Detect the desktop's configured interface font and use its family for all
application UI text, instead of iced's generic sans-serif.
- sys::ui_font reads the setting per platform: GNOME/Cinnamon/MATE
gsettings, KDE kdeglobals, Xfce xfconf, the XDG Settings portal, GTK
settings.ini and a Fontconfig fallback on Linux; the non-client message
font (SystemParametersInfoForDpi at 96 DPI) on Windows; the AppKit system
font on macOS.
- ui_font::apply remaps generic sans-serif in iced's shared font database
to that family. iced's Font::DEFAULT is sans-serif, so every widget,
canvas text, bold/italic variant and ribbon measurement follows it with
no call-site changes. A family that is not installed (or a generic alias)
keeps iced's own choice. The font's weight and style are ignored.
- Live updates: portal SettingChanged on Linux, a 2 s poll on Windows. A
change bumps the font-system version so laid-out text reshapes, and
iced::font::set_defaults relays out every window; ribbon large-button
widths re-measure. Without a portal, Linux needs a restart; macOS has no
user-adjustable UI font.
- Monospaced text, drawing text (own cosmic-text font systems) and the web
build's font loading are unchanged.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
