Develop LVGL GUI applicaitons using EEZ Studio¶

#include   <unistd.h>
#include   <time.h>
#include   <sys/time.h>
#include   <fcntl.h>
#include   <stdlib.h>
#include   <string.h>
#include   <stdio.h>
#include   <stdlib.h>
#include   <limits.h>
#include   <errno.h>
#include   <poll.h>
#include   <stdbool.h>
#include   <getopt.h>

#include   "lvgl/lvgl.h"
#include   "lvgl/lv_drivers/lv_drv_conf.h"

/* Added to run EEZ Studio generated source code */ 
#include "ui.h"
      
#if    USE_FBDEV && USE_EVDEV
  #undef   RUNS_ON_WAYLAND
#elif  USE_WAYLAND
  #define  RUNS_ON_WAYLAND
#else
  #error   LVGL drivers configration error.
#endif

#ifdef RUNS_ON_WAYLAND
  #include "lvgl/lv_drivers/wayland/wayland.h"
#else
#include   "lvgl/lv_drivers/display/fbdev.h"
#include   "lvgl/lv_drivers/indev/evdev.h"

typedef struct {
    lv_coord_t width;
    lv_coord_t height;
    bool end;
    lv_color_t *buff;
    lv_disp_draw_buf_t draw_buf;
    lv_disp_drv_t drv;
    lv_disp_t *disp;
    lv_indev_drv_t indev_drv;
    lv_indev_t *mouse_indev;
} dispinf_fbevdev_t;
#endif /* RUNS_ON_WAYLAND */

#define MAX_JSON_ARR 8
#define WINDOW_WIDTH 640
#define WINDOW_HEIGHT 480

#ifndef RUNS_ON_WAYLAND

/* Create fbdev window with evdev */
static dispinf_fbevdev_t *create_fbdev_window()
{
    uint32_t width, height;
    dispinf_fbevdev_t *dispinf;
    lv_disp_drv_t *disp_drv;
    lv_obj_t *cursor_obj;
    bool ret;

    /* Init Linux frame buffer device for LVGL */
    fbdev_init();
    fbdev_get_sizes(&width, &height, NULL);

    dispinf = lv_mem_alloc(sizeof (dispinf_fbevdev_t));
    if (!dispinf) {
        printf("ERROR!! memory allocation failed at lv_mem_alloc()\n");
        return NULL;
    }

    dispinf->buff = lv_mem_alloc(width * height * sizeof(lv_color_t));
    if (!dispinf->buff) {
        printf("ERROR!! memory allocation failed at lv_mem_alloc()\n");
        lv_mem_free(dispinf);
        return NULL;
    }
    lv_disp_draw_buf_init(&dispinf->draw_buf, dispinf->buff, NULL,
                            width * height);

    disp_drv = &dispinf->drv;
    /* Initialize and register a display driver */
    lv_disp_drv_init(disp_drv);

    disp_drv->draw_buf     = &dispinf->draw_buf;
    disp_drv->flush_cb     = fbdev_flush;
    disp_drv->hor_res      = (lv_coord_t)width;
    disp_drv->ver_res      = (lv_coord_t)height;
    disp_drv->physical_hor_res = (lv_coord_t)width;
    disp_drv->physical_ver_res = (lv_coord_t)height;

    dispinf->disp = lv_disp_drv_register(disp_drv);

    dispinf->width = (lv_coord_t)width;
    dispinf->height = (lv_coord_t)height;

    /* Init evdev for LVGL */
    evdev_init();

    lv_indev_drv_init(&dispinf->indev_drv);

    dispinf->indev_drv.type = LV_INDEV_TYPE_POINTER;
    /* This function will be called periodically (by the library)
       to get the mouse position and state */
    dispinf->indev_drv.read_cb = evdev_read;

    dispinf->mouse_indev = lv_indev_drv_register(&dispinf->indev_drv);

