Zombie Keys - Like "dead keys", but undead! 🧟

[peterjc]

Many European layouts use dead keys where the key does not generate a complete character by itself, but acts in combination with the following key-press.

For example, on the US international layout, pressing circumflex ^ followed by a gives â. And wikipedia tells me following it with a space typically gives the dead key's normal character alone.

Now, I want to do something like that but different. I want the first press to give the base character, but be primed for something to trigger on the second key, or revert to normal after a timeout or if the second key is not on the trigger list. This is an "undead" key in the sense I want something to happen immediately without the traditional dead key's waiting state - a zombie key if you like.

I'm going to use the following toy example with the Zombie theme (but I have a real use-case in mind for Japanese layouts with modifier keys).

• We have a set of "Zombie Keys", which on their own appear to be normal (walking dead). In this example these will be just the z key.
• We have a set of "Release Keys", which on their own appear to be normal. In this example these will be just the "m" key.

If you press a zombie key you get its letter as normal (here z) but the system is primed ("infected") for half a second. If while "infected" you press a "Release Key" (here m), this triggers a special rule action - sending the backspace key (to remove the initial zombie key z), followed by sending the unicode sequence for 🧟 (in hex mode) or send "!ZOMBIE!" (when I can't send the emoji).

The real use-case is to replace a base character with a modified version (the three modifications I have in mind are for Japanese, dakuten or ten-ten like か→が, handakuten or maru like は→ぱ, or small forms like あ→ぁ).

```json { "description": "Undead or Zombie Keys - Toy example v2", "manipulators": [ { "description": "Begin a Zombie infection on Z", "from": { "key_code": "z" }, "to": [ { "key_code": "z" }, { "set_variable": { "name": "infected", "value": true } } ], "parameters": { "basic.to_delayed_action_delay_milliseconds": 500 }, "to_delayed_action": { "to_if_invoked": [ { "set_variable": { "name": "infected", "value": false } } ] }, "type": "basic" }, { "conditions": [ { "input_sources": [ { "input_source_id": "com.apple.keylayout.UnicodeHexInput", "language": "" } ], "type": "input_source_if" }, { "name": "infected", "type": "variable_if", "value": true } ], "description": "Send the UTF-16 unicode 0xd83e 0xdddf for zombie 🧟", "from": { "key_code": "m" }, "to": [ { "key_code": "delete_or_backspace" }, { "sticky_modifier": { "left_option": "on" } }, { "key_code": "d", "modifiers": "left_option" }, { "key_code": "8", "modifiers": "left_option" }, { "key_code": "3", "modifiers": "left_option" }, { "key_code": "e", "modifiers": "left_option" }, { "key_code": "d", "modifiers": "left_option" }, { "key_code": "d", "modifiers": "left_option" }, { "key_code": "d", "modifiers": "left_option" }, { "key_code": "f", "modifiers": "left_option" }, { "sticky_modifier": { "left_option": "off" } }, { "set_variable": { "name": "infected", "value": false } } ], "type": "basic" }, { "conditions": [ { "name": "infected", "type": "variable_if", "value": true } ], "description": "Send !ZOMBIE! as can't send emoji 🧟", "from": { "key_code": "m" }, "to": [ { "key_code": "delete_or_backspace" }, { "key_code": "1", "modifiers": "shift" }, { "key_code": "z", "modifiers": "shift" }, { "key_code": "o", "modifiers": "shift" }, { "key_code": "m", "modifiers": "shift" }, { "key_code": "b", "modifiers": "shift" }, { "key_code": "i", "modifiers": "shift" }, { "key_code": "e", "modifiers": "shift" }, { "key_code": "1", "modifiers": "shift" }, { "sticky_modifier": { "left_option": "off" } }, { "set_variable": { "name": "infected", "value": false } } ], "type": "basic" }, { "description": "Clear Zombie infection on space", "from": { "key_code": "spacebar" }, "to": [ { "key_code": "spacebar" }, { "set_variable": { "name": "infected", "value": false } } ], "type": "basic" } ] }```

The example as shown works BUT if the timeout is too long or you type too fast there is a window for a false trigger - for example z, o, m triggers if typed quickly. Is there an easy way to ensure other keys (like o here) clear the variable immediately - short of adding a rule to all of them (as done for the spacebar here)?

We can't use to_delayed_action.to_if_canceled as that will trigger on any following key including the release key m breaking the example.

[peterjc]

I forgot to link to enhancement request #4117 which could be one way to handle this.