# QwtPlotLayout Class Reference

Layout engine for QwtPlot. More...

`#include <qwt_plot_layout.h>`

List of all members.

## Public Types
enum | Options { AlignScales = 1, IgnoreScrollbars = 2, IgnoreFrames = 4, IgnoreMargin = 8, IgnoreLegend = 16 }
## Public Member Functions
| QwtPlotLayout ()
virtual | ~QwtPlotLayout ()
void | setMargin (int)
int | margin () const
void | setCanvasMargin (int margin, int axis=-1)
int | canvasMargin (int axis) const
void | setAlignCanvasToScales (bool)
bool | alignCanvasToScales () const
void | setSpacing (int)
int | spacing () const
void | setLegendPosition (QwtPlot::LegendPosition pos, double ratio)
void | setLegendPosition (QwtPlot::LegendPosition pos)
QwtPlot::LegendPosition | legendPosition () const
void | setLegendRatio (double ratio)
double | legendRatio () const
virtual QSize | minimumSizeHint (const QwtPlot *) const
virtual void | activate (const QwtPlot *, const QRect &rect, int options=0)
virtual void | invalidate ()
const QRect & | titleRect () const
const QRect & | legendRect () const
const QRect & | scaleRect (int axis) const
const QRect & | canvasRect () const
## Protected Member Functions
QRect | layoutLegend (int options, const QRect &) const
QRect | alignLegend (const QRect &canvasRect, const QRect &legendRect) const
void | expandLineBreaks (int options, const QRect &rect, int &dimTitle, int dimAxes[QwtPlot::axisCnt]) const
void | alignScales (int options, QRect &canvasRect, QRect 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.

## Member Enumeration Documentation

enum QwtPlotLayout::Options

Options to configure the plot layout engine

- AlignScales
  Unused
- IgnoreScrollbars
  Ignore the dimension of the scrollbars. There are no scrollbars, when the plot is rendered to a paint device (QwtPlot::print() ).
- IgnoreFrames
  Ignore all frames. QwtPlot::print() doesn't paint them.
- IgnoreMargin
  Ignore the margin().
- IgnoreLegend
  Ignore the legend.

See also:
  activate()

## Constructor & Destructor Documentation

QwtPlotLayout::QwtPlotLayout | ( |  | ) | `[explicit]`

Constructor.

QwtPlotLayout::~QwtPlotLayout | ( |  | ) | `[virtual]`

Destructor.

## Member Function Documentation

void QwtPlotLayout::activate | ( | const QwtPlot * | plot,
|  | const QRect & | plotRect,
|  | int | options = `0` |
| ) |  |  | `[virtual]`

Recalculate the geometry of all components.

Parameters:

  | plot | Plot to be layout
  | plotRect | Rect where to place the components
  | options | Options

See also:
  invalidate(), Options, titleRect(), legendRect(), scaleRect(), canvasRect()

bool QwtPlotLayout::alignCanvasToScales | ( |  | ) | 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.

Returns:
  align-canvas-to-axis-scales setting

See also:
  setAlignCanvasToScales, setCanvasMargin()

Note:
  In this context the term 'scale' means the backbone of a scale.

QRect QwtPlotLayout::alignLegend | ( | const QRect & | canvasRect,
|  | const QRect & | legendRect |
| ) |  |  | const`[protected]`

Align the legend to the canvas

Parameters:

  | canvasRect | Geometry of the canvas
  | legendRect | Maximum geometry for the legend

Returns:
  Geometry for the aligned legend

void QwtPlotLayout::alignScales | ( | int | options,
|  | QRect & | canvasRect,
|  | QRect | scaleRect[QwtPlot::axisCnt] |
| ) |  |  | const`[protected]`

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

See also:
  Options

int QwtPlotLayout::canvasMargin | ( | int | axis | ) | const

Returns:
  Margin around the scale tick borders

See also:
  setCanvasMargin()

const QRect & QwtPlotLayout::canvasRect | ( |  | ) | const

Returns:
  Geometry for the canvas

See also:
  activate(), invalidate()

void QwtPlotLayout::expandLineBreaks | ( | int | options,
|  | const QRect & | rect,
|  | int & | dimTitle,
|  | 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:

  | options | Options how to layout the legend
  | rect | Bounding rect for title, axes and canvas.
  | dimTitle | Expanded height of the title widget
  | dimAxis | Expanded heights of the axis in axis orientation.

