显示栅格数据的类更多...

#include <qwt_plot_rasteritem.h>

类 QwtPlotRasterItem 继承关系图:

类
class	PrivateData

Public 类型
enum	CachePolicy { NoCache , PaintCache }
	缓存策略更多...

enum	PaintAttribute { PaintInDeviceResolution = 1 }
	绘制属性更多...

Public 类型继承自 QwtPlotItem
enum	RttiValues { Rtti_PlotItem = 0 , Rtti_PlotGrid , Rtti_PlotScale , Rtti_PlotLegend , Rtti_PlotMarker , Rtti_PlotCurve , Rtti_PlotSpectroCurve , Rtti_PlotIntervalCurve , Rtti_PlotHistogram , Rtti_PlotSpectrogram , Rtti_PlotGraphic , Rtti_PlotTradingCurve , Rtti_PlotBarChart , Rtti_PlotMultiBarChart , Rtti_PlotShape , Rtti_PlotTextLabel , Rtti_PlotZone , Rtti_PlotVectorField , Rtti_PlotArrowMarker , Rtti_PlotBoxChart , Rtti_PlotUserItem = 1000 }
	运行时类型信息更多...

enum	ItemAttribute { Legend = 0x01 , AutoScale = 0x02 , Margins = 0x04 }
	绘图项属性更多...

enum	ItemInterest { ScaleInterest = 0x01 , LegendInterest = 0x02 }
	绘图项关注的事件类型更多...

enum	RenderHint { RenderAntialiased = 0x1 }
	渲染提示更多...

Public 成员函数
	QwtPlotRasterItem (const QString &title=QString())
	构造函数

	QwtPlotRasterItem (const QwtText &title)
	构造函数（带标题）

virtual	~QwtPlotRasterItem ()
	析构函数

void	setPaintAttribute (PaintAttribute, bool on=true)
	设置绘制属性

bool	testPaintAttribute (PaintAttribute) const
	测试绘制属性

void	setAlpha (int alpha)
	设置栅格数据的 alpha 值

int	alpha () const
	获取栅格项的 alpha 值

void	setCachePolicy (CachePolicy)
	更改缓存策略

CachePolicy	cachePolicy () const
	获取缓存策略

void	invalidateCache ()
	使绘制缓存失效

virtual void	draw (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect) const override
	绘制栅格数据

virtual QRectF	pixelHint (const QRectF &) const
	像素提示

virtual QwtInterval	interval (Qt::Axis) const
	获取轴的边界区间

virtual QRectF	boundingRect () const override
	获取数据的边界矩形

Public 成员函数继承自 QwtPlotItem
	QwtPlotItem ()
	Default constructor

	QwtPlotItem (const QString &title)
	Constructor with title as QString

	QwtPlotItem (const QwtText &title)
	Constructor with title as QwtText

virtual	~QwtPlotItem ()
	Destructor

void	attach (QwtPlot *plot)
	Attach the item to a plot

void	detach ()
	Detach the item from the plot

QwtPlot *	plot () const
	Get the plot the item is attached to

void	setTitle (const QString &title)
	Set the title using a QString

void	setTitle (const QwtText &title)
	Set the title using a QwtText

const QwtText &	title () const
	Get the title

virtual int	rtti () const
	Runtime type information

void	setItemAttribute (ItemAttribute, bool on=true)
	Set an item attribute

bool	testItemAttribute (ItemAttribute) const
	Test an item attribute

void	setItemInterest (ItemInterest, bool on=true)
	Set an item interest

bool	testItemInterest (ItemInterest) const
	Test an item interest

void	setRenderHint (RenderHint, bool on=true)
	Set a render hint

bool	testRenderHint (RenderHint) const
	Test a render hint

void	setRenderThreadCount (uint numThreads)
	Set the number of render threads

uint	renderThreadCount () const
	Get the number of render threads

void	setLegendIconSize (const QSize &)
	Set the legend icon size

QSize	legendIconSize () const
	Get the legend icon size

double	z () const
	Get the z-value

void	setZ (double z)
	Set the z-value

void	show ()
	Show the item

void	hide ()
	Hide the item

virtual void	setVisible (bool)
	Set the visibility

bool	isVisible () const
	Check if the item is visible

void	setAxes (QwtAxisId xAxis, QwtAxisId yAxis)
	Set both axes

void	setXAxis (QwtAxisId)
	Set the x-axis

QwtAxisId	xAxis () const
	Get the x-axis

void	setYAxis (QwtAxisId)
	Set the y-axis

QwtAxisId	yAxis () const
	Get the y-axis

virtual void	itemChanged ()
	Notify the plot that the item has changed

virtual void	legendChanged ()
	Notify the item that the legend has changed

virtual void	getCanvasMarginHint (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, double &left, double &top, double &right, double &bottom) const
	Get margin hints for the canvas

virtual void	updateScaleDiv (const QwtScaleDiv &, const QwtScaleDiv &)
	Update the item with new scale divisions

virtual void	updateLegend (const QwtPlotItem *, const QList< QwtLegendData > &)
	Update the item with changes of the legend

QRectF	scaleRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the scale rectangle

QRectF	paintRect (const QwtScaleMap &, const QwtScaleMap &) const
	Calculate the paint rectangle

virtual QList< QwtLegendData >	legendData () const
	Return legend data

virtual QwtGraphic	legendIcon (int index, const QSizeF &) const
	Return a legend icon

