QwtLegendData Class Reference

Attributes of an entry on a legend. More...

#include <qwt_legend_data.h>

Public Types
enum	Mode { ReadOnly , Clickable , Checkable }
	Mode defining how a legend entry interacts. More...
enum	Role { ModeRole , TitleRole , IconRole , UserRole = 32 }
	Identifier how to interpret a QVariant. More...

Public Member Functions
	QwtLegendData ()
	Constructor.
	QwtLegendData (const QwtLegendData &)
	Copy constructor.
	QwtLegendData (QwtLegendData &&) noexcept=default
	~QwtLegendData ()
	Destructor.
QwtLegendData &	operator= (const QwtLegendData &)
	Copy assignment.
QwtLegendData &	operator= (QwtLegendData &&) noexcept=default
void	setValues (const QMap< int, QVariant > &)
	Set the legend attributes.
const QMap< int, QVariant > &	values () const
	Return the legend attributes.
void	setValue (int role, const QVariant &)
	Set an attribute value.
QVariant	value (int role) const
	Return the attribute value for a specific role.
bool	hasRole (int role) const
	Check if a value exists for a specific role.
bool	isValid () const
	Check if the legend data is valid.
QwtGraphic	icon () const
	Return the icon.
QwtText	title () const
	Return the title.
Mode	mode () const
	Return the mode.

Detailed Description

Attributes of an entry on a legend.

QwtLegendData is an abstract container (like QAbstractModel) to exchange attributes that are only known between the plot item and the legend. By overloading QwtPlotItem::legendData() any other set of attributes could be used that can be handled by a modified (or completely different) implementation of a legend.

See also

QwtLegend, QwtPlotLegendItem

Note

The stockchart example implements a legend as a tree with checkable items

Member Enumeration Documentation

Mode

enum QwtLegendData::Mode

Mode defining how a legend entry interacts.

Enumerator
ReadOnly	The legend item is not interactive, like a label.
Clickable	The legend item is clickable, like a push button.
Checkable	The legend item is checkable, like a checkable button.

Role

enum QwtLegendData::Role

Identifier how to interpret a QVariant.

Enumerator
ModeRole	The value is a Mode.
TitleRole	The value is a title.
IconRole	The value is an icon.
UserRole	Values < UserRole are reserved for internal use.

Member Function Documentation

hasRole()

bool QwtLegendData::hasRole

(

int

role

)

const

Check if a value exists for a specific role.

Parameters

role	Attribute role

Returns

True, when the internal map has an entry for role

See also

setValue(), value()

icon()

QwtGraphic QwtLegendData::icon

(

)

const

Return the icon.

Returns

Value of the IconRole attribute

See also

title(), mode()

isValid()

bool QwtLegendData::isValid

(

)

const

Check if the legend data is valid.

Returns

True, when the internal map is empty

See also

setValues(), setValue()

mode()

QwtLegendData::Mode QwtLegendData::mode

(

)

const

Return the mode.

Returns

Value of the ModeRole attribute

ReadOnly when no mode is set

See also

title(), icon()

setValue()

void QwtLegendData::setValue	(	int	role,
		const QVariant &	data
	)

Set an attribute value.

Parameters

role	Attribute role
data	Attribute value

See also

value()

setValues()

void QwtLegendData::setValues

(

const QMap< int, QVariant > &

map

)

Set the legend attributes.

QwtLegendData actually is a QMap<int, QVariant> with some convenience interfaces

Parameters

map

Values

See also

values()

title()

QwtText QwtLegendData::title

(

)

const

Return the title.

Returns

Value of the TitleRole attribute

See also

icon(), mode()

value()

QVariant QwtLegendData::value

(

int

role

)

const

Return the attribute value for a specific role.

Parameters

role	Attribute role

Returns

Attribute value for a specific role

See also

setValue()

values()

const QMap< int, QVariant > & QwtLegendData::values

(

)

const

Return the legend attributes.

Returns

Legend attributes

See also

setValues()

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

• /home/runner/work/QWT/QWT/src/plot/qwt_legend_data.h
• /home/runner/work/QWT/QWT/src/plot/qwt_legend_data.cpp