Vector graphics painting class. More...

#include <Wt/WPainter.h>

Classes
class	Image
	An image that can be rendered on a WPainter. More...

Public Types
typedef PainterChangeFlag	ChangeFlag
	Typedef for enum Wt::PainterChangeFlag.

Public Member Functions
	WPainter ()
	Default constructor. More...

	WPainter (WPaintDevice *device)
	Creates a painter on a given paint device.

	~WPainter ()
	Destructor.

bool	begin (WPaintDevice *device)
	Begins painting on a paint device. More...

bool	isActive () const
	Returns whether this painter is active on a paint device. More...

bool	end ()
	Ends painting. More...

WPaintDevice *	device () const
	Returns the device on which this painter is active (or 0 if not active). More...

void	setRenderHint (RenderHint hint, bool on=true)
	Sets a render hint. More...

WFlags< RenderHint >	renderHints () const
	Returns the current render hints. More...

void	drawArc (const WRectF &rectangle, int startAngle, int spanAngle)
	Draws an arc. More...

void	drawArc (double x, double y, double width, double height, int startAngle, int spanAngle)
	Draws an arc. More...

void	drawChord (const WRectF &rectangle, int startAngle, int spanAngle)
	Draws a chord. More...

void	drawChord (double x, double y, double width, double height, int startAngle, int spanAngle)
	Draws a chord. More...

void	drawEllipse (const WRectF &rectangle)
	Draws an ellipse. More...

void	drawEllipse (double x, double y, double width, double height)
	Draws an ellipse. More...

void	drawImage (const WPointF &point, const Image &image)
	Draws an image. More...

void	drawImage (const WPointF &point, const Image &image, const WRectF &sourceRect)
	Draws part of an image. More...

void	drawImage (const WRectF &rect, const Image &image)
	Draws an image inside a rectangle. More...

void	drawImage (const WRectF &rect, const Image &image, const WRectF &sourceRect)
	Draws part of an image inside a rectangle. More...

void	drawImage (double x, double y, const Image &image, double sx=0, double sy=0, double sw=-1, double sh=-1)
	Draws part of an image. More...

void	drawLine (const WLineF &line)
	Draws a line. More...

void	drawLine (const WPointF &p1, const WPointF &p2)
	Draws a line. More...

void	drawLine (double x1, double y1, double x2, double y2)
	Draws a line. More...

void	drawLines (const WLineF *lines, int lineCount)
	Draws an array of lines. More...

void	drawLines (const WPointF *pointPairs, int lineCount)
	Draws an array of lines. More...

void	drawLines (const std::vector< WLineF > &lines)
	Draws an array of lines. More...

void	drawLines (const std::vector< WPointF > &pointPairs)
	Draws an array of lines. More...

void	drawPath (const WPainterPath &path)
	Draws a (complex) path. More...

void	drawStencilAlongPath (const WPainterPath &stencil, const WPainterPath &path, bool softClipping=false)
	Draws a WPainterPath on every anchor point of a path. More...

void	drawPie (const WRectF &rectangle, int startAngle, int spanAngle)
	Draws a pie. More...

void	drawPie (double x, double y, double width, double height, int startAngle, int spanAngle)
	Draws a pie. More...

void	drawPoint (const WPointF &position)
	Draws a point. More...

void	drawPoint (double x, double y)
	Draws a point. More...

void	drawPoints (const WPointF *points, int pointCount)
	Draws a number of points. More...

void	drawPolygon (const WPointF *points, int pointCount)
	Draws a polygon. More...

void	drawPolyline (const WPointF *points, int pointCount)
	Draws a polyline. More...

void	drawRect (const WRectF &rectangle)
	Draws a rectangle. More...

void	drawRect (double x, double y, double width, double height)
	Draws a rectangle. More...

void	drawRects (const WRectF *rectangles, int rectCount)
	Draws a number of rectangles. More...

void	drawRects (const std::vector< WRectF > &rectangles)
	Draws a number of rectangles. More...

void	drawText (const WRectF &rect, WFlags< AlignmentFlag > alignmentFlags, TextFlag textFlag, const WString &text, const WPointF *clipPoint=nullptr)
	Draws text. More...

void	drawText (const WRectF &rectangle, WFlags< AlignmentFlag > flags, const WString &text)
	Draws text. More...

void	drawText (double x, double y, double width, double height, WFlags< AlignmentFlag > flags, const WString &text)
	Draws text. More...

