Fix caret can disappear from script editor on Windows

[Hilderin]

Fixes #92821
Also probably fixes #92634 but did not find a way to reproduce more than once.

This was not easy to reproduce! To reproduce I did Alt-Tab while resizing the editor windows. And even then, it takes multiple retries to reproduce the problem.

I’m pretty certain that the problem came from a situation where a new SetTimer was called before the timer was actually triggered resulting in a situation where activate_timer_id and move_timer_id had the same timer_id. Both SetTimer for activate_timer_id and move_timer_id had the same nIDEvent, so the second SetTimer replaced the first timer.

Documentation for SetTimer from Microsoft:
https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-settimer

With some debug print line, we can see that the activate timer can in some situations be created before the resize is triggered:

I did 2 modifications:

• Changed the nIDEvent for activate_timer_id to 2.
• When WM_ACTIVATE is received but activate_timer_id != 0, a new SetTimer is created anyway, replacing the first one. That should prevent the weird case where activate_timer_id was never triggered and resetted.

[KoBeWi]

I gave it some testing and it fixes all problems listed in the linked issues.

[bruvzg]

Not important, but Instead of using hard-coded 1 and 2 it would be much better for readability (and to avoid future mistakes) to add an enum with IDs, somehting like:

enum TimerID {
    TIMER_ID_MOVE_REDRAW = 1,
    TIMER_ID_WINDOW_ACTIVATION = 2,
};

[Hilderin]

Good idea, I pushed modifications to add the enum.

[akien-mga]

Thanks!