Qwt: Using QwtPlotPicker on multiple plots

[Uwe]

Have a look at the implementation of PlotMatrix::alignVAxes in the plot matrix example; http://qwt.svn.sourceforge.net/viewv...pp?view=markup.

The trick is to calculate the maximum extent of all vertical axes and to assign it to all of them.

HTH,
Uwe

PS: Please start a new thread, when you ask for something completely different.

[y.shan]

yeah, that plotmatrix example also helped me alot,
i had the same problem with aligning my plots vertically (if that is the problem you have) and i solved it like this way

void myPlotFrame::paintEvent(QPaintEvent *pe)
{
    QListIterator<QwtPlot*> it(myPlots); //i have a QList<QwtPlot*> for my plots
    QwtPlot *current_plot;
    int maxExtent = 0;
 
    while (it.hasNext())
    {
        current_plot = it.next();
 
        QwtScaleWidget *scaleWidget = current_plot->axisWidget(QwtPlot::yLeft);
        QwtScaleDraw *sd = scaleWidget->scaleDraw();
        sd->setMinimumExtent(0);
 
        const int extent = sd->extent(
        QPen(Qt::black, scaleWidget->penWidth()),
        scaleWidget->font() );
        if ( extent > maxExtent )
        maxExtent = extent;
    }
 
    it.toFront();
    while (it.hasNext())
    {
        current_plot = it.next();
        QwtScaleWidget *scaleWidget = current_plot->axisWidget(QwtPlot::yLeft);
        scaleWidget->scaleDraw()->setMinimumExtent(maxExtent);
    }
}

void myPlotFrame::paintEvent(QPaintEvent *pe)
{
    QListIterator<QwtPlot*> it(myPlots); //i have a QList<QwtPlot*> for my plots
    QwtPlot *current_plot;
    int maxExtent = 0;

    while (it.hasNext())
    {
        current_plot = it.next();

        QwtScaleWidget *scaleWidget = current_plot->axisWidget(QwtPlot::yLeft);
        QwtScaleDraw *sd = scaleWidget->scaleDraw();
        sd->setMinimumExtent(0);

        const int extent = sd->extent(
        QPen(Qt::black, scaleWidget->penWidth()),
        scaleWidget->font() );
        if ( extent > maxExtent )
        maxExtent = extent;
    }

    it.toFront();
    while (it.hasNext())
    {
        current_plot = it.next();
        QwtScaleWidget *scaleWidget = current_plot->axisWidget(QwtPlot::yLeft);
        scaleWidget->scaleDraw()->setMinimumExtent(maxExtent);
    }
}

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