 0 + +Comments are ignored by the engine. They are useful for explaining what you +are doing; for referring back to at a later date, or for others reading +your QML files. + +Comments can also be used to prevent the execution of code, which is +sometimes useful for tracking down problems. + +\code +Text { + text: "Hello world!" + //opacity: 0.5 +} +\endcode + +In the above example, the Text object will have normal opacity, since the +line opacity: 0.5 has been turned into a comment. + +*/ diff --git a/doc/src/declarative/qmltexthandling.qdoc b/doc/src/declarative/qmltexthandling.qdoc new file mode 100644 index 0000000..7906193 --- /dev/null +++ b/doc/src/declarative/qmltexthandling.qdoc @@ -0,0 +1,76 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of this +** file. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! +\page texthandling.html +\title QML Text Handling and Validators +\ingroup QML Features +\previouspage {QML Mouse Events}{Mouse Events} +\nextpage {Keyboard Focus in QML}{Keyboard Focus} +\contentspage QML Features + +\tableofcontents + +\section1 Text Elements + +\list +\o \l{Text} +\o \l{TextInput} +\o \l{TextEdit} +\endlist + +\section1 Validators +\list +\o \l{IntValidator} +\o \l{DoubleValidator} +\o \l{RegExpValidator} +\endlist + +\section1 Displaying Text in QML +QML provides several elements to display text onto the screen. The \l Text +element will display formatted text onto the screen, the \l TextEdit element +will place a multiline line edit onto the screen, and the \l TextInput will +place a single editable line field onto the screen. + +To learn more about their specific features and properties, visit their +respective element documentation. + +\section1 Validating Input Text +The \l {Validators}{validator} elements enforce the type and format of +\l TextInput objects. + +\snippet doc/src/snippets/declarative/texthandling.qml int validator +The validator elements bind to \c {TextInput}'s \c validator property. + +\snippet doc/src/snippets/declarative/texthandling.qml regexp validator +The regular expression in the snippet will only allow the inputted text to be +\c {fruit basket}. + +Note that QML parses JavaScript regular expressions, while Qt's +\l {QRegExp} class' regular expressions are based on Perl regular expressions. + +*/ diff --git a/doc/src/declarative/qmlviewer.qdoc b/doc/src/declarative/qmlviewer.qdoc index 585b402..2e3cdc7 100644 --- a/doc/src/declarative/qmlviewer.qdoc +++ b/doc/src/declarative/qmlviewer.qdoc @@ -31,34 +31,34 @@ \title QML Viewer \ingroup qttools -The Declarative UI package includes \QQV, a tool for loading QML documents that -makes it easy to quickly develop and debug QML applications. It invokes the QML -runtime to load QML documents and also includes additional features useful for +The Declarative UI package includes \QQV, a tool for loading QML documents that +makes it easy to quickly develop and debug QML applications. It invokes the QML +runtime to load QML documents and also includes additional features useful for the development of QML-based applications. -The QML Viewer is a tool for testing and developing QML applications. It is -\e not intended for use in a production environment and should not be used for the +The QML Viewer is a tool for testing and developing QML applications. It is +\e not intended for use in a production environment and should not be used for the deployment of QML applications. In those cases, the QML runtime should be invoked from a Qt application instead; see \l {Qt Declarative UI Runtime} for more information. The viewer is located at \c QTDIR/bin/qmlviewer. To load a \c .qml file -with the viewer, run the viewer and select the file to be opened, or provide the +with the viewer, run the viewer and select the file to be opened, or provide the file path on the command line: \code qmlviewer myqmlfile.qml \endcode - + On Mac OS X, the QML Viewer application is named "QMLViewer" instead. You -can launch the viewer by opening the QMLViewer application from the Finder, or +can launch the viewer by opening the QMLViewer application from the Finder, or from the command line: \code QMLViewer.app/Contents/MacOS/QMLViewer myqmlfile.qml \endcode -The QML Viewer has a number of configuration options involving features such as +The QML Viewer has a number of configuration options involving features such as fullscreen display, module import path configurations, video recording of QML animations, and OpenGL support. @@ -68,7 +68,7 @@ To see the configuration options, run \c qmlviewer with the \c -help argument. \section1 Adding module import paths Additional module import paths can be provided using the \c -I flag. -For example, the \l{declarative/cppextensions/plugins}{QML plugins example} creates +For example, the \l{declarative/cppextensions/plugins}{QML plugins example} creates a C++ plugin identified as \c com.nokia.TimeExample. Since this has a namespaced identifier, the viewer has to be run with the \c -I flag from