Sets the GtkStyle for a widget (widget->style). You probably don't want to use this function; it interacts badly with themes, because themes work by replacing the GtkStyle. Instead, use gtk_widget_modify_style().
a GtkStyle, or NULL to remove the effect of a previous gtk_widget_set_style() and go back to the default style. [allow-none]
See Implementation
Sets the GtkStyle for a widget (widget->style). You probably don't want to use this function; it interacts badly with themes, because themes work by replacing the GtkStyle. Instead, use gtk_widget_modify_style().