QwtPlotLegendItem - Man Page

A class which draws a legend inside the plot canvas.

Synopsis

#include <qwt_plot_legenditem.h>

Inherits QwtPlotItem.

Public Types

enum BackgroundMode { LegendBackground, ItemBackground }
Background mode.

QwtPlotLegendItem ()
Constructor.
virtual ~QwtPlotLegendItem ()
Destructor.
virtual int rtti () const override
void setAlignmentInCanvas (Qt::Alignment)
Set the alignmnet.
Qt::Alignment alignmentInCanvas () const
void setOffsetInCanvas (Qt::Orientations, int numPixels)
Set the distance between the legend and the canvas border.
int offsetInCanvas (Qt::Orientation) const
void setMaxColumns (uint)
Limit the number of columns.
uint maxColumns () const
void setMargin (int)
Set the margin around legend items.
int margin () const
void setSpacing (int)
Set the spacing between the legend items.
int spacing () const
void setItemMargin (int)
int itemMargin () const
void setItemSpacing (int)
int itemSpacing () const
void setFont (const QFont &)
QFont font () const
void setBorderRadius (double)
double borderRadius () const
void setBorderPen (const QPen &)
QPen borderPen () const
void setBackgroundBrush (const QBrush &)
Set the background brush.
QBrush backgroundBrush () const
void setBackgroundMode (BackgroundMode)
Set the background mode.
BackgroundMode backgroundMode () const
void setTextPen (const QPen &)
Set the pen for drawing text labels.
QPen textPen () const
virtual void draw (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect) const override
void clearLegend ()
Remove all items from the legend.
virtual void updateLegend (const QwtPlotItem *, const QList< QwtLegendData > &) override
virtual QRect geometry (const QRectF &canvasRect) const
virtual QSize minimumSize (const QwtLegendData &) const
virtual int heightForWidth (const QwtLegendData &, int width) const
QList< const QwtPlotItem * > plotItems () const
QList< QRect > legendGeometries (const QwtPlotItem *) const

Protected Member Functions

virtual void drawLegendData (QPainter *, const QwtPlotItem *, const QwtLegendData &, const QRectF &) const
virtual void drawBackground (QPainter *, const QRectF &rect) const

Detailed Description

A class which draws a legend inside the plot canvas.

QwtPlotLegendItem can be used to draw a inside the plot canvas. It can be used together with a QwtLegend or instead of it to have more space for the plot canvas.

In opposite to QwtLegend the legend item is not interactive. To identify mouse clicks on a legend item an event filter needs to be installed catching mouse events ob the plot canvas. The geometries of the legend items are available using legendGeometries().

The legend item is aligned to plot canvas according to its alignment() flags. It might have a background for the complete legend ( usually semi transparent ) or for each legend item.

Note: An external QwtLegend with a transparent background on top the plot canvas might be another option with a similar effect.

Definition at line 41 of file qwt_plot_legenditem.h.

Member Enumeration Documentation

enum QwtPlotLegendItem::BackgroundMode

Background mode. Depending on the mode the complete legend or each item might have an background.

The default setting is LegendBackground.

See also: setBackgroundMode(), setBackgroundBrush(), drawBackground()

Enumerator

LegendBackground: The legend has a background.
ItemBackground: Each item has a background.

Definition at line 54 of file qwt_plot_legenditem.h.

Member Function Documentation

Qt::Alignment QwtPlotLegendItem::alignmentInCanvas () const

Returns: Alignment flags
See also: setAlignmentInCanvas()

Definition at line 223 of file qwt_plot_legenditem.cpp.

QBrush QwtPlotLegendItem::backgroundBrush () const

Returns: Brush is used to fill the background
See also: setBackgroundBrush(), backgroundMode(), drawBackground()

Definition at line 522 of file qwt_plot_legenditem.cpp.

QwtPlotLegendItem::BackgroundMode QwtPlotLegendItem::backgroundMode () const

Returns: backgroundMode
See also: setBackgroundMode(), backgroundBrush(), drawBackground()

Definition at line 550 of file qwt_plot_legenditem.cpp.

