QAnimationGroup Class

The QAnimationGroup class is an abstract base class for groups of animations. More...

Header: #include <QAnimationGroup>
qmake: QT += core
Since: Qt 4.6
Inherits: QAbstractAnimation
Inherited By:

QParallelAnimationGroup and QSequentialAnimationGroup

This class was introduced in Qt 4.6.

Public Functions

QAnimationGroup(QObject *parent = nullptr)
virtual ~QAnimationGroup()
void addAnimation(QAbstractAnimation *animation)
QAbstractAnimation *animationAt(int index) const
int animationCount() const
void clear()
int indexOfAnimation(QAbstractAnimation *animation) const
void insertAnimation(int index, QAbstractAnimation *animation)
void removeAnimation(QAbstractAnimation *animation)
QAbstractAnimation *takeAnimation(int index)

Reimplemented Protected Functions

virtual bool event(QEvent *event) override

Detailed Description

An animation group is a container for animations (subclasses of QAbstractAnimation). A group is usually responsible for managing the state of its animations, i.e., it decides when to start, stop, resume, and pause them. Currently, Qt provides two such groups: QParallelAnimationGroup and QSequentialAnimationGroup. Look up their class descriptions for details.

Since QAnimationGroup inherits from QAbstractAnimation, you can combine groups, and easily construct complex animation graphs. You can query QAbstractAnimation for the group it belongs to (using the group() function).

To start a top-level animation group, you simply use the start() function from QAbstractAnimation. By a top-level animation group, we think of a group that itself is not contained within another group. Starting sub groups directly is not supported, and may lead to unexpected behavior.

QAnimationGroup provides methods for adding and retrieving animations. Besides that, you can remove animations by calling removeAnimation(), and clear the animation group by calling clear(). You may keep track of changes in the group's animations by listening to QEvent::ChildAdded and QEvent::ChildRemoved events.

QAnimationGroup takes ownership of the animations it manages, and ensures that they are deleted when the animation group is deleted.

See also QAbstractAnimation, QVariantAnimation, and The Animation Framework.

Member Function Documentation

QAnimationGroup::QAnimationGroup(QObject *parent = nullptr)

Constructs a QAnimationGroup. parent is passed to QObject's constructor.

[virtual] QAnimationGroup::~QAnimationGroup()

Destroys the animation group. It will also destroy all its animations.

void QAnimationGroup::addAnimation(QAbstractAnimation *animation)

Adds animation to this group. This will call insertAnimation with index equals to animationCount().

Note: The group takes ownership of the animation.

See also removeAnimation().

QAbstractAnimation *QAnimationGroup::animationAt(int index) const

Returns a pointer to the animation at index in this group. This function is useful when you need access to a particular animation. index is between 0 and animationCount() - 1.

See also animationCount() and indexOfAnimation().

int QAnimationGroup::animationCount() const

Returns the number of animations managed by this group.

See also indexOfAnimation(), addAnimation(), and animationAt().

void QAnimationGroup::clear()

Removes and deletes all animations in this animation group, and resets the current time to 0.

See also addAnimation() and removeAnimation().

[override virtual protected] bool QAnimationGroup::event(QEvent *event)

Reimplements: QAbstractAnimation::event(QEvent *event).

int QAnimationGroup::indexOfAnimation(QAbstractAnimation *animation) const

Returns the index of animation. The returned index can be passed to the other functions that take an index as an argument.

See also insertAnimation(), animationAt(), and takeAnimation().

void QAnimationGroup::insertAnimation(int index, QAbstractAnimation *animation)

Inserts animation into this animation group at index. If index is 0 the animation is inserted at the beginning. If index is animationCount(), the animation is inserted at the end.

Note: The group takes ownership of the animation.

See also takeAnimation(), addAnimation(), indexOfAnimation(), and removeAnimation().

void QAnimationGroup::removeAnimation(QAbstractAnimation *animation)

Removes animation from this group. The ownership of animation is transferred to the caller.

See also takeAnimation(), insertAnimation(), and addAnimation().

QAbstractAnimation *QAnimationGroup::takeAnimation(int index)

Returns the animation at index and removes it from the animation group.

Note: The ownership of the animation is transferred to the caller.

See also removeAnimation(), addAnimation(), insertAnimation(), and indexOfAnimation().