QGraphicsItemAnimation Class

The QGraphicsItemAnimation class provides simple animation support for QGraphicsItem . 更多...

头: #include <QGraphicsItemAnimation>
CMake: find_package(Qt6 REQUIRED COMPONENTS Widgets)
target_link_libraries(mytarget PRIVATE Qt6::Widgets)
qmake: QT += widgets
继承: QObject
状态: Deprecated

This class is deprecated. We strongly advise against using it in new code.

公共函数

QGraphicsItemAnimation (QObject * parent = nullptr)
virtual ~QGraphicsItemAnimation ()
void clear ()
qreal horizontalScaleAt (qreal step ) const
qreal horizontalShearAt (qreal step ) const
QGraphicsItem * item () const
QPointF posAt (qreal step ) const
QList<QPair<qreal, QPointF>> posList () const
qreal rotationAt (qreal step ) const
QList<QPair<qreal, qreal>> rotationList () const
QList<QPair<qreal, QPointF>> scaleList () const
void setItem (QGraphicsItem * item )
void setPosAt (qreal step , const QPointF & point )
void setRotationAt (qreal step , qreal angle )
void setScaleAt (qreal step , qreal sx , qreal sy )
void setShearAt (qreal step , qreal sh , qreal sv )
void setTimeLine (QTimeLine * timeLine )
void setTranslationAt (qreal step , qreal dx , qreal dy )
QList<QPair<qreal, QPointF>> shearList () const
QTimeLine * timeLine () const
QTransform transformAt (qreal step ) const
QList<QPair<qreal, QPointF>> translationList () const
qreal verticalScaleAt (qreal step ) const
qreal verticalShearAt (qreal step ) const
qreal xTranslationAt (qreal step ) const
qreal yTranslationAt (qreal step ) const

公共槽

void setStep (qreal step )

保护函数

virtual void afterAnimationStep (qreal step )
virtual void beforeAnimationStep (qreal step )

详细描述

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() 函数。

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 () 函数。

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.

另请参阅 QTimeLine and 图形视图框架 .

成员函数文档编制

QGraphicsItemAnimation:: QGraphicsItemAnimation ( QObject * parent = nullptr)

Constructs an animation object with the given parent .

[virtual noexcept] QGraphicsItemAnimation:: ~QGraphicsItemAnimation ()

Destroys the animation object.

[virtual protected] void QGraphicsItemAnimation:: afterAnimationStep ( qreal step )

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.

[virtual protected] void QGraphicsItemAnimation:: beforeAnimationStep ( qreal step )

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.

void QGraphicsItemAnimation:: clear ()

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

qreal QGraphicsItemAnimation:: horizontalScaleAt ( qreal step ) const

Returns the horizontal scale for the item at the specified step 值。

另请参阅 setScaleAt ().

qreal QGraphicsItemAnimation:: horizontalShearAt ( qreal step ) const

Returns the horizontal shear for the item at the specified step 值。

另请参阅 setShearAt ().

QGraphicsItem *QGraphicsItemAnimation:: item () const

Returns the item on which the animation object operates.

另请参阅 setItem ().

QPointF QGraphicsItemAnimation:: posAt ( qreal step ) const

Returns the position of the item at the given step 值。

另请参阅 setPosAt ().

QList < QPair < qreal , QPointF >> QGraphicsItemAnimation:: posList () const

Returns all explicitly inserted positions.

另请参阅 posAt () 和 setPosAt ().

qreal QGraphicsItemAnimation:: rotationAt ( qreal step ) const

Returns the angle at which the item is rotated at the specified step 值。

另请参阅 setRotationAt ().

QList < QPair < qreal , qreal >> QGraphicsItemAnimation:: rotationList () const

Returns all explicitly inserted rotations.

另请参阅 rotationAt () 和 setRotationAt ().

QList < QPair < qreal , QPointF >> QGraphicsItemAnimation:: scaleList () const

Returns all explicitly inserted scales.

另请参阅 verticalScaleAt (), horizontalScaleAt (),和 setScaleAt ().

void QGraphicsItemAnimation:: setItem ( QGraphicsItem * item )

设置指定 item to be used in the animation.

另请参阅 item ().

void QGraphicsItemAnimation:: setPosAt ( qreal step , const QPointF & point )

Sets the position of the item at the given step value to the point 指定。

另请参阅 posAt ().

void QGraphicsItemAnimation:: setRotationAt ( qreal step , qreal angle )

Sets the rotation of the item at the given step value to the angle 指定。

另请参阅 rotationAt ().

void QGraphicsItemAnimation:: setScaleAt ( qreal step , qreal sx , qreal sy )

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

另请参阅 verticalScaleAt () 和 horizontalScaleAt ().

void QGraphicsItemAnimation:: setShearAt ( qreal step , qreal sh , qreal sv )

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

另请参阅 verticalShearAt () 和 horizontalShearAt ().

[slot] void QGraphicsItemAnimation:: setStep ( qreal step )

设置当前 step value for the animation, causing the transformations scheduled at this step to be performed.

void QGraphicsItemAnimation:: setTimeLine ( QTimeLine * timeLine )

Sets the timeline object used to control the rate of animation to the timeLine 指定。

另请参阅 timeLine ().

void QGraphicsItemAnimation:: setTranslationAt ( qreal step , qreal dx , qreal dy )

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

另请参阅 xTranslationAt () 和 yTranslationAt ().

QList < QPair < qreal , QPointF >> QGraphicsItemAnimation:: shearList () const

Returns all explicitly inserted shears.

另请参阅 verticalShearAt (), horizontalShearAt (),和 setShearAt ().

QTimeLine *QGraphicsItemAnimation:: timeLine () const

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

另请参阅 setTimeLine ().

QTransform QGraphicsItemAnimation:: transformAt ( qreal step ) const

Returns the transform used for the item at the specified step 值。

QList < QPair < qreal , QPointF >> QGraphicsItemAnimation:: translationList () const

Returns all explicitly inserted translations.

另请参阅 xTranslationAt (), yTranslationAt (),和 setTranslationAt ().

qreal QGraphicsItemAnimation:: verticalScaleAt ( qreal step ) const

Returns the vertical scale for the item at the specified step 值。

另请参阅 setScaleAt ().

qreal QGraphicsItemAnimation:: verticalShearAt ( qreal step ) const

Returns the vertical shear for the item at the specified step 值。

另请参阅 setShearAt ().

qreal QGraphicsItemAnimation:: xTranslationAt ( qreal step ) const

Returns the horizontal translation of the item at the specified step 值。

另请参阅 setTranslationAt ().

qreal QGraphicsItemAnimation:: yTranslationAt ( qreal step ) const

Returns the vertical translation of the item at the specified step 值。

另请参阅 setTranslationAt ().