color picker for little vGL

• 顏色回調函數

static void colorPicker_event_handler(lv_obj_t* obj, lv_event_t event)
 {
    if (event == LV_EVENT_VALUE_CHANGED) 
    {
        lv_color_t color = lv_cpicker_get_color(obj);
        printf("r=%d,g=%d,b=%d,a=%d\n",color.ch.red,color.ch.green,color.ch.blue,color.ch.alpha);
    }
}

• 顏色拾色器實現

void color_picker_demo(void)
{
    const lv_coord_t pickerSize = 200;
    static lv_style_t styleMain;
    lv_style_copy(&styleMain, &lv_style_plain);
    styleMain.line.width = 30;
    styleMain.body.main_color = LV_COLOR_WHITE;
    styleMain.body.grad_color = LV_COLOR_WHITE;

    static lv_style_t styleIndicator;
    lv_style_copy(&styleIndicator, &lv_style_pretty);
    styleIndicator.body.border.color = LV_COLOR_WHITE;

    styleIndicator.body.opa = LV_OPA_COVER;
    styleIndicator.body.border.opa = LV_OPA_COVER;

    lv_obj_t* src = lv_scr_act();
    lv_obj_t* colorPicker = lv_cpicker_create(src, NULL);
    lv_obj_set_size(colorPicker, pickerSize, pickerSize);
    
    lv_cpicker_set_type(colorPicker, LV_CPICKER_TYPE_DISC);
    lv_obj_align(colorPicker, NULL, LV_ALIGN_CENTER, 0, 0);

    lv_cpicker_set_style(colorPicker, LV_CPICKER_STYLE_MAIN, &styleMain);
    lv_cpicker_set_style(colorPicker, LV_CPICKER_STYLE_INDICATOR, &styleIndicator);
    lv_cpicker_set_indic_colored(colorPicker, true);

    lv_cpicker_set_preview(colorPicker, true);
   // lv_cpicker_set_color_mode_fixed(colorPicker, true);
    lv_obj_set_event_cb(colorPicker, colorPicker_event_handler);
}

• 調用color_picker_demo函數，編譯運行