1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
// Copyright 2021-2022 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
//
// For full documentation, see
// https://getreuer.info/posts/keyboards/autocorrection
#include "autocorrection.h"
#include <string.h>
#include "autocorrection_data.h"
#if AUTOCORRECTION_MIN_LENGTH < 4
// Odd output or hard locks on the board have been observed when the min typo
// length is 3 or lower (https://github.com/getreuer/qmk-keymap/issues/2).
// Additionally, autocorrection entries for short typos are more likely to false
// trigger, so it is suggested that typos be at least 5 characters.
#error "Min typo length is less than 4. Autocorrection may behave poorly."
#endif
bool process_autocorrection(uint16_t keycode, keyrecord_t* record) {
if (user_config.autocorrect) {
static uint8_t typo_buffer[AUTOCORRECTION_MAX_LENGTH] = {0};
static uint8_t typo_buffer_size = 0;
// Ignore key release; we only process key presses.
if (!record->event.pressed) { return true; }
#ifndef NO_ACTION_ONESHOT
const uint8_t mods = get_mods() | get_oneshot_mods();
#else
const uint8_t mods = get_mods();
#endif // NO_ACTION_ONESHOT
// Disable autocorrection while a mod other than shift is active.
if ((mods & ~MOD_MASK_SHIFT) != 0) {
typo_buffer_size = 0;
return true;
}
// The following switch cases address various kinds of keycodes. This logic is
// split over two switches rather than merged into one. The first switch may
// extract a basic keycode which is then further handled by the second switch,
// e.g. a layer-tap key with Caps Lock `LT(layer, KC_CAPS)`.
switch (keycode) {
#ifndef NO_ACTION_TAPPING
case QK_MOD_TAP ... QK_MOD_TAP_MAX: // Tap-hold keys.
#ifndef NO_ACTION_LAYER
case QK_LAYER_TAP ... QK_LAYER_TAP_MAX:
#endif // NO_ACTION_LAYER
// Ignore when tap-hold keys are held.
if (record->tap.count == 0) { return true; }
// Otherwise when tapped, get the basic keycode.
// Fallthrough intended.
#endif // NO_ACTION_TAPPING
// Handle shifted keys, e.g. symbols like KC_EXLM = S(KC_1).
case QK_LSFT ... QK_LSFT + 255:
case QK_RSFT ... QK_RSFT + 255:
keycode &= 0xff; // Get the basic keycode.
break;
// NOTE: Space Cadet keys expose no info to check whether they are being
// tapped vs. held. This makes autocorrection ambiguous, e.g. KC_LCPO might
// be '(', which we would treat as a word break, or it might be shift, which
// we would treat as having no effect. To behave cautiously, we allow Space
// Cadet keycodes to fall to the logic below and clear autocorrection state.
}
switch (keycode) {
// Ignore shifts, Caps Lock, one-shot mods, and layer switch keys.
case KC_NO:
case KC_LSFT:
case KC_RSFT:
case KC_CAPS:
case QK_ONE_SHOT_MOD ... QK_ONE_SHOT_MOD_MAX:
case QK_TO ... QK_TO_MAX:
case QK_MOMENTARY ... QK_MOMENTARY_MAX:
case QK_DEF_LAYER ... QK_DEF_LAYER_MAX:
case QK_TOGGLE_LAYER ... QK_TOGGLE_LAYER_MAX:
case QK_ONE_SHOT_LAYER ... QK_ONE_SHOT_LAYER_MAX:
case QK_LAYER_TAP_TOGGLE ... QK_LAYER_TAP_TOGGLE_MAX:
case QK_LAYER_MOD ... QK_LAYER_MOD_MAX:
return true; // Ignore these keys.
}
if (keycode == KC_QUOT) {
// Treat " (shifted ') as a word boundary.
if ((mods & MOD_MASK_SHIFT) != 0) { keycode = KC_SPC; }
} else if (!(KC_A <= keycode && keycode <= KC_Z)) {
if (keycode == KC_BSPC) {
// Remove last character from the buffer.
if (typo_buffer_size > 0) { --typo_buffer_size; }
return true;
} else if (KC_1 <= keycode && keycode <= KC_SLSH && keycode != KC_ESC) {
// Set a word boundary if space, period, digit, etc. is pressed.
// Behave more conservatively for the enter key. Reset, so that enter
// can't be used on a word ending.
if (keycode == KC_ENT) { typo_buffer_size = 0; }
keycode = KC_SPC;
} else {
// Clear state if some other non-alpha key is pressed.
typo_buffer_size = 0;
return true;
}
}
// If the buffer is full, rotate it to discard the oldest character.
if (typo_buffer_size >= AUTOCORRECTION_MAX_LENGTH) {
memmove(typo_buffer, typo_buffer + 1, AUTOCORRECTION_MAX_LENGTH - 1);
typo_buffer_size = AUTOCORRECTION_MAX_LENGTH - 1;
}
// Append `keycode` to the buffer.
// NOTE: `keycode` must be a basic keycode (0-255) by this point.
typo_buffer[typo_buffer_size++] = (uint8_t) keycode;
// Early return if not many characters have been buffered so far.
if (typo_buffer_size < AUTOCORRECTION_MIN_LENGTH) { return true; }
// Check whether the buffer ends in a typo. This is done using a trie
// stored in `autocorrection_data`.
uint16_t state = 0;
uint8_t code = pgm_read_byte(autocorrection_data + state);
for (int i = typo_buffer_size - 1; i >= 0; --i) {
const uint8_t key_i = typo_buffer[i];
if (code & 64) { // Check for match in node with multiple children.
code &= 63;
for (; code != key_i;
code = pgm_read_byte(autocorrection_data + (state += 3))) {
if (!code) { return true; }
}
// Follow link to child node.
state = (uint16_t)(
(uint_fast16_t)pgm_read_byte(autocorrection_data + state + 1)
| (uint_fast16_t)pgm_read_byte(autocorrection_data + state + 2) << 8);
// Otherwise check for match in node with a single child.
} else if (code != key_i) {
return true;
} else if (!(code = pgm_read_byte(autocorrection_data + (++state)))) {
++state;
}
// Stop if `state` becomes an invalid index. This should not normally
// happen, it is a safeguard in case of a bug, data corruption, etc.
if (state >= sizeof(autocorrection_data)) {
return true;
}
// Read first byte of the next node.
code = pgm_read_byte(autocorrection_data + state);
if (code & 128) { // A typo was found! Apply autocorrection.
const int backspaces = code & 63;
for (int i = 0; i < backspaces; ++i) { tap_code(KC_BSPC); }
send_string_P((char const*)(autocorrection_data + state + 1));
if (keycode == KC_SPC) {
typo_buffer[0] = KC_SPC;
typo_buffer_size = 1;
return true;
} else {
typo_buffer_size = 0;
return false;
}
}
}
return true;
}
return true;
}
|
