Sets our main struct and passes it to the parent class.
Adds a header bar to a #HdyHeaderGroup. The decoration layout of the widgets will be edited depending on their position in the composite header bar, the start widget displaying only the start of the user's decoration layout and the end widget displaying only its end while widgets in the middle won't display anything. A header bar can be set as having the focus to display all the decorations. See gtk_header_bar_set_decoration_layout().
Returns the list of headerbars associated with @self.
Get the main Gtk struct
the main Gtk struct as a void*
Removes a widget from a #HdyHeaderGroup
Sets the the currently focused header bar. If @header_bar is %NULL, the decoration will be spread as if the header bars of the group were only one, otherwise @header_bar will be the only one to receive the decoration.
the main Gtk struct