The legend widget. More...

#include <qwt_legend.h>

Inheritance diagram for QwtLegend:

Classes
class	PrivateData

Public Slots
virtual void	updateLegend (const QVariant &, const QList< QwtLegendData > &) QWT_OVERRIDE
	Update the entries for an item.

Public Slots inherited from QwtAbstractLegend
virtual void	updateLegend (const QVariant &itemInfo, const QList< QwtLegendData > &data)=0
	Update the entries for a plot item.

Signals
void	clicked (const QVariant &itemInfo, int index)
	A signal which is emitted when the user has clicked on a legend label, which is in QwtLegendData::Clickable mode.

void	checked (const QVariant &itemInfo, bool on, int index)
	A signal which is emitted when the user has clicked on a legend label, which is in QwtLegendData::Checkable mode.

Public Member Functions
	QwtLegend (QWidget *parent=NULL)
	Constructor.

virtual	~QwtLegend ()
	Destructor.

void	setMaxColumns (uint numColums)
	Set the maximum number of entries in a row.

uint	maxColumns () const

void	setDefaultItemMode (QwtLegendData::Mode)
	Set the default mode for legend labels.

QwtLegendData::Mode	defaultItemMode () const

QWidget *	contentsWidget ()
	The contents widget is the only child of the viewport of the internal QScrollArea and the parent widget of all legend items.

const QWidget *	contentsWidget () const
	The contents widget is the only child of the viewport of the internal QScrollArea and the parent widget of all legend items.

QWidget *	legendWidget (const QVariant &) const

QList< QWidget * >	legendWidgets (const QVariant &) const

QVariant	itemInfo (const QWidget *) const
	Find the item that is associated to a widget.

virtual bool	eventFilter (QObject , QEvent ) QWT_OVERRIDE
	Handle QEvent::ChildRemoved and QEvent::LayoutRequest events for the contentsWidget().

virtual QSize	sizeHint () const QWT_OVERRIDE
	Return a size hint.

virtual int	heightForWidth (int w) const QWT_OVERRIDE

QScrollBar *	horizontalScrollBar () const

QScrollBar *	verticalScrollBar () const

virtual void	renderLegend (QPainter *, const QRectF &, bool fillBackground) const QWT_OVERRIDE
	Render the legend into a given rectangle.

virtual void	renderItem (QPainter , const QWidget , const QRectF &, bool fillBackground) const
	Render a legend entry into a given rectangle.

virtual bool	isEmpty () const QWT_OVERRIDE

virtual int	scrollExtent (Qt::Orientation) const QWT_OVERRIDE
	Return the extent, that is needed for the scrollbars.

Public Member Functions inherited from QwtAbstractLegend
	QwtAbstractLegend (QWidget *parent=NULL)
	Constructor.

virtual	~QwtAbstractLegend ()
	Destructor.

Protected Slots
void	itemClicked ()
	Called internally when the legend has been clicked on.

void	itemChecked (bool)
	Called internally when the legend has been checked Emits a checked() signal.

Protected Member Functions
virtual QWidget *	createWidget (const QwtLegendData &) const
	Create a widget to be inserted into the legend.

virtual void	updateWidget (QWidget *, const QwtLegendData &)
	Update the widget.

Detailed Description

The legend widget.

The QwtLegend widget is a tabular arrangement of legend items. Legend items might be any type of widget, but in general they will be a QwtLegendLabel.

See also: QwtLegendLabel, QwtPlotItem, QwtPlot

Constructor & Destructor Documentation

◆ QwtLegend()

QwtLegend::QwtLegend ( QWidget * parent = NULL )

explicit

Constructor.

Parameters

parent Parent widget

Member Function Documentation

◆ checked

void QwtLegend::checked	(	const QVariant &	itemInfo,
		bool	on,
		int	index
	)

signal

A signal which is emitted when the user has clicked on a legend label, which is in QwtLegendData::Checkable mode.

Parameters

itemInfo	Info for the item of the selected legend label
index	Index of the legend label in the list of widgets that are associated with the plot item
on	True when the legend label is checked

Note: clicks are disabled as default

See also: setDefaultItemMode(), defaultItemMode(), QwtPlot::itemToInfo()

◆ clicked

void QwtLegend::clicked	(	const QVariant &	itemInfo,
		int	index
	)

signal

A signal which is emitted when the user has clicked on a legend label, which is in QwtLegendData::Clickable mode.

Parameters

itemInfo	Info for the item item of the selected legend item
index	Index of the legend label in the list of widgets that are associated with the plot item

Note: clicks are disabled as default

See also: setDefaultItemMode(), defaultItemMode(), QwtPlot::itemToInfo()

◆ contentsWidget() [1/2]

QWidget * QwtLegend::contentsWidget ( )

The contents widget is the only child of the viewport of the internal QScrollArea and the parent widget of all legend items.

Returns: Container widget of the legend items

◆ contentsWidget() [2/2]

const QWidget * QwtLegend::contentsWidget ( ) const

The contents widget is the only child of the viewport of the internal QScrollArea and the parent widget of all legend items.

Returns: Container widget of the legend items

◆ createWidget()

QWidget * QwtLegend::createWidget ( const QwtLegendData & legendData ) const

protectedvirtual

Create a widget to be inserted into the legend.

The default implementation returns a QwtLegendLabel.

Parameters

legendData Attributes of the legend entry

Returns: Widget representing data on the legend

Note: updateWidget() will called soon after createWidget() with the same attributes.

◆ defaultItemMode()

QwtLegendData::Mode QwtLegend::defaultItemMode ( ) const

Returns: Default item mode

See also: setDefaultItemMode()

◆ eventFilter()

bool QwtLegend::eventFilter	(	QObject *	object,
		QEvent *	event
	)

virtual

Handle QEvent::ChildRemoved and QEvent::LayoutRequest events for the contentsWidget().