QPen QwtPlotLegendItem::borderPen () const

Returns: Pen for drawing the border
See also: setBorderPen(), backgroundBrush()

Definition at line 496 of file qwt_plot_legenditem.cpp.

double QwtPlotLegendItem::borderRadius () const

Returns: Radius of the border
See also: setBorderRadius(), setBorderPen()

Definition at line 472 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::draw (QPainter * painter, const QwtScaleMap & xMap, const QwtScaleMap & yMap, const QRectF & canvasRect) const [override], [virtual]

Draw the legend

Parameters: painter Painter
xMap x Scale Map
yMap y Scale Map
canvasRect Contents rectangle of the canvas in painter coordinates

Implements QwtPlotItem.

Definition at line 587 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::drawBackground (QPainter * painter, const QRectF & rect) const [protected], [virtual]

Draw a rounded rect

Parameters: painter Painter
rect Bounding rectangle
See also: setBorderRadius(), setBorderPen(), setBackgroundBrush(), setBackgroundMode()

Definition at line 630 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::drawLegendData (QPainter * painter, const QwtPlotItem * plotItem, const QwtLegendData & data, const QRectF & rect) const [protected], [virtual]

Draw an entry on the legend

Parameters: painter Qt Painter
plotItem Plot item, represented by the entry
data Attributes of the legend entry
rect Bounding rectangle for the entry

Definition at line 780 of file qwt_plot_legenditem.cpp.

QFont QwtPlotLegendItem::font () const

Returns: Font used for drawing the text label
See also: setFont()

Definition at line 389 of file qwt_plot_legenditem.cpp.

QRect QwtPlotLegendItem::geometry (const QRectF & canvasRect) const [virtual]

Calculate the geometry of the legend on the canvas

Parameters: canvasRect Geometry of the canvas
Returns: Geometry of the legend

Definition at line 650 of file qwt_plot_legenditem.cpp.

int QwtPlotLegendItem::heightForWidth (const QwtLegendData & data, int width) const [virtual]

Returns: The preferred height, for a width.
Parameters: data Attributes of the legend entry
width Width

Definition at line 862 of file qwt_plot_legenditem.cpp.

int QwtPlotLegendItem::itemMargin () const

Returns: Margin around each item
See also: setItemMargin(), itemSpacing(), margin(), spacing()

Definition at line 335 of file qwt_plot_legenditem.cpp.

int QwtPlotLegendItem::itemSpacing () const

Returns: Spacing inside of each item
See also: setItemSpacing(), itemMargin(), margin(), spacing()

Definition at line 363 of file qwt_plot_legenditem.cpp.

QList< QRect > QwtPlotLegendItem::legendGeometries (const QwtPlotItem * plotItem) const

Returns: Geometries of the items of a plot item
Note: Usually a plot item has only one entry on the legend

Definition at line 895 of file qwt_plot_legenditem.cpp.

int QwtPlotLegendItem::margin () const

Returns: Margin around the legend items
See also: setMargin(), spacing(), itemMargin(), itemSpacing()

Definition at line 280 of file qwt_plot_legenditem.cpp.

uint QwtPlotLegendItem::maxColumns () const

Returns: Maximum number of columns
See also: maxColumns(), QwtDynGridLayout::maxColumns()

Definition at line 251 of file qwt_plot_legenditem.cpp.

QSize QwtPlotLegendItem::minimumSize (const QwtLegendData & data) const [virtual]

Minimum size hint needed to display an entry

Parameters: data Attributes of the legend entry
Returns: Minimum size

Definition at line 823 of file qwt_plot_legenditem.cpp.

int QwtPlotLegendItem::offsetInCanvas (Qt::Orientation orientation) const

Parameters: orientation Qt::Horizontal is for the left/right, Qt::Vertical for the top/bottom padding.
Returns: Distance between the legend and the canvas border
See also: setOffsetInCanvas()

Definition at line 444 of file qwt_plot_legenditem.cpp.

