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Diffstat (limited to 'common/achordion.c')
| -rw-r--r-- | common/achordion.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/common/achordion.c b/common/achordion.c new file mode 100644 index 0000000..07c1835 --- /dev/null +++ b/common/achordion.c @@ -0,0 +1,368 @@ +// Copyright 2022-2024 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. + +/** + * @file achordion.c + * @brief Achordion implementation + * + * For full documentation, see + * <https://getreuer.info/posts/keyboards/achordion> + */ + +#include "achordion.h" + +#if !defined(IS_QK_MOD_TAP) +// Attempt to detect out-of-date QMK installation, which would fail with +// implicit-function-declaration errors in the code below. +#error "achordion: QMK version is too old to build. Please update QMK." +#else + +// Copy of the `record` and `keycode` args for the current active tap-hold key. +static keyrecord_t tap_hold_record; +static uint16_t tap_hold_keycode = KC_NO; +// Timeout timer. When it expires, the key is considered held. +static uint16_t hold_timer = 0; +// Eagerly applied mods, if any. +static uint8_t eager_mods = 0; +// Flag to determine whether another key is pressed within the timeout. +static bool pressed_another_key_before_release = false; + +#ifdef ACHORDION_STREAK +// Timer for typing streak +static uint16_t streak_timer = 0; +#else +// When disabled, is_streak is never true +#define is_streak false +#endif + +// Achordion's current state. +enum { + // A tap-hold key is pressed, but hasn't yet been settled as tapped or held. + STATE_UNSETTLED, + // Achordion is inactive. + STATE_RELEASED, + // Active tap-hold key has been settled as tapped. + STATE_TAPPING, + // Active tap-hold key has been settled as held. + STATE_HOLDING, + // This state is set while calling `process_record()`, which will recursively + // call `process_achordion()`. This state is checked so that we don't process + // events generated by Achordion and potentially create an infinite loop. + STATE_RECURSING, +}; +static uint8_t achordion_state = STATE_RELEASED; + +#ifdef ACHORDION_STREAK +static void update_streak_timer(uint16_t keycode, keyrecord_t* record) { + if (achordion_streak_continue(keycode)) { + // We use 0 to represent an unset timer, so `| 1` to force a nonzero value. + streak_timer = record->event.time | 1; + } else { + streak_timer = 0; + } +} +#endif + +// Calls `process_record()` with state set to RECURSING. +static void recursively_process_record(keyrecord_t* record, uint8_t state) { + achordion_state = STATE_RECURSING; +#if defined(POINTING_DEVICE_ENABLE) && defined(POINTING_DEVICE_AUTO_MOUSE_ENABLE) + int8_t mouse_key_tracker = get_auto_mouse_key_tracker(); +#endif + process_record(record); +#if defined(POINTING_DEVICE_ENABLE) && defined(POINTING_DEVICE_AUTO_MOUSE_ENABLE) + set_auto_mouse_key_tracker(mouse_key_tracker); +#endif + achordion_state = state; +} + +// Sends hold press event and settles the active tap-hold key as held. +static void settle_as_hold(void) { + if (eager_mods) { + // If eager mods are being applied, nothing needs to be done besides + // updating the state. + achordion_state = STATE_HOLDING; + } else { + // Create hold press event. + recursively_process_record(&tap_hold_record, STATE_HOLDING); + } +} + +// Sends tap press and release and settles the active tap-hold key as tapped. +static void settle_as_tap(void) { + if (eager_mods) { // Clear eager mods if set. +#ifdef DUMMY_MOD_NEUTRALIZER_KEYCODE + neutralize_flashing_modifiers(get_mods()); +#endif // DUMMY_MOD_NEUTRALIZER_KEYCODE + unregister_mods(eager_mods); + eager_mods = 0; + } + + dprintln("Achordion: Plumbing tap press."); + tap_hold_record.tap.count = 1; // Revise event as a tap. + tap_hold_record.tap.interrupted = true; + // Plumb tap press event. + recursively_process_record(&tap_hold_record, STATE_TAPPING); + + send_keyboard_report(); +#if TAP_CODE_DELAY > 0 + wait_ms(TAP_CODE_DELAY); +#endif // TAP_CODE_DELAY > 0 + + dprintln("Achordion: Plumbing tap release."); + tap_hold_record.event.pressed = false; + // Plumb tap release event. + recursively_process_record(&tap_hold_record, STATE_TAPPING); +} + +bool process_achordion(uint16_t keycode, keyrecord_t* record) { + // Don't process events