QwtPlotAbstractBarChart(3) Qwt User's Guide QwtPlotAbstractBarChart(3) NAME QwtPlotAbstractBarChart - Abstract base class for bar chart items. SYNOPSIS #include Inherits QwtPlotSeriesItem. Inherited by QwtPlotBarChart, and QwtPlotMultiBarChart. Public Types enum LayoutPolicy { AutoAdjustSamples, ScaleSamplesToAxes, ScaleSampleToCanvas, FixedSampleSize } Mode how to calculate the bar width. Public Member Functions QwtPlotAbstractBarChart (const QwtText &title) virtual ~QwtPlotAbstractBarChart () Destructor. void setLayoutPolicy (LayoutPolicy) LayoutPolicy layoutPolicy () const void setLayoutHint (double) double layoutHint () const void setSpacing (int) Set the spacing. int spacing () const void setMargin (int) Set the margin. int margin () const void setBaseline (double) Set the baseline. double baseline () const virtual void getCanvasMarginHint (const QwtScaleMap &xMap, const QwtScaleMap &yMap, const QRectF &canvasRect, double &left, double &top, double &right, double &bottom) const override Calculate a hint for the canvas margin. Protected Member Functions double sampleWidth (const QwtScaleMap &map, double canvasSize, double boundingSize, double value) const Detailed Description Abstract base class for bar chart items. In opposite to almost all other plot items bar charts can't be displayed inside of their bounding rectangle and need a special API how to calculate the width of the bars and how they affect the layout of the attached plot. Definition at line 24 of file qwt_plot_abstract_barchart.h. Member Enumeration Documentation enum QwtPlotAbstractBarChart::LayoutPolicy Mode how to calculate the bar width. setLayoutPolicy(), setLayoutHint(), barWidthHint() Enumerator AutoAdjustSamples The sample width is calculated by dividing the bounding rectangle by the number of samples. The layoutHint() is used as a minimum width in paint device coordinates. See also boundingRectangle() ScaleSamplesToAxes layoutHint() defines an interval in axis coordinates ScaleSampleToCanvas The bar width is calculated by multiplying layoutHint() with the height or width of the canvas. See also boundingRectangle() FixedSampleSize layoutHint() defines a fixed width in paint device coordinates. Definition at line 32 of file qwt_plot_abstract_barchart.h. Constructor & Destructor Documentation QwtPlotAbstractBarChart::QwtPlotAbstractBarChart (const QwtText & title) [explicit] Constructor Parameters title Title of the chart Definition at line 48 of file qwt_plot_abstract_barchart.cpp. Member Function Documentation double QwtPlotAbstractBarChart::baseline () const Returns Value for the origin of the bar chart See also setBaseline(), QwtPlotSeriesItem::orientation() Definition at line 208 of file qwt_plot_abstract_barchart.cpp. void QwtPlotAbstractBarChart::getCanvasMarginHint (const QwtScaleMap & xMap, const QwtScaleMap & yMap, const QRectF & canvasRect, double & left, double & top, double & right, double & bottom) const [override], [virtual] Calculate a hint for the canvas margin. Bar charts need to reserve some space for displaying the bars for the first and the last sample. The hint is calculated from the layoutHint() depending on the layoutPolicy(). The margins are in target device coordinates ( pixels on screen ) Parameters xMap Maps x-values into pixel coordinates. yMap Maps y-values into pixel coordinates. canvasRect Contents rectangle of the canvas in painter coordinates left Returns the left margin top Returns the top margin right Returns the right margin bottom Returns the bottom margin Returns Margin See also layoutPolicy(), layoutHint(), QwtPlotItem::Margins QwtPlot::getCanvasMarginsHint(), QwtPlot::updateCanvasMargins() Reimplemented from QwtPlotItem. Definition at line 289 of file qwt_plot_abstract_barchart.cpp. double QwtPlotAbstractBarChart::layoutHint () const The combination of layoutPolicy() and layoutHint() define how the width of the bars is calculated Returns Layout policy of the chart item See also LayoutPolicy, setLayoutHint(), layoutPolicy() Definition at line 119 of file qwt_plot_abstract_barchart.cpp. QwtPlotAbstractBarChart::LayoutPolicy QwtPlotAbstractBarChart::layoutPolicy () const The combination of layoutPolicy() and layoutHint() define how the width of the bars is calculated Returns Layout policy of the chart item See also setLayoutPolicy(), layoutHint() Definition at line 89 of file qwt_plot_abstract_barchart.cpp. int QwtPlotAbstractBarChart::margin () const Returns Margin between the outmost bars and the contentsRect() of the canvas. See also setMargin(), spacing() Definition at line 176 of file qwt_plot_abstract_barchart.cpp. double QwtPlotAbstractBarChart::sampleWidth (const QwtScaleMap & map, double canvasSize, double boundingSize, double value) const [protected] Calculate the width for a sample in paint device coordinates Parameters map Scale map for the corresponding scale canvasSize Size of the canvas in paint device coordinates boundingSize Bounding size of the chart in plot coordinates ( used in AutoAdjustSamples mode ) value Value of the sample Returns Sample width See also layoutPolicy(), layoutHint() Definition at line 225 of file qwt_plot_abstract_barchart.cpp. void QwtPlotAbstractBarChart::setBaseline (double value) Set the baseline. The baseline is the origin for the chart. Each bar is painted from the baseline in the direction of the sample value. In case of a horizontal orientation() the baseline is interpreted as x - otherwise as y - value. The default value for the baseline is 0. Parameters value Value for the baseline See also baseline(), QwtPlotSeriesItem::orientation() Definition at line 195 of file qwt_plot_abstract_barchart.cpp. void QwtPlotAbstractBarChart::setLayoutHint (double hint) The combination of layoutPolicy() and layoutHint() define how the width of the bars is calculated Parameters hint Layout hint See also LayoutPolicy, layoutPolicy(), layoutHint() Definition at line 102 of file qwt_plot_abstract_barchart.cpp. void QwtPlotAbstractBarChart::setLayoutPolicy (LayoutPolicy policy) The combination of layoutPolicy() and layoutHint() define how the width of the bars is calculated Parameters policy Layout policy See also layoutPolicy(), layoutHint() Definition at line 73 of file qwt_plot_abstract_barchart.cpp. void QwtPlotAbstractBarChart::setMargin (int margin) Set the margin. The margin is the distance between the outmost bars and the contentsRect() of the canvas. The default setting is 5 pixels. Parameters margin Margin See also spacing(), margin() Definition at line 160 of file qwt_plot_abstract_barchart.cpp. void QwtPlotAbstractBarChart::setSpacing (int spacing) Set the spacing. The spacing is the distance between 2 samples ( bars for QwtPlotBarChart or a group of bars for QwtPlotMultiBarChart ) in paint device coordinates. See also spacing() Definition at line 132 of file qwt_plot_abstract_barchart.cpp. int QwtPlotAbstractBarChart::spacing () const Returns Spacing between 2 samples ( bars or groups of bars ) See also setSpacing(), margin() Definition at line 146 of file qwt_plot_abstract_barchart.cpp. Author Generated automatically by Doxygen for Qwt User's Guide from the source code. Version 6.2.0 Sun Jul 18 2021 QwtPlotAbstractBarChart(3)