Close event not detected after switching to another desktop and back

[fiso64]

Consider the script

#include WinEvent.ahk
WinEvent.Close((*) => MsgBox("notepad closed"), "ahk_exe notepad.exe")

To reproduce:

1. Open notepad.exe on the first virtual desktop
2. Switch to the second desktop (a message box should appear)
3. Switch back to the first desktop and close notepad
4. No message box appears.

[Descolada]

This behavior is mostly understandable. WinEvent detects window close events by storing a list of window handles which match the WinTitle criteria (in this case ahk_exe notepad.exe), and this list is updated whenever new windows are created or window titles change. This is necessary because after the window has closed there is no way to get the class, title etc, so we need to match the window before the close event. Now, WinEvent does this by using WinGetList which gets matching windows from the current desktop. In your use case, WinGetList gets called for the first desktop, then you switch to the second desktop which probably causes some window to change titles and WinGetList gets called again, doesn't find any matches, assumes Notepad has closed, and thus you get a MsgBox. Now you switch back to the first desktop and if you don't open any new windows nor window titles change then WinGetList doesn't get called and thus WinEvent won't know Notepad exists when you close it.

I need to think a bit whether this issue is solvable at all. I know that we could enumerate all virtual desktops, call EnumDesktopWindows to enumerate all windows of a specific virtual desktop, but I'm not sure that we can get window title, class etc like that, nor do I think can AHKs WinExist access those windows. Also it'd be much slower than the current approach because of all the callback required. So this may end up being an inherent limitation of the library, but I'm not sure yet.