PySide.QtGui.QGraphicsItemAnimation class provides simple animation support for PySide.QtGui.QGraphicsItem .
PySide.QtGui.QGraphicsItemAnimation class animates a PySide.QtGui.QGraphicsItem . You can schedule changes to the item's transformation matrix at specified steps. The PySide.QtGui.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 setStep() 函数。
PySide.QtGui.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 PySide.QtCore.QTimeLine . The timeline's PySide.QtCore.QTimeLine.valueChanged() signal is then connected to the setStep() slot. For example, you can set up an item for rotation by calling setRotationAt() for different step values. The animations timeline is set with the PySide.QtGui.QGraphicsItemAnimation.setTimeLine() 函数。
An example animation with a timeline follows:
ball = QGraphicsEllipseItem(0, 0, 20, 20)
timer = QTimeLine(5000)
timer.setFrameRange(0, 100)
animation = QGraphicsItemAnimation()
animation.setItem(ball)
animation.setTimeLine(timer)
for i in range(200):
animation.setPosAt(i / 200.0, QPointF(i, i))
scene = QGraphicsScene()
scene.setSceneRect(0, 0, 250, 250)
scene.addItem(ball)
view = QGraphicsView(scene)
view.show()
timer.start()
Note that steps lie between 0.0 and 1.0. It may be necessary to use PySide.QtCore.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.
另请参阅
PySide.QtCore.QTimeLine 图形视图框架
| 参数： | parent – PySide.QtCore.QObject |
|---|
Constructs an animation object with the given parent .
| 参数： | step – PySide.QtCore.qreal |
|---|
This method is meant to be overridden in subclasses that need to execute additional code after a new step has taken place. The animation step is provided for use in cases where the action depends on its value.
| 参数： | step – PySide.QtCore.qreal |
|---|
This method is meant to be overridden by subclassed that needs to execute additional code before a new step takes place. The animation step is provided for use in cases where the action depends on its value.
Clears the scheduled transformations used for the animation, but retains the item and timeline.
| 参数： | step – PySide.QtCore.qreal |
|---|---|
| 返回类型： | PySide.QtCore.qreal |
Returns the horizontal scale for the item at the specified step 值。
| 参数： | step – PySide.QtCore.qreal |
|---|---|
| 返回类型： | PySide.QtCore.qreal |
Returns the horizontal shear for the item at the specified step 值。
| 返回类型： | PySide.QtGui.QGraphicsItem |
|---|
Returns the item on which the animation object operates.
| 参数： | step – PySide.QtCore.qreal |
|---|---|
| 返回类型： | PySide.QtGui.QMatrix |
Returns the matrix used to transform the item at the specified step 值。
| 参数： | step – PySide.QtCore.qreal |
|---|---|
| 返回类型： | PySide.QtCore.QPointF |
Returns the position of the item at the given step 值。
| 返回类型： |
|---|
Returns all explicitly inserted positions.
Resets the item to its starting position and transformation.
You can call setStep(0) instead.
| 参数： | step – PySide.QtCore.qreal |
|---|---|
| 返回类型： | PySide.QtCore.qreal |
Returns the angle at which the item is rotated at the specified step 值。
| 返回类型： |
|---|
Returns all explicitly inserted rotations.
| 返回类型： |
|---|
Returns all explicitly inserted scales.
| 参数： | item – PySide.QtGui.QGraphicsItem |
|---|
设置指定 item to be used in the animation.
| 参数： |
|
|---|
Sets the position of the item at the given step value to the point 指定。
| 参数： |
|
|---|
Sets the rotation of the item at the given step value to the angle 指定。
| 参数： |
|
|---|
Sets the scale of the item at the given step value using the horizontal and vertical scale factors specified by sx and sy .
| 参数： |
|
|---|
Sets the shear of the item at the given step value using the horizontal and vertical shear factors specified by sh and sv .
| 参数： | x – PySide.QtCore.qreal |
|---|
设置当前 step value for the animation, causing the transformations scheduled at this step to be performed.
| 参数： | timeLine – PySide.QtCore.QTimeLine |
|---|
Sets the timeline object used to control the rate of animation to the timeLine 指定。
| 参数： |
|
|---|
Sets the translation of the item at the given step value using the horizontal and vertical coordinates specified by dx and dy .
| 返回类型： |
|---|
Returns all explicitly inserted shears.
| 返回类型： | PySide.QtCore.QTimeLine |
|---|
Returns the timeline object used to control the rate at which the animation occurs.
| 返回类型： |
|---|
Returns all explicitly inserted translations.
| 参数： | step – PySide.QtCore.qreal |
|---|---|
| 返回类型： | PySide.QtCore.qreal |
Returns the vertical scale for the item at the specified step 值。
| 参数： | step – PySide.QtCore.qreal |
|---|---|
| 返回类型： | PySide.QtCore.qreal |
Returns the vertical shear for the item at the specified step 值。
| 参数： | step – PySide.QtCore.qreal |
|---|---|
| 返回类型： | PySide.QtCore.qreal |
Returns the horizontal translation of the item at the specified step 值。
| 参数： | step – PySide.QtCore.qreal |
|---|---|
| 返回类型： | PySide.QtCore.qreal |
Returns the vertical translation of the item at the specified step 值。