Parameters

object	Object to be filtered
event	Event

Returns: Forwarded to QwtAbstractLegend::eventFilter()

◆ heightForWidth()

int QwtLegend::heightForWidth ( int width ) const

virtual

Returns: The preferred height, for a width.

Parameters

width Width

◆ horizontalScrollBar()

QScrollBar * QwtLegend::horizontalScrollBar ( ) const

Returns: Horizontal scrollbar

See also: verticalScrollBar()

◆ isEmpty()

bool QwtLegend::isEmpty ( ) const

virtual

Returns: True, when no item is inserted

Implements QwtAbstractLegend.

◆ itemClicked

void QwtLegend::itemClicked ( )

protectedslot

Called internally when the legend has been clicked on.

Emits a clicked() signal.

◆ itemInfo()

QVariant QwtLegend::itemInfo ( const QWidget * widget ) const

Find the item that is associated to a widget.

Parameters

widget Widget on the legend

Returns: Associated item info

See also: legendWidget()

◆ legendWidget()

QWidget * QwtLegend::legendWidget ( const QVariant & itemInfo ) const

Returns: First widget in the list of widgets associated to an item

Parameters

itemInfo Info about an item

See also: itemInfo(), QwtPlot::itemToInfo()

Note: Almost all types of items have only one widget

◆ legendWidgets()

QList< QWidget * > QwtLegend::legendWidgets ( const QVariant & itemInfo ) const

Returns: List of widgets associated to a item

Parameters

itemInfo Info about an item

See also: legendWidget(), itemInfo(), QwtPlot::itemToInfo()

◆ maxColumns()

uint QwtLegend::maxColumns ( ) const

Returns: Maximum number of entries in a row

See also: setMaxColumns(), QwtDynGridLayout::maxColumns()

◆ renderItem()

void QwtLegend::renderItem	(	QPainter *	painter,
		const QWidget *	widget,
		const QRectF &	rect,
		bool	fillBackground
	)		const

virtual

Render a legend entry into a given rectangle.

Parameters

painter	Painter
widget	Widget representing a legend entry
rect	Bounding rectangle
fillBackground	When true, fill rect with the widget background

Note: When widget is not derived from QwtLegendLabel renderItem does nothing beside the background

◆ renderLegend()

void QwtLegend::renderLegend	(	QPainter *	painter,
		const QRectF &	rect,
		bool	fillBackground
	)		const

virtual

Render the legend into a given rectangle.

Parameters

painter	Painter
rect	Bounding rectangle
fillBackground	When true, fill rect with the widget background

See also: renderLegend() is used by QwtPlotRenderer - not by QwtLegend itself

Implements QwtAbstractLegend.

◆ scrollExtent()

int QwtLegend::scrollExtent ( Qt::Orientation orientation ) const

virtual

Return the extent, that is needed for the scrollbars.

Parameters

orientation Orientation

Returns: The width of the vertical scrollbar for Qt::Horizontal and v.v.

Reimplemented from QwtAbstractLegend.

◆ setDefaultItemMode()

void QwtLegend::setDefaultItemMode ( QwtLegendData::Mode mode )

Set the default mode for legend labels.

Legend labels will be constructed according to the attributes in a QwtLegendData object. When it doesn't contain a value for the QwtLegendData::ModeRole the label will be initialized with the default mode of the legend.

Parameters

mode	Default item mode

See also: itemMode(), QwtLegendData::value(), QwtPlotItem::legendData()

Note: Changing the mode doesn't have any effect on existing labels.

◆ setMaxColumns()

void QwtLegend::setMaxColumns ( uint numColums )

Set the maximum number of entries in a row.

F.e when the maximum is set to 1 all items are aligned vertically. 0 means unlimited

Parameters

numColums Maximum number of entries in a row

See also: maxColumns(), QwtDynGridLayout::setMaxColumns()

◆ updateLegend

void QwtLegend::updateLegend	(	const QVariant &	itemInfo,
		const QList< QwtLegendData > &	legendData
	)

virtualslot

Update the entries for an item.

Parameters

itemInfo	Info for an item
legendData	List of legend entry attributes for the item

◆ updateWidget()

void QwtLegend::updateWidget	(	QWidget *	widget,
		const QwtLegendData &	legendData
	)

protectedvirtual

Update the widget.

Parameters

widget	Usually a QwtLegendLabel
legendData	Attributes to be displayed

See also: createWidget()

Note: When widget is no QwtLegendLabel updateWidget() does nothing.

◆ verticalScrollBar()

QScrollBar * QwtLegend::verticalScrollBar ( ) const

Returns: Vertical scrollbar

See also: horizontalScrollBar()

The documentation for this class was generated from the following files:

/home/runner/work/QWT/QWT/src/qwt_legend.h
/home/runner/work/QWT/QWT/src/qwt_legend.cpp

Classes

Public Slots

Signals

Public Member Functions

Protected Slots

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ QwtLegend()

Member Function Documentation

◆ checked

◆ clicked

◆ contentsWidget() [1/2]

◆ contentsWidget() [2/2]

◆ createWidget()

◆ defaultItemMode()

◆ eventFilter()

◆ heightForWidth()

◆ horizontalScrollBar()

◆ isEmpty()

◆ itemClicked

◆ itemInfo()

◆ legendWidget()

◆ legendWidgets()

◆ maxColumns()

◆ renderItem()

◆ renderLegend()

◆ scrollExtent()

◆ setDefaultItemMode()

◆ setMaxColumns()

◆ updateLegend

◆ updateWidget()

◆ verticalScrollBar()