tab_layout returns AttributeError for width when using HSTX display

[gh3262]

Using Feather RP2350 with an HSTX display running the Tab Layout Simple test with display is set up using:

if hasattr(supervisor. Runtime, "display") and supervisor.runtime.display is not None: # use the built-in HSTX display for Metro RP2350 display = supervisor.runtime.display

Getting error:

File "/lib/adafruit_displayio_layout/layouts/tab_layout.py", line 203, in add_content File "/lib/adafruit_displayio_layout/layouts/tab_layout.py", line 152, in _draw_tabs AttributeError: 'NoneType' object has no attribute 'width'

I was able to get it to work by editing the file - see attached screenshot.

Not sure if this will break boards with built in display.

[FoamyGuy]

As far as I understand it all built-in displays will be available at supervisor.runtime.display moving forward instead of board.DISPLAY, not just HSTX ones.

It would still be good to have some fallback logic though until the change has been in a stable release for longer though for sure.

The logic should probably also raise a more explicit exception if display is None and neither of the built-in options work for finding one. TabLayout needs access to display size in order to draw the tabs along the top currently so if we don't have a display we should let the user know with a more specific error.

Or something else to consider is getting rid of the display argument / property altogether. With a quick glance it appears that is only used for getting the display width. We currently have it marked as Optional in the typing, but the code breaks if it's None, so the current type annotation isn't really correct. I'd want to consider it a bit more before committing, but I'm thinking it might be good to just take a full_width or similar argument in __init__() instead of display and make it required. So the user can just pass in a number, which also adds the flexibility to make the tabs occupy less space than the full screen.