Layout engine for QwtPlot components 更多...

#include <qwt_plot_layout_engine.h>

类
struct	Dimensions
	Structure holding dimension values for layout calculation 更多...

class	LayoutData
	Data structure for layout calculation 更多...

Public 成员函数
	QwtPlotLayoutEngine ()
	Default constructor for QwtPlotLayoutEngine

QRectF	layoutLegend (int plotLayoutOptions, const LayoutData::LegendData &legendData, const QRectF &rect, const QSize &legendHint) const
	Calculate legend rectangle within available space

QRectF	alignLegend (const QSize &legendHint, const QRectF &canvasRect, const QRectF &legendRect) const
	Align legend rectangle relative to canvas

void	alignScales (int plotLayoutOptions, const LayoutData &layoutData, QRectF &canvasRect, QRectF scaleRect[QwtAxis::AxisPositions]) const
	Align scale rectangles with canvas

void	alignScalesToCanvas (int plotLayoutOptions, const LayoutData &layoutData, const QRectF &canvasRect, QRectF scaleRect[QwtAxis::AxisPositions]) const
	Align scale rectangles to canvas boundaries

Dimensions	layoutDimensions (int plotLayoutOptions, const LayoutData &layoutData, const QRectF &rect) const
	Iteratively calculate the layout dimensions for a QwtPlot

void	setSpacing (unsigned int spacing)
	Set spacing value

unsigned int	spacing () const
	Get spacing value

void	setAlignCanvas (int axisPos, bool on)
	Set canvas alignment to scale for a specific axis position

bool	alignCanvas (int axisPos) const
	Check if canvas is aligned to scale for a specific axis position

void	setCanvasMargin (int axisPos, int margin)
	Set canvas margin for a specific axis position

int	canvasMargin (int axisPos) const
	Get canvas margin for a specific axis position

void	setLegendPos (QwtPlot::LegendPosition pos)
	Set the legend position

QwtPlot::LegendPosition	legendPos () const
	Get the legend position

void	setLegendRatio (double ratio)
	Set the legend ratio

double	legendRatio () const
	Get the legend ratio

详细描述

Layout engine for QwtPlot components

Originally a private class in QwtPlotLayout, previously written as class LayoutEngine in qwt_plot_layout.cpp. It was extracted as a public class because other layouts need to use it.

构造及析构函数说明

◆ QwtPlotLayoutEngine()

QwtPlotLayoutEngine::QwtPlotLayoutEngine ( )

Default constructor for QwtPlotLayoutEngine

Initializes the layout engine with default values: legend position Bottom, legend ratio 1.0, spacing 5 pixels.

成员函数说明

◆ alignCanvas()

bool QwtPlotLayoutEngine::alignCanvas ( int axisPos ) const

Check if canvas is aligned to scale for a specific axis position

参数

[in] axisPos Axis position (0-3)

返回: True if canvas is aligned to scale

◆ alignLegend()

QRectF QwtPlotLayoutEngine::alignLegend	(	const QSize &	legendHint,
		const QRectF &	canvasRect,
		const QRectF &	legendRect
	)		const

Align legend rectangle relative to canvas

Adjusts the legend rectangle to be properly aligned with the canvas, ensuring it doesn't extend beyond the canvas boundaries when possible.

参数

[in]	legendHint	Preferred size hint for the legend
[in]	canvasRect	Canvas rectangle
[in]	legendRect	Initial legend rectangle

返回: Aligned legend rectangle

◆ alignScales()

void QwtPlotLayoutEngine::alignScales	(	int	plotLayoutOptions,
		const LayoutData &	layoutData,
		QRectF &	canvasRect,
		QRectF	scaleRect[QwtAxis::AxisPositions]
	)		const

Align scale rectangles with canvas

Adjusts the positions of scale rectangles to ensure proper alignment with the canvas, taking into account border distances and tick offsets. This function handles the complex layout calculation involving multiple axes and canvas spatial coordination.

参数

[in]	plotLayoutOptions	Layout options bitmask
[in]	layoutData	Precalculated layout data
[out]	canvasRect	Canvas rectangle (may be modified)
[out]	scaleRect	Array of scale rectangles (will be modified)

Initialize backbone offset First calculate the backbone offset for each axis, which consists of:

Add canvas margin if not aligning canvas to scale
Add canvas content margins if not ignoring frames

Handle the mutual influence of X and Y axes Iterate all axis positions and handle the spatial interaction between X and Y axes:

For X axes (horizontal): Check the influence of left and right Y axes Calculate left/right offsets, considering axis start/end distances and backbone offsets Adjust X axis rectangle position, and canvas rectangle if necessary

For Y axes (vertical): Check the influence of bottom and top X axes Calculate top/bottom offsets, considering axis start/end distances and backbone offsets Adjust Y axis rectangle position, and canvas rectangle if necessary

When the axis needs more space than available, the function adjusts the canvas rectangle

After mutual adjustment of all axes, the function performs final alignment to ensure axes are properly aligned with canvas edges

◆ alignScalesToCanvas()

void QwtPlotLayoutEngine::alignScalesToCanvas	(	int	plotLayoutOptions,
		const LayoutData &	layoutData,
		const QRectF &	canvasRect,
		QRectF	scaleRect[QwtAxis::AxisPositions]
	)		const

Align scale rectangles to canvas boundaries

Adjusts the positions of scale rectangles to align with canvas boundaries, taking into account border distances and tick offsets. Unlike alignScales, this function does not modify the canvas rectangle.

