QPainter save - restore ... Sincerely I dont know

[tonnot]

Save() Saves the current painter state (pushes the state onto a stack). A save() must be followed by a corresponding restore();
Restore :Restores the current painter state (pops a saved state off the stack).
At analogclock example code I see that it is used after setpen & setbrush. I understand the restore function (clear the set's ?) but save ?
Any easy explanation ?

[Lykurg]

Obviously you don't understand the restore function. It doesn't clear the sets. It restores the settings as they were when save() was called.

QPainter p;
p.save(); // = save point 1
// do fancy stuff with p
p.save(); // = save point 2
// do fancy stuff with p
p.restore(); // now p is like save point 2
// do fancy stuff with p
p.restore(); // now p is like save point 1

QPainter p;
p.save(); // = save point 1
// do fancy stuff with p
p.save(); // = save point 2
// do fancy stuff with p
p.restore(); // now p is like save point 2
// do fancy stuff with p
p.restore(); // now p is like save point 1

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[wysota]

It works for non-fancy stuff too

[tonnot]

Thanks Lykurg, now I understand it

[Lykurg]

It works for non-fancy stuff too

Indeed, after I spend several hours on intense testing, I can affirm it too. I would have never dreamed of that, it's amazing! Qt is so simple but powerful.