About the arc（bug?）

How-to
1

When the range setting is small.Set the arc is adjustable.
Where the arc starts and ends, it doesn’t work.（V7.10.1）
The code is as follows：

lv_obj_t* arc = lv_arc_create(lv_scr_act(), NULL);
lv_arc_set_adjustable(arc, true);//Set whether the arc is adjustable
lv_arc_set_rotation(arc, 90);//0 degree position
lv_obj_set_size(arc, 300, 300);
lv_obj_align(arc, NULL, LV_ALIGN_CENTER, 0, 0);
lv_arc_set_bg_angles(arc, 0, 360);
lv_arc_set_range(arc, 0, 4);
lv_arc_set_value(arc, 2);
2

@kisvegabor

4

I’ve tested it. To fix this add lv_arc_set_chg_rate(arc, 800);

The problem was that with a small change rate the arc couldn’t “grow” fast enough to jump to the next value. Therefore it sucked at the same value.

5

Hmm… wouldn’t it make sense to ignore the change rate when the arc is being dragged with a finger?

6

Thank you very much.
Add lv_arc_set_chg_rate(arc, 800); There are still problems because 800 is still too small.
lv_arc_set_chg_rate(arc, 3000); The problem is solved.

1 Like
7

Actually, the change rate is used only when the arc is set by a finger.