QSGOpacityNode Class

QSGOpacityNode class is used to change opacity of nodes. 更多...

Header: #include <QSGOpacityNode>
qmake: QT += quick
继承: QSGNode


QSGOpacityNode ()
virtual ~QSGOpacityNode () override
qreal opacity () const
void setOpacity (qreal opacity )


QSGOpacityNode class is used to change opacity of nodes.

Opacity applies to its subtree and can be nested. Multiple opacity nodes will be accumulated by multiplying their opacity. The accumulation happens as part of the rendering.

When nested opacity gets below a certain threshold, the subtree might be marked as blocked, causing isSubtreeBlocked () to return true. This is done for performance reasons.

注意: All classes with QSG prefix should be used solely on the scene graph's rendering thread. See 场景图形和渲染 了解更多信息。


QSGOpacityNode:: QSGOpacityNode ()

Constructs an opacity node with a default opacity of 1.

Opacity accumulates downwards in the scene graph so a node with two QSGOpacityNode instances above it, both with opacity of 0.5, will have effective opacity of 0.25.

The default opacity of nodes is 1.

[override virtual] QSGOpacityNode:: ~QSGOpacityNode ()

Deletes the opacity node.

qreal QSGOpacityNode:: opacity () const

Returns this opacity node's opacity.

另请参阅 setOpacity ().

void QSGOpacityNode:: setOpacity ( qreal opacity )

Sets the opacity of this node to opacity .

Before rendering the graph, the renderer will do an update pass over the subtree to propagate the opacity to its children.

The value will be bounded to the range 0 to 1.

另请参阅 opacity ().