ibus-wayland event flow


1. the wayland compositor send the input event to the application;
2. the application sends the input event to the wayland compositor by wayland text protocol;
3. wayland compositor sends the input event to the ibus-wayland process by input method protocol;
4. ibus-wayland process sends the input event to the ibus daemon by ibus protocol;
5. ibus daemon sends back the input method event to ibus-wayland process by ibus protocol;
6. ibus-wayland process sends back the input method event to the wayland compositor by input method protocol;
7. wayland compositor sends back the input method event to the application by wayland text protocol;