void	drawText (double x, double y, double width, double height, WFlags< AlignmentFlag > alignmentFlags, TextFlag textFlag, const WString &text)
	Draws text. More...

void	fillPath (const WPainterPath &path, const WBrush &brush)
	Fills a (complex) path. More...

void	fillRect (const WRectF &rectangle, const WBrush &brush)
	Fills a rectangle. More...

void	fillRect (double x, double y, double width, double height, const WBrush &brush)
	Fills a rectangle. More...

void	strokePath (const WPainterPath &path, const WPen &pen)
	Strokes a path. More...

void	setShadow (const WShadow &shadow)
	Sets a shadow effect. More...

const WShadow &	shadow () const
	Returns the current shadow effect. More...

void	setBrush (const WBrush &brush)
	Sets the fill style. More...

void	setFont (const WFont &font)
	Sets the font. More...

void	setPen (const WPen &pen)
	Sets the pen. More...

const WBrush &	brush () const
	Returns the current brush. More...

const WFont &	font () const
	Returns the current font. More...

const WPen &	pen () const
	Returns the current pen. More...

void	setClipping (bool enable)
	Enables or disables clipping. More...

bool	hasClipping () const
	Returns whether clipping is enabled. More...

void	setClipPath (const WPainterPath &clipPath)
	Sets the clip path. More...

WPainterPath	clipPath () const
	Returns the clip path. More...

void	resetTransform ()
	Resets the current transformation. More...

void	rotate (double angle)
	Rotates the logical coordinate system. More...

void	scale (double sx, double sy)
	Scales the logical coordinate system. More...

void	translate (const WPointF &offset)
	Translates the origin of the logical coordinate system. More...

void	translate (double dx, double dy)
	Translates the origin of the logical coordinate system. More...

void	setWorldTransform (const WTransform &matrix, bool combine=false)
	Sets a transformation for the logical coordinate system. More...

const WTransform &	worldTransform () const
	Returns the current world transformation matrix. More...

void	save ()
	Saves the current state. More...

void	restore ()
	Returns the last save state. More...

void	setViewPort (const WRectF &viewPort)
	Sets the viewport. More...

void	setViewPort (double x, double y, double width, double height)
	Sets the viewport. More...

WRectF	viewPort () const
	Returns the viewport. More...

void	setWindow (const WRectF &window)
	Sets the window. More...

void	setWindow (double x, double y, double width, double height)
	Sets the window. More...

WRectF	window () const
	Returns the current window. More...

WTransform	combinedTransform () const
	Returns the combined transformation matrix. More...

Detailed Description

Vector graphics painting class.

The painter class provides a vector graphics interface for painting. It needs to be used in conjunction with a WPaintDevice, onto which it paints. To start painting on a device, either pass the device through the constructor, or use begin().

A typical use is to instantiate a WPainter from within a specialized WPaintedWidget::paintEvent() implementation, to paint on the given paint device, but you can also use a painter to paint directly to a particular paint device of choice, for example to create SVG, PDF or PNG images (as resources).

The painter maintains state such as the current pen, brush, font, shadow, transformation and clipping settings (see setClipping() and setClipPath()). A particular state can be saved using save() and later restored using restore().

The painting system distinguishes between device coordinates, logical coordinates, and local coordinates. The device coordinate system ranges from (0, 0) in the top left corner of the device, to (device->width().toPixels(), device->height().toPixels()) for the bottom right corner. The logical coordinate system defines a coordinate system that may be chosen independent of the geometry of the device, which is convenient to make abstraction of the actual device size. Finally, the current local coordinate system may be different from the logical coordinate system because of a transformation set (using translate(), rotate(), and scale()). Initially, the local coordinate system coincides with the logical coordinate system, which coincides with the device coordinate system.

The device coordinates are defined in terms of pixels. Even though most underlying devices are actual vector graphics formats, when used in conjunction with a WPaintedWidget, these vector graphics are rendered by the browser onto a pixel-based canvas (like the rest of the user-interface). The coordinates are defined such that integer values correspond to an imaginary raster which separates the individual pixels, as in the figure below.

The device coordinate system for a 6x5 pixel device

As a consequence, to avoid anti-aliasing effects when drawing straight lines of width one pixel, you will need to use vertices that indicate the middle of a pixel to get a crisp one-pixel wide line, as in the example figure.

