/* Copyright 2017 Fredric Silberberg * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <inttypes.h> #include <stdint.h> #include "process_key_lock.h" #define BV_64(shift) (((uint64_t)1) << (shift)) #define GET_KEY_ARRAY(code) (((code) < 0x40) ? key_state[0] : ((code) < 0x80) ? key_state[1] : ((code) < 0xC0) ? key_state[2] : key_state[3]) #define GET_CODE_INDEX(code) (((code) < 0x40) ? (code) : ((code) < 0x80) ? (code)-0x40 : ((code) < 0xC0) ? (code)-0x80 : (code)-0xC0) #define KEY_STATE(code) (GET_KEY_ARRAY(code) & BV_64(GET_CODE_INDEX(code))) == BV_64(GET_CODE_INDEX(code)) #define SET_KEY_ARRAY_STATE(code, val) \ do { \ switch (code) { \ case 0x00 ... 0x3F: \ key_state[0] = (val); \ break; \ case 0x40 ... 0x7F: \ key_state[1] = (val); \ break; \ case 0x80 ... 0xBF: \ key_state[2] = (val); \ break; \ case 0xC0 ... 0xFF: \ key_state[3] = (val); \ break; \ } \ } while (0) #define SET_KEY_STATE(code) SET_KEY_ARRAY_STATE(code, (GET_KEY_ARRAY(code) | BV_64(GET_CODE_INDEX(code)))) #define UNSET_KEY_STATE(code) SET_KEY_ARRAY_STATE(code, (GET_KEY_ARRAY(code)) & ~(BV_64(GET_CODE_INDEX(code)))) #define IS_STANDARD_KEYCODE(code) ((code) <= 0xFF) // Locked key state. This is an array of 256 bits, one for each of the standard keys supported qmk. uint64_t key_state[4] = {0x0, 0x0, 0x0, 0x0}; bool watching = false; // Translate any OSM keycodes back to their unmasked versions. static inline uint16_t translate_keycode(uint16_t keycode) { if (keycode > QK_ONE_SHOT_MOD && keycode <= QK_ONE_SHOT_MOD_MAX) { return keycode ^ QK_ONE_SHOT_MOD; } else { return keycode; } } bool process_key_lock(uint16_t *keycode, keyrecord_t *record) { // We start by categorizing the keypress event. In the event of a down // event, there are several possibilities: // 1. The key is not being locked, and we are not watching for new keys. // In this case, we bail immediately. This is the common case for down events. // 2. The key was locked, and we need to unlock it. In this case, we will // reset the state in our map and return false. When the user releases the // key, the up event will no longer be masked and the OS will observe the // released key. // 3. KC_LOCK was just pressed. In this case, we set up the state machine // to watch for the next key down event, and finish processing // 4. The keycode is below 0xFF, and we are watching for new keys. In this case, // we will send the key down event to the os, and set the key_state for that // key to mask the up event. // 5. The keycode is above 0xFF, and we're wathing for new keys. In this case, // the user pressed a key that we cannot "lock", as it's a series of keys, // or a macro invocation, or a layer transition, or a custom-defined key, or // or some other arbitrary code. In this case, we bail immediately, reset // our watch state, and return true. // // In the event of an up event, there are these possibilities: // 1. The key is not being locked. In this case, we return true and bail // immediately. This is the common case. // 2. The key is being locked. In this case, we will mask the up event // by returning false, so the OS never sees that the key was released // until the user pressed the key again. // We translate any OSM keycodes back to their original keycodes, so that if the key being // one-shot modded is a standard keycode, we can handle it. This is the only set of special // keys that we handle uint16_t translated_keycode = translate_keycode(*keycode); if (record->event.pressed) { // Non-standard keycode, reset and return if (!(IS_STANDARD_KEYCODE(translated_keycode) || translated_keycode == KC_LOCK)) { watching = false; return true; } // If we're already watching, turn off the watch. if (translated_keycode == KC_LOCK) { watching = !watching; return false; } if (IS_STANDARD_KEYCODE(translated_keycode)) { // We check watching first. This is so that in the following scenario, we continue to // hold the key: KC_LOCK, KC_F, KC_LOCK, KC_F // If we checked in reverse order, we'd end up holding the key pressed after the second // KC_F press is registered, when the user likely meant to hold F if (watching) { watching = false; SET_KEY_STATE(translated_keycode); // We need to set the keycode passed in to be the translated keycode, in case we // translated a OSM back to the original keycode. *keycode = translated_keycode; // Let the standard keymap send the keycode down event. The up event will be masked. return true; } if (KEY_STATE(translated_keycode)) { UNSET_KEY_STATE(translated_keycode); // The key is already held, stop this process. The up event will be sent when the user // releases the key. return false; } } // Either the key isn't a standard key, or we need to send the down event. Continue standard // processing return true; } else { // Stop processing if it's a standard key and we're masking up. return !(IS_STANDARD_KEYCODE(translated_keycode) && KEY_STATE(translated_keycode)); } }