`GtkStyleContext` stores styling information affecting a widget.
In order to construct the final style information, `GtkStyleContext` queries information from all attached `GtkStyleProviders`. Style
providers can be either attached explicitly to the context through [[email protected]_provider], or to the display through [
[email protected]_provider_for_display]. The resulting style is a combination of all providers’ information in priority order.
For GTK widgets, any `GtkStyleContext` returned by [[email protected]_style_context] will already have a `GdkDisplay` and RTL/LTR
information set. The style context will also be updated automatically if any of these settings change on the widget.
Style Classes
Widgets can add style classes to their context, which can be used to associate different styles by class. The documentation for
individual widgets lists which style classes it uses itself, and which style classes may be added by applications to affect their
appearance.
Custom styling in UI libraries and applications
If you are developing a library with custom widgets that render differently than standard components, you may need to add a
`GtkStyleProvider` yourself with the gtk_style_provider_priority_fallback priority, either a
`GtkCssProvider` or a custom object implementing the `GtkStyleProvider` interface. This way themes may still attempt to style your UI
elements in a different way if needed so.
If you are using custom styling on an applications, you probably want then to make your style information prevail to the theme’s, so
you must use a `GtkStyleProvider` with the gtk_style_provider_priority_application priority, keep in
mind that the user settings in `XDG_CONFIG_HOME/gtk-4.0/gtk.css` will still take precedence over your changes, as it uses the
gtk_style_provider_priority_user priority.
Renders an option mark (as in a radio button), the
gtk_state_flag_checked state will determine whether the option is on or off, and
gtk_state_flag_inconsistent whether it should be marked as undefined.