that Achordion generated. + if (achordion_state == STATE_RECURSING) { + return true; + } + + // Determine whether the current event is for a mod-tap or layer-tap key. + const bool is_mt = IS_QK_MOD_TAP(keycode); + const bool is_tap_hold = is_mt || IS_QK_LAYER_TAP(keycode); + // Check that this is a normal key event, don't act on combos. + const bool is_key_event = IS_KEYEVENT(record->event); + + // Event while no tap-hold key is active. + if (achordion_state == STATE_RELEASED) { + if (is_tap_hold && record->tap.count == 0 && record->event.pressed && + is_key_event) { + // A tap-hold key is pressed and considered by QMK as "held". + const uint16_t timeout = achordion_timeout(keycode); + if (timeout > 0) { + achordion_state = STATE_UNSETTLED; + // Save info about this key. + tap_hold_keycode = keycode; + tap_hold_record = *record; + hold_timer = record->event.time + timeout; + pressed_another_key_before_release = false; + eager_mods = 0; + + if (is_mt) { // Apply mods immediately if they are "eager." + const uint8_t mod = mod_config(QK_MOD_TAP_GET_MODS(keycode)); + if (achordion_eager_mod(mod)) { + eager_mods = ((mod & 0x10) == 0) ? mod : (mod << 4); + register_mods(eager_mods); + } + } + + dprintf("Achordion: Key 0x%04X pressed.%s\n", keycode, + eager_mods ? " Set eager mods." : ""); + return false; // Skip default handling. + } + } + +#ifdef ACHORDION_STREAK + update_streak_timer(keycode, record); +#endif + return true; // Otherwise, continue with default handling. + } else if (record->event.pressed && tap_hold_keycode != keycode) { + // Track whether another key was pressed while using a tap-hold key. + pressed_another_key_before_release = true; + } + + // Release of the active tap-hold key. + if (keycode == tap_hold_keycode && !record->event.pressed) { + if (eager_mods) { + dprintln("Achordion: Key released. Clearing eager mods."); + // If Retro Tapping and no other key was pressed, settle as tapped. +#if defined(RETRO_TAPPING) || defined(RETRO_TAPPING_PER_KEY) + if (!pressed_another_key_before_release +#ifdef RETRO_TAPPING_PER_KEY + && get_retro_tapping(tap_hold_keycode, &tap_hold_record) +#endif // RETREO_TAPPING_PER_KEY + ) { + settle_as_tap(); + } +#endif // defined(RETRO_TAPPING) || defined(RETRO_TAPPING_PER_KEY) + + unregister_mods(eager_mods); + } else if (achordion_state == STATE_HOLDING) { + dprintln("Achordion: Key released. Plumbing hold release."); + tap_hold_record.event.pressed = false; + // Plumb hold release event. + recursively_process_record(&tap_hold_record, STATE_RELEASED); + } else if (!pressed_another_key_before_release) { + // No other key was pressed between the press and release of the tap-hold + // key, plumb a hold press and then a release. + dprintln("Achordion: Key released. Plumbing hold press and release."); + recursively_process_record(&tap_hold_record, STATE_HOLDING); + tap_hold_record.event.pressed = false; + recursively_process_record(&tap_hold_record, STATE_RELEASED); + } else { + dprintln("Achordion: Key released."); + } + + achordion_state = STATE_RELEASED; + tap_hold_keycode = KC_NO; + return false; + } + + if (achordion_state == STATE_UNSETTLED && record->event.pressed) { +#ifdef ACHORDION_STREAK + const uint16_t s_timeout = + achordion_streak_chord_timeout(tap_hold_keycode, keycode); + const bool is_streak = + streak_timer && s_timeout && + !timer_expired(record->event.time, (streak_timer + s_timeout)); +#endif + + // Press event occurred on a key other than the active tap-hold key. + + // If the other key is *also* a tap-hold key and considered by QMK to be + // held, then we settle the active key as held. This way, things like + // chording multiple home row modifiers will work, but let's our logic + // consider simply a single tap-hold key as "active" at a time. + // + // Otherwise, we call `achordion_chord()` to determine whether to settle the + // tap-hold key as tapped vs. held. We implement the tap or hold by plumbing + // events back into the handling pipeline so that QMK features and other + // user code can see them. This is done by calling `process_record()`, which + // in turn calls most handlers including `process_record_user()`. + if (!is_streak && + (!is_key_event || (is_tap_hold && record->tap.count == 