source: trunk/doc/src/examples/collidingmice-example.qdoc@ 609

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/*!
    \example graphicsview/collidingmice
    \title Colliding Mice Example

    The Colliding Mice example shows how to use the Graphics View
    framework to implement animated items and detect collision between
    items.

    \image collidingmice-example.png

    Graphics View provides the QGraphicsScene class for managing and
    interacting with a large number of custom-made 2D graphical items
    derived from the QGraphicsItem class, and a QGraphicsView widget
    for visualizing the items, with support for zooming and rotation.

    The example consists of an item class and a main function:
    the \c Mouse class represents the individual mice extending
    QGraphicsItem, and the \c main() function provides the main
    application window.

    We will first review the \c Mouse class to see how to animate
    items and detect item collision, and then we will review the \c
    main() function to see how to put the items into a scene and how to
    implement the corresponding view.

    \section1 Mouse Class Definition

    The \c mouse class inherits from QGraphicsItem. The
    QGraphicsItem class is the base class for all graphical items in
    the Graphics View framework, and provides a light-weight
    foundation for writing your own custom items.

    \snippet examples/graphicsview/collidingmice/mouse.h 0

    When writing a custom graphics item, you must implement
    QGraphicsItem's two pure virtual public functions: \l
    {QGraphicsItem::}{boundingRect()}, which returns an estimate of
    the area painted by the item, and \l {QGraphicsItem::}{paint()},
    which implements the actual painting. In addition, we reimplement
    the \l {QGraphicsItem::}{shape()} and \l {QGraphicsItem::}{advance()}.
    We reimplement \l {QGraphicsItem::}{shape()} to return an accurate
    shape of our mouse item; the default implementation simply returns
    the item's bounding rectangle. We reimplement \l {QGraphicsItem::}{advance()}
    to handle the animation so it all happens on one update.