QwtLegend(3) Qwt User's Guide QwtLegend(3) NAME QwtLegend - The legend widget. SYNOPSIS #include Inherits QwtAbstractLegend. Public Slots virtual void updateLegend (const QVariant &, const QList< QwtLegendData > &) override 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 *) override virtual QSize sizeHint () const override Return a size hint. virtual int heightForWidth (int w) const override QScrollBar * horizontalScrollBar () const QScrollBar * verticalScrollBar () const virtual void renderLegend (QPainter *, const QRectF &, bool fillBackground) const override virtual void renderItem (QPainter *, const QWidget *, const QRectF &, bool fillBackground) const virtual bool isEmpty () const override virtual int scrollExtent (Qt::Orientation) const override 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 *, 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 Definition at line 31 of file qwt_legend.h. Constructor & Destructor Documentation QwtLegend::QwtLegend (QWidget * parent = NULL) [explicit] Constructor Parameters parent Parent widget Definition at line 258 of file qwt_legend.cpp. 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 Definition at line 355 of file qwt_legend.cpp. 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 Definition at line 385 of file qwt_legend.cpp. 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. Definition at line 467 of file qwt_legend.cpp. QwtLegendData::Mode QwtLegend::defaultItemMode () const Returns Default item mode See also setDefaultItemMode() Definition at line 344 of file qwt_legend.cpp. bool QwtLegend::eventFilter (QObject * object, QEvent * event) [override], [virtual] Handle QEvent::ChildRemoved and QEvent::LayoutRequest events for the contentsWidget(). Parameters object Object to be filtered event Event Returns Forwarded to QwtAbstractLegend::eventFilter() Definition at line 559 of file qwt_legend.cpp. int QwtLegend::heightForWidth (int width) const [override], [virtual] Returns The preferred height, for a width. Parameters width Width Definition at line 538 of file qwt_legend.cpp. QScrollBar * QwtLegend::horizontalScrollBar () const Returns Horizontal scrollbar See also verticalScrollBar() Definition at line 364 of file qwt_legend.cpp. bool QwtLegend::isEmpty () const [override], [virtual] Returns True, when no item is inserted Implements QwtAbstractLegend. Definition at line 810 of file qwt_legend.cpp. void QwtLegend::itemChecked (bool on) [protected], [slot] Called internally when the legend has been checked Emits a checked() signal. Definition at line 638 of file qwt_legend.cpp. void QwtLegend::itemClicked () [protected], [slot] Called internally when the legend has been clicked on. Emits a clicked() signal. Definition at line 616 of file qwt_legend.cpp. 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() Definition at line 804 of file qwt_legend.cpp. 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 Definition at line 788 of file qwt_legend.cpp. 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() Definition at line 777 of file qwt_legend.cpp. uint QwtLegend::maxColumns () const Returns Maximum number of entries in a row See also setMaxColumns(), QwtDynGridLayout::maxColumns() Definition at line 310 of file qwt_legend.cpp. 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 Definition at line 727 of file qwt_legend.cpp. void QwtLegend::renderLegend (QPainter * painter, const QRectF & rect, bool fillBackground) const [override], [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. Definition at line 665 of file qwt_legend.cpp. int QwtLegend::scrollExtent (Qt::Orientation orientation) const [override], [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. Definition at line 821 of file qwt_legend.cpp. 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. Definition at line 335 of file qwt_legend.cpp. 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() Definition at line 296 of file qwt_legend.cpp. void QwtLegend::updateLegend (const QVariant & itemInfo, const QList< QwtLegendData > & legendData) [override], [virtual], [slot] Update the entries for an item. Parameters itemInfo Info for an item legendData List of legend entry attributes for the item Definition at line 396 of file qwt_legend.cpp. 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. Definition at line 489 of file qwt_legend.cpp. QScrollBar * QwtLegend::verticalScrollBar () const Returns Vertical scrollbar See also horizontalScrollBar() Definition at line 373 of file qwt_legend.cpp. Author Generated automatically by Doxygen for Qwt User's Guide from the source code. Version 6.2.0 Sun Jul 18 2021 QwtLegend(3)