mjhjmtu

I want to use Autokey to toggle the e key on and off in a program called "xyz". So if I press e, the program thinks I'm holding down e. I press e again, it thinks I released it. How do you do this please?

Or is there some other program that can do this?

bonus question: how do you do this with any Ubuntu program, such as fvwm2, xorg, xmodmap, xkb, xrdb, any way at all?

I'm not familiar with autokey, but this looks doable. Use Keyboard.press_key to send a key press event and Keyboard.release_key to send a key release event. To remember which one to send, you can use Store.set_value and Store.get_value.

Alternatively, you can use xdotool to inject input events into a window and xprop to attach data to a window. Run the following shell command (untested) to send alternate press/release events to the active window.

#!/bin/sh
window_id=$(xdotool getactivewindow)
case $(xprop -id "$window_id" -f key_e_is_down 32c -notype key_e_is_down) in
 *1) key_command=keydown; new_state=0;;
 *) key_command=keyup; new_state=1;;
esac
xdotool "$key_command" "e"
xprop -id "$window_id" -f key_e_is_down 32c -set key_e_is_down "$new_state"

If you want to bind this action to a key, but to have the key active only in one window, I'm not sure if Autokey can help you. The easiest way to do that is from the window manager, but most window managers can't do it. I use sawfish as my window manager, which can do this without any external tool.

(define (toggle-e w)
 (interactive "%W")
 (let ((down (window-get w 'key-e-is-down)))
 (synthesize-event (if down "Release+e" "e") w)
 (window-put w 'key-e-is-down (not down))))
(define xyz-window-map (make-keymap))
(bind-keys xyz-window-map "e" toggle-e)
(add-window-matcher 'WM_CLASS "^Xyz/" `((keymap . ,xyz-window-map)))