#include <qwt_plot_canvas.h>

Inheritance diagram for QwtPlotCanvas:

Classes
class	PrivateData

Public Types
enum	PaintAttribute { BackingStore = 1, Opaque = 2, HackStyledBackground = 4, ImmediatePaint = 8, OpenGLBuffer = 16 }
	Paint attributes. More...

typedef QFlags< PaintAttribute >	PaintAttributes
	Paint attributes. More...

Public Types inherited from QwtPlotAbstractCanvas
enum	FocusIndicator { NoFocusIndicator, CanvasFocusIndicator, ItemFocusIndicator }
	Focus indicator The default setting is NoFocusIndicator. More...

Public Slots
void	replot ()

Public Member Functions
const QPixmap *	backingStore () const

Q_INVOKABLE QPainterPath	borderPath (const QRect &) const

virtual bool	event (QEvent *)

Q_INVOKABLE void	invalidateBackingStore ()
	Invalidate the internal backing store. More...

	QwtPlotCanvas (QwtPlot *=NULL)
	Constructor. More...

void	setPaintAttribute (PaintAttribute, bool on=true)
	Changing the paint attributes. More...

bool	testPaintAttribute (PaintAttribute) const

virtual	~QwtPlotCanvas ()
	Destructor. More...

Public Member Functions inherited from QwtPlotAbstractCanvas
double	borderRadius () const

FocusIndicator	focusIndicator () const

QwtPlot *	plot ()
	Return parent plot widget. More...

const QwtPlot *	plot () const
	Return parent plot widget. More...

	QwtPlotAbstractCanvas (QWidget *canvasWidget)

void	setBorderRadius (double)

void	setFocusIndicator (FocusIndicator)

virtual	~QwtPlotAbstractCanvas ()

Protected Member Functions
virtual void	drawBorder (QPainter *)

virtual void	paintEvent (QPaintEvent *)

virtual void	resizeEvent (QResizeEvent *)

Protected Member Functions inherited from QwtPlotAbstractCanvas
QPainterPath	borderPath2 (const QRect &rect) const

QWidget *	canvasWidget ()

const QWidget *	canvasWidget () const

virtual void	drawBackground (QPainter *)

void	drawCanvas (QPainter *)

virtual void	drawFocusIndicator (QPainter *)

void	drawStyled (QPainter *, bool)

void	drawUnstyled (QPainter *)

void	fillBackground (QPainter *)

void	updateStyleSheetInfo ()
	Update the cached information about the current style sheet. More...

Properties
double	borderRadius

Private Member Functions
QImage	toImageFBO (const QSize &size)

Private Attributes
PrivateData *	d_data

Detailed Description

Canvas of a QwtPlot.

Canvas is the widget where all plot items are displayed

See also: QwtPlot::setCanvas(), QwtPlotGLCanvas

Definition at line 28 of file qwt_plot_canvas.h.

Member Typedef Documentation

typedef QFlags<PaintAttribute> QwtPlotCanvas::PaintAttributes

Paint attributes.

Definition at line 126 of file qwt_plot_canvas.h.

Member Enumeration Documentation

enum QwtPlotCanvas::PaintAttribute

Paint attributes.

The default setting enables BackingStore and Opaque.

See also: setPaintAttribute(), testPaintAttribute()

Enumerator
BackingStore	Paint double buffered reusing the content of the pixmap buffer when possible. Using a backing store might improve the performance significantly, when working with widget overlays ( like rubber bands ). Disabling the cache might improve the performance for incremental paints (using QwtPlotDirectPainter ). See also backingStore(), invalidateBackingStore()
Opaque	Try to fill the complete contents rectangle of the plot canvas. When using styled backgrounds Qt assumes, that the canvas doesn't fill its area completely ( f.e because of rounded borders ) and fills the area below the canvas. When this is done with gradients it might result in a serious performance bottleneck - depending on the size. When the Opaque attribute is enabled the canvas tries to identify the gaps with some heuristics and to fill those only. Warning Will not work for semitransparent backgrounds
HackStyledBackground	Try to improve painting of styled backgrounds. QwtPlotCanvas supports the box model attributes for customizing the layout with style sheets. Unfortunately the design of Qt style sheets has no concept how to handle backgrounds with rounded corners - beside of padding. When HackStyledBackground is enabled the plot canvas tries to separate the background from the background border by reverse engineering to paint the background before and the border after the plot items. In this order the border gets perfectly antialiased and you can avoid some pixel artifacts in the corners.
ImmediatePaint	When ImmediatePaint is set replot() calls repaint() instead of update(). See also replot(), QWidget::repaint(), QWidget::update()
OpenGLBuffer	Render the canvas via an OpenGL buffer. In OpenGLBuffer mode the plot scene will be rendered to a temporary OpenGL buffer, that will be translated to a QImage afterwards. Then this image will be painted to the canvas. This mode might be useful for "heavy" plots to achieve hardware acceleration on platforms, where the raster paint engine ( = software renderer ) would be used otherwise. But the penalty for copying out the buffer to the image makes this mode less optimal when looking for high refresh rates of a "lightweight" plot. On a hardware accelerated graphics system ( f.e. Qt4/X11 "native" ) using this mode does not make much sense. Unfortunately those systems have been removed from Qt5. Note The OpenGLBuffer mode has no effect, when "QwtOpenGL" has been disabled in qwtconfig.pri. See also QwtPlotOpenGLCanvas, QwtPlotGLCanvas

