1 /* Copyright 2017 Fredric Silberberg
3 * This program is free software: you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation, either version 2 of the License, or
6 * (at your option) any later version.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 #include "process_key_lock.h"
21 #define SHIFT(shift) (((uint64_t)1) << (shift))
22 #define GET_KEY_ARRAY(code) (((code) < 0x40) ? key_state[0] : \
23 ((code) < 0x80) ? key_state[1] : \
24 ((code) < 0xC0) ? key_state[2] : key_state[3])
25 #define GET_CODE_INDEX(code) (((code) < 0x40) ? (code) : \
26 ((code) < 0x80) ? (code) - 0x40 : \
27 ((code) < 0xC0) ? (code) - 0x80 : (code) - 0xC0)
28 #define KEY_STATE(code) (GET_KEY_ARRAY(code) & SHIFT(GET_CODE_INDEX(code))) == SHIFT(GET_CODE_INDEX(code))
29 #define SET_KEY_ARRAY_STATE(code, val) do { \
32 key_state[0] = (val); \
35 key_state[1] = (val); \
38 key_state[2] = (val); \
41 key_state[3] = (val); \
45 #define SET_KEY_STATE(code) SET_KEY_ARRAY_STATE(code, (GET_KEY_ARRAY(code) | SHIFT(GET_CODE_INDEX(code))))
46 #define UNSET_KEY_STATE(code) SET_KEY_ARRAY_STATE(code, (GET_KEY_ARRAY(code)) & ~(SHIFT(GET_CODE_INDEX(code))))
47 #define IS_STANDARD_KEYCODE(code) ((code) <= 0xFF)
49 // Locked key state. This is an array of 256 bits, one for each of the standard keys supported qmk.
50 uint64_t key_state[4] = { 0x0, 0x0, 0x0, 0x0 };
51 bool watching = false;
53 bool process_key_lock(uint16_t keycode, keyrecord_t *record) {
54 // We start by categorizing the keypress event. In the event of a down
55 // event, there are several possibilities:
56 // 1. The key is not being locked, and we are not watching for new keys.
57 // In this case, we bail immediately. This is the common case for down events.
58 // 2. The key was locked, and we need to unlock it. In this case, we will
59 // reset the state in our map and return false. When the user releases the
60 // key, the up event will no longer be masked and the OS will observe the
62 // 3. KC_LOCK was just pressed. In this case, we set up the state machine
63 // to watch for the next key down event, and finish processing
64 // 4. The keycode is below 0xFF, and we are watching for new keys. In this case,
65 // we will send the key down event to the os, and set the key_state for that
66 // key to mask the up event.
67 // 5. The keycode is above 0xFF, and we're wathing for new keys. In this case,
68 // the user pressed a key that we cannot "lock", as it's a series of keys,
69 // or a macro invocation, or a layer transition, or a custom-defined key, or
70 // or some other arbitrary code. In this case, we bail immediately, reset
71 // our watch state, and return true.
73 // In the event of an up event, there are these possibilities:
74 // 1. The key is not being locked. In this case, we return true and bail
75 // immediately. This is the common case.
76 // 2. The key is being locked. In this case, we will mask the up event
77 // by returning false, so the OS never sees that the key was released
78 // until the user pressed the key again.
79 if (record->event.pressed) {
80 // Non-standard keycode, reset and return
81 if (!(IS_STANDARD_KEYCODE(keycode) || keycode == KC_LOCK)) {
86 // If we're already watching, turn off the watch.
87 if (keycode == KC_LOCK) {
92 if (IS_STANDARD_KEYCODE(keycode)) {
93 // We check watching first. This is so that in the following scenario, we continue to
94 // hold the key: KC_LOCK, KC_F, KC_LOCK, KC_F
95 // If we checked in reverse order, we'd end up holding the key pressed after the second
96 // KC_F press is registered, when the user likely meant to hold F
99 SET_KEY_STATE(keycode);
100 // Let the standard keymap send the keycode down event. The up event will be masked.
104 if (KEY_STATE(keycode)) {
105 UNSET_KEY_STATE(keycode);
106 // The key is already held, stop this process. The up event will be sent when the user
112 // Either the key isn't a standard key, or we need to send the down event. Continue standard
116 // Stop processing if it's a standard key and we're masking up.
117 return !(IS_STANDARD_KEYCODE(keycode) && KEY_STATE(keycode));