the example's base directory: @@ -87,16 +87,16 @@ the path is explicitly added. \section1 Loading translation files -When the QML Viewer loads a QML file, it installs a translation file from a -"i18n" subdirectory relative to that initial file. This directory should contain +When the QML Viewer loads a QML file, it installs a translation file from a +"i18n" subdirectory relative to that initial file. This directory should contain translation files named "qml_<language>.qm", where <language> is a two-letter ISO 639 language, such as "qml_fr.qm", optionally followed by an underscore and an uppercase two-letter ISO 3166 country code, such as "qml_fr_FR.qm" or -"qml_fr_CA.qm". +"qml_fr_CA.qm". Such files can be created using \l {Qt Linguist}. -The actual translation file that is loaded depends on the system locale. +The actual translation file that is loaded depends on the system locale. Additionally, the viewer will load any translation files specified on the command line via the \c -translation option. @@ -110,7 +110,7 @@ shows how JavaScript code in QML files can be made to use translatable strings. Often, QML applications are prototyped with fake data that is later replaced by real data sources from C++ plugins. QML Viewer assists in this aspect by loading fake data into the application context: it looks for a directory named -"dummydata" in the same directory as the target QML file, and any \c .qml +"dummydata" in the same directory as the target QML file, and any \c .qml files in that directory are loaded as QML objects and bound to the root context as properties named after the files. @@ -124,7 +124,7 @@ ListView { width: 200; height: 300 model: lottoNumbers delegate: Text { text: number } -} +} \endqml If within the document's directory, there is a "dummydata" directory which @@ -146,30 +146,30 @@ Child properties are included when loaded from dummy data. The following documen refers to a \c clock.time property: \qml -import QtQuick 1.0 +import QtQuick 1.0 Text { text: clock.time } \endqml - + The text value could be filled by a \c dummydata/clock.qml file with a \c time property in the root context: \qml -import QtQuick 1.0 +import QtQuick 1.0 QtObject { property int time: 54321 } \endqml To replace this with real data, you can simply bind the real data object to the root context in C++ using QDeclarativeContext::setContextProperty(). This -is detailed in \l {Using QML in C++ Applications}. +is detailed in \l {Using QML Bindings in C++ Applications}. \section1 Using the \c runtime object QML applications that are loaded with the QML Viewer have access to a special -\c runtime property on the root context. This property provides additional +\c runtime property on the root context. This property provides additional information about the application's runtime environment through the following properties: \table -\row +\row \o \c runtime.isActiveWindow @@ -177,9 +177,9 @@ information about the application's runtime environment through the following pr window on the system. It is useful for "pausing" an application, particularly animations, when the QML Viewer loses focus or moves to the background. -For example, the following animation is only played when the QML Viewer is +For example, the following animation is only played when the QML Viewer is the active window: - + \qml Rectangle { width: 200; height: 200 @@ -200,9 +200,9 @@ through the \c active property of the \l {QML:Qt::application}{Qt.application} o \o \c runtime.orientation \o This property indicates the current orientation of the QML Viewer. On the -N900 platform and most S60 5.0-based or newer Symbian devices, this property -automatically updates to reflect the device's actual orientation; on other platforms, -this indicates the orientation currently selected in the QML Viewer's +N900 platform and most S60 5.0-based or newer Symbian devices, this property +automatically updates to reflect the device's actual orientation; on other platforms, +this indicates the orientation currently selected in the QML Viewer's \e {Settings -> Properties} menu. The \c orientation value can be one of the following: \list @@ -213,7 +213,7 @@ this indicates the orientation currently selected in the QML Viewer's \endlist When the viewer's orientation changes, the appearance of the loaded QML document -does not change unless it has been set to respond to changes in +does not change unless it has been set to respond to changes in \c runtime.orientation. For example, the following Rectangle changes its aspect ratio depending on the orientation of the QML Viewer: @@ -221,12 +221,12 @@ aspect ratio depending on the orientation of the QML Viewer: Rectangle { id: window width: 640; height: 480 - + states: State { name: "landscape" PropertyChanges { target: window; width: 480; height: 640 } } - state: (runtime.orientation == Orientation.Landscape + state: (runtime.orientation == Orientation.Landscape || runtime.orientation == Orientation.LandscapeInverted) ? 