Currently, IME is always enabled for all applications. This can cause some very annoying issues on winewayland. For example, fcitx takes over the character repeat functionality when enabled, and does it via repeatedly sending sequences of keyup/keydown, which leads to applications not being able to track hold duration of a button (can be reproduced on any game which requires holding a letter key). The spec states that the enable request should only be sent when a text edit is focused, and a disable request should be sent when it is unfocused. Windows provides a "similar-ish" mechanism: applications can use ImmAssociateContext/ImmAssociateContextEx to associate an IMC when IME should be enabled, and set associated IMC to null when it should be disabled. From my rather limited testing, it is implemented this way in Chromium/CEF, QT and Unity. Setting it to null internally results in deactivation of the currently associated context. This MR makes the ImeSetActiveContext function of the builtin IME utilize a new driver function to communicate activation status. It does not take into account which specific context was activated, thus semi-stub. This fixes behavior of applications using the above-mentioned components. I only implemented it for winewayland, it probably should also be implemented for winex11 too, but I'm not sure how. ~~Unfortunately this breaks IME input in Wine comctl32/user32 components. I am not sure how it is supposed to behave on Windows or how to test it at the current point, will look into it later. Having IME on by default appears to "fix" it, but that is very likely not the Windows behavior; moreover, at least Unity does not disable IME on start, which causes the above-mentioned issue to occur until a textbox is manually focused and unfocused.~~ Fixed -- v9: imm32/tests: Test which IME receives ImeSetActiveContext deactivation call after layout change https://gitlab.winehq.org/wine/wine/-/merge_requests/10007