    /* Set a cursor for the mouse */
    LV_IMG_DECLARE(mouse_cursor);
    /* Create an image object for the cursor */
    cursor_obj = lv_img_create(lv_scr_act());
    lv_img_set_src(cursor_obj, &mouse_cursor);
    /* Connect the image  object to the driver */
    lv_indev_set_cursor(dispinf->mouse_indev, cursor_obj);

    return dispinf;
}
      
static void close_fbdev_window(dispinf_fbevdev_t *dispinf)
{
    if (!dispinf) {
        printf("ERROR!! no object to be freed.\n");
        return;
    }

    if (dispinf->mouse_indev)
        lv_indev_delete(dispinf->mouse_indev);

    if (dispinf->disp)
        lv_disp_remove(dispinf->disp);

    if (dispinf->buff)
        lv_mem_free(dispinf->buff);

    lv_mem_free(dispinf);

    fbdev_exit();
}
#endif

int main(int argc, char *argv[])
{
#ifdef RUNS_ON_WAYLAND
    struct pollfd pfd;
    uint32_t time_till_next;
    int sleep;
    lv_disp_t *disp;
#else /* FBDEV and EVDEV  */
    dispinf_fbevdev_t *disp;
#endif    
    int32_t window_width = WINDOW_WIDTH;
    int32_t window_height = WINDOW_HEIGHT;
    int32_t ret = 0;

    int btn_cnt = 0;


    /*LVGL init*/
    lv_init();

#ifdef RUNS_ON_WAYLAND
    lv_wayland_init();

    disp = lv_wayland_create_window(window_width,window_height,
                            "Window Demo", NULL);
    if (disp == NULL) {
        printf("ERROR!! lv_wayland_create_window\n");
        goto APP_EXIT;
    }

    pfd.fd = lv_wayland_get_fd();
    pfd.events = POLLIN;

#else /* FBDEV and EVDEV  */
    disp = create_fbdev_window();
    if (disp == NULL) {
        printf("ERROR!! lv_wayland_create_window\n");
        goto APP_EXIT;
    }
    /* Clear end flag */
    disp->end = false;
    window_width = disp->width;
    window_height = disp->height;
#endif
    
    /* make_screen */
    /*Added to run EEZ Studio generated source code */
    ui_init();

    while(1) {
#ifdef RUNS_ON_WAYLAND    
        /* Handle any Wayland/LVGL timers/events */
        time_till_next = lv_wayland_timer_handler();

        /* Run until the last window closes */
        if (!lv_wayland_window_is_open(NULL)) {
            break;
        }

        /* Wait for something interesting to happen */
        if (time_till_next == LV_NO_TIMER_READY) {
            sleep = -1;
        } else if (time_till_next > INT_MAX) {
            sleep = INT_MAX;
        } else {
            sleep = time_till_next;
        }
        while ((poll(&pfd, 1, sleep) < 0) && (errno == EINTR));
#else /* FBDEV and EVDEV  */
        lv_timer_handler();
        usleep(5000);
        if (disp->end)
            break;
#endif
    }

APP_EXIT:

#ifdef RUNS_ON_WAYLAND
    lv_wayland_deinit();

#else /* FBDEV and EVDEV  */
    close_fbdev_window(disp);
#endif
    return 0;
}
/**
 * Set in lv_conf.h as `LV_TICK_CUSTOM_SYS_TIME_EXPR`
 */
uint32_t custom_tick_get(void)
{
    static uint64_t start_ms = 0;
    struct timeval tv_start;
    struct timeval tv_now;
    uint64_t now_ms;

    if(start_ms == 0) {
        gettimeofday(&tv_start, NULL);
        start_ms = (tv_start.tv_sec * 1000000 + tv_start.tv_usec) / 1000;
    }
    gettimeofday(&tv_now, NULL);
    now_ms = (tv_now.tv_sec * 1000000 + tv_now.tv_usec) / 1000;

    return (uint32_t)(now_ms - start_ms);
}

BIN = EEZ_sample
CFLAGS += -I${SDKTARGETSYSROOT}/usr/include/lvgl  -I${SDKTARGETSYSROOT}/usr/include/lvgl/lv_drivers -DLV_CONF_INCLUDE_SIMPLE
LDFLAGS += -llvgl -llv_drivers -lwayland-client -ltoml
SRC_DIR := ./ui
MAIN := $(SRC_DIR)/main.c
SRCS := $(shell find $(SRC_DIR) -name '*.c' ! -name 'main.c')
MAINOBJ = $(MAIN:.c=.o)
OBJS := $(SRCS:$(SRC_DIR)/%.c=$(SRC_DIR)/%.o)
.PHONY: all clean
all: default
%.o: %.c
    @$(CC)  $(CFLAGS) -c $< -o $@
default: $(OBJS) $(MAINOBJ)
    $(CC) -o $(BIN) $(MAINOBJ) $(OBJS) $(LDFLAGS)
clean:
    @echo "Cleaning ... "
    rm -f $(BIN) $(MAINOBJ) $(OBJS)