'landscape' : '' } \endqml diff --git a/doc/src/declarative/qmlviews.qdoc b/doc/src/declarative/qmlviews.qdoc new file mode 100644 index 0000000..4071d5d --- /dev/null +++ b/doc/src/declarative/qmlviews.qdoc @@ -0,0 +1,113 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of this +** file. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! +\page qml-views.html +\ingroup qml-features +\contentspage QML Features +\previouspage {QML Data Models}{Structuring Data with Models} +\nextpage {Extending QML Functionalities using C++} +\title Presenting Data with Views + +Views are containers for collections of items. They are feature-rich and can be +customizable to meet style or behavior requirements. + +\keyword qml-view-elements +A set of standard views are provided in the basic set of Qt Quick +graphical elements: + +\list +\o \l{ListView} arranges items in a horizontal or vertical list +\o \l{GridView} arranges items in a grid within the available space +\o \l{PathView} arranges items on a path +\o \l{WebView}{WebView} - available from the \l {QtWebKit QML Module}. +\endlist +Unlike other views, \l WebView is not a fully-featured view item, and needs +to be combined with a \l Flickable item to create a view that performs like +a Web browser. + +These elements have properties and behaviors exclusive to each element. Visit +their respective documentation for more information. + +\section1 Models + +Views display \l{qml-data-models}{models} onto the screen. A model could be a simple list of \l{QML Data Models#An Integer}{integer} or a \l{qml-c++-models}{C++ model}. + +To assign a model to a view, bind the view's \c model property to a model. +\snippet doc/src/snippets/declarative/listview.qml model +\snippet doc/src/snippets/declarative/listview.qml model + +For more information, consult the \l {QML Data Models} article. + +\keyword qml-view-delegate +\section1 View Delegates + +Views need a \e delegate to visually represent an item in a list. A view will +visual each item list according to the template defined by the delegate. +Properties of the model are accessible as well as an \c index property. +\snippet doc/src/snippets/declarative/listview.qml delegate +\image listview-setup.png + +\section1 Decorating Views + +Views allow visual customization through \e decoration properties such as the \c header, \c footer, and \c section properties. By binding an object, usually +another visual object, to these properties, the views are decoratable. A footer +may include a \l Rectangle element showcasing borders or a header that displays +a logo on top of the list. + +Suppose that a specific club wants to decorate its members list with its brand +colors. A member list is in a \c model and the \c delegate will display the +model's content. +\snippet doc/src/snippets/declarative/listview-decorations.qml model +\snippet doc/src/snippets/declarative/listview-decorations.qml delegate + +The club may decorate the members list by binding visual objects to the +\c header and \c footer properties. The visual object may be defined inline, in another file, or in a +\l {Component} element. +\snippet doc/src/snippets/declarative/listview-decorations.qml decorations +\image listview-decorations.png + +\section1 ListView Sections + +\l {ListView} contents may be grouped into \e sections, where related list items +are labelled according to their sections. Further, the sections may be decorated +with \l{qml-view-delegate}{delegates}. + +A list may contain a list indicating people's names and the team on which team +the person belongs. +\snippet doc/src/snippets/declarative/listview-sections.qml model +\snippet doc/src/snippets/declarative/listview-sections.qml delegate + +The ListView element has the \c section +\l{Property Binding#Attached Properties}{attached property} that can combine +adjacent and related elements into a section. The section's \c property +property is for selecting which list element property to use as sections. +The \c criteria can dictate how the section names are displayed and the +\c delegate is similar to the views' \l {qml-view-delegate}{delegate} property. +\snippet doc/src/snippets/declarative/listview-sections.qml section +\image listview-section.png +*/ diff --git a/doc/src/declarative/qmlwebkit.qdoc b/doc/src/declarative/qmlwebkit.qdoc new file mode 100644 index 0000000..354e60a --- /dev/null +++ b/doc/src/declarative/qmlwebkit.qdoc @@ -0,0 +1,55 @@ +/**************************************************************************** +** +** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of this +** file. