Widget Overview

Brief overview of widgets.

Added on 11th November 2014

The general steps to using a widget in GTK are:

  • We use the constructor Gtk.Widget() to create a new Gtk.Widget().

  • Connect all signals and events we wish to use to the appropriate handlers.

  • Set the attributes of the widget.

  • Pack the widget into a container using the appropriate call such as Gtk.Container.add() or Gtk.Box.pack_start().

  • Gtk.Widget.show() the widget.

show() lets GTK know that we are done setting the attributes of the widget, and it is ready to be displayed. You may also use Gtk.Widget.hide() to make it disappear again. The order in which you show the widgets is not important, but I suggest showing the window last so the whole window pops up at once rather than seeing the individual widgets come up on the screen as they're formed. The children of a widget (a window is a widget too) will not be displayed until the window itself is shown using the show() method.

Widget Hierarchy

For reference, a comprehensive hierarchy tree used to implement widgets may be found in the GTK online documetation at https://developer.gnome.org/gtk3/stable/ch02.html.

This documentation lists the C API objects, but it is straightforward to infer the Vala API class names, especially with the help of the Valadoc documentation at http://valadoc.org/#!api=gtk+-3.0/Gtk.

References and Further Reading