Qwt User's Guide
QwtPlotLayout Class Reference

Layout engine for QwtPlot. More...

#include <qwt_plot_layout.h>

Public Types

enum  Option {
  AlignScales = 0x01, IgnoreScrollbars = 0x02, IgnoreFrames = 0x04, IgnoreLegend = 0x08,
  IgnoreTitle = 0x10, IgnoreFooter = 0x20
}
typedef QFlags< OptionOptions
 Layout options.

Public Member Functions

 QwtPlotLayout ()
 Constructor.
virtual ~QwtPlotLayout ()
 Destructor.
void setCanvasMargin (int margin, int axis=-1)
int canvasMargin (int axis) const
void setAlignCanvasToScales (bool)
 Set the align-canvas-to-axis-scales flag for all axes.
void setAlignCanvasToScale (int axisId, bool)
bool alignCanvasToScale (int axisId) const
void setSpacing (int)
int spacing () const
void setLegendPosition (QwtPlot::LegendPosition pos, double ratio)
 Specify the position of the legend.
void setLegendPosition (QwtPlot::LegendPosition pos)
 Specify the position of the legend.
QwtPlot::LegendPosition legendPosition () const
void setLegendRatio (double ratio)
double legendRatio () const
virtual QSize minimumSizeHint (const QwtPlot *) const
virtual void activate (const QwtPlot *, const QRectF &rect, Options options=0x00)
 Recalculate the geometry of all components.
virtual void invalidate ()
QRectF titleRect () const
QRectF footerRect () const
QRectF legendRect () const
QRectF scaleRect (int axis) const
QRectF canvasRect () const

Protected Member Functions

void setTitleRect (const QRectF &)
 Set the geometry for the title.
void setFooterRect (const QRectF &)
 Set the geometry for the footer.
void setLegendRect (const QRectF &)
 Set the geometry for the legend.
void setScaleRect (int axis, const QRectF &)
 Set the geometry for an axis.
void setCanvasRect (const QRectF &)
 Set the geometry for the canvas.
QRectF layoutLegend (Options options, const QRectF &) const
QRectF alignLegend (const QRectF &canvasRect, const QRectF &legendRect) const
void expandLineBreaks (Options options, const QRectF &rect, int &dimTitle, int &dimFooter, int dimAxes[QwtPlot::axisCnt]) const
void alignScales (Options options, QRectF &canvasRect, QRectF scaleRect[QwtPlot::axisCnt]) const

Detailed Description

Layout engine for QwtPlot.

It is used by the QwtPlot widget to organize its internal widgets or by QwtPlot::print() to render its content to a QPaintDevice like a QPrinter, QPixmap/QImage or QSvgRenderer.

See also:
QwtPlot::setPlotLayout()

Member Enumeration Documentation

Options to configure the plot layout engine

See also:
activate(), QwtPlotRenderer
Enumerator:
AlignScales 

Unused.

IgnoreScrollbars 

Ignore the dimension of the scrollbars. There are no scrollbars, when the plot is not rendered to widgets.

IgnoreFrames 

Ignore all frames.

IgnoreLegend 

Ignore the legend.

IgnoreTitle 

Ignore the title.

IgnoreFooter 

Ignore the footer.


Member Function Documentation

void QwtPlotLayout::activate ( const QwtPlot plot,
const QRectF &  plotRect,
Options  options = 0x00 
) [virtual]

Recalculate the geometry of all components.

Parameters:
plotPlot to be layout
plotRectRectangle where to place the components
optionsLayout options
See also:
invalidate(), titleRect(), footerRect() legendRect(), scaleRect(), canvasRect()
bool QwtPlotLayout::alignCanvasToScale ( int  axisId) const

Return the align-canvas-to-axis-scales setting. The canvas may:

  • extend beyond the axis scale ends to maximize its size
  • align with the axis scale ends to control its size.
Parameters:
axisIdAxis index
Returns:
align-canvas-to-axis-scales setting
See also:
setAlignCanvasToScale(), setAlignCanvasToScale(), setCanvasMargin()
QRectF QwtPlotLayout::alignLegend ( const QRectF &  canvasRect,
const QRectF &  legendRect 
) const [protected]

Align the legend to the canvas

Parameters:
canvasRectGeometry of the canvas
legendRectMaximum geometry for the legend
Returns:
Geometry for the aligned legend
void QwtPlotLayout::alignScales ( Options  options,
QRectF &  canvasRect,
QRectF  scaleRect[QwtPlot::axisCnt] 
) const [protected]

Align the ticks of the axis to the canvas borders using the empty corners.

Parameters:
optionsLayout options
canvasRectGeometry of the canvas ( IN/OUT )
scaleRectGeometries of the scales ( IN/OUT )
See also:
Options
int QwtPlotLayout::canvasMargin ( int  axisId) const
Parameters:
axisIdAxis index
Returns:
Margin around the scale tick borders
See also:
setCanvasMargin()
QRectF QwtPlotLayout::canvasRect ( ) const
Returns:
Geometry for the canvas
See also:
activate(), invalidate()
void QwtPlotLayout::expandLineBreaks ( Options  options,
const QRectF &  rect,
int &  dimTitle,
int &  dimFooter,
int  dimAxis[QwtPlot::axisCnt] 
) const [protected]

Expand all line breaks in text labels, and calculate the height of their widgets in orientation of the text.

