lv_example_bar_6.c

#include "../../lv_examples.h"
#if LV_USE_BAR && LV_BUILD_EXAMPLES

static void set_value(void * bar, int32_t v)
{
    lv_bar_set_value(bar, v, LV_ANIM_OFF);
}

static void event_cb(lv_event_t * e)
{
    lv_obj_t * obj = lv_event_get_target(e);

    lv_draw_label_dsc_t label_dsc;
    lv_draw_label_dsc_init(&label_dsc);
    label_dsc.font = LV_FONT_DEFAULT;

    char buf[8];
    lv_snprintf(buf, sizeof(buf), "%d", (int)lv_bar_get_value(obj));

    lv_point_t txt_size;
    lv_text_get_size(&txt_size, buf, label_dsc.font, label_dsc.letter_space, label_dsc.line_space, LV_COORD_MAX,
                     label_dsc.flag);

    lv_area_t txt_area;
    txt_area.x1 = 0;
    txt_area.x2 = txt_size.x - 1;
    txt_area.y1 = 0;
    txt_area.y2 = txt_size.y - 1;

    lv_bar_t * bar = (lv_bar_t *) obj;
    const lv_area_t * indic_area = &bar->indic_area;

    /*If the indicator is long enough put the text inside on the right*/
    if(lv_area_get_width(indic_area) > txt_size.x + 20) {
        lv_area_align(indic_area, &txt_area, LV_ALIGN_RIGHT_MID, -10, 0);
        label_dsc.color = lv_color_white();
    }
    /*If the indicator is still short put the text out of it on the right*/
    else {
        lv_area_align(indic_area, &txt_area, LV_ALIGN_OUT_RIGHT_MID, 10, 0);
        label_dsc.color = lv_color_black();
    }
    label_dsc.text = buf;
    label_dsc.text_local = true;
    lv_layer_t * layer = lv_event_get_layer(e);
    lv_draw_label(layer, &label_dsc, &txt_area);
}

/**
 * Custom drawer on the bar to display the current value
 */
void lv_example_bar_6(void)
{
    lv_obj_t * bar = lv_bar_create(lv_screen_active());
    lv_obj_set_size(bar, 200, 20);
    lv_obj_center(bar);
    lv_obj_add_event_cb(bar, event_cb, LV_EVENT_DRAW_MAIN_END, NULL);

    lv_anim_t a;
    lv_anim_init(&a);
    lv_anim_set_var(&a, bar);
    lv_anim_set_values(&a, 0, 100);
    lv_anim_set_exec_cb(&a, set_value);
    lv_anim_set_duration(&a, 4000);
    lv_anim_set_playback_duration(&a, 4000);
    lv_anim_set_repeat_count(&a, LV_ANIM_REPEAT_INFINITE);
    lv_anim_start(&a);

}

#endif