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QwtPolarCanvas(3) Qwt User's Guide QwtPolarCanvas(3)


QwtPolarCanvas - Canvas of a QwtPolarPlot.


#include <qwt_polar_canvas.h>

Inherits QFrame.

Public Types

enum PaintAttribute { BackingStore = 0x01 }
Paint attributes. typedef QFlags< PaintAttribute > PaintAttributes

Public Member Functions

QwtPolarCanvas (QwtPolarPlot *)
Constructor. virtual ~QwtPolarCanvas ()
Destructor. QwtPolarPlot * plot ()
const QwtPolarPlot * plot () const
void setPaintAttribute (PaintAttribute, bool on=true)
Changing the paint attributes. bool testPaintAttribute (PaintAttribute) const
const QPixmap * backingStore () const
void invalidateBackingStore ()
Invalidate the internal backing store. QwtPointPolar invTransform (const QPoint &) const
QPoint transform (const QwtPointPolar &) const

Protected Member Functions

virtual void paintEvent (QPaintEvent *) override
virtual void resizeEvent (QResizeEvent *) override

Detailed Description

Canvas of a QwtPolarPlot.

The canvas is the widget, where all polar items are painted to.


In opposite to QwtPlot all axes are painted on the canvas.

See also


Definition at line 27 of file qwt_polar_canvas.h.

Member Typedef Documentation

typedef QFlags<PaintAttribute > QwtPolarCanvas::PaintAttributes

An ORed combination of PaintAttribute values.

Definition at line 50 of file qwt_polar_canvas.h.

Member Enumeration Documentation

enum QwtPolarCanvas::PaintAttribute

Paint attributes. The default setting enables BackingStore

See also

setPaintAttribute(), testPaintAttribute(), backingStore()


Paint double buffered and reuse the content of the pixmap buffer for some spontaneous repaints that happen when a plot gets unhidden, deiconified or changes the focus.

Definition at line 40 of file qwt_polar_canvas.h.

Member Function Documentation

const QPixmap * QwtPolarCanvas::backingStore () const


Backing store, might be null

Definition at line 170 of file qwt_polar_canvas.cpp.

QwtPointPolar QwtPolarCanvas::invTransform (const QPoint & pos) const

Translate a point from widget into plot coordinates


pos Point in widget coordinates of the plot canvas


Point in plot coordinates

See also


Definition at line 267 of file qwt_polar_canvas.cpp.

void QwtPolarCanvas::paintEvent (QPaintEvent * event) [override], [protected], [virtual]

Paint event


event Paint event

Definition at line 186 of file qwt_polar_canvas.cpp.

QwtPolarPlot * QwtPolarCanvas::plot ()


Parent plot widget

Definition at line 97 of file qwt_polar_canvas.cpp.

const QwtPolarPlot * QwtPolarCanvas::plot () const


Parent plot widget

Definition at line 103 of file qwt_polar_canvas.cpp.

void QwtPolarCanvas::resizeEvent (QResizeEvent * event) [override], [protected], [virtual]

Resize event


event Resize event

Definition at line 251 of file qwt_polar_canvas.cpp.

void QwtPolarCanvas::setPaintAttribute (PaintAttribute attribute, bool on = true)

Changing the paint attributes.


attribute Paint attribute
on On/Off

The default setting enables BackingStore

See also

testPaintAttribute(), paintCache()

Definition at line 118 of file qwt_polar_canvas.cpp.

bool QwtPolarCanvas::testPaintAttribute (PaintAttribute attribute) const

Test whether a paint attribute is enabled


attribute Paint attribute


true if the attribute is enabled

See also


Definition at line 164 of file qwt_polar_canvas.cpp.

QPoint QwtPolarCanvas::transform (const QwtPointPolar & polarPos) const

Translate a point from plot into widget coordinates


polarPos Point in plot coordinates


Point in widget coordinates

See also


Definition at line 310 of file qwt_polar_canvas.cpp.


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Sun Jul 18 2021 Version 6.2.0