Merge branch '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-1 into 4.7-integration

* '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-1: (39 commits)
  fix typo in documentation
  Improve Bearer Management related documentation in QNetworkAccessManager
  Compile with QT_NO_ACTION.
  Unbreak compilation outside Mac
  QDBusAbstractInterface: don't set lastError outside the object's own thread
  tst_bic: make it possible to test for cross-compilation
  Remove Q_PACKED from QChar and QLocale::Data.
  QDebug operator for QFlags
  Removing unneeded qDebug statement.
  Fixing incorrect addition of public API symbols.
  Removal erroneous inclusion of new Public API in qmacstyle.
  Doc: design changes
  qdoc: Fixed html error, but the problem is still there.
  qdoc: Changed number of columns to 1. Oila!
  Doc: Changes to the HTMLGenerator, style and js
  remove dead code that will never get called.
  add bytes and activeTime to corelwan.
  Fix formating of license header.
  fix irix build
  clarify wording of warning message
  ...

3 files changed, 969 insertions, 2 deletions

diff --git a/doc/src/declarative/advtutorial.qdoc b/doc/src/declarative/advtutorial.qdoc
index 47504ae..62536c6 100644
--- a/doc/src/declarative/advtutorial.qdoc
+++ b/doc/src/declarative/advtutorial.qdoc
@@ -468,6 +468,6 @@ By following this tutorial you've seen how you can write a fully functional appl
 \endlist
 
 There is so much more to learn about QML that we haven't been able to cover in this tutorial. Check out all the
-demos and examples and the \l {Declarative UI Using QML}{documentation} to find out all the things you can do with QML!
+demos and examples and the \l {Qt Quick} documentation to see all the things you can do with QML!
 
 */
diff --git a/doc/src/declarative/integrating.qdoc b/doc/src/declarative/integrating.qdoc
index c6f754b..728eb13 100644
--- a/doc/src/declarative/integrating.qdoc
+++ b/doc/src/declarative/integrating.qdoc
@@ -81,7 +81,7 @@ of simple and dynamic elements.
 
