Provided by: libqwt-doc_6.1.4-2build2_all 
NAME
QwtLegend - The legend widget.
SYNOPSIS
#include <qwt_legend.h>
Inherits QwtAbstractLegend.
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 width) 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 &)
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 & legendData) const [protected], [virtual]
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.
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 > & legendData)
[virtual], [slot]
Update the entries for an item.
Parameters:
itemInfo Info for an item
legendData List of legend entry attributes for the item
void QwtLegend::updateWidget (QWidget * widget, const QwtLegendData & legendData) [protected], [virtual]
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.
QScrollBar * QwtLegend::verticalScrollBar () const
Returns:
Vertical scrollbar
See also:
horizontalScrollBar()
Author
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Version 6.1.4 Wed Jan 2 2019 QwtLegend(3)