Abstract definition of how QPainter draws to a given device on a given platform. More...

Inherited by QAlphaPaintEngine, QPaintEngineEx, QPdfEngine, QPicturePaintEngine, QPreviewPaintEngine

Public Types
enum	PolygonDrawMode

enum	Type

Public Methods
	QPaintEngine (PaintEngineFeatures options=PaintEngineFeatures ())

virtual	~QPaintEngine ()

virtual bool	begin (QPaintDevice *pdev) = 0

virtual void	drawEllipse (const QRect &rect)

virtual void	drawEllipse (const QRectF &rect)

virtual void	drawImage (const QRectF &rect, const QImage &image, const QRectF &srcRect, Qt::ImageConversionFlags flags=Qt::AutoColor)

virtual void	drawLines (const QLine *lines, int lineCount)

virtual void	drawLines (const QLineF *lines, int lineCount)

virtual void	drawPath (const QPainterPath &path)

virtual void	drawPixmap (const QRectF &rect, const QPixmap &pixmap, const QRectF &srcRect) = 0

virtual void	drawPoints (const QPoint *points, int pointCount)

virtual void	drawPoints (const QPointF *points, int pointCount)

virtual void	drawPolygon (const QPoint *points, int pointCount, PolygonDrawMode mode)

virtual void	drawPolygon (const QPointF *points, int pointCount, PolygonDrawMode mode)

virtual void	drawRects (const QRect *rects, int rectCount)

virtual void	drawRects (const QRectF *rects, int rectCount)

virtual void	drawTextItem (const QPointF &point, const QTextItem &textItem)

virtual void	drawTiledPixmap (const QRectF &rect, const QPixmap &pixmap, const QPointF &point)

virtual bool	end () = 0

bool	hasFeature (PaintEngineFeatures feature) const

bool	isActive () const

QPaintDevice *	paintDevice () const

QPainter *	painter () const

void	setActive (bool state)

virtual Type	type () const = 0

virtual void	updateState (const QPaintEngineState &state) = 0

Friends
class	QPainter

class	QWidget

Detailed Description

The QPaintEngine class provides an abstract definition for how QPainter draws to a given device on a given platform.

CopperSpice provides implementations of QPaintEngine for the different painter backends. There is one paint engine for each window system and painting supported platform. This includes X11 on Unix/Linux and Cocoa on Mac OS X.

QPaintEngine implementations are also provided for OpenGL (accessible through QGLWidget) and PostScript (accessible through QPSPrinter on X11). There is another raster-based paint engine which is a fallback for when an engine does not support a certain capability.

Use the QPainter class to draw to a different backend, subclass QPaintEngine and reimplement all virtual methods. The QPaintEngine class implementation is then made available by subclassing QPaintDevice and reimplementing the virtual function QPaintDevice::paintEngine().

QPaintEngine is created and owned by the QPaintDevice that created it.

See also: QPainter, QPaintDevice::paintEngine(), Paint System

Member Enumeration Documentation

enum QPaintEngine::PolygonDrawMode

Constant	Value	Description
`QPaintEngine::OddEvenMode`	`0`	The polygon should be drawn using OddEven fill rule.
`QPaintEngine::WindingMode`	`1`	The polygon should be drawn using Winding fill rule.
`QPaintEngine::ConvexMode`	`2`	The polygon is a convex polygon and can be drawn using specialized algorithms where available.
`QPaintEngine::PolylineMode`	`3`	Only the outline of the polygon should be drawn.

enum QPaintEngine::Type

Constant	Value	Description
`QPaintEngine::X11`	`0`
`QPaintEngine::Windows`	`1`
`QPaintEngine::MacPrinter`	`4`
`QPaintEngine::CoreGraphics`	`3`	Mac OS X's Quartz2D (CoreGraphics)
`QPaintEngine::QuickDraw`	`2`	Mac OS X's QuickDraw
`QPaintEngine::QWindowSystem`	`5`	For Embedded Linux
`QPaintEngine::PostScript`	`6`	Not supported
`QPaintEngine::OpenGL`	`7`
`QPaintEngine::Picture`	`8`	QPicture format
`QPaintEngine::SVG`	`9`	Scalable Vector Graphics XML format
`QPaintEngine::Raster`	`10`
`QPaintEngine::Direct3D`	`11`	Windows only, Direct3D based engine
`QPaintEngine::Pdf`	`12`	Portable Document Format
`QPaintEngine::OpenVG`	`13`
`QPaintEngine::User`	`50`	First user type ID
`QPaintEngine::MaxUser`	`100`	Last user type ID
`QPaintEngine::OpenGL2`	`14`
`QPaintEngine::PaintBuffer`	`15`
`QPaintEngine::Blitter`	`16`

Constructor & Destructor Documentation

QPaintEngine::QPaintEngine ( PaintEngineFeatures options = PaintEngineFeatures() )

explicit

Creates a paint engine with the feature set specified by options.

QPaintEngine::~QPaintEngine ( )

virtual

Destroys the paint engine.

Method Documentation

bool QPaintEngine::begin ( QPaintDevice * pdev )

pure virtual

Reimplement this method to initialize your paint engine when painting is to start on the paint device pdev. Return true if the initialization was successful, otherwise return false.

See also: end(), isActive()

Implemented in QRasterPaintEngine::begin()

void QPaintEngine::drawEllipse ( const QRect & rect )

virtual

Reimplement this method to draw the largest ellipse that can be contained within rect. The default implementation calls drawPolygon().

void QPaintEngine::drawEllipse ( const QRectF & rect )

virtual

Reimplement this method to draw the largest ellipse that can be contained within rect. The default implementation calls drawPolygon().

