WMeasurePaintDevice Wt/WMeasurePaintDevice Wt/WMeasurePaintDevice. More...

Inheritance diagram for Wt::WMeasurePaintDevice:

Public Member Functions
	WMeasurePaintDevice (WPaintDevice *paintDevice)
	Creates a paint device to measure for the underlying device.

WRectF	boundingRect () const
	Returns the bounding rectangle of everything painted so far. More...

virtual WFlags< FeatureFlag >	features () const
	Returns device features.

virtual void	setChanged (WFlags< ChangeFlag > flags)
	Indicates changes in painter state. More...

virtual void	drawArc (const WRectF &rect, double startAngle, double spanAngle)
	Draws an arc. More...

virtual void	drawImage (const WRectF &rect, const std::string &imgUri, int imgWidth, int imgHeight, const WRectF &sourceRect)
	Draws an image. More...

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

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

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

virtual WTextItem	measureText (const WString &text, double maxWidth=-1, bool wordWrap=false)
	Measures rendered text size. More...

virtual WFontMetrics	fontMetrics ()
	Returns font metrics. More...

virtual void	init ()
	Initializes the device for painting. More...

virtual void	done ()
	Finishes painting on the device. More...

virtual bool	paintActive () const
	Returns whether painting is active. More...

virtual WLength	width () const
	Returns the device width. More...

virtual WLength	height () const
	Returns the device height. More...

Public Member Functions inherited from Wt::WPaintDevice
virtual	~WPaintDevice ()
	Destructor. More...

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

virtual void	setPainter (WPainter *painter)
	Sets the painter.

Additional Inherited Members
Public Types inherited from Wt::WPaintDevice
enum	ChangeFlag { Pen = 0x1, Brush = 0x2, Font = 0x4, Hints = 0x8, Transform = 0x10, Clipping = 0x20, Shadow = 0x40 }
	Enumeration to communicate painter state changes. More...

enum	FeatureFlag { CanWordWrap = 0x1, HasFontMetrics = 0x2 }
	Enumeration to indicate paint device features. More...

Detailed Description

WMeasurePaintDevice Wt/WMeasurePaintDevice Wt/WMeasurePaintDevice.

This implements a (pseudo)-paintdevice which measures the bounding rect of whatever is being painted on it, using fontmetrics from the underlying device.

The only output of the device is the computation of a bounding rect which is returned by boundingRect().

Member Function Documentation

◆ boundingRect()

WRectF Wt::WMeasurePaintDevice::boundingRect ( ) const

Returns the bounding rectangle of everything painted so far.

The bounding rect is returned in device coordinates (i.e. after all transformations applied).

◆ done()

void Wt::WMeasurePaintDevice::done ( )

virtual

Finishes painting on the device.

This method is called when a WPainter stopped painting.

See also: WPainter::end()

Implements Wt::WPaintDevice.

◆ drawArc()

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

virtual

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

virtual

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::WMeasurePaintDevice::drawLine	(	double	x1,
		double	y1,
		double	x2,
		double	y2
	)

virtual

Draws a line.

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

Implements Wt::WPaintDevice.

◆ drawPath()

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

virtual

Draws a path.

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

Implements Wt::WPaintDevice.

◆ drawText()

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

virtual

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::WMeasurePaintDevice::fontMetrics ( )

virtual

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()

WLength Wt::WMeasurePaintDevice::height ( ) const

virtual

Returns the device height.

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

Implements Wt::WPaintDevice.

◆ init()

void Wt::WMeasurePaintDevice::init ( )

virtual

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::WMeasurePaintDevice::measureText	(	const WString &	text,
		double	maxWidth = `-1`,
		bool	wordWrap = `false`
	)

virtual

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.