Large number of installed fonts cause GtkFontChooserDialog to hang during searches

[JerryCasiano]

This affects font selection in our preferences desktop pane. It happens with as few as a thousand fonts.

https://gitlab.gnome.org/GNOME/gtk/-/issues/6667

We have two options:

• Wait for upstream fix
• Roll our own font selection dialog

[AGI-chandler]

Font Manager was completely unusable on my system.  At times, I had to just kill the whole Gnome session to recover my computer.  With all the Noto fonts installed for different languages, I pared that down to a bit over 1600 fonts with a fontconfig config that i noted on the gtk issue. Font Manager is still a bit slow and choppy, but now usable at least.

[JerryCasiano]

Font Manager was completely unusable on my system.

That's unfortunate. Glad you found a workaround.

A few thousand fonts shouldn't really cause an issue, will definitely affect startup time adding a second or so per thousand on my system. I test with around 7500 fonts sometimes, on a decade old laptop, and while it definitely gets laggy at that point it's still somewhat usable. But I don't have very many of the Noto fonts installed because they're kind of a hog. I'm guessing graphics drivers, etc. probably also have a big effect with GTK 4.

GTK 4 has definitely regressed in this regard. It's partly why the port took so long, performance issues. Until GtkInscription landed the font list couldn't be done without resorting to deprecated widgets.

The Browse TreeView still can't be done without using deprecated widgets. :-(