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Diffstat (limited to 'quantum/process_keycode/process_key_lock.c')
| -rw-r--r-- | quantum/process_keycode/process_key_lock.c | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/quantum/process_keycode/process_key_lock.c b/quantum/process_keycode/process_key_lock.c new file mode 100644 index 0000000000..60b0fcd9b1 --- /dev/null +++ b/quantum/process_keycode/process_key_lock.c @@ -0,0 +1,120 @@ +/* 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 SHIFT(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) & SHIFT(GET_CODE_INDEX(code))) == SHIFT(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) | SHIFT(GET_CODE_INDEX(code)))) +#define UNSET_KEY_STATE(code) SET_KEY_ARRAY_STATE(code, (GET_KEY_ARRAY(code)) & ~(SHIFT(GET_CODE_INDEX(code)))) +#define IS_STANDARD_KEYCODE(code) ((code) <= 0xFF) +#define print_hex64(num) do { print_hex32((num & 0xFFFFFFFF00000000) >> 32); print_hex32(num & 0x00000000FFFFFFFF); } while (0) + +// 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; + +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. + if (record->event.pressed) { + // Non-standard keycode, reset and return + if (!(IS_STANDARD_KEYCODE(keycode) || keycode == KC_LOCK)) { + watching = false; + return true; + } + + // If we're already watching, turn off the watch. + if (keycode == KC_LOCK) { + watching = !watching; + return false; + } + + if (IS_STANDARD_KEYCODE(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(keycode); + // Let the standard keymap send the keycode down event. The up event will be masked. + return true; + } + + if (KEY_STATE(keycode)) { + UNSET_KEY_STATE(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(keycode) && KEY_STATE(keycode)); + } +} |