Graphics.UI.Gtk.Embedding.Socket

Container for widgets from other processes

Detail

Together with Plug, Socket provides the ability to embed widgets from one process into another process in a fashion that is transparent to the user. One process creates a Socket widget and, passes the that widget's window ID to the other process, which then creates a Plug with that window ID. Any widgets contained in the Plug then will appear inside the first applications window.

The socket's window ID is obtained by using socketGetId. Before using this function, the socket must have been realized, and for hence, have been added to its parent.

• Obtaining the window ID of a socket.

socket <- socketNew
widgetShow socket
containerAdd parent socket

-- The following call is only necessary if one of
-- the ancestors of the socket is not yet visible.
--
widgetRealize socket
socketId <- socketGetId socket
putStrLn ("The ID of the sockets window is " ++ show socketId)

Note that if you pass the window ID of the socket to another process that will create a plug in the socket, you must make sure that the socket widget is not destroyed until that plug is created. Violating this rule will cause unpredictable consequences, the most likely consequence being that the plug will appear as a separate toplevel window. You can check if the plug has been created by calling socketHasPlug. If this returns True, then the plug has been successfully created inside of the socket.

When Gtk+ is notified that the embedded window has been destroyed, then it will destroy the socket as well. You should always, therefore, be prepared for your sockets to be destroyed at any time when the main event loop is running.

The communication between a Socket and a Plug follows the XEmbed protocol. This protocol has also been implemented in other toolkits, e.g. Qt, allowing the same level of integration when embedding a Qt widget in Gtk+ or vice versa.

Class Hierarchy

| GObject
| +----Object
| +----Widget
| +----Container
| +----Socket