Initial import of the CDE 2.1.30 sources from the Open Group.

cde/programs/dtmail/MotifApp/UndoCmd.C

@@ -0,0 +1,67 @@
+/* $XConsortium: UndoCmd.C /main/3 1995/11/06 16:02:46 rswiston $ */
+/*
+ *+SNOTICE
+ *
+ *	RESTRICTED CONFIDENTIAL INFORMATION:
+ *	
+ *	The information in this document is subject to special
+ *	restrictions in a confidential disclosure agreement bertween
+ *	HP, IBM, Sun, USL, SCO and Univel.  Do not distribute this
+ *	document outside HP, IBM, Sun, USL, SCO, or Univel wihtout
+ *	Sun's specific written approval.  This documment and all copies
+ *	and derivative works thereof must be returned or destroyed at
+ *	Sun's request.
+ *
+ *	Copyright 1993 Sun Microsystems, Inc.  All rights reserved.
+ *
+ *+ENOTICE
+ */
+///////////////////////////////////////////////////////////////////////////////
+//////////////////////////////////////////////////////////////////////////////
+//         This example code is from the book:
+//
+//           Object-Oriented Programming with C++ and OSF/Motif
+//         by
+//           Douglas Young
+//           Prentice Hall, 1992
+//           ISBN 0-13-630252-1	
+//
+//         Copyright 1991 by Prentice Hall
+//         All Rights Reserved
+//
+//  Permission to use, copy, modify, and distribute this software for 
+//  any purpose except publication and without fee is hereby granted, provided 
+//  that the above copyright notice appear in all copies of the software.
+///////////////////////////////////////////////////////////////////////////////
+//////////////////////////////////////////////////////////////////////////////
+
+
+//////////////////////////////////////////////////////////
+// UndoCmd.C: An interface to undoing the last command
+//////////////////////////////////////////////////////////
+#include "UndoCmd.h"
+
+#define NULL  0
+
+// Declare a global object: theUndoCmd
+
+UndoCmd *theUndoCmd = new UndoCmd ( "Undo", "Undo" ); 
+
+UndoCmd::UndoCmd ( char *name, char *label ) : NoUndoCmd ( name, label, 0 )
+{
+    // Empty
+}
+
+void UndoCmd::doit()
+{
+    // If there is a current command, undo it
+    
+    if ( _lastCmd != NULL )
+    {
+	// Undo the previous command
+	
+	_lastCmd->undo();
+	
+	_lastCmd = NULL; // Make sure we can't undo twice
+    }
+}