By setting a viewPort() and a window(), a viewPort transformation is defined which maps logical coordinates onto device coordinates. By changing the world transformation (using setWorldTransform(), or translate(), rotate(), scale() operations), it is defined how current local coordinates map onto logical coordinates.

The painter provides support for clipping using an arbitrary path, but not that the WVmlImage paint device only has limited support for clipping.

Usage example:

class MyPaintedWidget : public Wt::WPaintedWidget
{
public:
  MyPaintedWidget()
    : foo_(100)
  {
     resize(200, 200); // provide a default size
  }
 
  void setFoo(int foo) {
     foo_ = foo;
     update(); // trigger a repaint
  }
 
protected:
  void paintEvent(Wt::WPaintDevice *paintDevice) {
    Wt::WPainter painter(paintDevice);
    painter.drawLine(20, 20, foo_, foo_);
    ...
  }
 
private:
  int foo_;
};

See also: WPaintedWidget::paintEvent(WPaintDevice *)

Constructor & Destructor Documentation

◆ WPainter()

Wt::WPainter::WPainter ( )

Default constructor.

Before painting, you must invoke begin(WPaintDevice *) on a paint device.

See also: WPainter(WPaintDevice *)

Member Function Documentation

◆ begin()

bool Wt::WPainter::begin ( WPaintDevice * device )

Begins painting on a paint device.

See also: end(), isActive()

◆ brush()

const WBrush& Wt::WPainter::brush ( ) const

Returns the current brush.

Returns the brush style that is currently used for filling.

See also: setBrush(const WBrush&)

◆ clipPath()

WPainterPath Wt::WPainter::clipPath ( ) const

Returns the clip path.

The clip path is returned as it was defined: in the local coordinates at time of definition.

See also: setClipPath(const WPainterPath&)

◆ combinedTransform()

WTransform Wt::WPainter::combinedTransform ( ) const

Returns the combined transformation matrix.

Returns the transformation matrix that maps coordinates to device coordinates. It is the combination of the current world transformation (which defines the transformation within the logical coordinate system) and the window/viewport transformation (which transforms logical coordinates to device coordinates).

See also: setWorldTransform(), setViewPort(), setWindow()

◆ device()

WPaintDevice* Wt::WPainter::device ( ) const

Returns the device on which this painter is active (or 0 if not active).

See also: begin(WPaintDevice *), WPainter(WPaintDevice *), isActive()

◆ drawArc() [1/2]

void Wt::WPainter::drawArc	(	const WRectF &	rectangle,
		int	startAngle,
		int	spanAngle
	)

Draws an arc.

Draws an arc using the current pen, and fills using the current brush.

The arc is defined as a segment from an ellipse, which fits in the rectangle. The segment starts at startAngle, and spans an angle given by spanAngle. These angles have as unit 1/16th of a degree, and are measured counter-clockwise starting from the 3 o'clock position.

See also: drawEllipse(const WRectF&), drawChord(const WRectF&, int, int); drawArc(double, double, double, double, int, int)

◆ drawArc() [2/2]

void Wt::WPainter::drawArc	(	double	x,
		double	y,
		double	width,
		double	height,
		int	startAngle,
		int	spanAngle
	)

Draws an arc.

This is an overloaded method for convenience.

See also: drawArc(const WRectF&, int, int)

◆ drawChord() [1/2]

void Wt::WPainter::drawChord	(	const WRectF &	rectangle,
		int	startAngle,
		int	spanAngle
	)

Draws a chord.

Draws an arc using the current pen, and connects start and end point with a line. The area is filled using the current brush.

The arc is defined as a segment from an ellipse, which fits in the rectangle. The segment starts at startAngle, and spans an angle given by spanAngle. These angles have as unit 1/16th of a degree, and are measured counter-clockwise starting at 3 o'clock.

See also: drawEllipse(const WRectF&), drawArc(const WRectF&, int, int); drawChord(double, double, double, double, int, int)

◆ drawChord() [2/2]

void Wt::WPainter::drawChord	(	double	x,
		double	y,
		double	width,
		double	height,
		int	startAngle,
		int	spanAngle
	)

Draws a chord.

This is an overloaded method for convenience.

See also: drawChord(const WRectF&, int, int)

◆ drawEllipse() [1/2]

void Wt::WPainter::drawEllipse ( const WRectF & rectangle )

Draws an ellipse.

Draws an ellipse using the current pen and fills it using the current brush.

The ellipse is defined as being bounded by the rectangle.

