/* -*- Mode: C++; tab-width: 3; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Mozilla Public
 * License Version 1.1 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.mozilla.org/MPL/
 * 
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 * 
 * The Original Code is the Mozilla browser.
 * 
 * The Initial Developer of the Original Code is Netscape
 * Communications, Inc.  Portions created by Netscape are
 * Copyright (C) 1999, Mozilla.  All Rights Reserved.
 * 
 * Contributor(s):
 *   Scott MacGregor <mscott@netscape.com>
 */

#include "nsISupports.idl"

interface nsIURI;
interface nsIFile;

/**
 * The external protocol service is used for finding and launching
 * platform specific applications for particular protocols.
 *
 * You can ask the external protocol service if it has an external
 * handler for a given protocol scheme. And you can ask it to load 
 * the url using the default handler.
 */
[scriptable, uuid(100FD4B3-4557-11d4-98D0-001083010E9B)]
interface nsIExternalProtocolService : nsISupports
{
  /**
   * Check whether a handler for a specific protocol exists.
   * @param aProtocolScheme The scheme from a url: http, ftp, mailto, etc.
   * @return true if we have a handler and false otherwise.
   */
  boolean externalProtocolHandlerExists(in string aProtocolScheme);

  /**
   * Check whether a handler for a specific protocol is "exposed" as a visible
   * feature of the current application.
   *
   * An exposed protocol handler is one that can be used in all contexts.  A
   * non-exposed protocol handler is one that can only be used internally by the
   * application.  For example, a non-exposed protocol would not be loaded by the
   * application in response to a link click or a X-remote openURL command.
   * Instead, it would be deferred to the system's external protocol handler.
   */
  boolean isExposedProtocol(in string aProtocolScheme);

  /**
   * Used to load a url via an external protocol handler (if one exists)
   * @param aURL The url to load
   */
  void loadUrl (in nsIURI aURL);  
};