QMK/keyboards/betalupi_ergodox/keymaps/default/spellcheck.c

#include "spellcheck.h"
#include "rawhid.h"

uint8_t spellcheck_buffer[SPELLCHECK_BUFFER_MAX] = {0};
uint8_t spellcheck_buffer_size = 0;

bool process_spellcheck(uint16_t keycode, keyrecord_t* record) {


	// 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


	// Disable autocorrection while a mod other than shift is active.
	if ((mods & ~MOD_MASK_SHIFT) != 0) {
		spellcheck_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
	// Ignore when tap-hold keys are held.
			if (record->tap.count == 0) { return true; }
	// Otherwise when tapped, get the basic keycode.
	// Fallthrough intended.
#endif

		// 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 (spellcheck_buffer_size > 0) { --spellcheck_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) { spellcheck_buffer_size = 0; }
			keycode = KC_SPC;
		} else {
			// Clear state if some other non-alpha key is pressed.
			spellcheck_buffer_size = 0;
			return true;
		}
	}

	// If the buffer is full, rotate it to discard the oldest character.
	if (spellcheck_buffer_size >= SPELLCHECK_BUFFER_MAX) {
		memmove(spellcheck_buffer, spellcheck_buffer + 1, SPELLCHECK_BUFFER_MAX - 1);
		spellcheck_buffer_size = SPELLCHECK_BUFFER_MAX - 1;
	}

	// NOTE: `keycode` must be a basic keycode (0-255) by this point.

	// A to Z keycodes
	if (keycode >= 0x04 && keycode <= 0x1D) {
		spellcheck_buffer[spellcheck_buffer_size++] = (uint8_t) keycode;
	} else if (spellcheck_buffer_size > 0) {
		hid_send_word();
		spellcheck_buffer_size = 0;
	}

	return true;
}