QPaintEngine¶

Inheritance diagram of QPaintEngine

Synopsis¶

Functions¶

def autoDestruct ()
def clearDirty (df)
def hasFeature (feature)
def isActive ()
def isExtended ()
def paintDevice ()
def painter ()
def setActive (newState)
def setAutoDestruct (autoDestr)
def setDirty (df)
def setSystemClip (baseClip)
def setSystemRect (rect)
def syncState ()
def systemClip ()
def systemRect ()
def testDirty (df)

Virtual functions¶

def begin (pdev)
def coordinateOffset ()
def drawEllipse (r)
def drawEllipse (r)
def drawImage (r, pm, sr[, flags=Qt.AutoColor])
def drawLines (lines, lineCount)
def drawLines (lines, lineCount)
def drawPath (path)
def drawPixmap (r, pm, sr)
def drawPoints (points, pointCount)
def drawPoints (points, pointCount)
def drawPolygon (points, pointCount, mode)
def drawPolygon (points, pointCount, mode)
def drawRects (rects, rectCount)
def drawRects (rects, rectCount)
def drawTextItem (p, textItem)
def drawTiledPixmap (r, pixmap, s)
def end ()
def type ()
def updateState (state)

Detailed Description¶

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

Qt 4.0 provides several premade implementations of PySide.QtGui.QPaintEngine for the different painter backends we support. We provide one paint engine for each window system and painting framework we support. This includes X11 on Unix/Linux and CoreGraphics on Mac OS X. In addition we provide PySide.QtGui.QPaintEngine implementations for OpenGL (accessible through PySide.QtOpenGL.QGLWidget ) and PostScript (accessible through QPSPrinter on X11). Additionally there is a raster-based paint engine that is a fallback for when an engine does not support a certain capability.

If one wants to use PySide.QtGui.QPainter to draw to a different backend, one must subclass PySide.QtGui.QPaintEngine and reimplement all its virtual functions. The PySide.QtGui.QPaintEngine implementation is then made available by subclassing PySide.QtGui.QPaintDevice and reimplementing the virtual function QPaintDevice.paintEngine() .

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

The big advantage of the PySide.QtGui.QPaintEngine approach opposed to Qt 3’s PySide.QtGui.QPainter /QPaintDevice::cmd() approach is that it is now possible to adapt to multiple technologies on each platform and take advantage of each to the fullest.

See also

PySide.QtGui.QPainter QPaintDevice.paintEngine() Paint System

class PySide.QtGui.QPaintEngine([features=0])¶

Parameters:	features – `PySide.QtGui.QPaintEngine.PaintEngineFeatures`

PySide.QtGui.QPaintEngine.PolygonDrawMode¶

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

PySide.QtGui.QPaintEngine.Type¶

Constant	Description
QPaintEngine.X11
QPaintEngine.Windows
QPaintEngine.MacPrinter
QPaintEngine.CoreGraphics	Mac OS X’s Quartz2D ( `CoreGraphics` )
QPaintEngine.QuickDraw	Mac OS X’s `QuickDraw`
QPaintEngine.QWindowSystem	Qt for Embedded Linux
QPaintEngine.PostScript
QPaintEngine.OpenGL
QPaintEngine.Picture	`PySide.QtGui.QPicture` format
QPaintEngine.SVG	Scalable Vector Graphics XML format
QPaintEngine.Raster
QPaintEngine.Direct3D	Windows only, `Direct3D` based engine
QPaintEngine.Pdf	Portable Document Format
QPaintEngine.OpenVG
QPaintEngine.User	First user type ID
QPaintEngine.MaxUser	Last user type ID
QPaintEngine.OpenGL2
QPaintEngine.PaintBuffer

PySide.QtGui.QPaintEngine.PaintEngineFeature¶

This enum is used to describe the features or capabilities that the paint engine has. If a feature is not supported by the engine, PySide.QtGui.QPainter will do a best effort to emulate that feature through other means and pass on an alpha blended PySide.QtGui.QImage to the engine with the emulated results. Some features cannot be emulated: AlphaBlend and PorterDuff .

