Version 1.8 of gecko-sdk. Downloaded from here:...

gecko-sdk/idl/nsIURIContentListener.idl

+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * 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 mozilla.org code.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1999
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either of the GNU General Public License Version 2 or later (the "GPL"),
+ * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+#include "nsISupports.idl"
+
+interface nsIRequest;
+interface nsIStreamListener;
+interface nsIURI;
+
+/**
+ * nsIURIContentListener is an interface used by components which
+ * want to know (and have a chance to handle) a particular content type.
+ * Typical usage scenarios will include running applications which register
+ * a nsIURIContentListener for each of its content windows with the uri
+ * dispatcher service. 
+ *
+ * @status FROZEN
+ */
+[scriptable, uuid(94928AB3-8B63-11d3-989D-001083010E9B)]
+interface nsIURIContentListener : nsISupports
+{
+ /**
+  * Gives the original content listener first crack at stopping a load before
+  * it happens.
+  *
+  * @param aURI   URI that is being opened.
+  *
+  * @return       <code>false</code> if the load can continue;
+  *               <code>true</code> if the open should be aborted.
+  */
+  boolean onStartURIOpen(in nsIURI aURI);
+
+ /**
+  * Notifies the content listener to hook up an nsIStreamListener capable of
+  * consuming the data stream.
+  *
+  * @param aContentType         Content type of the data.
+  * @param aIsContentPreferred  Indicates whether the content should be
+  *                             preferred by this listener.
+  * @param aRequest             Request that is providing the data.
+  * @param aContentHandler      nsIStreamListener that will consume the data.
+  *                             This should be set to <code>nsnull</code> if
+  *                             this content listener can't handle the content
+  *                             type.
+  *
+  * @return                     <code>true</code> if the consumer wants to
+  *                             handle the load completely by itself.  This
+  *                             causes the URI Loader do nothing else...
+  *                             <code>false</code> if the URI Loader should
+  *                             continue handling the load and call the
+  *                             returned streamlistener's methods. 
+  */
+  boolean doContent(in string aContentType,
+                    in boolean aIsContentPreferred,
+                    in nsIRequest aRequest,
+                    out nsIStreamListener aContentHandler);
+
+ /**
+  * When given a uri to dispatch, if the URI is specified as 'preferred 
+  * content' then the uri loader tries to find a preferred content handler
+  * for the content type. The thought is that many content listeners may
+  * be able to handle the same content type if they have to. i.e. the mail
+  * content window can handle text/html just like a browser window content
+  * listener. However, if the user clicks on a link with text/html content,
+  * then the browser window should handle that content and not the mail
+  * window where the user may have clicked the link.  This is the difference
+  * between isPreferred and canHandleContent.
+  *
+  * @param aContentType         Content type of the data.
+  * @param aDesiredContentType  Indicates that aContentType must be converted
+  *                             to aDesiredContentType before processing the
+  *                             data.  This causes a stream converted to be
+  *                             inserted into the nsIStreamListener chain.
+  *                             This argument can be <code>nsnull</code> if
+  *                             the content should be consumed directly as
+  *                             aContentType.
+  *
+  * @return                     <code>true</code> if this is a preferred
+  *                             content handler for aContentType;
+  *                             <code>false<code> otherwise.
+  */
+  boolean isPreferred(in string aContentType, out string aDesiredContentType);
+
+ /**
+  * When given a uri to dispatch, if the URI is not specified as 'preferred
+  * content' then the uri loader calls canHandleContent to see if the content
+  * listener is capable of handling the content.
+  *
+  * @param aContentType         Content type of the data.
+  * @param aIsContentPreferred  Indicates whether the content should be
+  *                             preferred by this listener.
+  * @param aDesiredContentType  Indicates that aContentType must be converted
+  *                             to aDesiredContentType before processing the
+  *                             data.  This causes a stream converted to be
+  *                             inserted into the nsIStreamListener chain.
+  *                             This argument can be <code>nsnull</code> if
+  *                             the content should be consumed directly as
+  *                             aContentType.
+  *
+  * @return                     <code>true</code> if the data can be consumed.
+  *                             <code>false</code> otherwise.
+  *
+  * Note: I really envision canHandleContent as a method implemented
+  * by the docshell as the implementation is generic to all doc
+  * shells. The isPreferred decision is a decision made by a top level
+  * application content listener that sits at the top of the docshell
+  * hierarchy.
+  */
+  boolean canHandleContent(in string aContentType, 
+                           in boolean aIsContentPreferred, 
+                           out string aDesiredContentType);
+
+ /**
+  * The load context associated with a particular content listener.
+  * The URI Loader stores and accesses this value as needed.
+  */
+  attribute nsISupports loadCookie;
+
+ /**
+  * The parent content listener if this particular listener is part of a chain
+  * of content listeners (i.e. a docshell!)
+  *
+  * @note If this attribute is set to an object that implements
+  *       nsISupportsWeakReference, the implementation should get the
+  *       nsIWeakReference and hold that.  Otherwise, the implementation
+  *       should not refcount this interface; it should assume that a non
+  *       null value is always valid.  In that case, the caller is
+  *       responsible for explicitly setting this value back to null if the
+  *       parent content listener is destroyed.
+  */
+  attribute nsIURIContentListener parentContentListener;
+};
+