Never set minimum/maximum size
a long time ago we used minimum/maximum window sizes for the minimum and maximum length of the panel, but now this is not necessary anymore as they are stored separatedly.
setting minimum then maximum then resizing can sometimes cause several subsequent resize attempts, and a wrong order of setminimum/setMaximum can even fail the resize completely
The size is saved as a private member as source of truth: when we reposition the panel we can have not yet received a configure event of the last size we called resize() upon, making that former resize fail