See also: drawArc(const WRectF&, int, int); drawEllipse(double, double, double, double)

◆ drawEllipse() [2/2]

void Wt::WPainter::drawEllipse	(	double	x,
		double	y,
		double	width,
		double	height
	)

Draws an ellipse.

This is an overloaded method for convenience.

See also: drawEllipse(const WRectF&)

◆ drawImage() [1/5]

void Wt::WPainter::drawImage	(	const WPointF &	point,
		const Image &	image
	)

Draws an image.

Draws the image so that the top left corner corresponds to point.

This is an overloaded method provided for convenience.

◆ drawImage() [2/5]

void Wt::WPainter::drawImage	(	const WPointF &	point,
		const Image &	image,
		const WRectF &	sourceRect
	)

Draws part of an image.

Draws the sourceRect rectangle from an image to the location point.

This is an overloaded method provided for convenience.

◆ drawImage() [3/5]

void Wt::WPainter::drawImage	(	const WRectF &	rect,
		const Image &	image
	)

Draws an image inside a rectangle.

Draws the image inside rect (If necessary, the image is scaled to fit into the rectangle).

This is an overloaded method provided for convenience.

◆ drawImage() [4/5]

void Wt::WPainter::drawImage	(	const WRectF &	rect,
		const Image &	image,
		const WRectF &	sourceRect
	)

Draws part of an image inside a rectangle.

Draws the sourceRect rectangle from an image inside rect (If necessary, the image is scaled to fit into the rectangle).

◆ drawImage() [5/5]

void Wt::WPainter::drawImage	(	double	x,
		double	y,
		const Image &	image,
		double	sx = `0`,
		double	sy = `0`,
		double	sw = `-1`,
		double	sh = `-1`
	)

Draws part of an image.

Draws the sourceRect rectangle with top left corner (sx, sy) and size sw x sh from an image to the location (x, y).

◆ drawLine() [1/3]

void Wt::WPainter::drawLine ( const WLineF & line )

Draws a line.

Draws a line using the current pen.

See also: drawLine(const WPointF&, const WPointF&), drawLine(double, double, double, double)

◆ drawLine() [2/3]

void Wt::WPainter::drawLine	(	const WPointF &	p1,
		const WPointF &	p2
	)

Draws a line.

Draws a line defined by two points.

See also: drawLine(const WLineF&), drawLine(double, double, double, double)

◆ drawLine() [3/3]

void Wt::WPainter::drawLine	(	double	x1,
		double	y1,
		double	x2,
		double	y2
	)

Draws a line.

Draws a line defined by two points.

See also: drawLine(const WLineF&), drawLine(const WPointF&, const WPointF&)

◆ drawLines() [1/4]

void Wt::WPainter::drawLines ( const std::vector< WLineF > & lines )

Draws an array of lines.

Draws the lines given in the vector.

◆ drawLines() [2/4]

void Wt::WPainter::drawLines ( const std::vector< WPointF > & pointPairs )

Draws an array of lines.

Draws a number of lines that are specified by pairs of begin- and endpoints. The vector should hold a number of points that is a multiple of two.

◆ drawLines() [3/4]

void Wt::WPainter::drawLines	(	const WLineF *	lines,
		int	lineCount
	)

Draws an array of lines.

Draws the lineCount first lines from the given array of lines.

◆ drawLines() [4/4]

void Wt::WPainter::drawLines	(	const WPointF *	pointPairs,
		int	lineCount
	)

Draws an array of lines.

Draws lineCount lines, where each line is specified using a begin and end point that are read from an array. Thus, the pointPairs array must have at least 2*lineCount points.

◆ drawPath()

void Wt::WPainter::drawPath ( const WPainterPath & path )

Draws a (complex) path.

Draws and fills the given path using the current pen and brush.

See also: strokePath(const WPainterPath&, const WPen&), fillPath(const WPainterPath&, const WBrush&)

◆ drawPie() [1/2]

void Wt::WPainter::drawPie	(	const WRectF &	rectangle,
		int	startAngle,
		int	spanAngle
	)

Draws a pie.

Draws an arc using the current pen, and connects start and end point with the center of the corresponding ellipse. The area is filled using the current brush.

The arc is defined as a segment from an ellipse, which fits in the rectangle. The segment starts at startAngle, and spans an angle given by spanAngle. These angles have as unit 1/16th of a degree, and are measured counter-clockwise starting at 3 o'clock.

