Question

This is my first attempt at writing a QT app, and I’m just trying to get a feel for how it works. My goal is to have a 400×400 widget which knows the exact position of the mouse when the mouse is hovering over it. For example, if the mouse was hovering in the top left corner, the position might be 10,10 (or something similar). If the mouse is in the bottom right corner, it might say 390,390.

Eventually, these coordinates will be displayed in a label on the main window, but that should be trivial. I’m stuck at the actual fetching of the coordinates. Any ideas?

Answer 1

For your widget, you must enable mouse tracking.

Then, you can either install an event filter, paying attention to mouse events and looking for the move event, or you can inherit from QWidget and override the mouse event, looking for mouse move events.

http://doc.qt.io/qt-4.8/qwidget.html#mouseTracking-prop

http://doc.qt.io/qt-4.8/eventsandfilters.html

http://doc.qt.io/qt-4.8/qmouseevent.html