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! +\page qmlwebkit.html + +\title QtWebKit QML Module + +Qt WebKit QML + +\section1 WebKit QML Elements +\list +\o \l WebView +\endlist + +\section1 QtWebKit Module +The QtWebKit Module has a QML element, \l{WebView} for displaying web content +from a \c URL. + +Import the QtWebKit module before declaring a \c WebView element: +\qml +import QtWebKit 1.0 +\endqml + +\section1 Simple Usage +\snippet doc/src/snippets/declarative/webview/webview.qml document +\image webview.png + +\sa {Models and Views: WebView Example}{WebView Example}, {QML Web Browser} + +*/ diff --git a/doc/src/declarative/qtbinding.qdoc b/doc/src/declarative/qtbinding.qdoc index 03290aa..d11825e 100644 --- a/doc/src/declarative/qtbinding.qdoc +++ b/doc/src/declarative/qtbinding.qdoc @@ -27,10 +27,13 @@ /*! \page qtbinding.html -\target qtbinding -\title Using QML in C++ Applications +\ingroup qml-features +\previouspage {Extending QML Functionalities using C++} +\nextpage {Integrating QML Code with Existing Qt UI Code} +\contentspage QML Features +\title Using QML Bindings in C++ Applications -QML is designed to be easily extensible from C++. The classes in the +QML is designed to be easily extensible to and from C++. The classes in the Qt Declarative module allow QML components to be loaded and manipulated from C++, and through Qt's \l{The Meta-Object System}{meta-object system}, QML and C++ objects can easily communicate through Qt signals and slots. In addition, QML plugins can be written to create @@ -85,7 +88,7 @@ delete rectangleInstance; QML documents can also be loaded using QDeclarativeView. This class provides a convenient QWidget-based view for embedding QML components into QGraphicsView-based applications. (For other -methods of integrating QML into QWidget-based applications, see \l {Integrating QML with existing Qt +methods of integrating QML into QWidget-based applications, see \l {Integrating QML Code with existing Qt UI code}.) @@ -262,8 +265,8 @@ Note that custom C++ types do not have to inherit from QDeclarativeItem; this is a displayable item. If the item is not displayable, it can simply inherit from QObject. For more information on defining new QML elements, see the \l {Tutorial: Writing QML extensions with C++} -{Writing QML extensions with C++} tutorial and the \l {Extending QML in C++} reference -documentation. +{Writing QML extensions with C++} tutorial and the +\l {Extending QML Functionalities using C++} reference documentation. @@ -496,7 +499,8 @@ can be registered using qmlRegisterUncreatableType(). To be accessible from QML must begin with a capital letter. See the \l {Tutorial: Writing QML extensions with C++}{Writing QML extensions with C++} tutorial and -the \l {Extending QML in C++} reference documentation for more information. +the \l {Extending QML Functionalities using C++} reference documentation for +more information. \section2 Automatic type conversion from strings diff --git a/doc/src/declarative/qtprogrammers.qdoc b/doc/src/declarative/qtprogrammers.qdoc index b7d09a1..e48dc9a 100644 --- a/doc/src/declarative/qtprogrammers.qdoc +++ b/doc/src/declarative/qtprogrammers.qdoc @@ -30,8 +30,6 @@ \target qtprogrammers \title QML for Qt Programmers -\section1 Overview - While QML does not require Qt knowledge to use, if you \e are already familiar with Qt, much of your knowledge is directly relevant to learning and using QML. Of course, an application with a UI defined in QML also uses Qt for all the non-UI logic. @@ -48,7 +46,8 @@ QML provides direct access to the following concepts from Qt: \o Qt models - used directly in data binding (QAbstractItemModel) \endlist -Qt knowledge is \e required for \l {Extending QML in C++}, and also for \l{Integrating QML with existing Qt UI code}. +Qt knowledge is \e required for \l {Extending QML Functionalities using C++}, +and also for \l{Integrating QML Code with existing Qt UI code}. \section1 QML Items compared with QWidgets diff --git a/doc/src/declarative/qtquick-intro.qdoc b/doc/src/declarative/qtquick-intro.qdoc new file mode 100644 index 0000000..02b2c44 --- /dev/null +++ b/doc/src/declarative/qtquick-intro.qdoc @@ -0,0 +1,119 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of this +** file. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! +\page qml-intro.html +\title Intro to Qt Quick + +Qt Quick is a collection of technologies that are designed to help developers +create the kind of intuitive, modern, and fluid user interfaces that are +increasingly used on mobile phones, media players, set-top boxes, and other +portable devices. Qt Quick consists of a rich set of user interface +\l{QML Elements}{elements}, a \l{QML Syntax}{declarative} language for +describing user interfaces, and a language \l{QtDeclarative Module}{runtime}. A +collection of C++ APIs is used to integrate these high level features with +classic Qt applications. Version 2.1 of the Qt Creator integrated development +environment (IDE) introduces tools for developing Qt Quick applications. + +\image qml-clocks-example.png + +\section1 The QML Language + +QML is a high level, scripted language. Its commands, more correctly +\e elements, leverage the power and efficiency of the Qt libraries to make easy +to use commands that perform intuitive functions. Drawing a rectangle, +displaying an image, and application events -- all are possible