tkh’s blog

Qt Designer and OpenGL

I designed a GUI for an OpenGL application using Qt Designer, and encountered some glitches. First, you have to subclass QGLWidget class, say MyGLWidget, and put OpenGL stuff there. Then open Qt Designer and place a some container widget in a window as a place folder for MyGLWidget. You should use QWidget because QGLWidget inherits directly from it. However, QWidget is not available in Qt Designer. So you are forced to use QFrame as a place folder and promote it to a custom widget class and specify MyGLWidget. Now save the GUI layout to a .ui file, and hand edit it and delete the lines which declares some of QFrame properties. You also need to rename QFrame in the custom widget section to QWidget. Now you should be able to compile your code.

Actually I found a ML thread about this and a Trolltech engineer said that they would add QWidget in Qt Designer. Apparently it’s not fixed yet. I really want the fix!

VTK and Qt license

I had to check if VTK license is compatible with GPL. The archive of a debian ML shows that it is compatible. Now I’m sure I can use Qt as a GUI for VTK based programs.