#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.
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.
	QwtPlotCanvas (QwtPlot *=NULL)
	Constructor.
void	setPaintAttribute (PaintAttribute, bool on=true)
	Changing the paint attributes.
bool	testPaintAttribute (PaintAttribute) const
virtual	~QwtPlotCanvas ()
	Destructor.
Protected Member Functions
virtual void	drawBorder (QPainter *)
virtual void	paintEvent (QPaintEvent *)
virtual void	resizeEvent (QResizeEvent *)
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 ) [protected, virtual]

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 ) [protected, virtual]

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 ) [protected, virtual]

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]

Reimplemented from QwtPlotAbstractCanvas.

Definition at line 153 of file qwt_plot_canvas.h.

Property Documentation

double QwtPlotCanvas::borderRadius [read, write]

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