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QPropertyAnimation Class Reference
^{[QtCore module]}

The QPropertyAnimation class animates Qt properties More...

Inherits QVariantAnimation.

Methods

• __init__ (self, QObject parent = None)
• __init__ (self, QObject target, QByteArray propertyName, QObject parent = None)
• bool event (self, QEvent event)
• QByteArray propertyName (self)
• setPropertyName (self, QByteArray propertyName)
• setTargetObject (self, QObject target)
• QObject targetObject (self)
• updateCurrentValue (self, QVariant value)
• updateState (self, QAbstractAnimation.State newState, QAbstractAnimation.State oldState)

QPropertyAnimation interpolates over Qt properties. As property values are stored in QVariants, the class inherits QVariantAnimation, and supports animation of the same variant types as its super class.

A class declaring properties must be a QObject. To make it possible to animate a property, it must provide a setter (so that QPropertyAnimation can set the property's value). Note that this makes it possible to animate many of Qt's widgets. Let's look at an example:

 QPropertyAnimation *animation = new QPropertyAnimation(myWidget, "geometry");
 animation->setDuration(10000);
 animation->setStartValue(QRect(0, 0, 100, 30));
 animation->setEndValue(QRect(250, 250, 100, 30));

 animation->start();

The property name and the QObject instance of which property should be animated are passed to the constructor. You can then specify the start and end value of the property. The procedure is equal for properties in classes you have implemented yourself--just check with QVariantAnimation that your QVariant type is supported.

The QVariantAnimation class description explains how to set up the animation in detail. Note, however, that if a start value is not set, the property will start at the value it had when the QPropertyAnimation instance was created.

QPropertyAnimation works like a charm on its own. For complex animations that, for instance, contain several objects, QAnimationGroup is provided. An animation group is an animation that can contain other animations, and that can manage when its animations are played. Look at QParallelAnimationGroup for an example.

Method Documentation

QPropertyAnimation.__init__ (self, QObject parent = None)

The parent argument, if not None, causes self to be owned by Qt instead of PyQt.

Construct a QPropertyAnimation object. parent is passed to QObject's constructor.

QPropertyAnimation.__init__ (self, QObject target, QByteArray propertyName, QObject parent = None)

The parent argument, if not None, causes self to be owned by Qt instead of PyQt.

Construct a QPropertyAnimation object. parent is passed to QObject's constructor. The animation changes the property propertyName on target. The default duration is 250ms.

See also targetObject and propertyName.

bool QPropertyAnimation.event (self, QEvent event)

Reimplemented from QObject.event().

QByteArray QPropertyAnimation.propertyName (self)

QPropertyAnimation.setPropertyName (self, QByteArray propertyName)

QPropertyAnimation.setTargetObject (self, QObject target)

QObject QPropertyAnimation.targetObject (self)

QPropertyAnimation.updateCurrentValue (self, QVariant value)

Reimplemented from QVariantAnimation.updateCurrentValue().

This virtual function is called by QVariantAnimation whenever the current value changes. value is the new, updated value. It updates the current value of the property on the target object.

See also currentValue and currentTime.

QPropertyAnimation.updateState (self, QAbstractAnimation.State newState, QAbstractAnimation.State oldState)

Reimplemented from QAbstractAnimation.updateState().

If the startValue is not defined when the state of the animation changes from Stopped to Running, the current property value is used as the initial value for the animation.