See also: drawEllipse(const WRectF&), drawArc(const WRectF&, int, int); drawPie(double, double, double, double, int, int)

◆ drawPie() [2/2]

void Wt::WPainter::drawPie	(	double	x,
		double	y,
		double	width,
		double	height,
		int	startAngle,
		int	spanAngle
	)

Draws a pie.

This is an overloaded method for convenience.

See also: drawPie(const WRectF&, int, int)

◆ drawPoint() [1/2]

void Wt::WPainter::drawPoint ( const WPointF & position )

Draws a point.

Draws a single point using the current pen. This is implemented by drawing a very short line, centered around the given position. To get the result of a single point, you should use a pen with a Wt::PenCapStyle::Square or Wt::PenCapStyle::Round pen cap style.

See also: drawPoint(double, double)

◆ drawPoint() [2/2]

void Wt::WPainter::drawPoint	(	double	x,
		double	y
	)

Draws a point.

This is an overloaded method for convenience.

See also: drawPoint(const WPointF&)

◆ drawPoints()

void Wt::WPainter::drawPoints	(	const WPointF *	points,
		int	pointCount
	)

Draws a number of points.

Draws the pointCount first points from the given array of points.

See also: drawPoint(const WPointF&)

◆ drawPolygon()

void Wt::WPainter::drawPolygon	(	const WPointF *	points,
		int	pointCount
	)

Draws a polygon.

Draws a polygon that is specified by a list of points, using the current pen. The polygon is closed by connecting the last point with the first point, and filled using the current brush.

See also: drawPath(const WPainterPath&), drawPolyline()

◆ drawPolyline()

void Wt::WPainter::drawPolyline	(	const WPointF *	points,
		int	pointCount
	)

Draws a polyline.

Draws a polyline that is specified by a list of points, using the current pen.

See also: drawPath(const WPainterPath&), drawPolygon()

◆ drawRect() [1/2]

void Wt::WPainter::drawRect ( const WRectF & rectangle )

Draws a rectangle.

Draws and fills a rectangle using the current pen and brush.

See also: drawRect(double, double, double, double)

◆ drawRect() [2/2]

void Wt::WPainter::drawRect	(	double	x,
		double	y,
		double	width,
		double	height
	)

Draws a rectangle.

This is an overloaded method for convenience.

See also: drawRect(const WRectF&)

◆ drawRects() [1/2]

void Wt::WPainter::drawRects ( const std::vector< WRectF > & rectangles )

Draws a number of rectangles.

Draws and fills a list of rectangles using the current pen and brush.

See also: drawRect(const WRectF&)

◆ drawRects() [2/2]

void Wt::WPainter::drawRects	(	const WRectF *	rectangles,
		int	rectCount
	)

Draws a number of rectangles.

Draws and fills the rectCount first rectangles from the given array, using the current pen and brush.

See also: drawRect(const WRectF&)

◆ drawStencilAlongPath()

void Wt::WPainter::drawStencilAlongPath	(	const WPainterPath &	stencil,
		const WPainterPath &	path,
		bool	softClipping = `false`
	)

Draws a WPainterPath on every anchor point of a path.

Draws the first WPainterPath on every anchor point of the second path. When rendering to an HTML canvas, this will cause far less JavaScript to be generated than separate calls to drawPath. Also, it's possible for either path to be JavaScript bound through, e.g. applying a JavaScript bound WTransform without deforming the other path. This is used by WCartesianChart to draw data series markers that don't change size when zooming in.

If one of the anchor points of the path is outside of the current clipping area, the stencil will be drawn if softClipping is disabled, and it will not be drawn when softClipping is enabled.

◆ drawText() [1/4]

void Wt::WPainter::drawText	(	const WRectF &	rect,
		WFlags< AlignmentFlag >	alignmentFlags,
		TextFlag	textFlag,
		const WString &	text,
		const WPointF *	clipPoint = `nullptr`
	)

Draws text.

Draws text using inside the rectangle, using the current font. The text is aligned inside the rectangle following alignment indications given in flags. The text is drawn using the current transformation, pen color (pen()) and font settings (font()).

AlignmentFlags is the logical OR of a horizontal and vertical alignment. Orientation::Horizontal alignment may be one of AlignmentFlag::Left, AlignmentFlag::Center, or AlignmentFlag::Right. Orientation::Vertical alignment is one of AlignmentFlag::Top, AlignmentFlag::Middle or AlignmentFlag::Bottom.

