Refactor the classes

[lesamouraipourpre]

The aim of this refactor is as follows:

• Deduplicate any code in the subclasses and move it up to LabelBase
• Where code only applies to one of the subclasses, have no knowledge of it in the other subclass or the base class.
• Remove max_glyphs - the removal of max_size from displayio.Group makes it redundant. - Try to remove max_glyphs restriction from label #131
• Make all variables private/protected (start with an _). Note: This may break any external code which relied on access to these.

These changes have been tested on a PyPortal. I can not see any problems with the examples but it's possible I'm missing a fault.

[jposada202020]

Just to open the discussion here, for me I would keep some of the variables public:

• anchor_position
• anchored_position
• base_alignment
• label_direction
  As any change in these variables will change library behavior. However, this is just a personal(functional) preference. So no problem either way.
  Also, you mentioned that you test the examples, so I guess we would cover a lot of the example code in the learning guides.

[lesamouraipourpre]

anchor_point, anchored_position & label_direction are all available as properties of LabelBase
base_alignment is currently only a constructor parameter but could easily be made into a property as well.

[jposada202020]

good it is solved then could do PR for the basealignment after :)

[FoamyGuy]

The PyPortal example: https://github.com/lesamouraipourpre/Adafruit_CircuitPython_Display_Text/blob/refactor/examples/display_text_pyportal.py

crashes with this traceback on the branch from this PR:

Traceback (most recent call last):
  File "code.py", line 41, in <module>
AttributeError: 'Label' object has no attribute 'height'

it looks like height was previously set in the constructor here:

Adafruit_CircuitPython_Display_Text/adafruit_display_text/label.py

Line 102 in 5b0c5fe

self.height = self._font.get_bounding_box()[1]

but was made private with the leading underscore in these changes.

Perhaps we should make an explicit height (and width) property that acts as a convenience accessor for bounding_box so that they actually get documented as properties rather than just happening to exist by virtue of being set in __init__()

I'm working on testing the rest of the examples as well.

[FoamyGuy]

I tested all of the other examples and all are working as intended. I looked over these changes and everything looks good to me beyond the height property issue mentioned above.

The only other thought that I had is it might be worthwhile to temporarily (for a few months / release versions) check if user code passed in a max_glyphs and if so print a warning message that tells them it's no longer necessary and can be safely removed. I'm not 100% sure if we do want to do this though as it could lead to extra "spam" being printed in the serial console and there does not seem to be any harm in user code passing it in with this version, it just gets ignored. It may be worth asking some more of the team members to see if folks think it's a good idea or not.

Thanks for working on this @lesamouraipourpre!

[lesamouraipourpre]

I've added height and width properties to LabelBase. The previously defined height and width were defined differently on Label and BitmapLabel. They are now defined on the root class based on the bounding_box.

max_glyphs - I've added a printed message "Please update your code: 'max_glyphs' is not needed anymore."

[FoamyGuy]

Looks good to me. I Re-tested the display_text_pyportal.py example successfully after the latest commits and all is well.

Thanks again @lesamouraipourpre