QwtPainter Class Reference

A collection of QPainter workarounds. More...

#include <qwt_painter.h>

Static Public Member Functions
static QPixmap	backingStore (QWidget *, const QSize &)
static qreal	devicePixelRatio (const QPaintDevice *)
static void	drawBackgound (QPainter *, const QRectF &, const QWidget *)
static void	drawColorBar (QPainter *, const QwtColorMap &, const QwtInterval &, const QwtScaleMap &, Qt::Orientation, const QRectF &)
static void	drawEllipse (QPainter *, const QRectF &)
	Wrapper for QPainter::drawEllipse() More...
static void	drawFocusRect (QPainter *, const QWidget *)
	Draw a focus rectangle on a widget using its style. More...
static void	drawFocusRect (QPainter *, const QWidget *, const QRect &)
	Draw a focus rectangle on a widget using its style. More...
static void	drawFrame (QPainter *, const QRectF &rect, const QPalette &palette, QPalette::ColorRole foregroundRole, int lineWidth, int midLineWidth, int frameStyle)
static void	drawImage (QPainter *, const QRectF &, const QImage &)
	Wrapper for QPainter::drawImage() More...
static void	drawLine (QPainter *, const QLineF &)
	Wrapper for QPainter::drawLine() More...
static void	drawLine (QPainter *, const QPointF &p1, const QPointF &p2)
	Wrapper for QPainter::drawLine() More...
static void	drawLine (QPainter *, qreal x1, qreal y1, qreal x2, qreal y2)
	Wrapper for QPainter::drawLine() More...
static void	drawPath (QPainter *, const QPainterPath &)
	Wrapper for QPainter::drawPath() More...
static void	drawPie (QPainter *, const QRectF &r, int a, int alen)
	Wrapper for QPainter::drawPie() More...
static void	drawPixmap (QPainter *, const QRectF &, const QPixmap &)
	Wrapper for QPainter::drawPixmap() More...
static void	drawPoint (QPainter *, const QPoint &)
	Wrapper for QPainter::drawPoint() More...
static void	drawPoint (QPainter *, const QPointF &)
	Wrapper for QPainter::drawPoint() More...
static void	drawPoint (QPainter *, qreal x, qreal y)
	Wrapper for QPainter::drawPoint() More...
static void	drawPoints (QPainter *, const QPoint *, int pointCount)
	Wrapper for QPainter::drawPoints() More...
static void	drawPoints (QPainter *, const QPointF *, int pointCount)
	Wrapper for QPainter::drawPoints() More...
static void	drawPoints (QPainter *, const QPolygon &)
	Wrapper for QPainter::drawPoints() More...
static void	drawPoints (QPainter *, const QPolygonF &)
	Wrapper for QPainter::drawPoints() More...
static void	drawPolygon (QPainter *, const QPolygon &)
	Wrapper for QPainter::drawPolygon() More...
static void	drawPolygon (QPainter *, const QPolygonF &)
	Wrapper for QPainter::drawPolygon() More...
static void	drawPolyline (QPainter *, const QPoint *, int pointCount)
	Wrapper for QPainter::drawPolyline() More...
static void	drawPolyline (QPainter *, const QPointF *, int pointCount)
	Wrapper for QPainter::drawPolyline() More...
static void	drawPolyline (QPainter *, const QPolygon &)
	Wrapper for QPainter::drawPolyline() More...
static void	drawPolyline (QPainter *, const QPolygonF &)
	Wrapper for QPainter::drawPolyline() More...
static void	drawRect (QPainter *, const QRectF &rect)
	Wrapper for QPainter::drawRect() More...
static void	drawRect (QPainter *, qreal x, qreal y, qreal w, qreal h)
	Wrapper for QPainter::drawRect() More...
static void	drawRoundedFrame (QPainter *, const QRectF &, qreal xRadius, qreal yRadius, const QPalette &, int lineWidth, int frameStyle)
static void	drawRoundFrame (QPainter *, const QRectF &, const QPalette &, int lineWidth, int frameStyle)
static void	drawSimpleRichText (QPainter *, const QRectF &, int flags, const QTextDocument &)
static void	drawText (QPainter *, const QPointF &, const QString &)
	Wrapper for QPainter::drawText() More...
static void	drawText (QPainter *, const QRectF &, int flags, const QString &)
	Wrapper for QPainter::drawText() More...
static void	drawText (QPainter *, qreal x, qreal y, const QString &)
	Wrapper for QPainter::drawText() More...
static void	drawText (QPainter *, qreal x, qreal y, qreal w, qreal h, int flags, const QString &)
	Wrapper for QPainter::drawText() More...
static qreal	effectivePenWidth (const QPen &)
static void	fillPixmap (const QWidget *, QPixmap &, const QPoint &offset=QPoint())
static void	fillRect (QPainter *, const QRectF &, const QBrush &)
	Wrapper for QPainter::fillRect() More...
static int	horizontalAdvance (const QFontMetrics &, const QString &)
static int	horizontalAdvance (const QFontMetrics &, QChar)
static qreal	horizontalAdvance (const QFontMetricsF &, const QString &)
static qreal	horizontalAdvance (const QFontMetricsF &, QChar)
static bool	isAligning (const QPainter *)
static bool	isX11GraphicsSystem ()
static bool	polylineSplitting ()
static bool	roundingAlignment ()
static bool	roundingAlignment (const QPainter *)
static QFont	scaledFont (const QFont &, const QPaintDevice *=nullptr)
static void	setPolylineSplitting (bool)
	En/Disable line splitting for the raster paint engine. More...
static void	setRoundingAlignment (bool)

