Doubts about "lv_style_remove_prop"

General discussion
1
  • 1 if a nested for loop is needed?

From the logic of lv_style_set_prop, each prop in style->values_and_props is unique. Therefore, I don’t understand why a nested for loop is needed in the following code.

bool lv_style_remove_prop(lv_style_t * style, lv_style_prop_t prop)
{
    LV_ASSERT_STYLE(style);

    if(lv_style_is_const(style)) {
        LV_LOG_ERROR("Cannot remove prop from const style");
        return false;
    }

    if(style->prop_cnt == 0)  return false;

    uint8_t * tmp = (lv_style_prop_t *)style->values_and_props + style->prop_cnt * sizeof(lv_style_value_t);
    uint8_t * old_props = (uint8_t *)tmp;
    uint32_t i;
    for(i = 0; i < style->prop_cnt; i++) {
        if(old_props[i] == prop) {
            lv_style_value_t * old_values = (lv_style_value_t *)style->values_and_props;

            size_t size = (style->prop_cnt - 1) * (sizeof(lv_style_value_t) + sizeof(lv_style_prop_t));
            uint8_t * new_values_and_props = lv_malloc(size);
            if(new_values_and_props == NULL) return false;
            style->values_and_props = new_values_and_props;
            style->prop_cnt--;

            tmp = new_values_and_props + style->prop_cnt * sizeof(lv_style_value_t);
            uint8_t * new_props = (uint8_t *)tmp;
            lv_style_value_t * new_values = (lv_style_value_t *)new_values_and_props;

            uint32_t j;
            for(i = j = 0; j <= style->prop_cnt;
                j++) { /*<=: because prop_cnt already reduced but all the old props. needs to be checked.*/
                if(old_props[j] != prop) {
                    new_values[i] = old_values[j];
                    new_props[i++] = old_props[j];
                }
            }

            lv_free(old_values);
            return true;
        }
    }

    return false;
}
  • 2 Comment on trans_delete
    I read function calling and find that , in the comment of trans_delete ,
/**
 * Remove the transition from object's part's property.
 * - Remove the transition from `_lv_obj_style_trans_ll` and free it
 * - Delete pending transitions
 * @param obj pointer to an object which transition(s) should be removed
 * @param part a part of object or 0xFF to remove from all parts
 * @param prop a property or 0xFF to remove all properties
 * @param tr_limit delete transitions only "older" than this. `NULL` if not used
 */

0xFF to remove all properties
The ability to use 0xFF to remove all properties seems not implemented in lv_style_remove_prop.