[QMK] feature/streak

keymap.c

#include <string.h>

#include QMK_KEYBOARD_H

#include "streak.h"

enum keycodes {
	STREAK = SAFE_RANGE,
};

bool process_record_user(uint16_t keycode, keyrecord_t *record) {
	if (!process_streak(STREAK, keycode, record)) { return false; }

	update_streak(STREAK, keycode, record);
	return true;
}

streak.c

#include <string.h>

#include "streak.h"

typedef struct {
	uint16_t keycode;
	uint8_t mods;
} streak_item;

static streak_item streak[STREAK_N] = {{0}};

void update_streak(uint16_t trigger, uint16_t keycode, keyrecord_t *record) {
	static uint16_t streak_timer = 0;

	if (record->event.pressed) { return; }
	if (keycode == trigger)    { return; }

	switch (keycode) {
		case KC_LCTL ... KC_RGUI:
			// Ignore mods.
			return;
	}

	if (timer_elapsed(streak_timer) >= STREAK_TERM) {
		// Start a new streak.
		streak_timer = timer_read();
		streak[0] = (streak_item){keycode, get_mods()};
		for (size_t i = 1; i < STREAK_N; i++) {
			streak[i] = (streak_item){0, 0};
		}
	} else {
		// Append to existing streak.
		for (size_t i = 0; i < STREAK_N; i++) {
			if (streak[i].keycode != 0) {
				// If the streak is full, don't do anything.
				// To start a new streak, wait until STREAK_TERM
				// elapses.
				continue;
			}
			streak[i] = (streak_item){keycode, get_mods()};
			break;
		}
	}
}

bool process_streak(uint16_t trigger, uint16_t keycode, keyrecord_t *record) {
	if (keycode != trigger)     { return true; }
	if (!record->event.pressed) { return false; }

	for (size_t i = 0; i < STREAK_N; i++) {
		// Reached the end of the streak.
		if (streak[i].keycode == 0) { break; }

		set_mods(streak[i].mods);
		tap_code16(streak[i].keycode);
		clear_mods();
	}

	return false;
}

streak.h

#include QMK_KEYBOARD_H

#ifndef STREAK_N
#define STREAK_N 3
#endif

#ifndef STREAK_TERM
#define STREAK_TERM 1000
#endif

void update_streak(uint16_t trigger, uint16_t keycode, keyrecord_t *record);
bool process_streak(uint16_t trigger, uint16_t keycode, keyrecord_t *record);