See also:
  Options

void QwtPlotLayout::invalidate | ( |  | ) | `[virtual]`

Invalidate the geometry of all components.

See also:
  activate()

QRect QwtPlotLayout::layoutLegend | ( | int | options,
|  | const QRect & | rect |
| ) |  |  | const`[protected]`

Find the geometry for the legend

Parameters:

  | options | Options how to layout the legend
  | rect | Rectangle where to place the legend

Returns:
  Geometry for the legend

See also:
  Options

QwtPlot::LegendPosition QwtPlotLayout::legendPosition | ( |  | ) | const

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()

const QRect & QwtPlotLayout::legendRect | ( |  | ) | const

Returns:
  Geometry for the legend

See also:
  activate(), invalidate()

int QwtPlotLayout::margin | ( |  | ) | const

Returns:
  margin

See also:
  setMargin(), spacing(), QwtPlot::margin()

QSize QwtPlotLayout::minimumSizeHint | ( | const QwtPlot * | plot | ) | const`[virtual]`

Return a minimum size hint.

See also:
  QwtPlot::minimumSizeHint()

const QRect & QwtPlotLayout::scaleRect | ( | int | axis | ) | const

Parameters:

  | axis | Axis index

Returns:
  Geometry for the scale

See also:
  activate(), invalidate()

void QwtPlotLayout::setAlignCanvasToScales | ( | bool | alignCanvasToScales | ) |

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.

Parameters:

  | alignCanvasToScales | New align-canvas-to-axis-scales setting

See also:
  setCanvasMargin()

Note:
  In this context the term 'scale' means the backbone of a scale.

Warning:
  In case of alignCanvasToScales == true canvasMargin will have no effect

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:

  | margin | New margin
  | axis | One 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 alignCanvasToScales is true

void QwtPlotLayout::setLegendPosition | ( | QwtPlot::LegendPosition | pos | ) |

Specify the position of the legend.

Parameters:

  | pos | The legend's position. Valid values are `QwtPlot::LeftLegend`, `QwtPlot::RightLegend`, `QwtPlot::TopLegend`, `QwtPlot::BottomLegend`.

See also:
  QwtPlot::setLegendPosition()

void QwtPlotLayout::setLegendPosition | ( | QwtPlot::LegendPosition | pos,
|  | double | ratio |
| ) |  |  |

Specify the position of the legend.

Parameters:

  | pos | The legend's position.
  | ratio | Ratio between legend and the bounding rect of title, canvas and axes. The legend will be shrinked 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()

void QwtPlotLayout::setLegendRatio | ( | double | ratio | ) |

Specify the relative size of the legend in the plot

Parameters:

  | ratio | Ratio between legend and the bounding rect of title, canvas and axes. The legend will be shrinked 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::setMargin | ( | int | margin | ) |

Change the margin of the plot. The margin is the space around all components.

Parameters:

  | margin | new margin

See also:
  margin(), setSpacing(), QwtPlot::setMargin()

void QwtPlotLayout::setSpacing | ( | int | spacing | ) |

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

Parameters:

  | spacing | new spacing

See also:
  setMargin(), spacing()

int QwtPlotLayout::spacing | ( |  | ) | const

Returns:
  spacing

See also:
  margin(), setSpacing()

const QRect & QwtPlotLayout::titleRect | ( |  | ) | const

Returns:
  Geometry for the title

See also:
  activate(), invalidate()