TextFlag determines how the text is rendered in the rectangle. Text can be rendered on one line or by wrapping the words within the rectangle.

If a clipPoint is provided, the text will not be drawn if the point is outside of the clipPath().

Note: If the clip path is not a polygon, i.e. it has rounded segments in it, an approximation will be used instead by having the polygon pass through the control points, and the begin and end point of arcs.; HtmlCanvas: on older browsers implementing Html5 canvas, text will be rendered horizontally (unaffected by rotation and unaffected by the scaling component of the transformation matrix). In that case, text is overlayed on top of painted shapes (in DOM div's), and is not covered by shapes that are painted after the text. Use the SVG and VML renderers (WPaintedWidget::inlineSvgVml) for the most accurate font rendering. Native HTML5 text rendering is supported on Firefox3+, Chrome2+ and Safari4+.; TextFlag::WordWrap: using the TextFlag::WordWrap TextFlag is currently only supported by the SVG backend. The code generated by the SVG backend uses features currently only supported by Inkscape. Inkscape currently supports only Side::Top vertical alignments.

◆ drawText() [2/4]

void Wt::WPainter::drawText	(	const WRectF &	rectangle,
		WFlags< AlignmentFlag >	flags,
		const WString &	text
	)

Draws text.

This is an overloaded method for convenience, it will render text on a single line.

See also: drawText(const WRectF&, WFlags<AlignmentFlag>, TextFlag textFlag, const WString&)

◆ drawText() [3/4]

void Wt::WPainter::drawText	(	double	x,
		double	y,
		double	width,
		double	height,
		WFlags< AlignmentFlag >	alignmentFlags,
		TextFlag	textFlag,
		const WString &	text
	)

Draws text.

This is an overloaded method for convenience.

See also: drawText(const WRectF& rect, WFlags<AlignmentFlag> alignmentFlags, TextFlag textFlag, const WString& text)

◆ drawText() [4/4]

void Wt::WPainter::drawText	(	double	x,
		double	y,
		double	width,
		double	height,
		WFlags< AlignmentFlag >	flags,
		const WString &	text
	)

Draws text.

This is an overloaded method for convenience.

See also: drawText(const WRectF&, WFlags<AlignmentFlag>, const WString&)

◆ end()

bool Wt::WPainter::end ( )

Ends painting.

This method is called automatically from the destructor.

◆ fillPath()

void Wt::WPainter::fillPath	(	const WPainterPath &	path,
		const WBrush &	brush
	)

Fills a (complex) path.

Like drawPath(const WPainterPath&), but does not stroke the path, and fills the path with the given brush.

See also: drawPath(const WPainterPath&), strokePath(const WPainterPath&, const WPen&)

◆ fillRect() [1/2]

void Wt::WPainter::fillRect	(	const WRectF &	rectangle,
		const WBrush &	brush
	)

Fills a rectangle.

Like drawRect(const WRectF&), but does not stroke the rect, and fills the rect with the given brush.

See also: drawRect(const WRectF&)

◆ fillRect() [2/2]

void Wt::WPainter::fillRect	(	double	x,
		double	y,
		double	width,
		double	height,
		const WBrush &	brush
	)

Fills a rectangle.

This is an overloaded method for convenience.

See also: fillRect(const WRectF&, const WBrush&)

◆ font()

const WFont& Wt::WPainter::font ( ) const

Returns the current font.

Returns the font that is currently used for rendering text. The default font is a 10pt sans serif font.

See also: setFont(const WFont&)

◆ hasClipping()

bool Wt::WPainter::hasClipping ( ) const

Returns whether clipping is enabled.

Note: Clipping support is limited for the VML renderer.

See also: setClipping(bool), setClipPath(const WPainterPath&)

◆ isActive()

bool Wt::WPainter::isActive ( ) const

Returns whether this painter is active on a paint device.

See also: begin(WPaintDevice *), end()

◆ pen()

const WPen& Wt::WPainter::pen ( ) const

Returns the current pen.

Returns the pen that is currently used for stroking.

See also: setPen(const WPen&)

◆ renderHints()

WFlags<RenderHint> Wt::WPainter::renderHints ( ) const

Returns the current render hints.

Returns the logical OR of render hints currently set.

See also: setRenderHint(RenderHint, bool).

◆ resetTransform()

void Wt::WPainter::resetTransform ( )

Resets the current transformation.

Resets the current transformation to the identity transformation matrix, so that the logical coordinate system coincides with the device coordinate system.

