make switching between dark mode and light mode easier

Whenever I want to switch from light mode to dark mode or the other way around, I have to go through the following steps:

1. Open the Options dialog
2. Select "Environment" on the left
3. Click the Theme dropdown and pick a different theme
4. Click OK to save the changed preference
5. Confirm the next popup dialog ("theme change will take effect after restart")
6. Close Qt Creator
7. Start Qt Creator again
8. Open last session again
9. Wait for CMake project parsing to run, then close General Messages again
10. Close and reopen the current source file to make spurious error markers go away

Ignoring the last two steps, which are not universally needed, I hope this makes it clear that having to go through all that for such a simple operation is not user friendly.

Switching between light mode and dark mode and back again is something that a user probably does multiple times a day, every time the lighting conditions in the room change. So it should be just as convenient as switching the light on/off in the room.

My suggestion:

Provide a button or switch that is easy to reach, that does not involve opening any other windows, which makes it possible to switch between dark/light mode with a single click, and which has an immediate effect. Or alternatively, a menu action having the same effect, with a keyboard shortcut assigned to it by default.

This probably also requires extending the theme setting in the Options dialog somewhat. Instead of one theme setting, it could have a Light Theme setting and a Dark Theme setting, allowing the user to pick their preferred light theme and dark theme.