* Using an External Client Widget::
* External Client Widget Resource Settings::
* Motif-Specific Info About the External Client Widget::
-* External Client Widget Internals::
@end menu
made by parent or child widgets.
-@node Motif-Specific Info About the External Client Widget, External Client Widget Internals, External Client Widget Resource Settings, Top
+@node Motif-Specific Info About the External Client Widget, , External Client Widget Resource Settings, Top
@chapter Motif-Specific Info About the External Client Widget
By default, the external client widget has navigation type
@kbd{Ctrl-@key{TAB}} and @kbd{Shift-@key{TAB}} are silently filtered by
the external client widget and are not seen by Emacs.
-@node External Client Widget Internals, , Motif-Specific Info About the External Client Widget, Top
-@chapter External Client Widget Internals
-
-The following text is lifted verbatim from Ben Wing's comments in
-@file{ExternalShell.c}.
-
-This is a special Shell that is designed to use an externally-
-provided window created by someone else (possibly another process).
-That other window should have an associated widget of class
-ExternalClient. The two widgets communicate with each other using
-ClientMessage events and properties on the external window.
-
-Ideally this feature should be independent of Emacs. Unfortunately
-there are lots and lots of specifics that need to be dealt with
-for this to work properly, and some of them can't conveniently
-be handled within the widget's methods. Some day the code may
-be rewritten so that the embedded-widget feature can be used by
-any application, with appropriate entry points that are called
-at specific points within the application.
-
-This feature is similar to the OLE (Object Linking & Embedding)
-feature provided by MS Windows.
-
-Communication between this shell and the client widget:
-
-Communication is through ClientMessage events with message_type
-EXTW_NOTIFY and format 32. Both the shell and the client widget
-communicate with each other by sending the message to the same
-window (the "external window" below), and the data.l[0] value is
-used to determine who sent the message.
-
-The data is formatted as follows:
-
-data.l[0] = who sent this message: external_shell_send (0) or
- external_client_send (1)
-data.l[1] = message type (see enum en_extw_notify below)
-data.l[2-4] = data associated with this message
-
-EventHandler() handles messages from the other side.
-
-extw_send_notify_3() sends a message to the other side.
-
-extw_send_geometry_value() is used when an XtWidgetGeometry structure
- needs to be sent. This is too much data to fit into a
- ClientMessage, so the data is stored in a property and then
- extw_send_notify_3() is called.
-
-extw_get_geometry_value() receives an XtWidgetGeometry structure from a
- property.
-
-extw_wait_for_response() is used when a response to a sent message
- is expected. It looks for a matching event within a
- particular timeout.
-
-The particular message types are as follows:
-
-1) extw_notify_init (event_window, event_mask)
-
-This is sent from the shell to the client after the shell realizes
-its EmacsFrame widget on the client's "external window". This
-tells the client that it should start passing along events of the
-types specified in event_mask. event_window specifies the window
-of the EmacsFrame widget, which is a child of the client's
-external window.
-
-extw_notify_init (client_type)
-
-When the client receives an extw_notify_init message from the
-shell, it sends back a message of the same sort specifying the type
-of the toolkit used by the client (Motif, generic Xt, or Xlib).
-
-2) extw_notify_end ()
-
-This is sent from the shell to the client when the shell's
-EmacsFrame widget is destroyed, and tells the client to stop
-passing events along.
-
-3) extw_notify_qg (result)
-
-This is sent from the client to the shell when a QueryGeometry
-request is received on the client. The XtWidgetGeometry structure
-specified in the QueryGeometry request is passed on in the
-EXTW_QUERY_GEOMETRY property (of type EXTW_WIDGET_GEOMETRY) on the
-external window. result is unused.
-
-In response, the shell passes the QueryGeometry request down the
-widget tree, and when a response is received, sends a message of
-type extw_notify_qg back to the client, with result specifying the
-GeometryResult value. If this value is XtGeometryAlmost, the
-returned XtWidgetGeometry structure is stored into the same property
-as above. [BPW is there a possible race condition here?]
-
-4) extw_notify_gm (result)
-
-A very similar procedure to that for extw_notify_qg is followed
-when the shell's RootGeometryManager method is called, indicating
-that a child widget wishes to change the shell's geometry. The
-XtWidgetGeometry structure is stored in the EXTW_GEOMETRY_MANAGER
-property.
-
-5) extw_notify_focus_in (), extw_notify_focus_out ()
-
-These are sent from the client to the shell when the client gains
-or loses the keyboard focus. It is done this way because Xt
-maintains its own concept of keyboard focus and only the client
-knows this information.
-
@summarycontents
@contents
@bye
projects / chise / xemacs-chise.git / blobdiff