QBackingStore 类

QBackingStore class provides a drawing area for QWindow . 更多...

头：	#include <QBackingStore>
qmake:	QT += gui
Since:	Qt 5.0

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公共函数

	QBackingStore (QWindow * window )
	~QBackingStore ()
void	beginPaint (const QRegion & region )
void	endPaint ()
void	flush (const QRegion & region , QWindow * win = Q_NULLPTR, const QPoint & offset = QPoint())
QPlatformBackingStore *	handle () const
bool	hasStaticContents () const
QPaintDevice *	paintDevice ()
void	resize (const QSize & size )
bool	scroll (const QRegion & area , int dx , int dy )
void	setStaticContents (const QRegion & region )
QSize	size () const
QRegion	staticContents () const
QWindow *	window () const

详细描述

QBackingStore class provides a drawing area for QWindow .

QBackingStore enables the use of QPainter 进行描绘在 QWindow with type RasterSurface. The other way of rendering to a QWindow is through the use of OpenGL with QOpenGLContext .

A QBackingStore contains a buffered representation of the window contents, and thus supports partial updates by using QPainter to only update a sub region of the window contents.

QBackingStore might be used by an application that wants to use QPainter without OpenGL acceleration and without the extra overhead of using the QWidget or QGraphicsView UI stacks. For an example of how to use QBackingStore see the 光栅窗口范例 .

成员函数文档编制

QBackingStore:: QBackingStore ( QWindow * window )

构造空表面为给定顶层 window .

QBackingStore:: ~QBackingStore ()

销毁此表面。

void QBackingStore:: beginPaint (const QRegion & region )

This function is called before painting onto the surface begins, with the region in which the painting will occur.

另请参阅 endPaint () 和 paintDevice ().

void QBackingStore:: endPaint ()

This function is called after painting onto the surface has ended.

另请参阅 beginPaint () 和 paintDevice ().

void QBackingStore:: flush (const QRegion & region , QWindow * win = Q_NULLPTR, const QPoint & offset = QPoint())

Flushes the given region from the specified window win onto the screen.

注意， offset parameter is currently unused.

QPlatformBackingStore *QBackingStore:: handle () const

Returns a pointer to the QPlatformBackingStore implementation

bool QBackingStore:: hasStaticContents () const

Returns a boolean indicating if this window has static contents or not.

QPaintDevice *QBackingStore:: paintDevice ()

Implement this function to return the appropriate paint device.

void QBackingStore:: resize (const QSize & size )

Sets the size of the windowsurface to be size .

另请参阅 size ().

bool QBackingStore:: scroll (const QRegion & area , int dx , int dy )

卷动给定 area dx 像素到右侧和 dy 向下；两者 dx and dy 可能为负值。

返回 true 如果卷动区域成功；否则 false。

void QBackingStore:: setStaticContents (const QRegion & region )

Set region 作为此窗口的静态内容。

另请参阅 staticContents ().

QSize QBackingStore:: size () const

Returns the current size of the windowsurface.

QRegion QBackingStore:: staticContents () const

返回指针指向 QRegion that has the static contents of this window.

另请参阅 setStaticContents ().

QWindow *QBackingStore:: window () const

返回关联此表面的顶层窗口指针。