When create lv_img by copying a previous one that has source from image-file (such as png file), it can't display anything

Bug (archived)
1

Description

I created the first lv_img’s obj that has a source from PNG file.
And I copied to the second one, but the second one can’t show anything.

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

  • ESP32

What do you want to achieve?

File-type source of the first lv_img’s obj is copied to the second one too.

What have you tried so far?

Code to reproduce


lv_obj_t *first_img;
lv_obj_t *second_img;
const char* src_file = "/sd/pictures/png_file.png";

  first_img= lv_img_create(lv_scr_act(),NULL);
    lv_img_set_src(first_img, src_file);
    lv_obj_set_pos(first_img,0,0);
    lv_obj_set_hidden(first_img, true);

  second_img= lv_img_create(lv_scr_act(), first_img);
    lv_obj_set_pos(second_img,180,0);

Screenshot and/or video

2

I am not a expert, but try,

const char src_file[ ] = “/sd/pictures/png_file.png”;

or

const char src_file[ ] = “/sd/pictures/png_file.png”;

const char* src_file_pointer = &src_file;

3

Thank you.
The problem is not by char* variable.
The first lv_img’s obj can work well when set by

lv_img_set_src(first_img, src_file);

But the second lv_img’s obj that if created by copying with

second_img = lv_img_create(lv_scr_act(), first_img);

The source of the first if its type is LV_IMG_SRC_FILE
doesn’t seem copy to the second as it should to be.

4

can you put a screenshot?
If you debug, in lv_img_create function, do you get to this line? :
lv_img_set_src(new_img, copy_ext->src);

5

CODE Test1

Test by the first lv_img’obj only, it can display well

  lv_obj_t *first_img;
  const char* src_file = "/sd/pictures/png_file.png";

  first_img= lv_img_create(lv_scr_act(),NULL);
    lv_img_set_src(first_img, src_file);
    lv_obj_set_pos(first_img,0,0);

PHOTO_20191001_132048

CODE Test2

Test by copying the first obj to the second. And hidden the first.
The second can’t display anything.

(My screen’s background set to black color.)

  lv_obj_t *first_img;
  lv_obj_t *second_img;
  const char* src_file = "/sd/pictures/png_file.png";
  
    first_img= lv_img_create(lv_scr_act(),NULL);
      lv_img_set_src(first_img, src_file);
      lv_obj_set_pos(first_img,0,0);
      lv_obj_set_hidden(first_img, true);
  
    second_img= lv_img_create(lv_scr_act(), first_img);
      lv_obj_set_pos(second_img,180,0);

PHOTO_20191001_132234

6

I think the second one is hidden too. because the hidden property is copied to the second_img from first_img.
so add this:
lv_obj_set_hidden(second_img, true);
after the creation of second_img or hide the first one, after you create the second one.

1 Like
7

New knowledge for me,
when create by copying, the hidden attrib is also copied.

Thank you.