COcodedokode·Aug 7, 2024
Please let me rant a bit about X11 input APIs.
One of the major flaws in X11 is its poorly designed keyboard input system. When a key is pressed, the keypress event sends a "keycode" - an 8-bit number that references the current layout. This means you're limited to injecting characters that are present in the current layout.
The implications of this design are frustrating. For instance, if you're connecting to a remote system via VNC and the client and server have different keyboard layouts, you'll run into all sorts of issues. Similarly, how do you create an on-screen keyboard that can inject keypresses for characters not available in the current layout? And what if you want to programmatically send some text, but the user has the wrong layout active? It's a mess.
I guess because of this in Debian most of characters in on-screen keyboard
Read the rest
didn't work (they "fixed" it by showing only characters present in active layouts instead of fixing the root issue).
The common workaround for this is an ugly hack: you modify the keyboard layout, find unused spots, add desired characters, send key press event and restore the keyboard layout back. See the code: [2]
Also, Wayland which was supposed to get rid of legacy problems, seems to have inherited this ugly design. Also, there seem to be no sane API for managing layouts or switching them programatically, or subscribing to layout change event. Also, you cannot use modifiers like Ctrl to switch layouts because then combinations like Ctrl + C stop working. Keyboard APIs on Linux are broken in the worst way possible since beginning, probably because most developers use only ASCII and do not have experience using multiple layouts.
A better idea would be to allow to send arbitrary Unicode strings and maybe integrate regular input and IME input (input system for typing Asian characters).
[1] https://www.x.org/releases/X11R7.6/doc/xproto/x11protocol.ht...
[2] https://github.com/Zirias/xmoji/blob/master/src/bin/xmoji/ke...