Add API to provide user-defined fallback fonts

When depending on Qt's font merging for providing glyphs for certain
languages, there are currently some drawbacks. For one, you will
typically get a system font which might not fit together with the
main font of the application.

In addition, you might get some glyphs from one font and other from
another (typically for Chinese where the character sets are so large
that fonts will often only implement parts).

And finally, you may get the wrong glyphs for writing systems with
regional differences, if your application is e.g. written in Japanese
and then run on a Chinese system, you might get Chinese versions of
characters which are shared between the languages.

Without language-based font matching in Qt, there's no silver bullet
for fixing this. This patch introduces API which makes it possible for
users to provide the solution themselves, either by selecting
application-provided fonts as fallbacks for certain scripts or by
hardcoding system fonts for a specific language.

[ChangeLog][Fonts] Added API to override default fallback font
families for specific scripts.

Task-number: QTBUG-121131
Change-Id: I23ee17b7dfe1c1e481c87cc67a05a0522841b598
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

0 files changed, 0 insertions, 0 deletions