Wt::WVmlImage Class Reference

A paint device for rendering using the VML pseudo-standard. More...

#include <Wt/WVmlImage.h>

Inheritance diagram for Wt::WVmlImage:

Public Member Functions
	WVmlImage (const WLength &width, const WLength &height, bool paintUpdate)
	Create a VML paint device. More...
virtual WFlags< PaintDeviceFeatureFlag >	features () const override
	Returns device features.
virtual void	setChanged (WFlags< PainterChangeFlag > flags) override
	Indicates changes in painter state. More...
virtual void	drawArc (const WRectF &rect, double startAngle, double spanAngle) override
	Draws an arc. More...
virtual void	drawImage (const WRectF &rect, const std::string &imgUri, int imgWidth, int imgHeight, const WRectF &sourceRect) override
	Draws an image. More...
virtual void	drawLine (double x1, double y1, double x2, double y2) override
	Draws a line. More...
virtual void	drawRect (const WRectF &rectangle) override
	Draws a rectangle. More...
virtual void	drawPath (const WPainterPath &path) override
	Draws a path. More...
virtual void	drawText (const WRectF &rect, WFlags< AlignmentFlag > alignmentFlags, TextFlag textFlag, const WString &text, const WPointF *clipPoint) override
	Draws text. More...
virtual WTextItem	measureText (const WString &text, double maxWidth=-1, bool wordWrap=false) override
	Measures rendered text size. More...
virtual WFontMetrics	fontMetrics () override
	Returns font metrics. More...
virtual void	init () override
	Initializes the device for painting. More...
virtual void	done () override
	Finishes painting on the device. More...
virtual bool	paintActive () const override
	Returns whether painting is active. More...
virtual std::string	rendered () override
	Internal method.
virtual WLength	width () const override
	Returns the device width. More...
virtual WLength	height () const override
	Returns the device height. More...
Public Member Functions inherited from Wt::WPaintDevice
virtual	~WPaintDevice ()
	Destructor. More...

Protected Member Functions
virtual WPainter *	painter () const override
	Returns the painter that is currently painting on the device. More...
virtual void	setPainter (WPainter *painter) override
	Sets the painter.

Additional Inherited Members
Public Types inherited from Wt::WPaintDevice
typedef PaintDeviceFeatureFlag	FeatureFlag
	Typedef for enum Wt::PaintDeviceFeatureFlag.

Detailed Description

A paint device for rendering using the VML pseudo-standard.

The WVmlImage is used by WPaintedWidget to render to the browser using the Vector Markup Language (VML) (to support graphics on Internet Explorer browsers).

Note

The current implementation has only limited support for clipping: only rectangular areas aligned with the X/Y axes can be used as clipping path.

Constructor & Destructor Documentation

WVmlImage()

Wt::WVmlImage::WVmlImage	(	const WLength &	width,
		const WLength &	height,
		bool	paintUpdate
	)

Create a VML paint device.

If paintUpdate is true, then only a VML fragment will be rendered that can be used to update the DOM of an existing VML image, instead of a full VML image.

Member Function Documentation

done()

void Wt::WVmlImage::done ( )

overridevirtual

Finishes painting on the device.

This method is called when a WPainter stopped painting.

See also

WPainter::end()

Implements Wt::WPaintDevice.

drawArc()

void Wt::WVmlImage::drawArc ( const WRectF &  rect, double  startAngle, double  spanAngle  )

overridevirtual

Draws an arc.

The arc describes the segment of an ellipse enclosed by the rect. The segment starts at startAngle, and spans an angle given by spanAngle. These angles have as unit degree, and are measured counter-clockwise starting from the 3 o'clock position.

The arc must be stroked, filled, and transformed using the current painter settings.

Implements Wt::WPaintDevice.

drawImage()

void Wt::WVmlImage::drawImage ( const WRectF &  rect, const std::string &  imageUri, int  imgWidth, int  imgHeight, const WRectF &  sourceRect  )

overridevirtual

Draws an image.

Draws sourceRect from the image with URL imageUri and original dimensions imgWidth and imgHeight to the location, into the rectangle defined by rect.

The image is transformed using the current painter settings.

Implements Wt::WPaintDevice.

drawLine()

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

overridevirtual

Draws a line.

The line must be stroked and transformed using the current painter settings.

Implements Wt::WPaintDevice.

drawPath()

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

overridevirtual

Draws a path.

The path must be stroked, filled, and transformed using the current painter settings.

Implements Wt::WPaintDevice.

drawRect()

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

overridevirtual

Draws a rectangle.

The rect must be stroked, filled, and transformed using the current painter settings.

Implements Wt::WPaintDevice.

drawText()

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

overridevirtual

Draws text.

The text must be rendered, stroked and transformed using the current painter settings.

If clipPoint is not null, a check is performed whether the point is inside of the current clip area. If not, the text is not drawn.

Implements Wt::WPaintDevice.

fontMetrics()

WFontMetrics Wt::WVmlImage::fontMetrics ( )

overridevirtual

Returns font metrics.

This returns font metrics for the current font.

Throws a std::logic_error if the underlying device does not provide font metrics.

Implements Wt::WPaintDevice.

height()

virtual WLength Wt::WVmlImage::height ( ) const

overridevirtual

Returns the device height.

The device height, in pixels, establishes the height of the device coordinate system.

Implements Wt::WPaintDevice.

init()

void Wt::WVmlImage::init ( )

overridevirtual

Initializes the device for painting.

This method is called when a WPainter starts painting.

See also

WPainter::begin(WPaintDevice *), painter()

Implements Wt::WPaintDevice.

measureText()

WTextItem Wt::WVmlImage::measureText ( const WString &  text, double  maxWidth = -1, bool  wordWrap = false  )

overridevirtual

Measures rendered text size.

Returns the bounding rect of the given text when rendered using the current font.

If maxWidth != -1, then the text is truncated to fit in the width.

If wordWrap = true then text is truncated only at word boundaries. Note that in this case the whitespace at the truncated position is included in the text but not accounted for by the returned width (since usually you will not render the whitespace at the end of a line).

Throws a std::logic_error if the underlying device does not provide font metrics.

Implements Wt::WPaintDevice.

paintActive()

virtual bool Wt::WVmlImage::paintActive ( ) const

overridevirtual

Returns whether painting is active.

See also

init(), painter()

Implements Wt::WPaintDevice.

painter()

virtual WPainter* Wt::WVmlImage::painter ( ) const

overrideprotectedvirtual

Returns the painter that is currently painting on the device.

See also

init()

Implements Wt::WPaintDevice.

setChanged()

void Wt::WVmlImage::setChanged ( WFlags< PainterChangeFlag >  flags )

overridevirtual

Indicates changes in painter state.

The flags argument is the logical OR of one or more change flags.

See also

ChangeFlag

Implements Wt::WPaintDevice.

width()

virtual WLength Wt::WVmlImage::width ( ) const

overridevirtual

Returns the device width.

The device width, in pixels, establishes the width of the device coordinate system.

Implements Wt::WPaintDevice.