main.c

#include <unistd.h>
#include <pthread.h>
#include <time.h>
#include <sys/time.h>

#include "lvgl/lvgl.h"
#include "lv_drivers/indev/evdev.h"
#include "lv_drivers/display/monitor.h"
#include "SDL2/include/SDL2/SDL.h"

#include "gui_guider/generated/gui_guider.h"
#include "gui_guider/generated/events_init.h"
#include "gui_guider/custom/custom.h"

static void hal_init(void);
static void input_device(void);
static int tick_thread(void * data);

/* GUI-Guider struct*/
lv_ui guider_ui;

int main(void)
{
    /*LittlevGL init*/
    lv_init();

    /*Initialize the HAL (display, input devices, tick) for LittlevGL*/
    hal_init();

    /*Create a GUI-Guider app */
	setup_ui(&guider_ui);
    events_init(&guider_ui);
    custom_init(&guider_ui);

    /*Handle LitlevGL tasks (tickless mode)*/
    while(1) {
        lv_task_handler();
        usleep(5000);
    }

    return 0;
}

/**
 * Initialize the Hardware Abstraction Layer (HAL) for the Littlev graphics library
 */
static void hal_init(void)
{
    /* Use the 'monitor' driver which creates window on PC's monitor to simulate a display*/
    monitor_init();

    /*Create a display buffer*/
    static lv_disp_buf_t disp_buf1;
    static lv_color_t buf1_1[480*10];
    lv_disp_buf_init(&disp_buf1, buf1_1, NULL, 480*10);

    /*Create a display*/
    lv_disp_drv_t disp_drv;
    lv_disp_drv_init(&disp_drv);            /*Basic initialization*/
    disp_drv.buffer = &disp_buf1;
    disp_drv.flush_cb = monitor_flush;    /*Used when `LV_VDB_SIZE != 0` in lv_conf.h (buffered drawing)*/
    lv_disp_drv_register(&disp_drv);

    input_device();

    /* Tick init.
     * You have to call 'lv_tick_inc()' in periodically to inform LittelvGL about how much time were elapsed
     * Create an SDL thread to do this*/
    // SDL_CreateThread(tick_thread, "tick", NULL);
}

/**
 * A task to measure the elapsed time for LittlevGL
 * @param data unused
 * @return never return
 */
static int tick_thread(void * data)
{
    (void)data;

    while(1) {
        // SDL_Delay(5);   /*Sleep for 5 millisecond*/
        lv_tick_inc(5); /*Tell LittelvGL that 5 milliseconds were elapsed*/
    }

    return 0;
}

static void input_device(void)
{
    // Event device - for touch screen
    evdev_init();
    lv_indev_drv_t indev_drv;
    lv_indev_drv_init(&indev_drv);
    indev_drv.type = LV_INDEV_TYPE_POINTER;
    indev_drv.read_cb = evdev_read;
    /*Add a display the LittlevGL sing the frame buffer driver*/
    lv_indev_drv_register(&indev_drv);
}

/*Set in lv_conf.h as `LV_TICK_CUSTOM_SYS_TIME_EXPR`*/
uint32_t custom_tick_get(void)
{
    static uint64_t start_ms = 0;
    if(start_ms == 0) {
        struct timeval tv_start;
        gettimeofday(&tv_start, NULL);
        start_ms = (tv_start.tv_sec * 1000000 + tv_start.tv_usec) / 1000;
    }

    struct timeval tv_now;
    gettimeofday(&tv_now, NULL);
    uint64_t now_ms;
    now_ms = (tv_now.tv_sec * 1000000 + tv_now.tv_usec) / 1000;

    uint32_t time_ms = now_ms - start_ms;
    return time_ms;
}