with declarative +programming. + +The language also allows more flexibility of these commands by using +\l{About JavaScript}{JavaScript} to implement the high level user interface +logic. + +A QML element usually has various \e properties that help define the element. +For example, if we created an element called Circle then the radius of the +circle would be a property. Building user interfaces by importing these elements +is one of the great feature of QML and Qt Quick. +\image qml-texteditor5_newfile.png + +\section1 QtDeclarative Module + +To make Qt Quick possible, Qt introduces the \l {QtDeclarative} module. The +module creates a JavaScript runtime that QML runs under with a Qt based backend. +Because QtDeclarative and QML are built upon Qt, they inherit many of Qt's +technology, namely the \l{Signals and Slots}{signals and slots} mechanism and +the \l{The Meta-Object System}{meta-object} system. Data created using C++ are +directly accessible from QML and QML objects are also accessible from C++ code. + +In conjunction with the QML language, the QtDeclarative module separates the +interface logic in QML from the application logic in C++. + +\section1 Creator Tools + +Qt Creator is a complete integrated development environment (IDE) for creating +applications with Qt Quick and the Qt application framework. + +\image qmldesigner-visual-editor.png + +The main goal for Qt Creator is meeting the development needs of Qt Quick +developers who are looking for simplicity, usability, productivity, +extendibility and openness, while aiming to lower the barrier of entry for +newcomers to Qt Quick and Qt. The key features of Qt Creator allow UI designers +and developers to accomplish the following tasks: +\list +\o Get started with Qt Quick application development quickly and easily with +examples, tutorials, and project wizards. +\o Design application user interface with the integrated editor, Qt Quick +Designer, or use graphics software to design the user interface and use scripts +to export the design to Qt Quick Designer. +\o Develop applications with the advanced code editor that provides new powerful +features for completing code snippets, refactoring code, and viewing the element +hierarchy of QML files. +\o Build and deploy Qt Quick applications that target multiple desktop and +mobile platforms, such as Microsoft Windows, Mac OS X, Linux, Symbian, and +Maemo. +\o Debug JavaScript functions and execute JavaScript expressions in the current +context, and inspect QML at runtime to explore the object structure, debug +animations, and inspect colors. +\o Deploy applications to mobile devices and create application installation +packages for Symbian and Maemo devices that can be published in the Ovi Store +and other channels. +\o Easily access information with the integrated context-sensitive Qt Help +system. +\endlist + +\image qtcreator-target-selector.png + +\section1 Where to Go from Here + +The \l {Qt Quick} page has links to various Qt Quick topics such as QML +features, addons, and tools. + +The \l {QML Examples and Demos} page has a gallery of QML applications. +*/ + + + diff --git a/doc/src/declarative/scope.qdoc b/doc/src/declarative/scope.qdoc index 3317037..9a9934a 100644 --- a/doc/src/declarative/scope.qdoc +++ b/doc/src/declarative/scope.qdoc @@ -24,41 +24,17 @@ ** $QT_END_LICENSE$ ** ****************************************************************************/ - -/* - - - -and requires extension to -fit naturally with QML. - - -JavaScript has only b -JavaScript has a very simple built in scope is very simple - -script, and the precede d - -and \l {Integrating JavaScript}{JavaScript} are executed in a scope chain -automatically established by QML when a component instance is constructed. QML is a \e {dynamically scoped} -language. Different object instances instantiated from the same component can exist in -different scope chains. - -\image qml-scope.png - - -*/ - /*! \page qdeclarativescope.html \title QML Scope \tableofcontents -QML property bindings, inline functions and imported JavaScript files all -run in a JavaScript scope. Scope controls which variables an expression can +QML property bindings, inline functions and imported JavaScript files all +run in a JavaScript scope. Scope controls which variables an expression can access, and which variable takes precedence when two or more names conflict. -As JavaScript's built-in scope mechanism is very simple, QML enhances it to fit +As JavaScript's built-in scope mechanism is very simple, QML enhances it to fit more naturally with the QML language extensions. \section1 JavaScript Scope @@ -67,8 +43,8 @@ QML's scope extensions do not interfere with JavaScript's natural scoping. JavaScript programmers can reuse their existing knowledge when programming functions, property bindings or imported JavaScript files in QML. -In the following example, the \c {addConstant()} method will add 13 to the -parameter passed just as the programmer would expect