QwtNullPaintDevice man page

QwtNullPaintDevice —

A null paint device doing nothing.

Synopsis

#include <qwt_null_paintdevice.h>

Inherits QPaintDevice.

Inherited by QwtGraphic, and QwtStyleSheetRecorder.

Public Types

enum Mode { NormalMode, PolygonPathMode, PathMode }
Render mode.

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 (PaintDeviceMetricdeviceMetric) 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 (Modemode)

Set the render mode

Parameters:

mode New mode

See Also:

mode()

virtual QSize QwtNullPaintDevice::sizeMetrics () const [protected], [pure virtual]

Returns:

Size needed to implement metric()

Implemented in QwtGraphic.

Author

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Info

Thu Dec 11 2014 Version 6.1.2 Qwt User's Guide