 \section2 Adding QML widgets to a QGraphicsScene
 
-If you have an existing UI based on the \l{The Graphics View Framework}{Graphics View Framework},
+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 
diff --git a/doc/src/declarative/qml-intro.qdoc b/doc/src/declarative/qml-intro.qdoc
new file mode 100644
index 0000000..64a4949
--- /dev/null
+++ b/doc/src/declarative/qml-intro.qdoc
@@ -0,0 +1,967 @@
+/****************************************************************************
+**
+** 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.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** 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 Beginning 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
+
+    \code
+    SomeElement {
+        id: myObject
+        ... some other things here ...
+    }
+    \endcode
+
+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
+
+    \code
+    import Qt 4.7
+
+    // This is a comment. And below myRectangle is defined.
+    Rectangle {
+        id: myRectangle
+        width: 500
+        height: 400
+    }
+    \endcode
+
+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 command
+
+    \code
+    qml 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}{text}
+property to "Hello World!". So to set the text to 'Hello world' and the
+background colour to light gray,
+
+    \code
+    import Qt 4.7
+    
+    Rectangle {
+        id: myRectangle
+        width: 500
+        height: 400
+
+        Text { text: "Hello World!" }
+
+        color: "lightgray"
+    }
+    \endcode
+
+
+\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
+
+    \code
+    Text {
+        text: "<h2>Hello World</h2>"; color: "darkgreen"
+        x: 100; y:100
+    }
+    \endcode
+
+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,
+
+    \code
+    Text {
+        text: "<h1>Hello world again</h1>"
+        color: "#002288"
+        x: 100; y: 100
+    }
+    \endcode
+
+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"}.
+
+    \code
+    Image {
+        source: "images/qt-logo.png"
+    }
+    \endcode
+
+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,
+
+    \code
+    Image {
+        source: "images/qt-logo.png"
+        x: 100; y: 150
+        width: 150; height: 150
+    }
+    \endcode
+
+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.
+
+    \code
+    import Qt 4.7
+
+    Rectangle {
+        id: myRectangle
+        width: 500
+        height: 400
+        
+        // A light gray background
+        color: "lightgray"
+
+        // Position and color some text
+        Text {
+            text: "<h1>Hello world again</h1>"
+            color: "darkgreen"
+            x: 100; y: 100
+        }
+
+        // Using the opportunity to resize the image.
+        Image {
+            source: "images/qt-logo.png"
+            x: 100; y: 150
+            width: 150; height: 150
+        }
+
+    }
+    \endcode
+
+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
+
+    \code
+    import Qt 4.7
+
+    Rectangle {
+        id: myWin
+        width: 500
+        height: 400
+
+        Image {
+            id: image1
+            source: "images/qt-logo.png"
+            width: 150; height: 150
+            anchors.bottom: myWin.bottom
+        }
+    }
+    \endcode
+
+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
+
+    \code
+    import Qt 4.7
+
+    Rectangle {
+        id: myWin
+        width: 500
+        height: 400
+
+        Image {
+            id: image1
+            source: "images/qt-logo.png"
+            width: 150; height: 150
+            anchors.bottom: myWin.bottom
+            anchors.horizontalCenter: myWin.horizontalCenter
+            anchors.bottomMargin: 10
+        }
+    }
+    \endcode
+
+
+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
+
+    \code
+    Text {
+        text: "<h2>The Qt Logo</h2>"
+        anchors.bottom: image1.top
+        anchors.horizontalCenter: myWin.horizontalCenter
+        anchors.bottomMargin: 15
+    }
+    \endcode
+
+\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:
+
+    \code
+    myRectangle.anchors.top  // Wrong
+    \endcode
+
+we use
+
+    \code
+    myRectangle.top         // Correct
+    \endcode
+
+
+
+
+\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
+additonal 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
+
+    \code
+    myList: [ listElement1, listElement2, ... } ]
+    \endcode
+
+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,
+
+    \code
+    import Qt 4.7
+
+    Rectangle {
+        id: myWin
+        width: 500
+        height: 400
+
+        Image {
+            id: image1
+            source: "images/qt-logo.png"
+            width: 150; height: 150
+            anchors.bottom: myWin.bottom
+            anchors.horizontalCenter: myWin.horizontalCenter
+            anchors.bottomMargin: 10
+
+            transform: Rotation {
+                origin.x: 75; origin.y: 75
+                axis{ x: 0; y: 0; z:1 }  angle: -90
+            }
+
+        }
+        
+        Text {
+            text: "<h2>The Qt Logo -- taking it easy</h2>"
+            anchors.bottom: image1.top
+            anchors.horizontalCenter: myWin.horizontalCenter
+            anchors.bottomMargin: 15
+
+            transform: [
+                Scale { xScale: 1.5; yScale: 1.2 } ,
+            
+                Rotation {
+                    origin.x: 75; origin.y: 75
+                    axis{ x: 0; y: 0; z:1 }  angle: -45
+                }
+            ]
+        }
+    }
+    \endcode
+
+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.
+
+    \code
+    import Qt 4.7
+
+    Rectangle {
+        id: mainRec
+        width:  600
+        height: 400
+
+        Image {
+            id: image1
+            source: "images/qt-logo.png"
+            x: 200; y: 100
+            width: 100; height: 100
+            
+            // Animate a rotation
+            transformOrigin: Item.Center
+            NumberAnimation on rotation {
+                from: 0; to: 360
+                duration: 2000
+                loops: Animation.Infinite
+            }
+        }
