On Linux X11 + Fcitx5, IME pre-edit text is not in TextEdit #7975
Description
Describe the bug
My setups:
- X11 + Fcitx5 (the buggy one): Debian 13 [Cinnamon 6.4.10 + X11 + Fcitx5 5.1.2]
- Wayland + IBus (for reference): Fedora KDE Plasma Desktop 43 [Wayland + IBus 1.5.33-rc2]
For both setups, the Korean IME I used is the same one called “Hangul” with the same icon. (The about page of the IBus one states that the author is Peng Huang. I can't find the about page for the Fcitx5 one. The Fcitx5 one has this description: “Hangul Wrapper For Fcitx”)
I am not sure whether this behavior is caused by X11 or Fcitx5.
It is also unclear whether this should be addressed in egui (via winit usage) or whether it is a limitation in winit itself and an issue should be opened there.
For now, I am documenting the observed behavior here as a starting point.
IME pre-edit text works correctly in applications like LibreOffice on my X11 + Fcitx5 setup
Chinese Example:
Korean Example:
IME pre-edit text works correctly in egui on my Wayland + IBus setup
Chinese Example:
Korean Example:
IME pre-edit text is not in TextEdit in egui on my X11 + Fcitx5 setup
Chinese Example:
Korean Example:
(It appears that the Korean IME is in some kind of compatibility mode where the pre-edit text is displayed in a separate text control instead of inside the application.)
This is not a big deal for Chinese or Japanese IMEs.
But for Korean IMEs, since the pre-edit text is not part of the TextEdit buffer under X11 + Fcitx5, losing focus on the TextEdit causes uncommitted Hangul characters to be dropped.
Uncommitted Hangul remains after losing focus on Wayland + IBus (correct behavior)
Uncommitted Hangul is lost after losing focus on X11 + Fcitx5 (incorrect behavior)
Notice that the third Hangul character is missing.
To Reproduce
Steps to reproduce the behavior:
- run the demo App.
- open the TextEdit demo.
- type with various IMEs.
Expected behavior
The X11 + Fcitx5 setup should work like the Wayland + IBus setup.
Screenshots
See above.
Desktop (please complete the following information):
- OS: Debian 13 [Cinnamon 6.4.10 + X11 + Fcitx5 5.1.2]
- Native (eframe+wgpu)
- Version current main (between 0.33.3 and the next release. 0.33.3 is even more broken: IMEs only works when the cursor is at the beginning.)