Draw marker during drag and rectangle during zoom

[missoni]

Hello!
I am new to Qwt and I have a persistent problem which I cannot solve, so I decided to ask for help.

I plot a histogram and set markers in form of vertical lines on it. These markers divide my original histogram into many small colored histograms. I derive from QwtPlotPicker and override widgetMouse..Event() functions in order to catch mouse events and place markers on mouse click. Now, if I want to move an existing marker, I use the same MyPlotPicker instance as before. I store the start and end position of the mouse drag and move the marker into the new position. But I cannot persuade MyPlotPicker to draw a temporary marker during dragging. I tried drawing a marker on-the-fly in void MyPlotPicker::widgetMouseMoveEvent( QMouseEvent * event), but it did not work out.

I also use MyPlotPicker for zooming. If a drag is performed during right-button mouse click pressed, I interpret it as zooming into the selected area. Here, again: I do not know how to draw a rectangular selection in the area where I want to zoom into. I have tried reloading drawRubberBand, but the function seems to never be called. Any idea as to what am I doing wrong?

I use the Qwt 6.0.0 RC5 under Windows with Qt 4.6.1.

Thank you in advance!

[Uwe]

I have added the itemeditor example to SVN trunk. It demonstrates how to use the new QwtPlotOverlay class for building some sort of graphical editors.

Maybe it helps,
Uwe

[missoni]

Thank you very much! Your example has helped me implement my own marker dragger.