◆ restore()

void Wt::WPainter::restore ( )

Returns the last save state.

Pops the last saved state from the state stack.

See also: save()

◆ rotate()

void Wt::WPainter::rotate ( double angle )

Rotates the logical coordinate system.

Rotates the logical coordinate system around its origin. The angle is specified in degrees, and positive values are clock-wise.

See also: scale(double, double), translate(double, double), resetTransform()

◆ save()

void Wt::WPainter::save ( )

Saves the current state.

A copy of the current state is saved on a stack. This state will may later be restored by popping this state from the stack using restore().

The state that is saved is the current pen, brush, font, shadow, transformation and clipping settings (see setClipping() and setClipPath()).

See also: restore()

◆ scale()

void Wt::WPainter::scale	(	double	sx,
		double	sy
	)

Scales the logical coordinate system.

Scales the logical coordinate system around its origin, by a factor in the X and Y directions.

See also: rotate(double), translate(double, double), resetTransform()

◆ setBrush()

void Wt::WPainter::setBrush ( const WBrush & brush )

Sets the fill style.

Changes the fills style for subsequent draw operations.

See also: brush(), setPen(const WPen&)

◆ setClipPath()

void Wt::WPainter::setClipPath ( const WPainterPath & clipPath )

Sets the clip path.

Sets the path that is used for clipping subsequent drawing operations. The clip path is only used when clipping is enabled using setClipping(bool). The path is specified in local coordinates.

Note: Clipping support is limited for the VML renderer.

See also: clipPath(), setClipping(bool)

◆ setClipping()

void Wt::WPainter::setClipping ( bool enable )

Enables or disables clipping.

Enables are disables clipping for subsequent operations using the current clip path set using setClipPath().

Note: Clipping support is limited for the VML renderer. Only clipping with a rectangle is supported for the VML renderer (see WPainterPath::addRect()). The rectangle must, after applying the combined transformation system, be aligned with the window.

See also: hasClipping(), setClipPath(const WPainterPath&)

◆ setFont()

void Wt::WPainter::setFont ( const WFont & font )

Sets the font.

Changes the font for subsequent text rendering. Note that only font sizes that are defined as an explicit size (see FontSize::FixedSize) will render correctly in all devices (SVG, VML, and HtmlCanvas).

The list of fonts that will render correctly with VML (on IE<9) are limited to the following: http://www.ampsoft.net/webdesign-l/WindowsMacFonts.html

Careful, for a font family that contains a space, you need to add quotes, to WFont::setFamily() e.g.

WFont mono;
mono.setFamily(FontFamily::Monospace, "'Courier New'");
mono.setSize(18);

See also: font(), drawText()

◆ setPen()

void Wt::WPainter::setPen ( const WPen & pen )

Sets the pen.

Changes the pen used for stroking subsequent draw operations.

See also: pen(), setBrush(const WBrush&)

◆ setRenderHint()

void Wt::WPainter::setRenderHint	(	RenderHint	hint,
		bool	on = `true`
	)

Sets a render hint.

Renderers may ignore particular hints for which they have no support.

◆ setShadow()

void Wt::WPainter::setShadow ( const WShadow & shadow )

Sets a shadow effect.

The shadow effect is applied to all things drawn (paths, text and images).

Note: With the VML backend (IE), the shadow is not applied to images, and the shadow color is always black; only the opacity (alpha) channel is taken into account.

See also: LowQualityShadows

◆ setViewPort() [1/2]

void Wt::WPainter::setViewPort ( const WRectF & viewPort )

Sets the viewport.

Selects the part of the device that will correspond to the logical coordinate system.

By default, the viewport spans the entire device: it is the rectangle (0, 0) to (device->width(), device->height()). The window defines how the viewport is mapped to logical coordinates.

See also: viewPort(), setWindow(const WRectF&)

◆ setViewPort() [2/2]

void Wt::WPainter::setViewPort	(	double	x,
		double	y,
		double	width,
		double	height
	)

Sets the viewport.

This is an overloaded method for convenience.

See also: setViewPort(const WRectF&)

◆ setWindow() [1/2]

void Wt::WPainter::setWindow ( const WRectF & window )

Sets the window.

Defines the viewport rectangle in logical coordinates, and thus how logical coordinates map onto the viewPort.

By default, is (0, 0) to (device->width(), device->height()). Thus, the default window and viewport leave logical coordinates identical to device coordinates.

