QwtMatrixRasterData - setting a fixed column width

[Buffy]

I'm generating a plot like the rasterview example. Sometimes my users data only has one column of information. By default qwt will spread this column out over the entire plot area. So the data always takes up the same width if there is one column or 50 columns. Is there a way to set the width of the columns without also scaling the color map and axes data. I would like to solve this for the screen, exporting to a pdf, and for printing.

This is what I'm getting:
DoNotWantItWide.jpg

This is what I want:
WantItNarrow.jpg
Thanks
Buffy

[Uwe]

It's the application ( your ! ) code that is responsible for the geometry of the plot widget. See QLayout, QWidget::setGeometry ...

Uwe

[Buffy]

Uwe,
Thank you very much for your input but I still seem to be missing something. My original problem was I was not setting the alignment when I called addWidget so the layout was stretching my data and not paying attention to the geometry I was trying to set.

Now I'm setting the geometry and minimum width for the widget and adding the widget with an alignment so that it doesn't stretch to take up the entire space. This widget then gets added to a grid layout. All of this is fine and good. My problem is that this is setting the entire widgets width including the rasterview's labels and color map area.

So I haven't found a way to calculate how much space is needed so my column of data is a set size. For example, both the following images have the same geometry and min width in the same grid layout.
This one is the way I want it
notOverWritten.jpg

This one needs more space to show what I want. Notice that the labels and the color bar overlap each other and there is no room for the column of data. How do I set the plot width without the labels and color map bar or how do I work the numbers backwards to determine the space required?
overwritting.jpg

Thanks in advance for any help,
Buffy

[Uwe]

... how do I work the numbers backwards to determine the space required?

virtual QSize YourPlot::sizeHint() const
{
    const int dim = 10000; // something large
    plotLayout()->activate( this, QRectF( 0, 0, dim, dim ) );
 
    const int canvasWidth = ...; // this is the number of pixels you want to have for your canvas
    int w = canvasWidth + dim - plotLayout()->canvasRect().width();
 
    plotLayout()->invalidate();
 
    return QSize( w, QwtPlot::sizeHint().height() );
}

virtual QSize YourPlot::sizeHint() const
{
    const int dim = 10000; // something large
    plotLayout()->activate( this, QRectF( 0, 0, dim, dim ) );

    const int canvasWidth = ...; // this is the number of pixels you want to have for your canvas
    int w = canvasWidth + dim - plotLayout()->canvasRect().width();

    plotLayout()->invalidate();

    return QSize( w, QwtPlot::sizeHint().height() );
}

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The idea is to calculate the layout with some large rectangle. As the canvas gets all the additional space you can easily calculate the fixed parts by subtracting the calculated canvas width. Then add the width you need.

Uwe