QwtNullPaintDevice Class Reference

A null paint device doing nothing. More...

#include <qwt_null_paintdevice.h>

Inheritance diagram for QwtNullPaintDevice:

Public Types
enum	Mode { NormalMode, PolygonPathMode, PathMode }
	Render mode. More...

Public Member Functions
	QwtNullPaintDevice ()
	Constructor.
virtual	~QwtNullPaintDevice ()
	Destructor.
void	setMode (Mode)
Mode	mode () const
virtual QPaintEngine *	paintEngine () const
	See QPaintDevice::paintEngine()
virtual int	metric (PaintDeviceMetric metric) const
virtual void	drawRects (const QRect *, int)
	See QPaintEngine::drawRects()
virtual void	drawRects (const QRectF *, int)
	See QPaintEngine::drawRects()
virtual void	drawLines (const QLine *, int)
	See QPaintEngine::drawLines()
virtual void	drawLines (const QLineF *, int)
	See QPaintEngine::drawLines()
virtual void	drawEllipse (const QRectF &)
	See QPaintEngine::drawEllipse()
virtual void	drawEllipse (const QRect &)
	See QPaintEngine::drawEllipse()
virtual void	drawPath (const QPainterPath &)
	See QPaintEngine::drawPath()
virtual void	drawPoints (const QPointF *, int)
	See QPaintEngine::drawPoints()
virtual void	drawPoints (const QPoint *, int)
	See QPaintEngine::drawPoints()
virtual void	drawPolygon (const QPointF *, int, QPaintEngine::PolygonDrawMode)
	See QPaintEngine::drawPolygon()
virtual void	drawPolygon (const QPoint *, int, QPaintEngine::PolygonDrawMode)
	See QPaintEngine::drawPolygon()
virtual void	drawPixmap (const QRectF &, const QPixmap &, const QRectF &)
	See QPaintEngine::drawPixmap()
virtual void	drawTextItem (const QPointF &, const QTextItem &)
	See QPaintEngine::drawTextItem()
virtual void	drawTiledPixmap (const QRectF &, const QPixmap &, const QPointF &s)
	See QPaintEngine::drawTiledPixmap()
virtual void	drawImage (const QRectF &, const QImage &, const QRectF &, Qt::ImageConversionFlags)
	See QPaintEngine::drawImage()
virtual void	updateState (const QPaintEngineState &state)
	See QPaintEngine::updateState()

Protected Member Functions
virtual QSize	sizeMetrics () const =0

Detailed Description

A null paint device doing nothing.

Sometimes important layout/rendering geometries are not available or changeable from the public Qt class interface. ( f.e hidden in the style implementation ).

QwtNullPaintDevice can be used to manipulate or filter out this information by analyzing the stream of paint primitives.

F.e. QwtNullPaintDevice is used by QwtPlotCanvas to identify styled backgrounds with rounded corners.

Member Enumeration Documentation

enum QwtNullPaintDevice::Mode

Render mode.

See Also

setMode(), mode()

Enumerator
NormalMode	All vector graphic primitives are painted by the corresponding draw methods
PolygonPathMode	Vector graphic primitives ( beside polygons ) are mapped to a QPainterPath and are painted by drawPath. In PathMode mode only a few draw methods are called: drawPath() drawPixmap() drawImage() drawPolygon()
PathMode	Vector graphic primitives are mapped to a QPainterPath and are painted by drawPath. In PathMode mode only a few draw methods are called: drawPath() drawPixmap() drawImage()

Member Function Documentation

int QwtNullPaintDevice::metric ( PaintDeviceMetric  deviceMetric ) const

virtual

See QPaintDevice::metric()

Parameters

deviceMetric

Type of metric

Returns

Metric information for the given paint device metric.

See Also

sizeMetrics()

QwtNullPaintDevice::Mode QwtNullPaintDevice::mode

(

)

const

Returns

Render mode

See Also

setMode()

void QwtNullPaintDevice::setMode

(

Mode

mode

)

Set the render mode

Parameters

mode

New mode

See Also

mode()

virtual QSize QwtNullPaintDevice::sizeMetrics ( ) const

protectedpure virtual

Returns

Size needed to implement metric()

Implemented in QwtGraphic.