QMainWindow setting normal size

[mqt]

Question 1.

I would like to start a main window maximized. I also want to allow the user to restore. When the user restores the window first time, I want the window to be a particular size, say 500*400. Later user may change the size with mouse. I am looking for something like resize() function which will not act immediately (currently it is Maximized view) and will act when viewNormal() is called or restore button is clicked.

Question 2.
Is there any way to get the size of maximized window when it is not actually maximized? The Desktop size gives the size without considering Window Task Bar and hence that height/widht is slightly larger than maximized window. I dont want to show the window maximized. But I want to do some calculations based on the hieght available for maximized window.