Static Private Attributes
static bool	m_polylineSplitting = true
static bool	m_roundingAlignment = true

Detailed Description

A collection of QPainter workarounds.

Definition at line 36 of file qwt_painter.h.

Member Function Documentation

backingStore()

QPixmap QwtPainter::backingStore ( QWidget *  widget, const QSize &  size  )

static

Returns

A pixmap that can be used as backing store

Parameters

widget	Widget, for which the backingstore is intended
size	Size of the pixmap

Definition at line 1525 of file qwt_painter.cpp.

devicePixelRatio()

qreal QwtPainter::devicePixelRatio ( const QPaintDevice *  paintDevice )

static

Returns

Pixel ratio for a paint device

Parameters

paintDevice

Paint device

Definition at line 1491 of file qwt_painter.cpp.

drawBackgound()

void QwtPainter::drawBackgound ( QPainter *  painter, const QRectF &  rect, const QWidget *  widget  )

static

Fill rect with the background of a widget

Parameters

painter	Painter
rect	Rectangle to be filled
widget	Widget

See also

QStyle::PE_Widget, QWidget::backgroundRole()

Definition at line 1351 of file qwt_painter.cpp.

drawColorBar()

void QwtPainter::drawColorBar ( QPainter *  painter, const QwtColorMap &  colorMap, const QwtInterval &  interval, const QwtScaleMap &  scaleMap, Qt::Orientation  orientation, const QRectF &  rect  )

static

Draw a color bar into a rectangle

Parameters

painter	Painter
colorMap	Color map
interval	Value range
scaleMap	Scale map
orientation	Orientation
rect	Target rectangle

Definition at line 1205 of file qwt_painter.cpp.

drawEllipse()

void QwtPainter::drawEllipse ( QPainter *  painter, const QRectF &  rect  )

static

Wrapper for QPainter::drawEllipse()

Definition at line 426 of file qwt_painter.cpp.

drawFocusRect() [1/2]

void QwtPainter::drawFocusRect ( QPainter *  painter, const QWidget *  widget  )

static

Draw a focus rectangle on a widget using its style.

Definition at line 815 of file qwt_painter.cpp.

drawFocusRect() [2/2]

void QwtPainter::drawFocusRect ( QPainter *  painter, const QWidget *  widget, const QRect &  rect  )

static

Draw a focus rectangle on a widget using its style.

Definition at line 821 of file qwt_painter.cpp.

drawFrame()

void QwtPainter::drawFrame ( QPainter *  painter, const QRectF &  rect, const QPalette &  palette, QPalette::ColorRole  foregroundRole, int  frameWidth, int  midLineWidth, int  frameStyle  )

static

Draw a rectangular frame

Parameters

painter	Painter
rect	Frame rectangle
palette	Palette
foregroundRole	Foreground role used for QFrame::Plain
frameWidth	Frame width
midLineWidth	Used for QFrame::Box
frameStyle	bitwise OR´ed value of QFrame::Shape and QFrame::Shadow

Definition at line 911 of file qwt_painter.cpp.

drawImage()

void QwtPainter::drawImage ( QPainter *  painter, const QRectF &  rect, const QImage &  image  )

static

Wrapper for QPainter::drawImage()

Definition at line 773 of file qwt_painter.cpp.

drawLine() [1/3]

void QwtPainter::drawLine ( QPainter *  painter, const QLineF &  line  )

inlinestatic

Wrapper for QPainter::drawLine()

Definition at line 161 of file qwt_painter.h.

