Fix IME window position not taking into account window transform

[roughbits01]

Fixes #107411

Before:

Screen.Recording.2025-06-11.at.17.25.12.mov

After:

Screen.Recording.2025-06-11.at.17.26.55.mov

[adamscott]

Great work, @roughbits01 !

[Sauermann]

I'm wondering, if there are other cases besides IME LineEdit and TextEdit, where this issue happens.
In that case this fix would be better moved to get_popup_base_transform, so that other nodes also benefit from this fix.

[roughbits01]

I'm wondering, if there are other cases besides IME LineEdit and TextEdit, where this issue happens. In that case this fix would be better moved to get_popup_base_transform, so that other nodes also benefit from this fix.

I can't seem to find any documentation about get_popup_base_transform. Do you know why is it used here? Maybe @bruvzg knows. Also note that get_popup_base_transform is never called when I tested (running the MRP on MacOS ) because get_window()->get_embedder() is null.

[bruvzg]

'popup_base_transform`, is for native windows, which are completely independent of parent and use screen coordinates. But IME is a sub element of the native window, and uses native window client area coordinates. So it's a different thing. I do not think there are any other cases of IME use except line/text edit.

[akien-mga]

Thanks!