QwtPlotMultiBarChart not equal width

[Uwe]

Looks like a bug to me - related to the disabled x axis.

A possible workaround is to use the following code:

#if 0
enableAxis(xAxis, false);
#else
// workaround
 QwtScaleDraw *scaleDraw = axisScaleDraw( QwtPlot::xBottom );
 scaleDraw->enableComponent(QwtScaleDraw::Backbone, false);
 xAxis_scaleDraw->enableComponent(QwtScaleDraw::Ticks, false);
 xAxis_scaleDraw->enableComponent(QwtScaleDraw::Labels, false);
#endif

#if 0
enableAxis(xAxis, false);
#else
// workaround
 QwtScaleDraw *scaleDraw = axisScaleDraw( QwtPlot::xBottom );
 scaleDraw->enableComponent(QwtScaleDraw::Backbone, false);
 xAxis_scaleDraw->enableComponent(QwtScaleDraw::Ticks, false);
 xAxis_scaleDraw->enableComponent(QwtScaleDraw::Labels, false);
#endif

To copy to clipboard, switch view to plain text mode 

HTH,
Uwe

[nanthiran_2005]

Hi Uwe,

Thanks for the help. The line which disable the label helps. However, I still have to manually set the margin of yLeft and yRight. Otherwise, the bar chart will not be equal of width.
Attached below is the portion of code which help me to get the bar chart I want.

QwtPlot::Axis yAxis = QwtPlot::yLeft,
                  xAxis = QwtPlot::xBottom;
    setAxisScale(yAxis, 0, 100, 20);
    setAxisAutoScale(xAxis);
    enableAxis(yAxis, true);
 
    QwtScaleDraw *yAxis_scaleDraw = axisScaleDraw(yAxis);
    yAxis_scaleDraw->enableComponent(QwtScaleDraw::Backbone, false);
    yAxis_scaleDraw->enableComponent(QwtScaleDraw::Ticks, false);
 
    QwtScaleDraw *xAxis_scaleDraw = axisScaleDraw(xAxis);
    xAxis_scaleDraw->enableComponent(QwtScaleDraw::Backbone, false);
    xAxis_scaleDraw->enableComponent(QwtScaleDraw::Ticks, false);
    xAxis_scaleDraw->enableComponent(QwtScaleDraw::Labels, false);
 
    plotLayout()->setCanvasMargin(0);
    plotLayout()->setCanvasMargin(20, QwtPlot::yLeft); 
    plotLayout()->setCanvasMargin(20, QwtPlot::yRight);

QwtPlot::Axis yAxis = QwtPlot::yLeft,
                  xAxis = QwtPlot::xBottom;
    setAxisScale(yAxis, 0, 100, 20);
    setAxisAutoScale(xAxis);
    enableAxis(yAxis, true);

    QwtScaleDraw *yAxis_scaleDraw = axisScaleDraw(yAxis);
    yAxis_scaleDraw->enableComponent(QwtScaleDraw::Backbone, false);
    yAxis_scaleDraw->enableComponent(QwtScaleDraw::Ticks, false);

    QwtScaleDraw *xAxis_scaleDraw = axisScaleDraw(xAxis);
    xAxis_scaleDraw->enableComponent(QwtScaleDraw::Backbone, false);
    xAxis_scaleDraw->enableComponent(QwtScaleDraw::Ticks, false);
    xAxis_scaleDraw->enableComponent(QwtScaleDraw::Labels, false);

    plotLayout()->setCanvasMargin(0);
    plotLayout()->setCanvasMargin(20, QwtPlot::yLeft); 
    plotLayout()->setCanvasMargin(20, QwtPlot::yRight);

To copy to clipboard, switch view to plain text mode