drawLine() [2/3]

void QwtPainter::drawLine ( QPainter *  painter, const QPointF &  p1, const QPointF &  p2  )

static

Wrapper for QPainter::drawLine()

Definition at line 541 of file qwt_painter.cpp.

drawLine() [3/3]

void QwtPainter::drawLine ( QPainter *  painter, qreal  x1, qreal  y1, qreal  x2, qreal  y2  )

inlinestatic

Wrapper for QPainter::drawLine()

Definition at line 154 of file qwt_painter.h.

drawPath()

void QwtPainter::drawPath ( QPainter *  painter, const QPainterPath &  path  )

static

Wrapper for QPainter::drawPath()

Definition at line 341 of file qwt_painter.cpp.

drawPie()

void QwtPainter::drawPie ( QPainter *  painter, const QRectF &  r, int  a, int  alen  )

static

Wrapper for QPainter::drawPie()

Definition at line 414 of file qwt_painter.cpp.

drawPixmap()

void QwtPainter::drawPixmap ( QPainter *  painter, const QRectF &  rect, const QPixmap &  pixmap  )

static

Wrapper for QPainter::drawPixmap()

Definition at line 794 of file qwt_painter.cpp.

drawPoint() [1/3]

void QwtPainter::drawPoint ( QPainter *  painter, const QPoint &  pos  )

static

Wrapper for QPainter::drawPoint()

Definition at line 691 of file qwt_painter.cpp.

drawPoint() [2/3]

void QwtPainter::drawPoint ( QPainter *  painter, const QPointF &  pos  )

static

Wrapper for QPainter::drawPoint()

Definition at line 679 of file qwt_painter.cpp.

drawPoint() [3/3]

void QwtPainter::drawPoint ( QPainter *  painter, qreal  x, qreal  y  )

inlinestatic

Wrapper for QPainter::drawPoint()

Definition at line 136 of file qwt_painter.h.

drawPoints() [1/4]

void QwtPainter::drawPoints ( QPainter *  painter, const QPoint *  points, int  pointCount  )

static

Wrapper for QPainter::drawPoints()

Definition at line 714 of file qwt_painter.cpp.

drawPoints() [2/4]

void QwtPainter::drawPoints ( QPainter *  painter, const QPointF *  points, int  pointCount  )

static

Wrapper for QPainter::drawPoints()

Definition at line 747 of file qwt_painter.cpp.

drawPoints() [3/4]

void QwtPainter::drawPoints ( QPainter *  painter, const QPolygon &  polygon  )

inlinestatic

Wrapper for QPainter::drawPoints()

Definition at line 142 of file qwt_painter.h.

drawPoints() [4/4]

void QwtPainter::drawPoints ( QPainter *  painter, const QPolygonF &  polygon  )

inlinestatic

Wrapper for QPainter::drawPoints()

Definition at line 148 of file qwt_painter.h.

drawPolygon() [1/2]

void QwtPainter::drawPolygon ( QPainter *  painter, const QPolygon &  polygon  )

static

Wrapper for QPainter::drawPolygon()

Definition at line 620 of file qwt_painter.cpp.

drawPolygon() [2/2]

void QwtPainter::drawPolygon ( QPainter *  painter, const QPolygonF &  polygon  )

static

Wrapper for QPainter::drawPolygon()

Definition at line 561 of file qwt_painter.cpp.

drawPolyline() [1/4]

void QwtPainter::drawPolyline ( QPainter *  painter, const QPoint *  points, int  pointCount  )

static

Wrapper for QPainter::drawPolyline()

Definition at line 657 of file qwt_painter.cpp.

drawPolyline() [2/4]

void QwtPainter::drawPolyline ( QPainter *  painter, const QPointF *  points, int  pointCount  )

static

Wrapper for QPainter::drawPolyline()

Definition at line 598 of file qwt_painter.cpp.

drawPolyline() [3/4]

void QwtPainter::drawPolyline ( QPainter *  painter, const QPolygon &  polygon  )

static

Wrapper for QPainter::drawPolyline()

Definition at line 637 of file qwt_painter.cpp.

drawPolyline() [4/4]

void QwtPainter::drawPolyline ( QPainter *  painter, const QPolygonF &  polygon  )

static

Wrapper for QPainter::drawPolyline()

Definition at line 578 of file qwt_painter.cpp.

drawRect() [1/2]

void QwtPainter::drawRect ( QPainter *  painter, const QRectF &  rect  )

static

Wrapper for QPainter::drawRect()

Definition at line 353 of file qwt_painter.cpp.