QList< const QwtPlotItem * > QwtPlotLegendItem::plotItems () const

Returns: All plot items with an entry on the legend
Note: A plot item might have more than one entry on the legend

Definition at line 886 of file qwt_plot_legenditem.cpp.

int QwtPlotLegendItem::rtti () const [override], [virtual]

Returns: QwtPlotItem::Rtti_PlotLegend

Reimplemented from QwtPlotItem.

Definition at line 192 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setAlignmentInCanvas (Qt::Alignment alignment)

Set the alignmnet. Alignment means the position of the legend relative to the geometry of the plot canvas.

Parameters: alignment Alignment flags
See also: alignmentInCanvas(), setMaxColumns()
Note: To align a legend with many items horizontally the number of columns need to be limited

Definition at line 210 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setBackgroundBrush (const QBrush & brush)

Set the background brush. The brush is used to fill the background

Parameters: brush Brush
See also: backgroundBrush(), setBackgroundMode(), drawBackground()

Definition at line 509 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setBackgroundMode (BackgroundMode mode)

Set the background mode. Depending on the mode the complete legend or each item might have an background.

The default setting is LegendBackground.

See also: backgroundMode(), setBackgroundBrush(), drawBackground()

Definition at line 537 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setBorderPen (const QPen & pen)

Set the pen for drawing the border

Parameters: pen Border pen
See also: borderPen(), setBackgroundBrush()

Definition at line 483 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setBorderRadius (double radius)

Set the radius for the border

Parameters: radius A value <= 0 defines a rectangular border
See also: borderRadius(), setBorderPen()

Definition at line 457 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setFont (const QFont & font)

Change the font used for drawing the text label

Parameters: font Legend font
See also: font()

Definition at line 374 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setItemMargin (int margin)

Set the margin around each item

Parameters: margin Margin
See also: itemMargin(), setItemSpacing(), setMargin(), setSpacing()

Definition at line 319 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setItemSpacing (int spacing)

Set the spacing inside of each item

Parameters: spacing Spacing
See also: itemSpacing(), setItemMargin(), setMargin(), setSpacing()

Definition at line 346 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setMargin (int margin)

Set the margin around legend items. The default setting for the margin is 0.

Parameters: margin Margin in pixels
See also: margin(), setSpacing(), setItemMargin(), setItemSpacing

Definition at line 264 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setMaxColumns (uint maxColumns)

Limit the number of columns. When aligning the legend horizontally ( Qt::AlignLeft, Qt::AlignRight ) the number of columns needs to be limited to avoid, that the width of the legend grows with an increasing number of entries.

Parameters: maxColumns Maximum number of columns. 0 means unlimited.
See also: maxColumns(), QwtDynGridLayout::setMaxColumns()

Definition at line 238 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setOffsetInCanvas (Qt::Orientations orientations, int numPixels)

Set the distance between the legend and the canvas border. The default setting is 10 pixels.

Parameters: orientations Qt::Horizontal is for the left/right, Qt::Vertical for the top/bottom offset.
numPixels Distance in pixels
See also: setMargin()

Definition at line 405 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setSpacing (int spacing)

Set the spacing between the legend items.

Parameters: spacing Spacing in pixels
See also: spacing(), setMargin()

Definition at line 294 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::setTextPen (const QPen & pen)

Set the pen for drawing text labels.

Parameters: pen Text pen
See also: textPen(), setFont()

Definition at line 561 of file qwt_plot_legenditem.cpp.

int QwtPlotLegendItem::spacing () const

Returns: Spacing between the legend items
See also: setSpacing(), margin(), itemSpacing(), itemMargin()

Definition at line 308 of file qwt_plot_legenditem.cpp.

QPen QwtPlotLegendItem::textPen () const

Returns: Pen for drawing text labels
See also: setTextPen(), font()

Definition at line 574 of file qwt_plot_legenditem.cpp.

void QwtPlotLegendItem::updateLegend (const QwtPlotItem * plotItem, const QList< QwtLegendData > & data) [override], [virtual]

Update the legend items according to modifications of a plot item

Parameters: plotItem Plot item
data Attributes of the legend entries