pub fn apply_to_egui(ctx: &Context, theme: &Theme)Expand description
Apply theme to egui’s visuals and store it for ThemeExt::active_theme.
Also install Roboto ahead of the application’s proportional fonts.
Call it once at startup and again after the theme changes. Inside eframe::App::ui the root
Ui already exists, so follow the call with ui.set_style(ui.ctx().global_style()) for the
panels shown in that Ui to use the theme in the same frame.