+    }
+    \endcode
+
+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.
+
+    \code
+    import Qt 4.7
+
+    Rectangle {
+        id: mainRec
+        width:  600
+        height: 400
+
+        Image {
+            id: image1
+            source: "images/qt-logo.png"
+            x: 200; y: 100
+            width: 100; height: 100
+
+            // Animate a rotation
+            transform: Rotation {
+                origin.x: 50; origin.y: 50; axis {x:0; y:1; z:0} angle:0
+                NumberAnimation on angle  {
+                    from: 0; to: 360;
+                    duration: 3000;
+                    loops: Animation.Infinite
+                }
+            }
+        }
+    }
+    \endcode
+
+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
+
+    \code
+    import Qt 4.7
+
+    Rectangle {
+        id: mainRec
+        width:  600
+        height: 400
+        z: 0
+
+        Image {
+            id: image1
+            source: "images/qt-logo.png"
+            x: 20; y: 20 ; z: 1
+            width: 100; height: 100
+        }
+
+        Image {
+            id: image2
+            source: "images/qt-logo.png"
+            width: 100; height: 100
+            x: (mainRec.width - 100)/2; y: (mainRec.height - 100)/2
+            z: 2
+        }
+    }
+    \endcode
+
+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.
+
+    \code
+    SequentialAnimation on x {
+        loops: Animation.Infinite
+        NumberAnimation { from: 20; to: 450; easing.type: "InOutQuad";
+duration: 2000 }
+        PauseAnimation { duration: 500 }
+    }
+    \endcode
+
+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
+
+    \code
+    Rectangle {
+        id: mainRec
+        width:  600
+        height: 400
+        z: 0
+
+        Image {
+            id: image2
+            source: "images/qt-logo.png"
+            width: 100; height: 100
+            x: (mainRec.width - 100)/2; y: (mainRec.height - 100)/2
+            z: 2
+        }
+
+        Image {
+            id: image1
+            source: "images/qt-logo.png"
+            x: 20; y: 20 ; z: 1
+            width: 100; height: 100
+
+            SequentialAnimation on x {
+                loops: Animation.Infinite
+                NumberAnimation {
+                    from: 20; to: 450
+                    easing.type: "InOutQuad"; duration: 2000
+                }
+                PauseAnimation { duration: 500 }
+            }
+            
+            SequentialAnimation on y {
+                loops: Animation.Infinite
+                NumberAnimation {
+                    from: 20; to: 250
+                    easing.type: "InOutQuad"; duration: 2000
+                }
+                PauseAnimation { duration: 500 }
+            }
+
+            SequentialAnimation on scale {
+                loops: Animation.Infinite
+                NumberAnimation { from: 1; to: 0.5; duration: 1000 }
+                NumberAnimation { from: 0.5; to: 1; duration: 1000 }
+                PauseAnimation { duration: 500 }
+            }
+        }
+    }
+    \endcode
+
+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
+
+    \code
+    import Qt 4.7
+
+    Rectangle {
+        id: mainRectangle
+        width:  600
+        height: 400
+        color: "black"
+
+        Rectangle {
+            id: sky
+            width: 600
+            height: 200
+            y: 0
+            color: "lightblue"
+        }
+
+        Rectangle {
+            id: ground
+            width: 600; height: 200
+            y: 200
+            color: "green"
+        }
+
+        MouseArea {
+            id: mousearea
+            anchors.fill: mainRectangle
+        }
+
+        states: [ State {
+                name: "night"
+                when: mousearea.pressed == true
+                PropertyChanges { target: sky; color: "darkblue" }
+                PropertyChanges { target: ground; color: "black" }
+            },
+            State {
+                name: "daylight"
+                when: mousearea.pressed == false
+                PropertyChanges { target: sky; color: "lightblue" }
+                PropertyChanges { target: ground; color: "green" }
+            }
+        ]
+
+        transitions: [ Transition {
+                from: "daylight"; to: "night"
+                ColorAnimation { duration: 1000 }
+            },
+            Transition {
+                from: "night"; to: "daylight"
+                ColorAnimation { duration: 500 }
+            }
+        ]
+    }
+    \endcode
+
+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
+
+In the Qt \e {examples/declarative/toys} folder you will find a folder
+\e {dial} which contains the \e dial 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 dial-example.qml.
+
+\e {Dial.qml} can be found in the \e content sub-directory. It defines a 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 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 needle_shadow.png image has a 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/toys/dial/content/Dial.qml  needle_shadow
+
+And the needle
+
+\snippet ../../examples/declarative/toys/dial/content/Dial.qml  needle
+
+The final image is the overlay which simply has a position defined.
+
+\snippet ../../examples/declarative/toys/dial/content/Dial.qml  overlay
+
+\e {dial-example.qml} in the \e {examples/declarative/toys/dial} 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 dial-example. So the
+start of the file looks like
+
+    \code
+    import Qt 4.7
+    import "content"
+    \endcode
+
+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/toys/dial/dial-example.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.
+
+    \code
+    SpringFollow on angle {
+        spring: 1.4
+        damping: .15
+        to: Math.min(Math.max(-130, root.value*2.6 - 130), 133)
+    }
+    \endcode
+
+This is part of the \c needleRotation that rotates the needle and causes the
+rotation of its shadow. \l SpringFollow is an element that modifies the value
+of that rotation angle \e to 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.
+
+
+
+*/
+
+
+