irrespective of the +In the following example, the \c {addConstant()} method will add 13 to the +parameter passed just as the programmer would expect irrespective of the value of the QML object's \c a and \c b properties. \code @@ -83,8 +59,8 @@ QtObject { } \endcode -That QML respects JavaScript's normal scoping rules even applies in bindings. -This totally evil, abomination of a binding will assign 12 to the QML object's +That QML respects JavaScript's normal scoping rules even applies in bindings. +This totally evil, abomination of a binding will assign 12 to the QML object's \c a property. \code @@ -101,13 +77,13 @@ with local variables declared in another. \section1 Element Names and Imported JavaScript Files -\l {QML Document}s include import statements that define the element names -and JavaScript files visible to the document. In addition to their use in the -QML declaration itself, element names are used by JavaScript code when accessing -\l {Attached Properties} and enumeration values. +\l {QML Document}s include import statements that define the element names +and JavaScript files visible to the document. In addition to their use in the +QML declaration itself, element names are used by JavaScript code when accessing +\l {Attached Properties} and enumeration values. -The effect of an import applies to every property binding, and JavaScript -function in the QML document, even those in nested inline components. The +The effect of an import applies to every property binding, and JavaScript +function in the QML document, even those in nested inline components. The following example shows a simple QML file that accesses some enumeration values and calls an imported JavaScript function. @@ -130,10 +106,10 @@ ListView { \section1 Binding Scope Object -Property bindings are the most common use of JavaScript in QML. Property +Property bindings are the most common use of JavaScript in QML. Property bindings associate the result of a JavaScript expression with a property of an -object. The object to which the bound property belongs is known as the binding's -scope object. In this QML simple declaration the \l Item object is the +object. The object to which the bound property belongs is known as the binding's +scope object. In this QML simple declaration the \l Item object is the binding's scope object. \code @@ -144,21 +120,21 @@ Item { Bindings have access to the scope object's properties without qualification. In the previous example, the binding accesses the \l Item's \c parent property -directly, without needing any form of object prefix. QML introduces a more -structured, object-oriented approach to JavaScript, and consequently does not +directly, without needing any form of object prefix. QML introduces a more +structured, object-oriented approach to JavaScript, and consequently does not require the use of the JavaScript \c this property. Care must be used when accessing \l {Attached Properties} from bindings due to their interaction with the scope object. Conceptually attached properties exist on \e all objects, even if they only have an effect on a subset of those. -Consequently unqualified attached property reads will always resolve to an -attached property on the scope object, which is not always what the programmer +Consequently unqualified attached property reads will always resolve to an +attached property on the scope object, which is not always what the programmer intended. -For example, the \l PathView element attaches interpolated value properties to +For example, the \l PathView element attaches interpolated value properties to its delegates depending on their position in the path. As PathView only -meaningfully attaches these properties to the root element in the delegate, any -sub-element that accesses them must explicitly qualify the root object, as shown +meaningfully attaches these properties to the root element in the delegate, any +sub-element that accesses them must explicitly qualify the root object, as shown below. \code @@ -181,7 +157,7 @@ the unset \c {PathView.scale} attached property on itself. Each QML component in a QML document defines a logical scope. Each document has at least one root component, but can also have other inline sub-components. -The component scope is the union of the object ids within the component and the +The component scope is the union of the object ids within the component and the component's root element's properties. \code @@ -195,7 +171,7 @@ Item { anchors.top: parent.top } - Text { + Text { text: titleElement.text font.pixelSize: 18 anchors.bottom: parent.bottom @@ -203,7 +179,7 @@ Item { } \endcode -The example above shows a simple QML component that displays a rich text title +The example above shows a simple QML component that displays a rich text title string at the top, and a smaller copy of the same text at the bottom. The first \c Text element directly accesses the component's \c title property when forming the text to display. That the