Definition at line 43 of file qwt_plot_canvas.h.

Constructor & Destructor Documentation

QwtPlotCanvas::QwtPlotCanvas ( QwtPlot * plot = NULL )

explicit

Constructor.

Parameters

plot	Parent plot widget

See also: QwtPlot::setCanvas()

Definition at line 90 of file qwt_plot_canvas.cpp.

QwtPlotCanvas::~QwtPlotCanvas ( )

virtual

Destructor.

Definition at line 102 of file qwt_plot_canvas.cpp.

Member Function Documentation

const QPixmap * QwtPlotCanvas::backingStore ( ) const

Returns: Backing store, might be null

Definition at line 178 of file qwt_plot_canvas.cpp.

QPainterPath QwtPlotCanvas::borderPath ( const QRect & rect ) const

Calculate the painter path for a styled or rounded border

When the canvas has no styled background or rounded borders the painter path is empty.

Parameters

rect	Bounding rectangle of the canvas

Returns: Painter path, that can be used for clipping

Definition at line 383 of file qwt_plot_canvas.cpp.

void QwtPlotCanvas::drawBorder ( QPainter * painter )

protectedvirtual

Draw the border of the plot canvas

Parameters

painter Painter

See also: setBorderRadius()

Reimplemented from QwtPlotAbstractCanvas.

Definition at line 337 of file qwt_plot_canvas.cpp.

bool QwtPlotCanvas::event ( QEvent * event )

virtual

Qt event handler for QEvent::PolishRequest and QEvent::StyleChange

Parameters

event Qt Event

Returns: See QFrame::event()

Definition at line 196 of file qwt_plot_canvas.cpp.

void QwtPlotCanvas::invalidateBackingStore ( )

Invalidate the internal backing store.

Definition at line 184 of file qwt_plot_canvas.cpp.

void QwtPlotCanvas::paintEvent ( QPaintEvent * event )

protectedvirtual

Paint event

Parameters

event Paint event

Definition at line 223 of file qwt_plot_canvas.cpp.

void QwtPlotCanvas::replot ( )

slot

Invalidate the paint cache and repaint the canvas

See also: invalidatePaintCache()

Definition at line 364 of file qwt_plot_canvas.cpp.

void QwtPlotCanvas::resizeEvent ( QResizeEvent * event )

protectedvirtual

Resize event

Parameters

event Resize event

Definition at line 354 of file qwt_plot_canvas.cpp.

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

Changing the paint attributes.

Parameters

attribute	Paint attribute
on	On/Off

See also: testPaintAttribute(), backingStore()

Definition at line 115 of file qwt_plot_canvas.cpp.

bool QwtPlotCanvas::testPaintAttribute ( PaintAttribute attribute ) const

Test whether a paint attribute is enabled

Parameters

attribute Paint attribute

Returns: true, when attribute is enabled

See also: setPaintAttribute()

Definition at line 172 of file qwt_plot_canvas.cpp.

QImage QwtPlotCanvas::toImageFBO ( const QSize & size )

private

Definition at line 392 of file qwt_plot_canvas.cpp.

Member Data Documentation

PrivateData* QwtPlotCanvas::d_data

private

Definition at line 153 of file qwt_plot_canvas.h.

Property Documentation

double QwtPlotCanvas::borderRadius

readwrite

Definition at line 32 of file qwt_plot_canvas.h.

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

Classes

Public Types

Public Slots

Public Member Functions

Protected Member Functions

Properties

Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

Property Documentation