0) || + achordion_chord(tap_hold_keycode, &tap_hold_record, keycode, + record))) { + dprintln("Achordion: Plumbing hold press."); + settle_as_hold(); + +#ifdef REPEAT_KEY_ENABLE + // Edge case involving LT + Repeat Key: in a sequence of "LT down, other + // down" where "other" is on the other layer in the same position as + // Repeat or Alternate Repeat, the repeated keycode is set instead of the + // the one on the switched-to layer. Here we correct that. + if (get_repeat_key_count() != 0 && IS_QK_LAYER_TAP(tap_hold_keycode)) { + record->keycode = KC_NO; // Forget the repeated keycode. + clear_weak_mods(); + } +#endif // REPEAT_KEY_ENABLE + } else { + settle_as_tap(); + +#ifdef ACHORDION_STREAK + update_streak_timer(keycode, record); + if (is_streak && is_key_event && is_tap_hold && record->tap.count == 0) { + // If we are in a streak and resolved the current tap-hold key as a tap + // consider the next tap-hold key as active to be resolved next. + update_streak_timer(tap_hold_keycode, &tap_hold_record); + const uint16_t timeout = achordion_timeout(keycode); + tap_hold_keycode = keycode; + tap_hold_record = *record; + hold_timer = record->event.time + timeout; + achordion_state = STATE_UNSETTLED; + pressed_another_key_before_release = false; + return false; + } +#endif + } + + recursively_process_record(record, achordion_state); // Re-process event. + return false; // Block the original event. + } + +#ifdef ACHORDION_STREAK + // update idle timer on regular keys event + update_streak_timer(keycode, record); +#endif + return true; +} + +void achordion_task(void) { + if (achordion_state == STATE_UNSETTLED && + timer_expired(timer_read(), hold_timer)) { + dprintln("Achordion: Timeout. Plumbing hold press."); + settle_as_hold(); // Timeout expired, settle the key as held. + } + +#ifdef ACHORDION_STREAK +#define MAX_STREAK_TIMEOUT 800 + if (streak_timer && + timer_expired(timer_read(), (streak_timer + MAX_STREAK_TIMEOUT))) { + streak_timer = 0; // Expired. + } +#endif +} + +// Returns true if `pos` on the left hand of the keyboard, false if right. +static bool on_left_hand(keypos_t pos) { +#ifdef SPLIT_KEYBOARD + return pos.row < MATRIX_ROWS / 2; +#else + return (MATRIX_COLS > MATRIX_ROWS) ? pos.col < MATRIX_COLS / 2 + : pos.row < MATRIX_ROWS / 2; +#endif +} + +bool achordion_opposite_hands(const keyrecord_t* tap_hold_record, + const keyrecord_t* other_record) { + return on_left_hand(tap_hold_record->event.key) != + on_left_hand(other_record->event.key); +} + +// By default, use the BILATERAL_COMBINATIONS rule to consider the tap-hold key +// "held" only when it and the other key are on opposite hands. +__attribute__((weak)) bool achordion_chord(uint16_t tap_hold_keycode, + keyrecord_t* tap_hold_record, + uint16_t other_keycode, + keyrecord_t* other_record) { + return achordion_opposite_hands(tap_hold_record, other_record); +} + +// By default, the timeout is 1000 ms for all keys. +__attribute__((weak)) uint16_t achordion_timeout(uint16_t tap_hold_keycode) { + return 1000; +} + +// By default, Shift and Ctrl mods are eager, and Alt and GUI are not. +__attribute__((weak)) bool achordion_eager_mod(uint8_t mod) { + return (mod & (MOD_LALT | MOD_LGUI)) == 0; +} + +#ifdef ACHORDION_STREAK +__attribute__((weak)) bool achordion_streak_continue(uint16_t keycode) { + // If any mods other than shift or AltGr are held, don't continue the streak + if (get_mods() & (MOD_MASK_CG | MOD_BIT_LALT)) return false; + // This function doesn't get called for holds, so convert to tap version of + // keycodes + if (IS_QK_MOD_TAP(keycode)) keycode = QK_MOD_TAP_GET_TAP_KEYCODE(keycode); + if (IS_QK_LAYER_TAP(keycode)) keycode = QK_LAYER_TAP_GET_TAP_KEYCODE(keycode); + // Regular letters and punctuation continue the streak. + if (keycode >= KC_A && keycode <= KC_Z) return true; + switch (keycode) { + case KC_DOT: + case KC_COMMA: + case KC_QUOTE: + case KC_SPACE: + return true; + } + // All other keys end the streak + return false; +} + +__attribute__((weak)) uint16_t achordion_streak_chord_timeout( + uint16_t tap_hold_keycode, uint16_t next_keycode) { + return achordion_streak_timeout(tap_hold_keycode); +} + +__attribute__((weak)) uint16_t +achordion_streak_timeout(uint16_t tap_hold_keycode) { + return 200; +} +#endif + +#endif // version check |