See also: window(), setViewPort(const WRectF&)

◆ setWindow() [2/2]

void Wt::WPainter::setWindow	(	double	x,
		double	y,
		double	width,
		double	height
	)

Sets the window.

This is an overloaded method for convenience.

See also: setWindow(const WRectF&)

◆ setWorldTransform()

void Wt::WPainter::setWorldTransform	(	const WTransform &	matrix,
		bool	combine = `false`
	)

Sets a transformation for the logical coordinate system.

Sets a new transformation which transforms logical coordinates to device coordinates. When combine is true, the transformation is combined with the current world transformation matrix.

See also: worldTransform(); rotate(double), scale(double, double), translate(double, double); resetTransform()

◆ shadow()

const WShadow& Wt::WPainter::shadow ( ) const

Returns the current shadow effect.

See also: setShadow()

◆ strokePath()

void Wt::WPainter::strokePath	(	const WPainterPath &	path,
		const WPen &	pen
	)

Strokes a path.

Like drawPath(const WPainterPath&), but does not fill the path, and strokes the path with the given pen.

See also: drawPath(const WPainterPath&), fillPath(const WPainterPath&, const WBrush&)

◆ translate() [1/2]

void Wt::WPainter::translate ( const WPointF & offset )

Translates the origin of the logical coordinate system.

Translates the origin of the logical coordinate system to a new location relative to the current logical coordinate system.

See also: translate(double, double), rotate(double), scale(double, double), resetTransform()

◆ translate() [2/2]

void Wt::WPainter::translate	(	double	dx,
		double	dy
	)

Translates the origin of the logical coordinate system.

Translates the origin of the logical coordinate system to a new location relative to the logical coordinate system.

See also: translate(const WPointF& offset), rotate(double), scale(double, double), resetTransform()

◆ viewPort()

WRectF Wt::WPainter::viewPort ( ) const

Returns the viewport.

See also: setViewPort(const WRectF&)

◆ window()

WRectF Wt::WPainter::window ( ) const

Returns the current window.

See also: setViewPort(const WRectF&)

◆ worldTransform()

const WTransform& Wt::WPainter::worldTransform ( ) const

Returns the current world transformation matrix.

See also: setWorldTransform()

Classes

Public Types

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ WPainter()

Member Function Documentation

◆ begin()

◆ brush()

◆ clipPath()

◆ combinedTransform()

◆ device()

◆ drawArc() [1/2]

◆ drawArc() [2/2]

◆ drawChord() [1/2]

◆ drawChord() [2/2]

◆ drawEllipse() [1/2]

◆ drawEllipse() [2/2]

◆ drawImage() [1/5]

◆ drawImage() [2/5]

◆ drawImage() [3/5]

◆ drawImage() [4/5]

◆ drawImage() [5/5]

◆ drawLine() [1/3]

◆ drawLine() [2/3]

◆ drawLine() [3/3]

◆ drawLines() [1/4]

◆ drawLines() [2/4]

◆ drawLines() [3/4]

◆ drawLines() [4/4]

◆ drawPath()

◆ drawPie() [1/2]

◆ drawPie() [2/2]

◆ drawPoint() [1/2]

◆ drawPoint() [2/2]

◆ drawPoints()

◆ drawPolygon()

◆ drawPolyline()

◆ drawRect() [1/2]

◆ drawRect() [2/2]

◆ drawRects() [1/2]

◆ drawRects() [2/2]

◆ drawStencilAlongPath()

◆ drawText() [1/4]

◆ drawText() [2/4]

◆ drawText() [3/4]

◆ drawText() [4/4]

◆ end()

◆ fillPath()

◆ fillRect() [1/2]

◆ fillRect() [2/2]

◆ font()

◆ hasClipping()

◆ isActive()

◆ pen()

◆ renderHints()

◆ resetTransform()

◆ restore()

◆ rotate()

◆ save()

◆ scale()

◆ setBrush()

◆ setClipPath()

◆ setClipping()

◆ setFont()

◆ setPen()

◆ setRenderHint()

◆ setShadow()

◆ setViewPort() [1/2]

◆ setViewPort() [2/2]

◆ setWindow() [1/2]

◆ setWindow() [2/2]

◆ setWorldTransform()

◆ shadow()

◆ strokePath()

◆ translate() [1/2]

◆ translate() [2/2]

◆ viewPort()

◆ window()

◆ worldTransform()