source: trunk/src/gui/graphicsview/qgraphicsitemanimation.cpp@ 651

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/*!
    \class QGraphicsItemAnimation
    \brief The QGraphicsItemAnimation class provides simple animation
    support for QGraphicsItem.
    \since 4.2
    \ingroup graphicsview-api
    \deprecated

    The QGraphicsItemAnimation class animates a QGraphicsItem. You can
    schedule changes to the item's transformation matrix at
    specified steps. The QGraphicsItemAnimation class has a 
    current step value. When this value changes the transformations 
    scheduled at that step are performed. The current step of the 
    animation is set with the \c setStep() function.

    QGraphicsItemAnimation will do a simple linear interpolation
    between the nearest adjacent scheduled changes to calculate the 
    matrix. For instance, if you set the position of an item at values
    0.0 and 1.0, the animation will show the item moving in a straight
    line between these positions. The same is true for scaling and 
    rotation.

    It is usual to use the class with a QTimeLine. The timeline's
    \l{QTimeLine::}{valueChanged()} signal is then connected to the 
    \c setStep() slot. For example, you can set up an item for rotation
    by calling \c setRotationAt() for different step values.
    The animations timeline is set with the setTimeLine() function.

    An example animation with a timeline follows:

    \snippet doc/src/snippets/timeline/main.cpp 0

    Note that steps lie between 0.0 and 1.0. It may be necessary to use
    \l{QTimeLine::}{setUpdateInterval()}. The default update interval
    is 40 ms. A scheduled transformation cannot be removed when set,
    so scheduling several transformations of the same kind (e.g.,
    rotations) at the same step is not recommended.