drawRect() [2/2]

void QwtPainter::drawRect ( QPainter *  painter, qreal  x, qreal  y, qreal  w, qreal  h  )

static

Wrapper for QPainter::drawRect()

Definition at line 347 of file qwt_painter.cpp.

drawRoundedFrame()

void QwtPainter::drawRoundedFrame ( QPainter *  painter, const QRectF &  rect, qreal  xRadius, qreal  yRadius, const QPalette &  palette, int  lineWidth, int  frameStyle  )

static

Draw a rectangular frame with rounded borders

Parameters

painter	Painter
rect	Frame rectangle
xRadius	x-radius of the ellipses defining the corners
yRadius	y-radius of the ellipses defining the corners
palette	QPalette::WindowText is used for plain borders QPalette::Dark and QPalette::Light for raised or sunken borders
lineWidth	Line width
frameStyle	bitwise OR´ed value of QFrame::Shape and QFrame::Shadow

Definition at line 1065 of file qwt_painter.cpp.

drawRoundFrame()

void QwtPainter::drawRoundFrame ( QPainter *  painter, const QRectF &  rect, const QPalette &  palette, int  lineWidth, int  frameStyle  )

static

Draw a round frame

Parameters

painter	Painter
rect	Frame rectangle
palette	QPalette::WindowText is used for plain borders QPalette::Dark and QPalette::Light for raised or sunken borders
lineWidth	Line width
frameStyle	bitwise OR´ed value of QFrame::Shape and QFrame::Shadow

Definition at line 845 of file qwt_painter.cpp.

drawSimpleRichText()

void QwtPainter::drawSimpleRichText ( QPainter *  painter, const QRectF &  rect, int  flags, const QTextDocument &  text  )

static

Draw a text document into a rectangle

Parameters

painter	Painter
rect	Target rectangle
flags	Alignments/Text flags, see QPainter::drawText()
text	Text document

Definition at line 489 of file qwt_painter.cpp.

drawText() [1/4]

void QwtPainter::drawText ( QPainter *  painter, const QPointF &  pos, const QString &  text  )

static

Wrapper for QPainter::drawText()

Definition at line 445 of file qwt_painter.cpp.

drawText() [2/4]

void QwtPainter::drawText ( QPainter *  painter, const QRectF &  rect, int  flags, const QString &  text  )

static

Wrapper for QPainter::drawText()

Definition at line 470 of file qwt_painter.cpp.

drawText() [3/4]

void QwtPainter::drawText ( QPainter *  painter, qreal  x, qreal  y, const QString &  text  )

static

Wrapper for QPainter::drawText()

Definition at line 438 of file qwt_painter.cpp.

drawText() [4/4]

void QwtPainter::drawText ( QPainter *  painter, qreal  x, qreal  y, qreal  w, qreal  h, int  flags, const QString &  text  )

static

Wrapper for QPainter::drawText()

Definition at line 462 of file qwt_painter.cpp.

effectivePenWidth()

qreal QwtPainter::effectivePenWidth ( const QPen &  pen )

inlinestatic

Returns

pen.widthF() expanded to at least 1.0

Parameters

pen

Pen

Definition at line 201 of file qwt_painter.h.

fillPixmap()

void QwtPainter::fillPixmap ( const QWidget *  widget, QPixmap &  pixmap, const QPoint &  offset = QPoint()  )

static

Fill a pixmap with the content of a widget

In Qt >= 5.0 QPixmap::fill() is a nop, in Qt 4.x it is buggy for backgrounds with gradients. Thus fillPixmap() offers an alternative implementation.

Parameters

widget	Widget
pixmap	Pixmap to be filled
offset	Offset

See also

QPixmap::fill()

Definition at line 1311 of file qwt_painter.cpp.

fillRect()

void QwtPainter::fillRect ( QPainter *  painter, const QRectF &  rect, const QBrush &  brush  )

static

Wrapper for QPainter::fillRect()

Definition at line 382 of file qwt_painter.cpp.

horizontalAdvance() [1/4]

int QwtPainter::horizontalAdvance ( const QFontMetrics &  fontMetrics, const QString &  text  )

static

Distance appropriate for drawing a subsequent character after text.

Parameters

fontMetrics	Font metrics
text	Text

Returns

horizontal advance in pixels

Definition at line 1379 of file qwt_painter.cpp.

horizontalAdvance() [2/4]

int QwtPainter::horizontalAdvance ( const QFontMetrics &  fontMetrics, QChar  ch  )

static

Distance appropriate for drawing a subsequent character after ch.

