The QSGOpacityNode class is used to change opacity of nodes. More...

#include <qsgnode.h>

Inheritance diagram for QSGOpacityNode:

Collaboration diagram for QSGOpacityNode:

Public Member Functions
	QSGOpacityNode ()
	Constructs an opacity node with a default opacity of 1.

	~QSGOpacityNode () override
	Deletes the opacity node.

void	setOpacity (qreal opacity)
	Sets the opacity of this node to opacity.

qreal	opacity () const
	Returns this opacity node's opacity.

void	setCombinedOpacity (qreal opacity)
	Sets the combined opacity of this node to opacity.

qreal	combinedOpacity () const
	Returns this node's accumulated opacity.

bool	isSubtreeBlocked () const override
	For performance reasons, we block the subtree when the opacity is below a certain threshold.

Public Member Functions inherited from QSGNode
	QSGNode ()
	Constructs a new node.

virtual	~QSGNode ()
	Destroys the node.

QSGNode *	parent () const
	Returns the parent node of this node.

void	removeChildNode (QSGNode *node)
	Removes node from this node's list of children.

void	removeAllChildNodes ()
	Removes all child nodes from this node's list of children.

void	prependChildNode (QSGNode *node)
	Prepends node to this node's the list of children.

void	appendChildNode (QSGNode *node)
	Appends node to this node's list of children.

void	insertChildNodeBefore (QSGNode node, QSGNode before)
	Inserts node to this node's list of children before the node specified with before.

void	insertChildNodeAfter (QSGNode node, QSGNode after)
	Inserts node to this node's list of children after the node specified with after.

void	reparentChildNodesTo (QSGNode *newParent)

int	childCount () const
	Returns the number of child nodes.

QSGNode *	childAtIndex (int i) const
	Returns the child at index i.

QSGNode *	firstChild () const
	Returns the first child of this node.

QSGNode *	lastChild () const
	Returns the last child of this node.

QSGNode *	nextSibling () const
	Returns the node after this in the parent's list of children.

QSGNode *	previousSibling () const
	Returns the node before this in the parent's list of children.

NodeType	type () const
	Returns the type of this node.

QT_DEPRECATED void	clearDirty ()

void	markDirty (DirtyState bits)
	Notifies all connected renderers that the node has dirty bits.

QT_DEPRECATED DirtyState	dirtyState () const

Flags	flags () const
	Returns the set of flags for this node.

void	setFlag (Flag, bool=true)
	Sets the flag f on this node if enabled is true; otherwise clears the flag.

void	setFlags (Flags, bool=true)
	Sets the flags f on this node if enabled is true; otherwise clears the flags.

virtual void	preprocess ()
	Override this function to do processing on the node before it is rendered.

Additional Inherited Members
Public Types inherited from QSGNode
enum	NodeType { BasicNodeType , GeometryNodeType , TransformNodeType , ClipNodeType , OpacityNodeType , RootNodeType , RenderNodeType }
	Can be used to figure out the type of node. More...

enum	Flag { OwnedByParent = 0x0001 , UsePreprocess = 0x0002 , OwnsGeometry = 0x00010000 , OwnsMaterial = 0x00020000 , OwnsOpaqueMaterial = 0x00040000 , IsVisitableNode = 0x01000000 }
	The QSGNode::Flag enum describes flags on the QSGNode. More...

enum	DirtyStateBit { DirtySubtreeBlocked = 0x0080 , DirtyMatrix = 0x0100 , DirtyNodeAdded = 0x0400 , DirtyNodeRemoved = 0x0800 , DirtyGeometry = 0x1000 , DirtyMaterial = 0x2000 , DirtyOpacity = 0x4000 , DirtyForceUpdate = 0x8000 , DirtyUsePreprocess = UsePreprocess , DirtyPropagationMask }
	Used in QSGNode::markDirty() to indicate how the scene graph has changed. More...

Protected Member Functions inherited from QSGNode
	QSGNode (NodeType type)
	Constructs a new node with the given node type.

	QSGNode (QSGNodePrivate &dd, NodeType type)
	Constructs a new node with the given node type.

Protected Attributes inherited from QSGNode
QScopedPointer< QSGNodePrivate >	d_ptr

Detailed Description

The QSGOpacityNode class is used to change opacity of nodes.

\inmodule QtQuick

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.

Note: All classes with QSG prefix should be used solely on the scene graph's rendering thread. See \l {Scene Graph and Rendering} for more information.

Definition at line 275 of file qsgnode.h.

Constructor & Destructor Documentation

◆ QSGOpacityNode()

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.

Definition at line 1278 of file qsgnode.cpp.

◆ ~QSGOpacityNode()

QSGOpacityNode::~QSGOpacityNode ( )

override

Deletes the opacity node.

Definition at line 1289 of file qsgnode.cpp.

Member Function Documentation

◆ combinedOpacity()

qreal QSGOpacityNode::combinedOpacity ( ) const

inline

Returns this node's accumulated opacity.

This value is calculated during rendering and only stored in the opacity node temporarily.

Definition at line 285 of file qsgnode.h.

◆ isSubtreeBlocked()

bool QSGOpacityNode::isSubtreeBlocked ( ) const

overridevirtual

For performance reasons, we block the subtree when the opacity is below a certain threshold.

Reimplemented from QSGNode.

Definition at line 1366 of file qsgnode.cpp.

References OPACITY_THRESHOLD.

◆ opacity()

qreal QSGOpacityNode::opacity ( ) const

inline

Returns this opacity node's opacity.

Definition at line 282 of file qsgnode.h.

Referenced by setCombinedOpacity(), setOpacity(), QSGOpenVGNodeVisitor::visit(), QSGSoftwareRenderableNodeUpdater::visit(), and QSGBatchRenderer::Updater::visitOpacityNode().

Here is the caller graph for this function:

◆ setCombinedOpacity()

void QSGOpacityNode::setCombinedOpacity ( qreal opacity )

Sets the combined opacity of this node to opacity.

This function is meant to be called by the node preprocessing prior to rendering the tree, so it will not mark the tree as dirty.

Definition at line 1352 of file qsgnode.cpp.

References opacity().

Referenced by QSGBatchRenderer::Updater::visitOpacityNode().

Here is the call graph for this function:

Here is the caller graph for this function:

◆ 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.

Definition at line 1312 of file qsgnode.cpp.

References QSGNode::DirtyOpacity, QSGNode::dirtyState(), QSGNode::DirtySubtreeBlocked, QSGNode::markDirty(), opacity(), and OPACITY_THRESHOLD.

Referenced by QQuickMaterialRippleBackgroundNode::QQuickMaterialRippleBackgroundNode(), QQuickOpacityAnimatorJob::updateCurrentTime(), QQuickMaterialRippleWaveNode::updateCurrentTime(), QQuickMaterialRippleBackgroundNode::updateCurrentTime(), QQuickUniversalBusyIndicatorNode::updateCurrentTime(), and QQuickUniversalProgressBarNode::updateCurrentTime().

Here is the call graph for this function:

Here is the caller graph for this function:

The documentation for this class was generated from the following files:

qtdeclarative/src/quick/scenegraph/coreapi/qsgnode.h (5cdd7fa66203808e3adcf48386fa0aea0d525889)
qtdeclarative/src/quick/scenegraph/coreapi/qsgnode.cpp (0ba9ff8b0552fe0928770b5b4cd5f43d3aa3445c)

Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QSGOpacityNode()

◆ ~QSGOpacityNode()

Member Function Documentation

◆ combinedOpacity()

◆ isSubtreeBlocked()

◆ opacity()

◆ setCombinedOpacity()

◆ setOpacity()