lvgl/examples/anim/lv_example_anim_2.c

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

static void anim_x_cb(void * var, int32_t v)
{
    lv_obj_set_x((lv_obj_t *) var, v);
}

static void anim_size_cb(void * var, int32_t v)
{
    lv_obj_set_size((lv_obj_t *) var, v, v);
}

/**
 * @title Infinite playback animation
 * @brief Grow a red circle while sliding it right, then reverse and repeat.
 *
 * A red circular object sits on the left edge of the active screen. One
 * `lv_anim_t` drives `lv_obj_set_size` from 10 to 50 over 1000 ms; the same
 * configured animation is then reused with `lv_obj_set_x` running from 10
 * to 240. Both run with `lv_anim_path_ease_in_out`, a 300 ms reverse stage
 * after a 100 ms reverse delay, a 500 ms gap between cycles, and
 * `LV_ANIM_REPEAT_INFINITE`.
 */
void lv_example_anim_2(void)
{

    lv_obj_t * obj = lv_obj_create(lv_screen_active());
    lv_obj_remove_flag(obj, LV_OBJ_FLAG_SCROLLABLE);
    lv_obj_set_style_bg_color(obj, lv_palette_main(LV_PALETTE_RED), 0);
    lv_obj_set_style_radius(obj, LV_RADIUS_CIRCLE, 0);

    lv_obj_align(obj, LV_ALIGN_LEFT_MID, 10, 0);

    lv_anim_t a;
    lv_anim_init(&a);
    lv_anim_set_var(&a, obj);
    lv_anim_set_values(&a, 10, 50);
    lv_anim_set_duration(&a, 1000);
    lv_anim_set_reverse_delay(&a, 100);
    lv_anim_set_reverse_duration(&a, 300);
    lv_anim_set_repeat_delay(&a, 500);
    lv_anim_set_repeat_count(&a, LV_ANIM_REPEAT_INFINITE);
    lv_anim_set_path_cb(&a, lv_anim_path_ease_in_out);

    lv_anim_set_exec_cb(&a, anim_size_cb);
    lv_anim_start(&a);
    lv_anim_set_exec_cb(&a, anim_x_cb);
    lv_anim_set_values(&a, 10, 240);
    lv_anim_start(&a);
}

#endif