参数

[in]	plotLayoutOptions	Layout options bitmask
[in]	layoutData	Precalculated layout data
[in]	canvasRect	Canvas rectangle
[out]	scaleRect	Array of scale rectangles (will be modified)

Initialize backbone offset First calculate the backbone offset for each axis, which consists of:

Add canvas margin if not aligning canvas to scale
Add canvas content margins if not ignoring frames

Handle the mutual influence of X and Y axes Iterate all axis positions and handle the spatial interaction between X and Y axes:

For X axes (horizontal): Check the influence of left and right Y axes Calculate left/right offsets, considering axis start/end distances and backbone offsets Adjust X axis rectangle position, and canvas rectangle if necessary

For Y axes (vertical): Check the influence of bottom and top X axes Calculate top/bottom offsets, considering axis start/end distances and backbone offsets Adjust Y axis rectangle position, and canvas rectangle if necessary

After mutual adjustment of all axes, the function performs final alignment to ensure axes are properly aligned with canvas edges

◆ canvasMargin()

int QwtPlotLayoutEngine::canvasMargin ( int axisPos ) const

Get canvas margin for a specific axis position

参数

[in] axisPos Axis position (0-3)

返回: Canvas margin value

◆ layoutDimensions()

QwtPlotLayoutEngine::Dimensions QwtPlotLayoutEngine::layoutDimensions	(	int	plotLayoutOptions,
		const LayoutData &	layoutData,
		const QRectF &	rect
	)		const

Iteratively calculate the layout dimensions for a QwtPlot

Determines the exact space (in pixels) that every visual component of a QwtPlot—title, footer, and the four axes—needs inside a given rectangle. Because the required size of one component affects the available space for all others, the algorithm loops until the dimensions stabilize.

参数

[in]	plotLayoutOptions	Layout options bitmask
[in]	layoutData	Precalculated layout data
[in]	rect	Available rectangle for layout

返回: Dimensions structure with calculated sizes

◆ layoutLegend()

QRectF QwtPlotLayoutEngine::layoutLegend	(	int	plotLayoutOptions,
		const LayoutData::LegendData &	legendData,
		const QRectF &	rect,
		const QSize &	legendHint
	)		const

Calculate legend rectangle within available space

Determines the optimal position and size for the legend based on the specified legend position and ratio constraints.

参数

[in]	plotLayoutOptions	Layout options bitmask
[in]	legendData	Precalculated legend data
[in]	rect	Available rectangle for layout
[in]	legendHint	Preferred size hint for the legend

返回: Calculated legend rectangle

◆ legendPos()

QwtPlot::LegendPosition QwtPlotLayoutEngine::legendPos ( ) const

Get the legend position

返回: Current legend position

◆ legendRatio()

double QwtPlotLayoutEngine::legendRatio ( ) const

Get the legend ratio

返回: Current legend ratio value

◆ setAlignCanvas()

void QwtPlotLayoutEngine::setAlignCanvas	(	int	axisPos,
		bool	on
	)

Set canvas alignment to scale for a specific axis position

参数

[in]	axisPos	Axis position (0-3)
[in]	on	True to align canvas to scale

◆ setCanvasMargin()

void QwtPlotLayoutEngine::setCanvasMargin	(	int	axisPos,
		int	margin
	)

Set canvas margin for a specific axis position

参数

[in]	axisPos	Axis position (0-3)
[in]	margin	New canvas margin value

◆ setLegendPos()

void QwtPlotLayoutEngine::setLegendPos ( QwtPlot::LegendPosition pos )

Set the legend position

参数

[in] pos New legend position

◆ setLegendRatio()

void QwtPlotLayoutEngine::setLegendRatio ( double ratio )

Set the legend ratio

参数

[in] ratio New legend ratio value

◆ setSpacing()

void QwtPlotLayoutEngine::setSpacing ( unsigned int spacing )

Set spacing value

参数

[in] spacing New spacing value in pixels

◆ spacing()

unsigned int QwtPlotLayoutEngine::spacing ( ) const

Get spacing value

返回: Current spacing value in pixels

该类的文档由以下文件生成:

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

类

Public 成员函数

详细描述

构造及析构函数说明

◆ QwtPlotLayoutEngine()

成员函数说明

◆ alignCanvas()

◆ alignLegend()

◆ alignScales()

◆ alignScalesToCanvas()

◆ canvasMargin()

◆ layoutDimensions()

◆ layoutLegend()

◆ legendPos()

◆ legendRatio()

◆ setAlignCanvas()

◆ setCanvasMargin()

◆ setLegendPos()

◆ setLegendRatio()

◆ setSpacing()

◆ spacing()