I am trying to use the minimal Qt VTK app as specified here on KUbuntu 24.04. This app uses a QVTKOpenGLNativeWidget to display a randomized mesh for interaction. The application has been built and run as specified in the example.
So normally, inside this widget, using the right mouse button (RMB) should zoom the camera, while clicking and dragging the left mouse button (LMB) is normally used to rotate the camera.
If KDE Plasma is used as Desktop Environment, however, a weird behavior is observed: Clicking and holding LMB inside the widget will start to drag the entire application’s window. If the LMB is then released, the camera keeps rotating, until LMB is pressed again.
I’ve tested this using KDE Plasma as Desktop Environment (which on KUbuntu 24.04 currently is version 5.27.12). If I switch the Desktop Environment to Gnome instead, this problem does not occur anymore - LMB can be used normally to rotate the camera.
Has anybody else experienced this type of problem? Do you have a possible solution here? Or is it maybe something related to KDE/Qt and the question should be asked on their forums instead?