Protected 成员函数
virtual QImage	renderImage (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &area, const QSize &imageSize) const =0
	渲染图像

virtual QwtScaleMap	imageMap (Qt::Orientation, const QwtScaleMap &map, const QRectF &area, const QSize &imageSize, double pixelSize) const
	Get the image map

Protected 成员函数继承自 QwtPlotItem
QwtGraphic	defaultIcon (const QBrush &, const QSizeF &) const
	Create a default icon

详细描述

显示栅格数据的类

成员枚举类型说明

◆ CachePolicy

enum QwtPlotRasterItem::CachePolicy

缓存策略

枚举值

NoCache

每次项目需要重绘时调用 renderImage()

PaintCache

当图像缓存无效，或比例尺或画布大小发生变化时，调用 renderImage()。

这种类型的缓存对于提高隐藏/显示操作或 alpha 值操作的性能很有用。所有其他情况由画布后备存储处理。

◆ PaintAttribute

enum QwtPlotRasterItem::PaintAttribute

绘制属性

枚举值
PaintInDeviceResolution	当图像根据数据像素（QwtRasterData::pixelHint()）渲染时，在传递给 QPainter 之前，可以将其扩展到绘制设备分辨率。扩展算法以与轴刻度相同的方式舍入像素边界，这通常比 Qt 中实现的缩放算法更好。禁用此标志可能有助于减少文档/文件的大小。这是否可能取决于特定 QPaintEngine 的实现。

构造及析构函数说明

◆ QwtPlotRasterItem() [1/2]

QwtPlotRasterItem::QwtPlotRasterItem ( const QString & title = QString() )

explicit

构造函数

◆ QwtPlotRasterItem() [2/2]

QwtPlotRasterItem::QwtPlotRasterItem ( const QwtText & title )

explicit

构造函数（带标题）

◆ ~QwtPlotRasterItem()

QwtPlotRasterItem::~QwtPlotRasterItem ( )

virtual

析构函数

成员函数说明

◆ alpha()

int QwtPlotRasterItem::alpha ( ) const

获取栅格项的 alpha 值

◆ boundingRect()

QRectF QwtPlotRasterItem::boundingRect ( ) const

overridevirtual

获取数据的边界矩形

重载 QwtPlotItem .

◆ cachePolicy()

QwtPlotRasterItem::CachePolicy QwtPlotRasterItem::cachePolicy ( ) const

获取缓存策略

◆ draw()

void QwtPlotRasterItem::draw	(	QPainter *	painter,
		const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	canvasRect
	)		const

overridevirtual

绘制栅格数据

实现了 QwtPlotItem.

被 QwtPlotSpectrogram 重载.

◆ imageMap()

QwtScaleMap QwtPlotRasterItem::imageMap	(	Qt::Orientation	orientation,
		const QwtScaleMap &	map,
		const QRectF &	area,
		const QSize &	imageSize,
		double	pixelSize
	)		const

protectedvirtual

Get the image map

Calculate a scale map for painting to an image

参数

orientation	Orientation, Qt::Horizontal means a X axis
map	Scale map for rendering the plot item
area	Area to be painted on the image
imageSize	Image size
pixelSize	Width/Height of a data pixel

返回: Calculated scale map

◆ interval()

QwtInterval QwtPlotRasterItem::interval ( Qt::Axis axis ) const

virtual

获取轴的边界区间

被 QwtPlotSpectrogram 重载.

◆ invalidateCache()

void QwtPlotRasterItem::invalidateCache ( )

使绘制缓存失效

◆ pixelHint()

QRectF QwtPlotRasterItem::pixelHint ( const QRectF & area ) const

virtual

像素提示

被 QwtPlotSpectrogram 重载.

◆ renderImage()

virtual QImage QwtPlotRasterItem::renderImage	(	const QwtScaleMap &	xMap,
		const QwtScaleMap &	yMap,
		const QRectF &	area,
		const QSize &	imageSize
	)		const

protectedpure virtual

渲染图像

在 QwtPlotSpectrogram 内被实现.

◆ setAlpha()

void QwtPlotRasterItem::setAlpha ( int alpha )

设置栅格数据的 alpha 值

◆ setCachePolicy()

void QwtPlotRasterItem::setCachePolicy ( QwtPlotRasterItem::CachePolicy policy )

更改缓存策略

◆ setPaintAttribute()

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

设置绘制属性

◆ testPaintAttribute()

bool QwtPlotRasterItem::testPaintAttribute ( PaintAttribute attribute ) const

测试绘制属性

该类的文档由以下文件生成:

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

类

Public 类型

Public 成员函数

Protected 成员函数

详细描述

成员枚举类型说明

◆ CachePolicy

◆ PaintAttribute

构造及析构函数说明

◆ QwtPlotRasterItem() [1/2]

◆ QwtPlotRasterItem() [2/2]

◆ ~QwtPlotRasterItem()

成员函数说明

◆ alpha()

◆ boundingRect()

◆ cachePolicy()

◆ draw()

◆ imageMap()

◆ interval()

◆ invalidateCache()

◆ pixelHint()

◆ renderImage()

◆ setAlpha()

◆ setCachePolicy()

◆ setPaintAttribute()

◆ testPaintAttribute()