Parameters:
optionsOptions how to layout the legend
rectBounding rectangle for title, footer, axes and canvas.
dimTitleExpanded height of the title widget
dimFooterExpanded height of the footer widget
dimAxisExpanded heights of the axis in axis orientation.
See also:
Options
QRectF QwtPlotLayout::footerRect ( ) const
Returns:
Geometry for the footer
See also:
activate(), invalidate()
void QwtPlotLayout::invalidate ( ) [virtual]

Invalidate the geometry of all components.

See also:
activate()
QRectF QwtPlotLayout::layoutLegend ( Options  options,
const QRectF &  rect 
) const [protected]

Find the geometry for the legend

Parameters:
optionsOptions how to layout the legend
rectRectangle where to place the legend
Returns:
Geometry for the legend
See also:
Options
Returns:
Position of the legend
See also:
setLegendPosition(), QwtPlot::setLegendPosition(), QwtPlot::legendPosition()
double QwtPlotLayout::legendRatio ( ) const
Returns:
The relative size of the legend in the plot.
See also:
setLegendPosition()
QRectF QwtPlotLayout::legendRect ( ) const
Returns:
Geometry for the legend
See also:
activate(), invalidate()
QSize QwtPlotLayout::minimumSizeHint ( const QwtPlot plot) const [virtual]
Returns:
Minimum size hint
Parameters:
plotPlot widget
See also:
QwtPlot::minimumSizeHint()
QRectF QwtPlotLayout::scaleRect ( int  axis) const
Parameters:
axisAxis index
Returns:
Geometry for the scale
See also:
activate(), invalidate()
void QwtPlotLayout::setAlignCanvasToScale ( int  axisId,
bool  on 
)

Change the align-canvas-to-axis-scales setting. The canvas may:

  • extend beyond the axis scale ends to maximize its size,
  • align with the axis scale ends to control its size.

The axisId parameter is somehow confusing as it identifies a border of the plot and not the axes, that are aligned. F.e when QwtPlot::yLeft is set, the left end of the the x-axes ( QwtPlot::xTop, QwtPlot::xBottom ) is aligned.

Parameters:
axisIdAxis index
onNew align-canvas-to-axis-scales setting
See also:
setCanvasMargin(), alignCanvasToScale(), setAlignCanvasToScales()
Warning:
In case of on == true canvasMargin() will have no effect

Set the align-canvas-to-axis-scales flag for all axes.

Parameters:
onTrue/False
See also:
setAlignCanvasToScale(), alignCanvasToScale()
void QwtPlotLayout::setCanvasMargin ( int  margin,
int  axis = -1 
)

Change a margin of the canvas. The margin is the space above/below the scale ticks. A negative margin will be set to -1, excluding the borders of the scales.

Parameters:
marginNew margin
axisOne of QwtPlot::Axis. Specifies where the position of the margin. -1 means margin at all borders.
See also:
canvasMargin()
Warning:
The margin will have no effect when alignCanvasToScale() is true
void QwtPlotLayout::setCanvasRect ( const QRectF &  rect) [protected]

Set the geometry for the canvas.

This method is intended to be used from derived layouts overloading activate()

See also:
canvasRect(), activate()
void QwtPlotLayout::setFooterRect ( const QRectF &  rect) [protected]

Set the geometry for the footer.

This method is intended to be used from derived layouts overloading activate()

See also:
footerRect(), activate()

Specify the position of the legend.

Parameters:
posThe legend's position.
ratioRatio between legend and the bounding rectangle of title, footer, canvas and axes. The legend will be shrunk if it would need more space than the given ratio. The ratio is limited to ]0.0 .. 1.0]. In case of <= 0.0 it will be reset to the default ratio. The default vertical/horizontal ratio is 0.33/0.5.
See also:
QwtPlot::setLegendPosition()

Specify the position of the legend.

Parameters:
posThe legend's position. Valid values are QwtPlot::LeftLegend, QwtPlot::RightLegend, QwtPlot::TopLegend, QwtPlot::BottomLegend.
See also:
QwtPlot::setLegendPosition()
void QwtPlotLayout::setLegendRatio ( double  ratio)

Specify the relative size of the legend in the plot

Parameters:
ratioRatio between legend and the bounding rectangle of title, footer, canvas and axes. The legend will be shrunk if it would need more space than the given ratio. The ratio is limited to ]0.0 .. 1.0]. In case of <= 0.0 it will be reset to the default ratio. The default vertical/horizontal ratio is 0.33/0.5.
void QwtPlotLayout::setLegendRect ( const QRectF &  rect) [protected]

Set the geometry for the legend.

This method is intended to be used from derived layouts overloading activate()

Parameters:
rectRectangle for the legend
See also:
legendRect(), activate()
void QwtPlotLayout::setScaleRect ( int  axis,
const QRectF &  rect 
) [protected]

Set the geometry for an axis.

This method is intended to be used from derived layouts overloading activate()

Parameters:
axisAxis index
rectRectangle for the scale
See also:
scaleRect(), activate()
void QwtPlotLayout::setSpacing ( int  spacing)

Change the spacing of the plot. The spacing is the distance between the plot components.

Parameters:
spacingNew spacing
See also:
setCanvasMargin(), spacing()
void QwtPlotLayout::setTitleRect ( const QRectF &  rect) [protected]

Set the geometry for the title.

This method is intended to be used from derived layouts overloading activate()

See also:
titleRect(), activate()
int QwtPlotLayout::spacing ( ) const
Returns:
Spacing
See also:
margin(), setSpacing()
QRectF QwtPlotLayout::titleRect ( ) const
Returns:
Geometry for the title
See also:
activate(), invalidate()

List of all members.

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