OutputProxy: display_data does not save an image in the context

[CRImier]

display_data does not yet have a way to save the state of the screen so that it comes up once the context is returned to.

Reproducing:

• Switch to devel branch
• Go to the 2048 game
• Switch to Zeromenu (click PROG2)
• Exit ZeroMenu (KEY_LEFT or click Back)

Result:

The 2048 game screen (that uses display_data) will not appear unless some other key is pressed. This is because, if display_data is used, the resulting image is not saved in the OutputProxy object.

Possible solutions:

• re-implement the display_data rendering logic from the driver in OutputProxy, maybe using Canvas (alternatively, just copy-paste the implementation that uses luma.oled.
  • would work properly
  • code duplication
  • unnecessarily tying luma canvas or Canvas into the output subsystem
• split the display_data rendering code into a (static) method that would return a PIL.Image, then get that method into OutputDevice and proxy it into OutputProxy
  • this method needs to be always available
  • side-effects are not sufficient - some other logic needs to be used, since the rendering method needs to be available regardless of whether context is the one active

[CRImier]

Fixed - went the second way, added a "direct method" way of proxying methods.