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diff --git a/doc/src/declarative/animation.qdoc b/doc/src/declarative/animation.qdoc new file mode 100644 index 0000000..1314493 --- /dev/null +++ b/doc/src/declarative/animation.qdoc @@ -0,0 +1,266 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** 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 either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! +\page qmlanimation.html +\title QML Animation + +Animation in QML is done by animating properties of objects. Properties of type +real, int, color, rect, point, and size can all be animated. + +QML supports three different forms of animation - basic property animation, +transitions, and property behaviors. + +\section1 Basic Property Animation + +The simplest form of animation is directly using \l PropertyAnimation, which can animate all of the property +types listed above. If the property you are animating is a number or color, you can alternatively use +NumberAnimation or ColorAnimation. These elements don't add any additional functionality, +but will help enforce type correctness and are slightly more efficient. + +A property animation can be specified as a value source. This is especially useful for repeating animations. + +The following example creates a bouncing effect: +\qml +Rectangle { + id: rect + width: 120; height: 200; + Image { + id: img + source: "qt-logo.png" + x: 60-img.width/2 + y: 0 + y: SequentialAnimation { + running: true + repeat: true + NumberAnimation { to: 200-img.height; easing: "easeOutBounce"; duration: 2000 } + PauseAnimation { duration: 1000 } + NumberAnimation { to: 0; easing: "easeOutQuad"; duration: 1000 } + } + } +} +\endqml + +\image propanim.gif + +When you assign an animation as a value source, you do not need to specify \c property +or \c target; they are automatically selected for you. You do, however, need to specify \c to, and explicitly +start the animation (usually via the \c running property). + +\qml +Rectangle { + id: rect + width: 200; height: 200; + Rectangle { + color: "red" + width: 50; height: 50 + x: NumberAnimation { to: 50; running: true } + } +} +\endqml + +A property animation can also be specified as a resource that is manipulated from script. + +\qml +PropertyAnimation { + id: animation + target: image + property: "scale" + from: 1; to: .5 +} +Image { + id: image + source: "image.png" + MouseRegion { + anchors.fill: parent + onPressed: animation.start() + } +} +\endqml + +As can be seen, when an animation is used like this (as opposed to as a value source) you will need +to explicitly set the \c target and \c property to animate. + +Animations can be joined into a group using SequentialAnimation and ParallelAnimation. + +\target state-transitions +\section1 Transitions + +QML transitions describe animations to perform when \l{qmlstates}{state} changes occur. A transition +can only be triggered by a state change. + +For example, a transition could describe how an item moves from its initial position to its new position: + +\code +transitions: [ + Transition { + NumberAnimation { + matchProperties: "x,y" + easing: "easeOutBounce" + duration: 200 + } + } +] +\endcode + +As you can see from the above example, transitions make use of the same basic animation classes introduced +above. However, you generally use a different set of properties when working with transitions. In the example, +no \c target or \c property has been specified. Instead, we have specified \c matchProperties, +which (along with \c matchTargets) acts as a selector to determine which property changes to animate; +in this case, we will animate any x,y properties that have changed on any objects. + +QML transitions also have selectors to determine which state changes a transition should apply to: + +\code +Transition { + from: "*" + to: "details" + ... +} +\endcode + +Transitions can happen in parallel, in sequence, or in any combination of the two. By default, the top-level +animations in a transition will happen in parallel. The following example shows a rather complex transition +making use of both sequential and parallel animations: + +\code +Transition { + from: "*" + to: "MyState" + reversible: true + SequentialAnimation { + ColorAnimation { duration: 1000 } + PauseAnimation { duration: 1000 } + ParallelAnimation { + NumberAnimation { + duration: 1000 + easing: "easeOutBounce" + matchTargets: box1 + matchProperties: "x,y" + } + NumberAnimation { + duration: 1000 + matchTargets: box2 + matchProperties: "x,y" + } + } + } +} +\endcode + +To insert an explicit animation into your transition, you can use \target and \property as normal. + +\code +Transition { + from: "*" + to: "MyState" + reversible: true + SequentialAnimation { + NumberAnimation { + duration: 1000 + easing: "easeOutBounce" + // animate myItem's x and y if they have changed in the state + matchTargets: myItem + matchProperties: "x,y" + } + NumberAnimation { + duration: 1000 + // animate myItem2's y to 200, regardless of what happens in the state + target: myItem2 + property: "y" + to: 200 + } + } +} +\endcode + +\section1 Property Behaviors + +A property behavior specifies a default animation to run whenever the property's value changes, regardless +of what caused the change. Unlike Transition, Behavior doesn't provide a way to indicate that a Behavior +should only apply under certain circumstances. + +In the following snippet, we specify that we want the x position of redRect to be animated +whenever it changes. The animation will last 300 milliseconds and use an InOutQuad easing curve. + +\qml +Rectangle { + id: redRect + color: "red" + width: 100; height: 100 + x: Behavior { NumberAnimation { duration: 300; easing: "InOutQuad" } } +} +\endqml + +Like using an animation as a value source, when used in a Behavior and animation does not need to specify +a \c target or \c property. + +To trigger this behavior, we could: +\list +\o Enter a state that changes x + +\qml +State { + name: "myState" + PropertyChanges { + target: redRect + x: 200 + ... + } +} +\endqml + +\o Update x from a script + +\qml +MouseRegion { + .... + onClicked: redRect.x = 24; +} +\endqml +\endlist + +If x were bound to another property, triggering the binding would also trigger the behavior. + +If a state change has a transition animation matching a property with a Behavior, the transition animation +will override the Behavior for that state change. + +*/ |