micropython-font-to-py/charsets/RTL_languages.md

Some languages are rendered from right to left (RTL) and others are boustrophedonic, rendering alternate lines in opposite directions. While the character sets can be handled in the usual way, the Writer and CWriter classes support only LTR rendering. Given that the GUI's are based on these classes, that limitation applies to their widgets.

A workround is to perform reversal in code. The CPython approach is

reversed_string = my_string[::-1]

but this is unavailable in MicroPython. Possible solutions are:

def reverse(s):
    l = list(s)
    l.reverse()
    return "".join(l)

or

def reverse(s):
    if not (l := len(s) // 2):
        return s
    return ''.join((reverse(s[l:]), reverse(s[:l])))

which aims to minimise the number of string creations.

Note that the Textbox widget relies on word wrap and scrolling: these features will only work with LTR text.

Main README

WRITER.md