QPaintEngine Class

Member Function Documentation

QPaintEngine::QPaintEngine(QPaintEngine::PaintEngineFeatures caps = PaintEngineFeatures())

Creates a paint engine with the featureset specified by caps.

[virtual] QPaintEngine::~QPaintEngine()

Destroys the paint engine.

[pure virtual] bool QPaintEngine::begin(QPaintDevice *pdev)

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.

See also end() and isActive().

[virtual] void QPaintEngine::drawEllipse(const QRectF &rect)

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

The default implementation calls drawPolygon().

[virtual] void QPaintEngine::drawEllipse(const QRect &rect)

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

[virtual] void QPaintEngine::drawImage(const QRectF &rectangle, const QImage &image, const QRectF &sr, Qt::ImageConversionFlags flags = Qt::AutoColor)

Reimplement this function to draw the part of the image specified by the sr rectangle in the given rectangle using the given conversion flags flags, to convert it to a pixmap.

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

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

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

This is an overloaded function.

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

[virtual] void QPaintEngine::drawPath(const QPainterPath &path)

The default implementation ignores the path and does nothing.

[pure virtual] void QPaintEngine::drawPixmap(const QRectF &r, const QPixmap &pm, const QRectF &sr)

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

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

Draws the first pointCount points in the buffer points

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

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.

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

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

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

This is an overloaded function.

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

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

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

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

This is an overloaded function.

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

[virtual] void QPaintEngine::drawTextItem(const QPointF &p, const QTextItem &textItem)

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

[virtual] void QPaintEngine::drawTiledPixmap(const QRectF &rect, const QPixmap &pixmap, const QPointF &p)

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.

[pure virtual] bool QPaintEngine::end()

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

See also begin() and isActive().

bool QPaintEngine::hasFeature(QPaintEngine::PaintEngineFeatures feature) const

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

bool QPaintEngine::isActive() const

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 nullptr.

QPainter *QPaintEngine::painter() const

Returns the paint engine's painter.

void QPaintEngine::setActive(bool state)

Sets the active state of the paint engine to state.

See also isActive().

[pure virtual] QPaintEngine::Type QPaintEngine::type() const

Reimplement this function to return the paint engine Type.

[pure virtual] void QPaintEngine::updateState(const QPaintEngineState &state)

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.