Constant	Description
QPaintEngine.AlphaBlend	The engine can alpha blend primitives.
QPaintEngine.Antialiasing	The engine can use antialising to improve the appearance of rendered primitives.
QPaintEngine.BlendModes	The engine supports blending modes.
QPaintEngine.BrushStroke	The engine supports drawing strokes that contain brushes as fills, not just solid colors (e.g. a dashed gradient line of width 2).
QPaintEngine.ConicalGradientFill	The engine supports conical gradient fills.
QPaintEngine.ConstantOpacity	The engine supports the feature provided by `QPainter.setOpacity()` .
QPaintEngine.LinearGradientFill	The engine supports linear gradient fills.
QPaintEngine.MaskedBrush	The engine is capable of rendering brushes that has a texture with an alpha channel or a mask.
QPaintEngine.ObjectBoundingModeGradients	The engine has native support for gradients with coordinate mode `QGradient.ObjectBoundingMode` . Otherwise, if `QPaintEngine.PatternTransform` is supported, object bounding mode gradients are converted to gradients with coordinate mode `QGradient.LogicalMode` and a brush transform for the coordinate mapping.
QPaintEngine.PainterPaths	The engine has path support.
QPaintEngine.PaintOutsidePaintEvent	The engine is capable of painting outside of paint events.
QPaintEngine.PatternBrush	The engine is capable of rendering brushes with the brush patterns specified in `Qt.BrushStyle` .
QPaintEngine.PatternTransform	The engine has support for transforming brush patterns.
QPaintEngine.PerspectiveTransform	The engine has support for performing perspective transformations on primitives.
QPaintEngine.PixmapTransform	The engine can transform pixmaps, including rotation and shearing.
QPaintEngine.PorterDuff	The engine supports Porter-Duff operations
QPaintEngine.PrimitiveTransform	The engine has support for transforming drawing primitives.
QPaintEngine.RadialGradientFill	The engine supports radial gradient fills.
QPaintEngine.RasterOpModes	The engine supports bitwise raster operations.
QPaintEngine.AllFeatures	All of the above features. This enum value is usually used as a bit mask.

PySide.QtGui.QPaintEngine.DirtyFlag¶

Constant	Description
QPaintEngine.DirtyPen	The pen is dirty and needs to be updated.
QPaintEngine.DirtyBrush	The brush is dirty and needs to be updated.
QPaintEngine.DirtyBrushOrigin	The brush origin is dirty and needs to updated.
QPaintEngine.DirtyFont	The font is dirty and needs to be updated.
QPaintEngine.DirtyBackground	The background is dirty and needs to be updated.
QPaintEngine.DirtyBackgroundMode	The background mode is dirty and needs to be updated.
QPaintEngine.DirtyTransform	The transform is dirty and needs to be updated.
QPaintEngine.DirtyClipRegion	The clip region is dirty and needs to be updated.
QPaintEngine.DirtyClipPath	The clip path is dirty and needs to be updated.
QPaintEngine.DirtyHints	The render hints is dirty and needs to be updated.
QPaintEngine.DirtyCompositionMode	The composition mode is dirty and needs to be updated.
QPaintEngine.DirtyClipEnabled	Whether clipping is enabled or not is dirty and needs to be updated.
QPaintEngine.DirtyOpacity	The constant opacity has changed and needs to be updated as part of the state change in `QPaintEngine.updateState()` .
QPaintEngine.AllDirty	Convenience enum used internally.

These types are used by PySide.QtGui.QPainter to trigger lazy updates of the various states in the PySide.QtGui.QPaintEngine using QPaintEngine.updateState() .

A paint engine must update every dirty state.

PySide.QtGui.QPaintEngine.extended¶

PySide.QtGui.QPaintEngine.selfDestruct¶

PySide.QtGui.QPaintEngine.active¶

PySide.QtGui.QPaintEngine.state¶

PySide.QtGui.QPaintEngine.gccaps¶

PySide.QtGui.QPaintEngine.autoDestruct()¶

Return type:	`PySide.QtCore.bool`

PySide.QtGui.QPaintEngine.begin(pdev)¶

Parameters:	pdev – `PySide.QtGui.QPaintDevice`
Return type:	`PySide.QtCore.bool`

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

PySide.QtGui.QPaintEngine.clearDirty(df)¶

Parameters:	df – `PySide.QtGui.QPaintEngine.DirtyFlags`

PySide.QtGui.QPaintEngine.coordinateOffset()¶

Return type:	`PySide.QtCore.QPoint`

Returns the offset from the painters origo to the engines origo. This value is used by PySide.QtGui.QPainter for engines who have internal double buffering.

