README Zh

#include "lvgl/lvgl.h" /*定义 LV_LVGL_H_INCLUDE_SIMPLE 可直接使用 "lvgl.h"*/

#define TFT_HOR_RES 320
#define TFT_VER_RES 240

static uint32_t my_tick_cb(void)
{
    return my_get_millisec();
}

static void my_flush_cb(lv_display_t * disp, const lv_area_t * area, uint8_t * px_map)
{
    /*将 px_map 写入帧缓冲或显示控制器对应区域*/
}

static void my_touch_read_cb(lv_indev_t * indev, lv_indev_data_t * data)
{
   if(my_touch_is_pressed()) {
       data->point.x = touchpad_x;
       data->point.y = touchpad_y;
       data->state = LV_INDEV_STATE_PRESSED;
   } else {
       data->state = LV_INDEV_STATE_RELEASED;
   }
}

void main(void)
{
    my_hardware_init();

    /*初始化 LVGL*/
    lv_init();

    /*设置毫秒级时钟回调，用于 LVGL 计时*/
    lv_tick_set_cb(my_tick_cb);

    /*创建显示对象，用于添加屏幕和控件*/
    lv_display_t * display = lv_display_create(TFT_HOR_RES, TFT_VER_RES);

    /*添加渲染缓冲，这里假设使用 16 位 RGB565 格式*/
    static uint8_t buf[TFT_HOR_RES * TFT_VER_RES / 10 * 2];
    lv_display_set_buffers(display, buf, NULL, sizeof(buf), LV_DISPLAY_RENDER_MODE_PARTIAL);

    /*设置刷新回调，将缓冲内容写入显示设备*/
    lv_display_set_flush_cb(display, my_flush_cb);

    /*创建输入设备用于触摸处理*/
    lv_indev_t * indev = lv_indev_create();
    lv_indev_set_type(indev, LV_INDEV_TYPE_POINTER);
    lv_indev_set_read_cb(indev, my_touch_read_cb);

    /*驱动已就绪，创建 UI*/
    lv_obj_t * label = lv_label_create(lv_screen_active());
    lv_label_set_text(label, "Hello world");
    lv_obj_center(label);

    /*循环执行 LVGL 任务*/
    while(1) {
        lv_timer_handler();
        my_sleep_ms(5);
    }
}

static void button_clicked_cb(lv_event_t * e)
{
  printf("Clicked\n");
}

[...]

lv_obj_t * button = lv_button_create(lv_screen_active());
lv_obj_center(button);
lv_obj_add_event_cb(button, button_clicked_cb, LV_EVENT_CLICKED, NULL);

lv_obj_t * label = lv_label_create(button);
lv_label_set_text(label, "Hello from LVGL!");

<screen>
	<view>
		<lv_button align="center">
			<event_cb callback="button_clicked_cb" />
			<lv_label text="Hello from LVGL!" />
		</lv_button>
	</view>
</screen>

static void my_observer_cb(lv_observer_t * observer, lv_subject_t * subject)
{
	printf("Slider value: %d\n", lv_subject_get_int(subject));
}

[...]

static lv_subject_t subject_value;
lv_subject_init_int(&subject_value, 35);
lv_subject_add_observer(&subject_value, my_observer_cb, NULL);

lv_style_t style_base;
lv_style_init(&style_base);
lv_style_set_bg_color(&style_base, lv_color_hex(0xff8800));
lv_style_set_bg_opa(&style_base, 255);
lv_style_set_radius(&style_base, 4);

lv_obj_t * slider = lv_slider_create(lv_screen_active());
lv_obj_center(slider);
lv_obj_set_size(slider, lv_pct(80), 16);
lv_obj_add_style(slider, &style_base, LV_PART_INDICATOR);
lv_obj_add_style(slider, &style_base, LV_PART_KNOB);
lv_obj_add_style(slider, &style_base, 0);
lv_obj_set_style_bg_opa(slider, LV_OPA_50, 0);
lv_obj_set_style_border_width(slider, 3, LV_PART_KNOB);
lv_obj_set_style_border_color(slider, lv_color_hex3(0xfff), LV_PART_KNOB);
lv_slider_bind_value(slider, &subject_value);

lv_obj_t * label = lv_label_create(lv_screen_active());
lv_obj_align(label, LV_ALIGN_CENTER, 0, -30);
lv_label_bind_text(label, &subject_value, "Temperature: %d °C");

<screen>
	<styles>
		<style name="style_base" bg_opa="100%" bg_color="0xff8800" radius="4" />
		<style name="style_border" border_color="0xfff" border_width="3" />
	</styles>

	<view>
		<lv_label bind_text="value" bind_text-fmt="Temperature: %d °C" align="center" y="-30" />
		<lv_slider align="center" bind_value="value" style_bg_opa="30%">
			<style name="style_base" />
			<style name="style_base" selector="knob" />
			<style name="style_base" selector="indicator" />
			<style name="style_border" selector="knob" />
		</lv_slider>
	</view>
</screen>

/*创建新屏幕并加载*/
lv_obj_t * scr = lv_obj_create(NULL);
lv_screen_load(scr);

/*设置列布局*/
lv_obj_set_flex_flow(scr, LV_FLEX_FLOW_COLUMN);
lv_obj_set_flex_align(scr, LV_FLEX_ALIGN_SPACE_EVENLY, /*垂直对齐*/
  					   LV_FLEX_ALIGN_START,	       /*主轴方向对齐*/
  					   LV_FLEX_ALIGN_CENTER);      /*交叉轴方向对齐*/

/*创建 5 个复选框*/
const char * texts[5] = {"Input 1", "Input 2", "Input 3", "Output 1", "Output 2"};
for(int i = 0; i < 5; i++) {
  lv_obj_t * cb = lv_checkbox_create(scr);
  lv_checkbox_set_text(cb, texts[i]);
}

/*更改状态*/
lv_obj_add_state(lv_obj_get_child(scr, 1), LV_STATE_CHECKED);
lv_obj_add_state(lv_obj_get_child(scr, 3), LV_STATE_DISABLED);

<screen>
	<view
		flex_flow="column"
		style_flex_main_place="space_evenly"
		style_flex_cross_place="start"
		style_flex_track_place="center"
	>
		<lv_checkbox text="Input 1"/>
		<lv_checkbox text="Input 2"/>
		<lv_checkbox text="Input 3" checked="true"/>
		<lv_checkbox text="Output 1"/>
		<lv_checkbox text="Output 2" disabled="true"/>
   </view>
</screen>