QwtPlotBarChart(3) Qwt User's Guide QwtPlotBarChart(3) NAME QwtPlotBarChart - QwtPlotBarChart displays a series of a values as bars. SYNOPSIS #include Inherits QwtPlotAbstractBarChart, and QwtSeriesStore< QPointF >. Public Types enum LegendMode { LegendChartTitle, LegendBarTitles } Legend modes. Public Member Functions QwtPlotBarChart (const QString &title=QString()) QwtPlotBarChart (const QwtText &title) virtual ~QwtPlotBarChart () Destructor. virtual int rtti () const override void setSamples (const QVector< QPointF > &) void setSamples (const QVector< double > &) void setSamples (QwtSeriesData< QPointF > *) void setSymbol (QwtColumnSymbol *) Assign a symbol. const QwtColumnSymbol * symbol () const void setLegendMode (LegendMode) LegendMode legendMode () const virtual void drawSeries (QPainter *, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, int from, int to) const override virtual QRectF boundingRect () const override virtual QwtColumnSymbol * specialSymbol (int sampleIndex, const QPointF &) const virtual QwtText barTitle (int sampleIndex) const Return the title of a bar. Protected Member Functions virtual void drawSample (QPainter *painter, const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, const QwtInterval &boundingInterval, int index, const QPointF &sample) const virtual void drawBar (QPainter *, int sampleIndex, const QPointF &sample, const QwtColumnRect &) const QwtColumnRect columnRect (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, const QwtInterval &boundingInterval, const QPointF &sample) const QList< QwtLegendData > legendData () const override Return all information, that is needed to represent the item on the legend. QwtGraphic legendIcon (int index, const QSizeF &) const override Detailed Description QwtPlotBarChart displays a series of a values as bars. Each bar might be customized individually by implementing a specialSymbol(). Otherwise it is rendered using a default symbol. Depending on its orientation() the bars are displayed horizontally or vertically. The bars cover the interval between the baseline() and the value. By activating the LegendBarTitles mode each sample will have its own entry on the legend. The most common use case of a bar chart is to display a list of y coordinates, where the x coordinate is simply the index in the list. But for other situations ( f.e. when values are related to dates ) it is also possible to set x coordinates explicitly. See also QwtPlotMultiBarChart, QwtPlotHistogram, QwtPlotCurve::Sticks, QwtPlotSeriesItem::orientation(), QwtPlotAbstractBarChart::baseline() Definition at line 41 of file qwt_plot_barchart.h. Member Enumeration Documentation enum QwtPlotBarChart::LegendMode Legend modes. The default setting is QwtPlotBarChart::LegendChartTitle. See also setLegendMode(), legendMode() Enumerator LegendChartTitle One entry on the legend showing the default symbol and the title() of the chart See also QwtPlotItem::title() LegendBarTitles One entry for each value showing the individual symbol of the corresponding bar and the bar title. See also specialSymbol(), barTitle() Definition at line 52 of file qwt_plot_barchart.h. Constructor & Destructor Documentation QwtPlotBarChart::QwtPlotBarChart (const QString & title = QString()) [explicit] Constructor Parameters title Title of the curve Definition at line 51 of file qwt_plot_barchart.cpp. QwtPlotBarChart::QwtPlotBarChart (const QwtText & title) [explicit] Constructor Parameters title Title of the curve Definition at line 41 of file qwt_plot_barchart.cpp. Member Function Documentation QwtText QwtPlotBarChart::barTitle (int sampleIndex) const [virtual] Return the title of a bar. In LegendBarTitles mode the title is displayed on the legend entry corresponding to a bar. The default implementation is a dummy, that is intended to be overloaded. Parameters sampleIndex Index of the bar Returns An empty text See also LegendBarTitles Definition at line 399 of file qwt_plot_barchart.cpp. QRectF QwtPlotBarChart::boundingRect () const [override], [virtual] Returns Bounding rectangle of all samples. For an empty series the rectangle is invalid. Reimplemented from QwtPlotSeriesItem. Definition at line 186 of file qwt_plot_barchart.cpp. QwtColumnRect QwtPlotBarChart::columnRect (const QwtScaleMap & xMap, const QwtScaleMap & yMap, const QRectF & canvasRect, const QwtInterval & boundingInterval, const QPointF & sample) const [protected] Calculate the geometry of a bar in widget coordinates Parameters xMap x map yMap y map canvasRect Contents rect of the canvas boundingInterval Bounding interval of sample values sample Value of the sample Returns Geometry of the column Definition at line 262 of file qwt_plot_barchart.cpp. void QwtPlotBarChart::drawBar (QPainter * painter, int sampleIndex, const QPointF & sample, const QwtColumnRect & rect) const [protected], [virtual] Draw a bar Parameters painter Painter sampleIndex Index of the sample represented by the bar sample Value of the sample rect Bounding rectangle of the bar Definition at line 