Quote Originally Posted by thejester View Post
1) Depending on where you move the second selection for the measurement, the measurement picker text runs through the default picker that that always displays the current x,y position. Is there something to do about that ?
The implementation of DistancePicker::trackerText is your code. Do you have another picker displaying this text ( f.e. the zoomer ).
2) When we zoom in to the plot, just after releasing the mouse for the zoom action, the plot zooms in to new selection, and then automagically a measurement is started.
Maybe you are using the same mouse events for the zoomer and your distance picker. You can redefine them using QwtEventPattern::setMousePattern/setKeyPattern.
Is it possible to do measurements only when user presses space bar for instance ?
Use QwtEventPattern::setMousePattern() and redefine the input events for your distance picker.

Uwe