root element's properties are directly @@ -211,18 +187,18 @@ accessible makes it trivial to distribute data throughout the component. The second \c Text element uses an id to access the first's text directly. IDs are specified explicitly by the QML programmer so they always take precedence -over other property names (except for those in the \l {JavaScript Scope}). For -example, in the unlikely event that the binding's \l {Binding Scope Object}{scope -object} had a \c titleElement property in the previous example, the \c titleElement +over other property names (except for those in the \l {JavaScript Scope}). For +example, in the unlikely event that the binding's \l {Binding Scope Object}{scope +object} had a \c titleElement property in the previous example, the \c titleElement id would still take precedence. \section1 Component Instance Hierarchy -In QML, component instances connect their component scopes together to form a -scope hierarchy. Component instances can directly access the component scopes of +In QML, component instances connect their component scopes together to form a +scope hierarchy. Component instances can directly access the component scopes of their ancestors. -The easiest way to demonstrate this is with inline sub-components whose component +The easiest way to demonstrate this is with inline sub-components whose component scopes are implicitly scoped as children of the outer component. \code @@ -239,16 +215,16 @@ Item { } \endcode -The component instance hierarchy allows instances of the delegate component +The component instance hierarchy allows instances of the delegate component to access the \c defaultColor property of the \c Item element. Of course, -had the delegate component had a property called \c defaultColor that would -have taken precedence. +had the delegate component had a property called \c defaultColor that would +have taken precedence. The component instance scope hierarchy extends to out-of-line components, too. -In the following example, the \c TitlePage.qml component creates two -\c TitleText instances. Even though the \c TitleText element is in a separate -file, it still has access to the \c title property when it is used from within -the \c TitlePage. QML is a dynamically scoped language - depending on where it +In the following example, the \c TitlePage.qml component creates two +\c TitleText instances. Even though the \c TitleText element is in a separate +file, it still has access to the \c title property when it is used from within +the \c TitlePage. QML is a dynamically scoped language - depending on where it is used, the \c title property may resolve differently. \code @@ -256,13 +232,13 @@ is used, the \c title property may resolve differently. import QtQuick 1.0 Item { property string title - - TitleText { + + TitleText { size: 22 anchors.top: parent.top } - TitleText { + TitleText { size: 18 anchors.bottom: parent.bottom } @@ -277,10 +253,10 @@ Text { } \endcode -Dynamic scoping is very powerful, but it must be used cautiously to prevent +Dynamic scoping is very powerful, but it must be used cautiously to prevent the behavior of QML code from becoming difficult to predict. In general it -should only be used in cases where the two components are already tightly -coupled in another way. When building reusable components, it is preferable +should only be used in cases where the two components are already tightly +coupled in another way. When building reusable components, it is preferable to use property interfaces, like this: \code @@ -289,14 +265,14 @@ import QtQuick 1.0 Item { id: root property string title - - TitleText { + + TitleText { title: root.title size: 22 anchors.top: parent.top } - TitleText { + TitleText { title: root.title size: 18 anchors.bottom: parent.bottom @@ -322,7 +298,7 @@ QML specific tasks a little easier. These extensions are described in the \l {QML Global Object} documentation. QML disallows element, id and property names that conflict with the properties -on the global object to prevent any confusion. Programmers can be confident +on the global object to prevent any confusion. Programmers can be confident that \c Math.min(10, 9) will always work as expected! */ diff --git a/doc/src/declarative/tutorial.qdoc b/doc/src/declarative/tutorial.qdoc index 1ee5e61..dc08ba0 100644 --- a/doc/src/declarative/tutorial.qdoc +++ b/doc/src/declarative/tutorial.qdoc @@ -144,7 +144,7 @@ An \l Item is the most basic visual element in QML and is often used as a contai We declare a \c cellColor property. This property is accessible from \e outside our component, this allows us to instantiate the cells with different colors. -This property is just an alias to an existing property - the color of the rectangle that compose the cell (see \l{Adding Properties}). +This property is just an alias to an existing property - the color of the rectangle that compose the cell (see \l{Property Binding}). \snippet examples/declarative/tutorials/helloworld/Cell.qml 5 |