⚠️ Deprecated ⚠️

This is deprecated since version 4.10.

Use method@Gtk.Widget.add_css_class instead

Adds a style class to @context, so later uses of the style context will make use of this new class for styling.

In the CSS file format, a GtkEntry defining a “search” class, would be matched by:

entry.search { ... }

While any widget defining a “search” class would be matched by:

.search { ... }

Parameters