This function only makes sense when the engine is active.

PySide.QtGui.QPaintEngine.drawEllipse(r)¶

Parameters:	r – `PySide.QtCore.QRectF`

Reimplement this function to draw the largest ellipse that can be contained within rectangle rect .

The default implementation calls PySide.QtGui.QPaintEngine.drawPolygon() .

PySide.QtGui.QPaintEngine.drawEllipse(r)

Parameters:	r – `PySide.QtCore.QRect`

The default implementation of this function calls the floating point version of this function

PySide.QtGui.QPaintEngine.drawImage(r, pm, sr[, flags=Qt.AutoColor])¶

Parameters:	r – `PySide.QtCore.QRectF` pm – `PySide.QtGui.QImage` sr – `PySide.QtCore.QRectF` flags – `PySide.QtCore.Qt.ImageConversionFlags`

PySide.QtGui.QPaintEngine.drawLines(lines, lineCount)¶

Parameters:	lines – `PySide.QtCore.QLineF` lineCount – `PySide.QtCore.int`

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

PySide.QtGui.QPaintEngine.drawLines(lines, lineCount)

Parameters:	lines – `PySide.QtCore.QLine` lineCount – `PySide.QtCore.int`

This is an overloaded function.

The default implementation converts the first lineCount lines in lines to a PySide.QtCore.QLineF and calls the floating point version of this function.

PySide.QtGui.QPaintEngine.drawPath(path)¶

Parameters:	path – `PySide.QtGui.QPainterPath`

The default implementation ignores the path and does nothing.

PySide.QtGui.QPaintEngine.drawPixmap(r, pm, sr)¶

Parameters:	r – `PySide.QtCore.QRectF` pm – `PySide.QtGui.QPixmap` sr – `PySide.QtCore.QRectF`

Reimplement this function to draw the part of the pm specified by the sr rectangle in the given r .

PySide.QtGui.QPaintEngine.drawPoints(points, pointCount)¶

Parameters:	points – `PySide.QtCore.QPointF` pointCount – `PySide.QtCore.int`

Draws the first pointCount points in the buffer points

PySide.QtGui.QPaintEngine.drawPoints(points, pointCount)

Parameters:	points – `PySide.QtCore.QPoint` pointCount – `PySide.QtCore.int`

Draws the first pointCount points in the buffer points

The default implementation converts the first pointCount QPoints in points to QPointFs and calls the floating point version of drawPoints.

PySide.QtGui.QPaintEngine.drawPolygon(points, pointCount, mode)¶

Parameters:	points – `PySide.QtCore.QPointF` pointCount – `PySide.QtCore.int` mode – `PySide.QtGui.QPaintEngine.PolygonDrawMode`

Reimplement this virtual function to draw the polygon defined by the pointCount first points in points , using mode mode .

Note

At least one of the PySide.QtGui.QPaintEngine.drawPolygon() functions must be reimplemented.

PySide.QtGui.QPaintEngine.drawPolygon(points, pointCount, mode)

Parameters:	points – `PySide.QtCore.QPoint` pointCount – `PySide.QtCore.int` mode – `PySide.QtGui.QPaintEngine.PolygonDrawMode`

This is an overloaded function.

Reimplement this virtual function to draw the polygon defined by the pointCount first points in points , using mode mode .

Note

At least one of the PySide.QtGui.QPaintEngine.drawPolygon() functions must be reimplemented.

PySide.QtGui.QPaintEngine.drawRects(rects, rectCount)¶

Parameters:	rects – `PySide.QtCore.QRect` rectCount – `PySide.QtCore.int`

This is an overloaded function.

The default implementation converts the first rectCount rectangles in the buffer rects to a PySide.QtCore.QRectF and calls the floating point version of this function.

