QGraphicsItemAnimation¶

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

Synopsis¶

Functions¶

def clear ()
def horizontalScaleAt (step)
def horizontalShearAt (step)
def item ()
def matrixAt (step)
def posAt (step)
def posList ()
def rotationAt (step)
def rotationList ()
def scaleList ()
def setItem (item)
def setPosAt (step, pos)
def setRotationAt (step, angle)
def setScaleAt (step, sx, sy)
def setShearAt (step, sh, sv)
def setTimeLine (timeLine)
def setTranslationAt (step, dx, dy)
def shearList ()
def timeLine ()
def translationList ()
def verticalScaleAt (step)
def verticalShearAt (step)
def xTranslationAt (step)
def yTranslationAt (step)

Virtual functions¶

def afterAnimationStep (step)
def beforeAnimationStep (step)

Slots¶

def reset ()
def setStep (x)

Detailed Description¶

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(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

QTimeLine Graphics View Framework

class QGraphicsItemAnimation([parent=None])¶

param parent

QObject

Constructs an animation object with the given parent .

PySide2.QtWidgets.QGraphicsItemAnimation.afterAnimationStep(step)¶

Parameters: step – 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.

PySide2.QtWidgets.QGraphicsItemAnimation.beforeAnimationStep(step)¶

Parameters: step – 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.

PySide2.QtWidgets.QGraphicsItemAnimation.clear()¶: Clears the scheduled transformations used for the animation, but retains the item and timeline.

PySide2.QtWidgets.QGraphicsItemAnimation.horizontalScaleAt(step)¶

Parameters: step – qreal
Return type: qreal

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

See also

setScaleAt()

PySide2.QtWidgets.QGraphicsItemAnimation.horizontalShearAt(step)¶

Parameters: step – qreal
Return type: qreal

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

See also

setShearAt()

PySide2.QtWidgets.QGraphicsItemAnimation.item()¶

Return type: QGraphicsItem

Returns the item on which the animation object operates.

See also

setItem()

PySide2.QtWidgets.QGraphicsItemAnimation.matrixAt(step)¶

Parameters: step – qreal
Return type: QMatrix

Returns the matrix used to transform the item at the specified step value.

PySide2.QtWidgets.QGraphicsItemAnimation.posAt(step)¶

Parameters: step – qreal
Return type: QPointF

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

See also

setPosAt()

PySide2.QtWidgets.QGraphicsItemAnimation.posList()¶

Return type

Returns all explicitly inserted positions.

See also

posAt() setPosAt()

PySide2.QtWidgets.QGraphicsItemAnimation.reset()¶

Resets the item to its starting position and transformation.

You can call setStep (0) instead.

PySide2.QtWidgets.QGraphicsItemAnimation.rotationAt(step)¶

Parameters: step – qreal
Return type: qreal

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

See also

setRotationAt()

PySide2.QtWidgets.QGraphicsItemAnimation.rotationList()¶

Return type

Returns all explicitly inserted rotations.

See also

rotationAt() setRotationAt()

PySide2.QtWidgets.QGraphicsItemAnimation.scaleList()¶

Return type

Returns all explicitly inserted scales.

PySide2.QtWidgets.QGraphicsItemAnimation.setItem(item)¶

Parameters: item – QGraphicsItem

Sets the specified item to be used in the animation.

See also

item()

PySide2.QtWidgets.QGraphicsItemAnimation.setPosAt(step, pos)¶

Parameters

step – qreal
pos – QPointF

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

See also

posAt()

PySide2.QtWidgets.QGraphicsItemAnimation.setRotationAt(step, angle)¶

Parameters

step – qreal
angle – qreal

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

See also

rotationAt()

PySide2.QtWidgets.QGraphicsItemAnimation.setScaleAt(step, sx, sy)¶

Parameters

step – qreal
sx – qreal
sy – qreal

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

PySide2.QtWidgets.QGraphicsItemAnimation.setShearAt(step, sh, sv)¶

Parameters

step – qreal
sh – qreal
sv – qreal

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

PySide2.QtWidgets.QGraphicsItemAnimation.setStep(x)¶

Parameters: x – qreal

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

PySide2.QtWidgets.QGraphicsItemAnimation.setTimeLine(timeLine)¶

Parameters: timeLine – QTimeLine

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

See also

timeLine()

PySide2.QtWidgets.QGraphicsItemAnimation.setTranslationAt(step, dx, dy)¶

Parameters

step – qreal
dx – qreal
dy – qreal

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()

PySide2.QtWidgets.QGraphicsItemAnimation.shearList()¶

Return type

Returns all explicitly inserted shears.

PySide2.QtWidgets.QGraphicsItemAnimation.timeLine()¶

Return type: QTimeLine

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

See also

setTimeLine()

PySide2.QtWidgets.QGraphicsItemAnimation.translationList()¶

Return type

Returns all explicitly inserted translations.

PySide2.QtWidgets.QGraphicsItemAnimation.verticalScaleAt(step)¶

Parameters: step – qreal
Return type: qreal

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

See also

setScaleAt()

PySide2.QtWidgets.QGraphicsItemAnimation.verticalShearAt(step)¶

Parameters: step – qreal
Return type: qreal

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

See also

setShearAt()

PySide2.QtWidgets.QGraphicsItemAnimation.xTranslationAt(step)¶

Parameters: step – qreal
Return type: qreal

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

See also

setTranslationAt()

PySide2.QtWidgets.QGraphicsItemAnimation.yTranslationAt(step)¶

Parameters: step – qreal
Return type: qreal

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

See also

setTranslationAt()

Qt Documentation

Table of Contents

QGraphicsItemAnimation¶

Synopsis¶

Functions¶

Virtual functions¶

Slots¶

Detailed Description¶