Problem with maximised window

[Perdrix]

Interesting: I reversed the order of the restoration so window state was restored first, but that made no difference.

Debugging through the geometry restoration, the call to showMaximized did show the window maximised but when I then let the application run the title bar was off screen again, and the maximised indicator in the window decorations showed it was not maximised.

[SamiV123]

@Perdrix

I recall having seem similar problems and I think the issues I had were these two:

• trying to save the window geometry after it has been closed / or made invisible.
• trying to save a QByteArray as such with QVariant/QJson/QSetting silently failing.

For the second problem I now always base64 encode the byte arrays.

In general I find it's much better to make your applications shutdown sequence always explicit and in such a shutdown function you do stuff as saving your state while all your resources (such as windows) are still allocated.

Leave the destructor for simple cases only that have no impact on the program logic.

[Perdrix]

@SamiV123 I'm saving the geometry etc. in closeEvent() not the dtor. So all windows should still be present and correct.

[Perdrix]

Changing the code to read:

	if (settings.contains("geometry") && settings.contains("maximised"))
	{
		const QByteArray geometry{ settings.value("geometry").toByteArray() };
		const bool maximised{ settings.value("maximised").toBool() };

		if (maximised)
		{
			setGeometry(screen()->availableGeometry());
			showMaximized();
		}
		else
		{
			restoreGeometry(geometry);
		}
	}

That's to say calling showMaximized() AFTER setGeometry(screen()-> etc..) seems to have resolved the problem.

Can someone please clarify the officially correct way to do this and the exact order in which it should be done (window state, geometry, showMaximized()).

[SamiV123]

@Perdrix said in Problem with maximised window:

Changing the code to read:

	if (settings.contains("geometry") && settings.contains("maximised"))
	{
		const QByteArray geometry{ settings.value("geometry").toByteArray() };
		const bool maximised{ settings.value("maximised").toBool() };

		if (maximised)
		{
			setGeometry(screen()->availableGeometry());
			showMaximized();
		}
		else
		{
			restoreGeometry(geometry);
		}
	}

That's to say calling showMaximized() AFTER setGeometry(screen()-> etc..) seems to have resolved the problem.

Can someone please clarify the officially correct way to do this and the exact order in which it should be done.

I think it's a red herring,

your "maximized" flag is saves as a bool in the settings so you get that value back properly while your geometry byte buffer is mangled.

Your maximized should be part of the geometry state already.

Try base64 encoding your geometry buffer like I suggested before.

[Perdrix]

@SamiV123 I don't believe that's the case - please see:

https://bugreports.qt.io/browse/QTBUG-46620

and

https://stackoverflow.com/questions/44005852/qdockwidgetrestoregeometry-not-working-correctly-when-qmainwindow-is-maximized

David

[Perdrix]

Arghh! If I now close the application while it is maximised and restart it, when I restore the window from maximised it doesn't go back the the size it was before it was maximised, but to the default initial size that would apply if there were no saved geometry or state.

If I maximise/restore without closing everything works as I expect.

David

[SamiV123]

I just checked what I've done in my own app, I also have a "MainWindow" with a QDockWidget and all I seem to be doing is to call QMainWindow::saveState and then restoreState and this works for me for restoring the dock state.

Then I use x(), y(), width() and height() to save the window geometry explicitly.

This has worked for me on Linux with X11 including fully maximized window.

FWIW I'm also doing the base64 encode step since I also spent time struggling with this same problem.

[Perdrix]

@Volker-Hilsheimer Any thoughts?

[Perdrix]

Reported under https://bugreports.qt.io/browse/QTBUG-118598