Reimplemented in QRasterPaintEngine::drawEllipse()

void QPaintEngine::drawImage	(	const QRectF &	rect,
		const QImage &	image,
		const QRectF &	srcRect,
		Qt::ImageConversionFlags	flags = `Qt::AutoColor`
	)

virtual

Reimplement this method to draw the part of the image specified by srcRect in the given rect using the given conversion flags, to convert it to a pixmap.

Reimplemented in QRasterPaintEngine::drawImage()

void QPaintEngine::drawLines	(	const QLine *	lines,
		int	lineCount
	)

virtual

The default implementation converts the list of lines starting at lines for the given number of lines, specified in lineCount, to a QLineF and calls the floating point version of this method.

Reimplemented in QRasterPaintEngine::drawLines()

void QPaintEngine::drawLines	(	const QLineF *	lines,
		int	lineCount
	)

virtual

The default implementation splits the list of lines starting at lines into lineCount separate calls to drawPath() or drawPolygon() depending on the feature set of the paint engine.

Reimplemented in QRasterPaintEngine::drawLines()

void QPaintEngine::drawPath ( const QPainterPath & path )

virtual

The default implementation ignores the path and does nothing.

void QPaintEngine::drawPixmap	(	const QRectF &	rect,
		const QPixmap &	pixmap,
		const QRectF &	srcRect
	)

pure virtual

Reimplement to draw a portion of the pixmap specified by the rectangle srcRect, in the given rect.

Implemented in QRasterPaintEngine::drawPixmap()

void QPaintEngine::drawPoints	(	const QPoint *	points,
		int	pointCount
	)

virtual

Draws points starting from points for the given number of points specified in pointCount.

Reimplemented in QRasterPaintEngine::drawPoints()

void QPaintEngine::drawPoints	(	const QPointF *	points,
		int	pointCount
	)

virtual

Draws points starting from points for the given number of points specified in pointCount.

Reimplemented in QRasterPaintEngine::drawPoints()

void QPaintEngine::drawPolygon	(	const QPoint *	points,
		int	pointCount,
		PolygonDrawMode	mode
	)

virtual

Draws a polygon defined by points starting at points for the given number of points specified in pointCount. The mode specifies the algorithm used to draw the polygon.

Note: At least one of the drawPolygon() methods must be reimplemented.

Reimplemented in QRasterPaintEngine::drawPolygon()

void QPaintEngine::drawPolygon	(	const QPointF *	points,
		int	pointCount,
		PolygonDrawMode	mode
	)

virtual

Draws a polygon defined by points starting at points for the given number of points specified in pointCount. The mode specifies the algorithm used to draw the polygon.

Note: At least one of the drawPolygon() methods must be reimplemented.

Reimplemented in QRasterPaintEngine::drawPolygon()

void QPaintEngine::drawRects	(	const QRect *	rects,
		int	rectCount
	)

virtual

The default implementation converts rectangles starting from rects for the given number of rectangles specified in rectCount, to QRectF and calls the floating point version of this method.

Reimplemented in QRasterPaintEngine::drawRects()

void QPaintEngine::drawRects	(	const QRectF *	rects,
		int	rectCount
	)

virtual

Draws rectangles starting from rects for the given number of rectangles specified in rectCount. The default implementation of this method calls drawPath() or drawPolygon() depending on the feature set of the paint engine.

Reimplemented in QRasterPaintEngine::drawRects()

void QPaintEngine::drawTextItem	(	const QPointF &	point,
		const QTextItem &	textItem
	)

virtual

Draws the text item textItem at position point. The default implementation of this function converts the text to a QPainterPath and paints the resulting path.

Reimplemented in QRasterPaintEngine::drawTextItem()

void QPaintEngine::drawTiledPixmap	(	const QRectF &	rect,
		const QPixmap &	pixmap,
		const QPointF &	point
	)

virtual

Reimplement this method to draw the pixmap in the given rect, starting at the given point. The pixmap will be drawn repeatedly until the rect is filled.

Reimplemented in QRasterPaintEngine::drawTiledPixmap()

bool QPaintEngine::end ( )

pure virtual

Reimplement this method to finish painting on the current paint device. Returns true if painting was finished successfully, otherwise return false.

See also: begin(), isActive()

Implemented in QRasterPaintEngine::end()

bool QPaintEngine::hasFeature ( PaintEngineFeatures feature ) const

inline

Returns true if the paint engine supports the specified feature, otherwise returns false.

bool QPaintEngine::isActive ( ) const

inline

Returns true if the paint engine is actively drawing, otherwise returns false.

See also: setActive()

QPaintDevice * QPaintEngine::paintDevice ( ) const

Returns the device that this engine is painting on, if painting is active, otherwise returns a nullptr.

QPainter * QPaintEngine::painter ( ) const

Returns the paint engine's painter.

void QPaintEngine::setActive ( bool state )

inline

Sets the active state of the paint engine to state.

See also: isActive()

Type QPaintEngine::type ( ) const

pure virtual

Reimplement this function to return the paint engine Type.

Implemented in QRasterPaintEngine::type()

void QPaintEngine::updateState ( const QPaintEngineState & state )

pure virtual

Reimplement this function to update the state of a paint engine.

When implemented, this function is responsible for checking the paint engine's current state and update the properties that are changed. Use the QPaintEngineState::state() function to find out which properties that must be updated, then use the corresponding get function to retrieve the current values for the given properties.

See also: QPaintEngineState

Public Types

Public Methods

Friends

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Method Documentation