class QGraphicsItemAnimation#

The QGraphicsItemAnimation class provides simple animation support for QGraphicsItem . More…

Synopsis#

Methods#

def __init__()
def clear()
def horizontalScaleAt()
def horizontalShearAt()
def item()
def posAt()
def posList()
def rotationAt()
def rotationList()
def scaleList()
def setItem()
def setPosAt()
def setRotationAt()
def setScaleAt()
def setShearAt()
def setTimeLine()
def setTranslationAt()
def shearList()
def timeLine()
def transformAt()
def translationList()
def verticalScaleAt()
def verticalShearAt()
def xTranslationAt()
def yTranslationAt()

Slots#

def setStep()

Note

This documentation may contain snippets that were automatically translated from C++ to Python. We always welcome contributions to the snippet translation. If you see an issue with the translation, you can also let us know by creating a ticket on https:/bugreports.qt.io/projects/PYSIDE

Detailed Description#

Warning

This section contains snippets that were automatically translated from C++ to Python and may contain errors.

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 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 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 setTimeLine() function.

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(0, 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 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.

See also

Graphics View Framework

__init__([parent=None])#

Parameters:: parent – QObject

Constructs an animation object with the given parent.

afterAnimationStep(step)#

Parameters:: step – float

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.

beforeAnimationStep(step)#

Parameters:: step – float

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.

clear()#

Clears the scheduled transformations used for the animation, but retains the item and timeline.

horizontalScaleAt(step)#

Parameters:: step – float
Return type:: float

Returns the horizontal scale for the item at the specified step value.

See also

setScaleAt()

horizontalShearAt(step)#

Parameters:: step – float
Return type:: float

Returns the horizontal shear for the item at the specified step value.

See also

setShearAt()

item()#

Return type:: QGraphicsItem

Returns the item on which the animation object operates.

See also

setItem()

posAt(step)#

Parameters:: step – float
Return type:: QPointF

Returns the position of the item at the given step value.

See also

setPosAt()

posList()#

Return type:: .list of std.pair qreal,QPointF

Returns all explicitly inserted positions.

See also

posAt() setPosAt()

rotationAt(step)#

Parameters:: step – float
Return type:: float

Returns the angle at which the item is rotated at the specified step value.

See also

setRotationAt()

rotationList()#

Return type:: .list of std.pair qreal,qreal

Returns all explicitly inserted rotations.

See also

rotationAt() setRotationAt()

scaleList()#

Return type:: .list of std.pair qreal,QPointF

Returns all explicitly inserted scales.

See also

verticalScaleAt() horizontalScaleAt() setScaleAt()

setItem(item)#

Parameters:: item – QGraphicsItem

Sets the specified item to be used in the animation.

See also

item()

setPosAt(step, pos)#

Parameters:

step – float
pos – QPointF

Sets the position of the item at the given step value to the point specified.

See also

posAt()

setRotationAt(step, angle)#

Parameters:

step – float
angle – float

Sets the rotation of the item at the given step value to the angle specified.

See also

rotationAt()

setScaleAt(step, sx, sy)#

Parameters:

step – float
sx – float
sy – float

Sets the scale of the item at the given step value using the horizontal and vertical scale factors specified by sx and sy.

See also

verticalScaleAt() horizontalScaleAt()

setShearAt(step, sh, sv)#

Parameters:

step – float
sh – float
sv – float

Sets the shear of the item at the given step value using the horizontal and vertical shear factors specified by sh and sv.

See also

verticalShearAt() horizontalShearAt()

setStep(x)#

Parameters:: x – float

Sets the current step value for the animation, causing the transformations scheduled at this step to be performed.

setTimeLine(timeLine)#

Parameters:: timeLine – QTimeLine

Sets the timeline object used to control the rate of animation to the timeLine specified.

See also

timeLine()

setTranslationAt(step, dx, dy)#

Parameters:

step – float
dx – float
dy – float

Sets the translation of the item at the given step value using the horizontal and vertical coordinates specified by dx and dy.

See also

xTranslationAt() yTranslationAt()

shearList()#

Return type:: .list of std.pair qreal,QPointF

Returns all explicitly inserted shears.

See also

verticalShearAt() horizontalShearAt() setShearAt()

timeLine()#

Return type:: QTimeLine

Returns the timeline object used to control the rate at which the animation occurs.

See also

setTimeLine()

transformAt(step)#

Parameters:: step – float
Return type:: QTransform

Returns the transform used for the item at the specified step value.

translationList()#

Return type:: .list of std.pair qreal,QPointF

Returns all explicitly inserted translations.

See also

xTranslationAt() yTranslationAt() setTranslationAt()

verticalScaleAt(step)#

Parameters:: step – float
Return type:: float

Returns the vertical scale for the item at the specified step value.

See also

setScaleAt()

verticalShearAt(step)#

Parameters:: step – float
Return type:: float

Returns the vertical shear for the item at the specified step value.

See also

setShearAt()

xTranslationAt(step)#

Parameters:: step – float
Return type:: float

Returns the horizontal translation of the item at the specified step value.

See also

setTranslationAt()

yTranslationAt(step)#

Parameters:: step – float
Return type:: float

Returns the vertical translation of the item at the specified step value.

See also

setTranslationAt()