#include <qwt_plot_canvas.h>

类 QwtPlotCanvas 继承关系图:

类
class	PrivateData

Public 类型
enum	PaintAttribute { BackingStore = 1 , Opaque = 2 , HackStyledBackground = 4 , ImmediatePaint = 8 }
	Paint attributes 更多...

Public 类型继承自 QwtPlotAbstractCanvas
enum	FocusIndicator { NoFocusIndicator , CanvasFocusIndicator , ItemFocusIndicator }
	Focus indicator 更多...

Public 槽
void	replot ()
	Invalidate the paint cache and repaint the canvas

Public 成员函数
	QwtPlotCanvas (QwtPlot *=nullptr)
	Constructor

void	setPaintAttribute (PaintAttribute, bool on=true)
	Change the paint attributes

bool	testPaintAttribute (PaintAttribute) const
	Test whether a paint attribute is enabled

const QPixmap *	backingStore () const
	Get the backing store

Q_INVOKABLE void	invalidateBackingStore ()
	Invalidate the internal backing store

virtual bool	event (QEvent *) override
	Qt event handler for QEvent::PolishRequest and QEvent::StyleChange

Q_INVOKABLE QPainterPath	borderPath (const QRect &) const
	Calculate the painter path for a styled or rounded border

Public 成员函数继承自 QwtPlotAbstractCanvas
	QwtPlotAbstractCanvas (QWidget *canvasWidget)
	Constructor

QwtPlot *	plot ()
	Return parent plot widget

const QwtPlot *	plot () const
	Return parent plot widget

void	setFocusIndicator (FocusIndicator)
	Set the focus indicator

FocusIndicator	focusIndicator () const
	Get the focus indicator

void	setBorderRadius (double)
	Set the radius for the corners of the border frame

double	borderRadius () const
	Get the radius for the corners of the border frame

Protected 成员函数
virtual void	paintEvent (QPaintEvent *) override
	Paint event handler

virtual void	resizeEvent (QResizeEvent *) override
	Resize event handler

virtual void	drawBorder (QPainter *) override
	Draw border

Protected 成员函数继承自 QwtPlotAbstractCanvas
QWidget *	canvasWidget ()

const QWidget *	canvasWidget () const

virtual void	drawFocusIndicator (QPainter *)
	Draw the focus indication

virtual void	drawBackground (QPainter *)
	Helper function for the derived plot canvas

void	fillBackground (QPainter *)
	Helper function for the derived plot canvas

void	drawCanvas (QPainter *)
	Draw the plot to the canvas

void	drawStyled (QPainter *, bool)
	Helper function for the derived plot canvas

void	drawUnstyled (QPainter *)
	Helper function for the derived plot canvas

QPainterPath	canvasBorderPath (const QRect &rect) const

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

属性
double	borderRadius

详细描述

Canvas of a QwtPlot

Canvas is the widget where all plot items are displayed

参见: QwtPlot::setCanvas(), QwtPlotGLCanvas, QwtPlotOpenGLCanvas

成员枚举类型说明

◆ PaintAttribute

enum QwtPlotCanvas::PaintAttribute

Paint attributes

The default setting enables BackingStore and Opaque.

参见: setPaintAttribute(), testPaintAttribute()

枚举值
BackingStore	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). 参见 backingStore(), invalidateBackingStore()
Opaque	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 (e.g. 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. 警告 Will not work for semitransparent backgrounds.
HackStyledBackground	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	ImmediatePaint When ImmediatePaint is set replot() calls repaint() instead of update(). 参见 replot(), QWidget::repaint(), QWidget::update()

构造及析构函数说明

◆ QwtPlotCanvas()

QwtPlotCanvas::QwtPlotCanvas ( QwtPlot * plot = nullptr )

explicit

Constructor

参数

[in] plot Parent plot widget

参见: QwtPlot::setCanvas()

Destructor

成员函数说明

◆ backingStore()

const QPixmap * QwtPlotCanvas::backingStore ( ) const

Get the backing store

返回: Backing store pixmap, might be null

◆ borderPath()

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

Calculate the painter path for a styled or rounded border

参数

[in] rect Bounding rectangle of the canvas

返回: Painter path that can be used for clipping

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

◆ drawBorder()

void QwtPlotCanvas::drawBorder ( QPainter * painter )

overrideprotectedvirtual

Draw border

Draw the border of the plot canvas

参数

painter Painter

参见: setBorderRadius()

重载 QwtPlotAbstractCanvas .

◆ event()

bool QwtPlotCanvas::event ( QEvent * event )

overridevirtual

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

参数

[in] event Qt Event

返回: See QFrame::event()

◆ paintEvent()

void QwtPlotCanvas::paintEvent ( QPaintEvent * event )

overrideprotectedvirtual

Paint event handler

Paint event

参数

event Paint event

◆ replot

void QwtPlotCanvas::replot ( )

slot

Invalidate the paint cache and repaint the canvas

参见: invalidatePaintCache()

◆ resizeEvent()

void QwtPlotCanvas::resizeEvent ( QResizeEvent * event )

overrideprotectedvirtual

Resize event handler

Resize event

参数

event Resize event

◆ setPaintAttribute()

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

Change the paint attributes

参数

[in]	attribute	Paint attribute
[in]	on	On/Off

参见: testPaintAttribute(), backingStore()

◆ testPaintAttribute()

bool QwtPlotCanvas::testPaintAttribute ( PaintAttribute attribute ) const

Test whether a paint attribute is enabled

参数

[in] attribute Paint attribute

返回: true when attribute is enabled

参见: setPaintAttribute()

该类的文档由以下文件生成:

/home/runner/work/QWT/QWT/src/plot/qwt_plot_canvas.h
/home/runner/work/QWT/QWT/src/plot/qwt_plot_canvas.cpp

类

Public 类型

Public 槽

Public 成员函数

Protected 成员函数

属性

详细描述

成员枚举类型说明

◆ PaintAttribute

构造及析构函数说明

◆ QwtPlotCanvas()

成员函数说明

◆ backingStore()

◆ borderPath()

◆ drawBorder()

◆ event()

◆ paintEvent()

◆ replot

◆ resizeEvent()

◆ setPaintAttribute()

◆ testPaintAttribute()