[Interest] Make a specific Unicode glyph wider in a QTextLayout

[Wang Gary]

> > So the question is, what's the proper approach to implement such a feature
> > using Qt's public API? Do the mentioned two approaches sound right?
> >
> Replace the non-visible character in the model with a visible one in the view?

Well, there are some reasons that I personally would like to avoid
that. Firstly this
feature itself is more of a view-level function, modifying the model
sounds weird[1].
Secondly, even replace them with other visible characters, it's still
not possible
to adjust the character width (e.g. replace the ZWSP to another character but
I still like to display it with wider than regular characters. And by
doing so may also
affect how the syntax-highlight stuff works.

[1]: context: my attempt is to add such feature to KDE Framework's KTextEditor,
currently it seems no existing actions are using methods to update the model to
affect the view if I recall correctly.

Best regards
Gary