QwtLegend Class Reference

The legend widget. More...

#include <qwt_legend.h>

Inheritance diagram for QwtLegend:

Public Slots
virtual void	updateLegend (const QVariant &, const QList< QwtLegendData > &)
	Update the entries for an item.
Signals
void	clicked (const QVariant &itemInfo, int index)
void	checked (const QVariant &itemInfo, bool on, int index)
Public Member Functions
	QwtLegend (QWidget *parent=NULL)
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 ()
const QWidget *	contentsWidget () const
QWidget *	legendWidget (const QVariant &) const
QList< QWidget * >	legendWidgets (const QVariant &) const
QVariant	itemInfo (const QWidget *) const
virtual bool	eventFilter (QObject *, QEvent *)
virtual QSize	sizeHint () const
	Return a size hint.
virtual int	heightForWidth (int w) const
QScrollBar *	horizontalScrollBar () const
QScrollBar *	verticalScrollBar () const
virtual void	renderLegend (QPainter *, const QRectF &, bool fillBackground) const
virtual void	renderItem (QPainter *, const QWidget *, const QRectF &, bool fillBackground) const
virtual bool	isEmpty () const
virtual int	scrollExtent (Qt::Orientation) const
Protected Slots
void	itemClicked ()
void	itemChecked (bool)
Protected Member Functions
virtual QWidget *	createWidget (const QwtLegendData &) const
	Create a widget to be inserted into the legend.
virtual void	updateWidget (QWidget *widget, const QwtLegendData &data)
	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

(

QWidget *

parent = NULL

)

[explicit]

Constructor

Parameters:

parent

Parent widget

---

Member Function Documentation

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()

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()

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

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

QWidget * QwtLegend::createWidget

(

const QwtLegendData &

data

)

const [protected, virtual]

Create a widget to be inserted into the legend.

The default implementation returns a QwtLegendLabel.

Parameters:

data	Attributes of the legend entry

Returns:

Widget representing data on the legend

Note:

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

QwtLegendData::Mode QwtLegend::defaultItemMode

(

)

const

Returns:

Default item mode

See also:

setDefaultItemMode()

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

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

Parameters:

object	Object to be filtered
event	Event

Returns:

Forwarded to QwtAbstractLegend::eventFilter()

int QwtLegend::heightForWidth

(

int

width

)

const [virtual]

Returns:

The preferred height, for a width.

Parameters:

width

Width

QScrollBar * QwtLegend::horizontalScrollBar

(

)

const

Returns:

Horizontal scrollbar

See also:

verticalScrollBar()

bool QwtLegend::isEmpty

(

)

const [virtual]

Returns:

True, when no item is inserted

Implements QwtAbstractLegend.

void QwtLegend::itemChecked

(

bool

on

)

[protected, slot]

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

void QwtLegend::itemClicked

(

)

[protected, slot]

Called internally when the legend has been clicked on. Emits a clicked() signal.

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()

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

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()

uint QwtLegend::maxColumns

(

)

const

Returns:

Maximum number of entries in a row

See also:

setMaxColumns(), QwtDynGridLayout::maxColumns()

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

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.

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.

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.

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()

void QwtLegend::updateLegend	(	const QVariant &	itemInfo,
		const QList< QwtLegendData > &	data
	)		[virtual, slot]

Update the entries for an item.

Parameters:

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

Implements QwtAbstractLegend.

void QwtLegend::updateWidget	(	QWidget *	widget,
		const QwtLegendData &	data
	)		[protected, virtual]

Update the widget.

Parameters:

widget	Usually a QwtLegendLabel
data	Attributes to be displayed

See also:

createWidget()

Note:

When widget is no QwtLegendLabel updateWidget() does nothing.

QScrollBar * QwtLegend::verticalScrollBar

(

)

const

Returns:

Vertical scrollbar

See also:

horizontalScrollBar()

List of all members.