147     lv_obj_t * btn = lv_obj_get_child(list, track_id);  in _lv_demo_music_list_btn_check()  local
148     lv_obj_t * icon = lv_obj_get_child(btn, 0);  in _lv_demo_music_list_btn_check()
151         lv_obj_add_state(btn, LV_STATE_CHECKED);  in _lv_demo_music_list_btn_check()
153         lv_obj_scroll_to_view(btn, LV_ANIM_ON);  in _lv_demo_music_list_btn_check()
156         lv_obj_clear_state(btn, LV_STATE_CHECKED);  in _lv_demo_music_list_btn_check()
173     lv_obj_t * btn = lv_obj_create(parent);  in add_list_btn()  local
174     lv_obj_remove_style_all(btn);  in add_list_btn()
176     lv_obj_set_size(btn, lv_pct(100), 110);  in add_list_btn()
178     lv_obj_set_size(btn, lv_pct(100), 60);  in add_list_btn()
181     lv_obj_add_style(btn, &style_btn, 0);  in add_list_btn()
182     lv_obj_add_style(btn, &style_btn_pr, LV_STATE_PRESSED);  in add_list_btn()
183     lv_obj_add_style(btn, &style_btn_chk, LV_STATE_CHECKED);  in add_list_btn()
184     lv_obj_add_style(btn, &style_btn_dis, LV_STATE_DISABLED);  in add_list_btn()
185     lv_obj_add_event_cb(btn, btn_click_event_cb, LV_EVENT_CLICKED, NULL);  in add_list_btn()
188         lv_obj_add_state(btn, LV_STATE_DISABLED);  in add_list_btn()
191     lv_obj_t * icon = lv_img_create(btn);  in add_list_btn()
195     lv_obj_t * title_label = lv_label_create(btn);  in add_list_btn()
200     lv_obj_t * artist_label = lv_label_create(btn);  in add_list_btn()
205     lv_obj_t * time_label = lv_label_create(btn);  in add_list_btn()
211     lv_obj_t * border = lv_img_create(btn);  in add_list_btn()
217     return btn;  in add_list_btn()
222     lv_obj_t * btn = lv_event_get_target(e);  in btn_click_event_cb()  local
224     uint32_t idx = lv_obj_get_child_id(btn);  in btn_click_event_cb()