PySide.QtGui.QPaintEngine.drawRects(rects, rectCount)

Parameters:	rects – `PySide.QtCore.QRectF` rectCount – `PySide.QtCore.int`

Draws the first rectCount rectangles in the buffer rects . The default implementation of this function calls PySide.QtGui.QPaintEngine.drawPath() or PySide.QtGui.QPaintEngine.drawPolygon() depending on the feature set of the paint engine.

PySide.QtGui.QPaintEngine.drawTextItem(p, textItem)¶

Parameters:	p – `PySide.QtCore.QPointF` textItem – `PySide.QtGui.QTextItem`

This function draws the text item textItem at position p . The default implementation of this function converts the text to a PySide.QtGui.QPainterPath and paints the resulting path.

PySide.QtGui.QPaintEngine.drawTiledPixmap(r, pixmap, s)¶

Parameters:	r – `PySide.QtCore.QRectF` pixmap – `PySide.QtGui.QPixmap` s – `PySide.QtCore.QPointF`

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

PySide.QtGui.QPaintEngine.end()¶

Return type:	`PySide.QtCore.bool`

Reimplement this function to finish painting on the current paint device. Return true if painting was finished successfully; otherwise return false.

PySide.QtGui.QPaintEngine.hasFeature(feature)¶

Parameters:	feature – `PySide.QtGui.QPaintEngine.PaintEngineFeatures`
Return type:	`PySide.QtCore.bool`

PySide.QtGui.QPaintEngine.isActive()¶

Return type:	`PySide.QtCore.bool`

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

See also

PySide.QtGui.QPaintEngine.setActive()

PySide.QtGui.QPaintEngine.isExtended()¶

Return type:	`PySide.QtCore.bool`

Returns true if the paint engine is a QPaintEngineEx derivative.

PySide.QtGui.QPaintEngine.paintDevice()¶

Return type:	`PySide.QtGui.QPaintDevice`

Returns the device that this engine is painting on, if painting is active; otherwise returns 0.

PySide.QtGui.QPaintEngine.painter()¶

Return type:	`PySide.QtGui.QPainter`

Returns the paint engine’s painter.

PySide.QtGui.QPaintEngine.setActive(newState)¶

Parameters:	newState – `PySide.QtCore.bool`

Sets the active state of the paint engine to state .

See also

PySide.QtGui.QPaintEngine.isActive()

PySide.QtGui.QPaintEngine.setAutoDestruct(autoDestr)¶

Parameters:	autoDestr – `PySide.QtCore.bool`

PySide.QtGui.QPaintEngine.setDirty(df)¶

Parameters:	df – `PySide.QtGui.QPaintEngine.DirtyFlags`

PySide.QtGui.QPaintEngine.setSystemClip(baseClip)¶

Parameters:	baseClip – `PySide.QtGui.QRegion`

Sets the system clip for this engine. The system clip defines the basis area that the engine has to draw in. All clips that are set will be be an intersection with the system clip.

Reset the systemclip to no clip by setting an empty region.

PySide.QtGui.QPaintEngine.setSystemRect(rect)¶

Parameters:	rect – `PySide.QtCore.QRect`

Sets the target rect for drawing within the backing store. This function should ONLY be used by the backing store.

PySide.QtGui.QPaintEngine.syncState()¶: Updates all dirty states in this engine. This function should ONLY be used when drawing with native handles directly and immediate sync from QPainters state to the native state is required.

PySide.QtGui.QPaintEngine.systemClip()¶

Return type:	`PySide.QtGui.QRegion`

Returns the system clip. The system clip is read only while the painter is active. An empty region indicates that system clip is not in use.

PySide.QtGui.QPaintEngine.systemRect()¶

Return type:	`PySide.QtCore.QRect`

Retrieves the rect for drawing within the backing store. This function should ONLY be used by the backing store.

PySide.QtGui.QPaintEngine.testDirty(df)¶

Parameters:	df – `PySide.QtGui.QPaintEngine.DirtyFlags`
Return type:	`PySide.QtCore.bool`

PySide.QtGui.QPaintEngine.type()¶

Return type:	`PySide.QtGui.QPaintEngine.Type`

Reimplement this function to return the paint engine QPaintEngine.Type .

PySide.QtGui.QPaintEngine.updateState(state)¶

Parameters:	state – `PySide.QtGui.QPaintEngineState`

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

PySide.QtGui.QPaintEngineState

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