Is it possible to define custom digits?

[S-Man42]

I am searching for a widget that allows me to enable only a symbols. E.g., taking the definition of a 16 segment display, it would be great, only to enable the three segments "a1", "g2" and "b", no matter that it is not mapped to any valid character.

Is this possible?

Next step would be to tap on an display segment and it would be enabled/disabled, giving out the tapped segment. E.g. If segment a is red, tap it -> turn into black and give out "a = false". Tap it again, enable it, give out "a = true".

Now you would be able to handle the display in any way you like... Show random patterns, like rotating cursor or something like that...