341 of file qwt_plot_barchart.cpp. void QwtPlotBarChart::drawSample (QPainter * painter, const QwtScaleMap & xMap, const QwtScaleMap & yMap, const QRectF & canvasRect, const QwtInterval & boundingInterval, int index, const QPointF & sample) const [protected], [virtual] Draw a sample Parameters painter Painter xMap x map yMap y map canvasRect Contents rect of the canvas boundingInterval Bounding interval of sample values index Index of the sample sample Value of the sample See also drawSeries() Definition at line 322 of file qwt_plot_barchart.cpp. void QwtPlotBarChart::drawSeries (QPainter * painter, const QwtScaleMap & xMap, const QwtScaleMap & yMap, const QRectF & canvasRect, int from, int to) const [override], [virtual] Draw an interval of the bar chart Parameters painter Painter xMap Maps x-values into pixel coordinates. yMap Maps y-values into pixel coordinates. canvasRect Contents rect of the canvas from Index of the first point to be painted to Index of the last point to be painted. If to < 0 the curve will be painted to its last point. See also drawSymbols() Implements QwtPlotSeriesItem. Definition at line 223 of file qwt_plot_barchart.cpp. QList< QwtLegendData > QwtPlotBarChart::legendData () const [override], [protected], [virtual] Return all information, that is needed to represent the item on the legend. In case of LegendBarTitles an entry for each bar is returned, otherwise the chart is represented like any other plot item from its title() and the legendIcon(). Returns Information, that is needed to represent the item on the legend See also title(), setLegendMode(), barTitle(), QwtLegend, QwtPlotLegendItem Reimplemented from QwtPlotItem. Definition at line 416 of file qwt_plot_barchart.cpp. QwtGraphic QwtPlotBarChart::legendIcon (int index, const QSizeF & size) const [override], [protected], [virtual] Returns Icon representing a bar or the chart on the legend When the legendMode() is LegendBarTitles the icon shows the bar corresponding to index - otherwise the bar displays the default symbol. Parameters index Index of the legend entry size Icon size See also setLegendMode(), drawBar(), QwtPlotItem::setLegendIconSize(), QwtPlotItem::legendData() Reimplemented from QwtPlotItem. Definition at line 462 of file qwt_plot_barchart.cpp. QwtPlotBarChart::LegendMode QwtPlotBarChart::legendMode () const Returns Legend mode See also setLegendMode() Definition at line 177 of file qwt_plot_barchart.cpp. int QwtPlotBarChart::rtti () const [override], [virtual] Returns QwtPlotItem::Rtti_PlotBarChart Reimplemented from QwtPlotItem. Definition at line 70 of file qwt_plot_barchart.cpp. void QwtPlotBarChart::setLegendMode (LegendMode mode) Set the mode that decides what to display on the legend In case of LegendBarTitles barTitle() needs to be overloaded to return individual titles for each bar. Parameters mode New mode See also legendMode(), legendData(), barTitle(), QwtPlotItem::ItemAttribute Definition at line 164 of file qwt_plot_barchart.cpp. void QwtPlotBarChart::setSamples (const QVector< double > & samples) Initialize data with an array of doubles The indices in the array are taken as x coordinate, while the doubles are interpreted as y values. Parameters samples Vector of y coordinates Note QVector is implicitly shared Definition at line 97 of file qwt_plot_barchart.cpp. void QwtPlotBarChart::setSamples (const QVector< QPointF > & samples) Initialize data with an array of points Parameters samples Vector of points Note QVector is implicitly shared QPolygonF is derived from QVector Definition at line 82 of file qwt_plot_barchart.cpp. void QwtPlotBarChart::setSamples (QwtSeriesData< QPointF > * data) Assign a series of samples setSamples() is just a wrapper for setData() without any additional value - beside that it is easier to find for the developer. Parameters data Data Warning The item takes ownership of the data object, deleting it when its not used anymore. Definition at line 119 of file qwt_plot_barchart.cpp. void QwtPlotBarChart::setSymbol (QwtColumnSymbol * symbol) Assign a symbol. The bar chart will take the ownership of the symbol, hence the previously set symbol will be delete by setting a new one. If symbol is NULL no symbol will be drawn. Parameters symbol Symbol See also symbol() Definition at line 134 of file qwt_plot_barchart.cpp. QwtColumnSymbol * QwtPlotBarChart::specialSymbol (int sampleIndex, const QPointF & sample) const [virtual] Needs to be overloaded to return a non default symbol for a specific sample Parameters sampleIndex Index of the sample represented by the bar sample Value of the sample Returns NULL, indicating to use the default symbol Definition at line 377 of file qwt_plot_barchart.cpp. const QwtColumnSymbol * QwtPlotBarChart::symbol () const Returns Current symbol or NULL, when no symbol has been assigned See also setSymbol() Definition at line 150 of file qwt_plot_barchart.cpp. Author Generated automatically by Doxygen for Qwt User's Guide from the source code. Version 6.2.0 Sun Jul 18 2021 QwtPlotBarChart(3)