Parameters

fontMetrics	Font metrics
ch	Character

Returns

horizontal advance in pixels

Definition at line 1414 of file qwt_painter.cpp.

horizontalAdvance() [3/4]

qreal QwtPainter::horizontalAdvance ( const QFontMetricsF &  fontMetrics, const QString &  text  )

static

Distance appropriate for drawing a subsequent character after text.

Parameters

fontMetrics	Font metrics
text	Text

Returns

horizontal advance in pixels

Definition at line 1397 of file qwt_painter.cpp.

horizontalAdvance() [4/4]

qreal QwtPainter::horizontalAdvance ( const QFontMetricsF &  fontMetrics, QChar  ch  )

static

Distance appropriate for drawing a subsequent character after ch.

Parameters

fontMetrics	Font metrics
ch	Character

Returns

horizontal advance in pixels

Definition at line 1431 of file qwt_painter.cpp.

isAligning()

bool QwtPainter::isAligning ( const QPainter *  painter )

static

Check if the painter is using a paint engine, that aligns coordinates to integers. Today these are all paint engines beside QPaintEngine::Pdf and QPaintEngine::SVG.

If we have an integer based paint engine it is also checked if the painter has a transformation matrix, that rotates or scales.

Parameters

painter

Painter

Returns

true, when the painter is aligning

See also

setRoundingAlignment()

Definition at line 267 of file qwt_painter.cpp.

isX11GraphicsSystem()

bool QwtPainter::isX11GraphicsSystem ( )

static

Check is the application is running with the X11 graphics system that has some special capabilities that can be used for incremental painting to a widget.

Returns

True, when the graphics system is X11

Definition at line 233 of file qwt_painter.cpp.

polylineSplitting()

bool QwtPainter::polylineSplitting ( )

inlinestatic

Returns

True, when line splitting for the raster paint engine is enabled.

See also

setPolylineSplitting()

Definition at line 170 of file qwt_painter.h.

roundingAlignment() [1/2]

bool QwtPainter::roundingAlignment ( )

inlinestatic

Check whether coordinates should be rounded, before they are painted to a paint engine that rounds to integer values. For other paint engines ( PDF, SVG ), this flag has no effect.

Returns

True, when rounding is enabled

See also

setRoundingAlignment(), isAligning()

Definition at line 183 of file qwt_painter.h.

roundingAlignment() [2/2]

bool QwtPainter::roundingAlignment ( const QPainter *  painter )

inlinestatic

Returns

roundingAlignment() && isAligning(painter);

Parameters

painter

Painter

Definition at line 192 of file qwt_painter.h.

scaledFont()

QFont QwtPainter::scaledFont ( const QFont &  font, const QPaintDevice *  paintDevice = nullptr  )

static

Adjust the DPI value of font according to the DPI value of the paint device

Parameters

font	Unscaled font
paintDevice	Paint device providing a DPI value. If paintDevice == null the DPI value of the primary screen will be used

Returns

Font being adjusted to the DPI value of the paint device

Definition at line 1450 of file qwt_painter.cpp.

setPolylineSplitting()

void QwtPainter::setPolylineSplitting ( bool  enable )

static

En/Disable line splitting for the raster paint engine.

In some Qt versions the raster paint engine paints polylines of many points much faster when they are split in smaller chunks: f.e all supported Qt versions >= Qt 5.0 when drawing an antialiased polyline with a pen width >=2.

Also the raster paint engine has a nasty bug in many versions ( Qt 4.8 - ... ) for short lines ( https://codereview.qt-project.org/#/c/99456 ), that is worked around in this mode.

The default setting is true.

See also

polylineSplitting()

Definition at line 335 of file qwt_painter.cpp.

setRoundingAlignment()

void QwtPainter::setRoundingAlignment ( bool  enable )

static

Enable whether coordinates should be rounded, before they are painted to a paint engine that floors to integer values. For other paint engines ( PDF, SVG ) this flag has no effect. QwtPainter stores this flag only, the rounding itself is done in the painting code ( f.e the plot items ).

The default setting is true.

See also

roundingAlignment(), isAligning()

Definition at line 315 of file qwt_painter.cpp.

Member Data Documentation

m_polylineSplitting

bool QwtPainter::m_polylineSplitting = true

staticprivate

Definition at line 131 of file qwt_painter.h.

m_roundingAlignment

bool QwtPainter::m_roundingAlignment = true

staticprivate

Definition at line 132 of file qwt_painter.h.

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The documentation for this class was generated from the following files:

• qwt_painter.h
• qwt_painter.cpp