How to use object padding

How-to
1

Description

May I ask you to help me with an object alignment? It seems I miss something important.
I try to use padding to create gaps between objects and between an object and a screen border.

I already tried many combination but the result is still the same - NO GAP. Unfortunately I did not find any example how to use it. I know it is possible to set offset of the alignment but I would like to use padding (or margin) because it can be constant for all objects independently on the alignment type (LEFT, MID, RIGHT)

What MCU/Processor/Board and compiler are you using?

ttgo watch + PlatformIO

What LVGL version are you using?

7.3.1

Code to reproduce

    lv_obj_t * container = lv_obj_create( lv_scr_act(), NULL );
    lv_obj_set_size(container, 240, 240);
    lv_obj_set_style_local_pad_inner( container, LV_OBJ_PART_MAIN, LV_STATE_DEFAULT, 10 );
    lv_obj_align(container, NULL, LV_ALIGN_IN_TOP_LEFT, 0, 0);

    lv_obj_t *btn1 = lv_btn_create(container, NULL);
    lv_obj_align(btn1, NULL, LV_ALIGN_IN_TOP_LEFT, 0, 0);

    lv_obj_t *btn2 = lv_btn_create(container, NULL);
    lv_obj_set_style_local_pad_left(btn2, LV_OBJ_PART_MAIN, LV_STATE_DEFAULT, 10 );
    lv_obj_set_style_local_pad_top(btn2, LV_OBJ_PART_MAIN, LV_STATE_DEFAULT, 10 );
    lv_obj_align(btn2, btn1, LV_ALIGN_OUT_BOTTOM_MID, 0, 0);
2

Hi
As the documentation in Base object section says:

Margin and padding gets important when Layout or Auto-fit is used by other widgets.

So I think, you have to use a container object instead of a simple object. and use lv_cont_set_layout based on the layout you want.

1 Like
3

That’s correct. Padding and margin are only used by container-based objects. They are ignored by lv_obj_align.

1 Like
4

It works with containers. Thanks a lot!

I just wondering why the function have the prefix lv_obj when it doesn’t work for common objects but for containers only.

5

It’s because style properties can be set on all objects, but not every object uses every style property.

This will be more logical in v8 when we introduce a new layout system that works on all objects.

6

It sounds great. I’m looking forward for v8. Thanks a lot for you support.