zmk/app/include/zmk/event-manager.h

/*
 * Copyright (c) 2020 Peter Johanson <peter@peterjohanson.com>
 *
 * SPDX-License-Identifier: MIT
 */
 
#pragma once

#include <stddef.h>
#include <kernel.h>
#include <zephyr/types.h>

struct zmk_event_type
{
    const char *name;
};

struct zmk_event_header {
    const struct zmk_event_type* event;
    u8_t last_listener_index;
};

#define ZMK_EV_EVENT_HANDLED 1
#define ZMK_EV_EVENT_CAPTURED 2

typedef int (*zmk_listener_callback_t)(const struct zmk_event_header *eh);
struct zmk_listener
{
    zmk_listener_callback_t callback;
};

struct zmk_event_subscription {
    const struct zmk_event_type *event_type;
    const struct zmk_listener *listener;
};

#define ZMK_EVENT_DECLARE(event_type) \
    struct event_type* new_##event_type(); \
    bool is_##event_type(const struct zmk_event_header *eh); \
    struct event_type* cast_##event_type(const struct zmk_event_header *eh); \
    extern const struct zmk_event_type zmk_event_##event_type;

#define ZMK_EVENT_IMPL(event_type) \
    const struct zmk_event_type zmk_event_##event_type = { \
        .name = STRINGIFY(event_type) \
    }; \
    const struct zmk_event_type* zmk_event_ref_##event_type __used __attribute__((__section__(".event_type"))) = &zmk_event_##event_type; \
    struct event_type* new_##event_type() { \
        struct event_type* ev = (struct event_type *) k_malloc(sizeof(struct event_type)); \
        ev->header.event = &zmk_event_##event_type; \
        return ev; \
    }; \
    bool is_##event_type(const struct zmk_event_header *eh) { \
        return eh->event == &zmk_event_##event_type; \
    }; \
    struct event_type* cast_##event_type(const struct zmk_event_header *eh) {\
        return (struct event_type*)eh; \
    };
    

#define ZMK_LISTENER(mod, cb) \
    const struct zmk_listener zmk_listener_##mod = { \
        .callback = cb \
    };

#define ZMK_SUBSCRIPTION(mod, ev_type) \
    const Z_DECL_ALIGN(struct zmk_event_subscription) _CONCAT(_CONCAT(zmk_event_sub_,mod),ev_type) __used __attribute__((__section__(".event_subscription"))) = { \
        .event_type = &zmk_event_##ev_type, \
        .listener = &zmk_listener_##mod, \
    };

#define ZMK_EVENT_RAISE(ev) \
    zmk_event_manager_raise((struct zmk_event_header *)ev);

#define ZMK_EVENT_RAISE_AFTER(ev, mod) \
    zmk_event_manager_raise_after((struct zmk_event_header *)ev, &zmk_listener_##mod);

#define ZMK_EVENT_RELEASE(ev) \
    zmk_event_manager_release((struct zmk_event_header *)ev);

int zmk_event_manager_raise(struct zmk_event_header *event);
int zmk_event_manager_raise_after(struct zmk_event_header *event, const struct zmk_listener *listener);
int zmk_event_manager_release(struct zmk_event_header *event);