QGraphicsItemAnimation

The QGraphicsItemAnimation class provides simple animation support for QGraphicsItem . More

Inheritance diagram of PySide2.QtWidgets.QGraphicsItemAnimation

Synopsis

Functions

Virtual functions

Slots

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:

QGraphicsItem *ball = new QGraphicsEllipseItem(0, 0, 20, 20);

QTimeLine *timer = new QTimeLine(5000);
timer->setFrameRange(0, 100);

QGraphicsItemAnimation *animation = new QGraphicsItemAnimation;
animation->setItem(ball);
animation->setTimeLine(timer);

for (int i = 0; i < 200; ++i)
    animation->setPosAt(i / 200.0, QPointF(i, i));

QGraphicsScene *scene = new QGraphicsScene();
scene->setSceneRect(0, 0, 250, 250);
scene->addItem(ball);

QGraphicsView *view = new 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.

class QGraphicsItemAnimation([parent=None])
param parent

QObject

Constructs an animation object with the given parent .

PySide2.QtWidgets.QGraphicsItemAnimation.afterAnimationStep(step)
Parameters

stepqreal

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

stepqreal

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

stepqreal

Return type

qreal

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

See also

setScaleAt()

PySide2.QtWidgets.QGraphicsItemAnimation.horizontalShearAt(step)
Parameters

stepqreal

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

stepqreal

Return type

QMatrix

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

PySide2.QtWidgets.QGraphicsItemAnimation.posAt(step)
Parameters

stepqreal

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()

Note

This function is deprecated.

Resets the item to its starting position and transformation.

You can call setStep (0) instead.

PySide2.QtWidgets.QGraphicsItemAnimation.rotationAt(step)
Parameters

stepqreal

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.

PySide2.QtWidgets.QGraphicsItemAnimation.scaleList()
Return type

Returns all explicitly inserted scales.

PySide2.QtWidgets.QGraphicsItemAnimation.setItem(item)
Parameters

itemQGraphicsItem

Sets the specified item to be used in the animation.

See also

item()

PySide2.QtWidgets.QGraphicsItemAnimation.setPosAt(step, pos)
Parameters
  • stepqreal

  • posQPointF

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
  • stepqreal

  • angleqreal

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
  • stepqreal

  • sxqreal

  • syqreal

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
  • stepqreal

  • shqreal

  • svqreal

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

xqreal

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

PySide2.QtWidgets.QGraphicsItemAnimation.setTimeLine(timeLine)
Parameters

timeLineQTimeLine

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
  • stepqreal

  • dxqreal

  • dyqreal

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

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

stepqreal

Return type

qreal

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

See also

setScaleAt()

PySide2.QtWidgets.QGraphicsItemAnimation.verticalShearAt(step)
Parameters

stepqreal

Return type

qreal

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

See also

setShearAt()

PySide2.QtWidgets.QGraphicsItemAnimation.xTranslationAt(step)
Parameters

stepqreal

Return type

qreal

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

PySide2.QtWidgets.QGraphicsItemAnimation.yTranslationAt(step)
Parameters

stepqreal

Return type

qreal

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