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lightning-sunbird  0.9+nobinonly
nsScriptEventManager.cpp
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00001 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
00002 /* ***** BEGIN LICENSE BLOCK *****
00003  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
00004  *
00005  * The contents of this file are subject to the Mozilla Public License Version
00006  * 1.1 (the "License"); you may not use this file except in compliance with
00007  * the License. You may obtain a copy of the License at
00008  * http://www.mozilla.org/MPL/
00009  *
00010  * Software distributed under the License is distributed on an "AS IS" basis,
00011  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
00012  * for the specific language governing rights and limitations under the
00013  * License.
00014  *
00015  * The Original Code is Mozilla Communicator
00016  *
00017  * The Initial Developer of the Original Code is
00018  * Netscape Communications
00019  * Portions created by the Initial Developer are Copyright (C) 2002
00020  * the Initial Developer. All Rights Reserved.
00021  *
00022  * Contributor(s):
00023  *  Rick Potts <rpotts@netscape.com>
00024  *
00025  * Alternatively, the contents of this file may be used under the terms of
00026  * either the GNU General Public License Version 2 or later (the "GPL"), or
00027  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
00028  * in which case the provisions of the GPL or the LGPL are applicable instead
00029  * of those above. If you wish to allow use of your version of this file only
00030  * under the terms of either the GPL or the LGPL, and not to allow others to
00031  * use your version of this file under the terms of the MPL, indicate your
00032  * decision by deleting the provisions above and replace them with the notice
00033  * and other provisions required by the GPL or the LGPL. If you do not delete
00034  * the provisions above, a recipient may use your version of this file under
00035  * the terms of any one of the MPL, the GPL or the LGPL.
00036  *
00037  * ***** END LICENSE BLOCK ***** */
00038 
00039 #include "nsScriptEventManager.h"
00040 
00041 #include "nsString.h"
00042 #include "nsReadableUtils.h"
00043 
00044 #include "nsIDOMNode.h"
00045 #include "nsIDOMHTMLScriptElement.h"
00046 #include "nsIDOMHTMLObjectElement.h"
00047 #include "nsIDOMDocument.h"
00048 
00049 #include "nsIScriptElement.h"
00050 
00051 #include "nsIScriptEventHandler.h"
00052 #include "nsIDocument.h"
00053 
00054 nsScriptEventManager::nsScriptEventManager(nsIDOMDocument *aDocument)
00055 {
00056   nsresult rv;
00057 
00058 
00059   rv = aDocument->GetElementsByTagName(NS_LITERAL_STRING("script"),
00060                                        getter_AddRefs(mScriptElements));
00061 
00062 }
00063 
00064 
00065 nsScriptEventManager::~nsScriptEventManager()
00066 {
00067 }
00068 
00069 
00070 NS_IMPL_ISUPPORTS1(nsScriptEventManager, nsIScriptEventManager)
00071 
00072 
00073 NS_IMETHODIMP
00074 nsScriptEventManager::FindEventHandler(const nsAString &aObjectName,
00075                                        const nsAString &aEventName,
00076                                        PRUint32 aArgCount,
00077                                        nsISupports **aScriptHandler)
00078 {
00079   nsresult rv;
00080 
00081   if (!mScriptElements) {
00082     return NS_ERROR_FAILURE;
00083   }
00084 
00085   // Null out the return value...
00086   if (!aScriptHandler) {
00087     return NS_ERROR_NULL_POINTER;
00088   }
00089   *aScriptHandler = nsnull;
00090 
00091   // Get the number of script elements in the current document...
00092   PRUint32 count = 0;
00093   rv = mScriptElements->GetLength(&count);
00094   if (NS_FAILED(rv)) {
00095     return rv;
00096   }
00097 
00098   //
00099   // Iterate over all of the SCRIPT elements looking for a handler.
00100   //
00101   // Walk the list backwards in order to pick up the most recently
00102   // defined script handler (if more than one is present)...
00103   //
00104   nsCOMPtr<nsIDOMNode> node;
00105   nsCOMPtr<nsIScriptEventHandler> handler;
00106 
00107   while (count--) {
00108     rv = mScriptElements->Item(count, getter_AddRefs(node));
00109     if (NS_FAILED(rv)) break;
00110 
00111     // Check if the SCRIPT element is an event handler.
00112     handler = do_QueryInterface(node, &rv);
00113     if (NS_FAILED(rv)) continue;
00114 
00115     PRBool bFound = PR_FALSE;
00116     rv = handler->IsSameEvent(aObjectName, aEventName, aArgCount, &bFound);
00117 
00118     if (NS_SUCCEEDED(rv) && bFound) {
00119         *aScriptHandler = handler;
00120         NS_ADDREF(*aScriptHandler);
00121 
00122         return NS_OK;
00123     }
00124   }
00125 
00126   // Errors just fall of the end and return 'rv'
00127   return rv;
00128 }
00129 
00130 NS_IMETHODIMP
00131 nsScriptEventManager::InvokeEventHandler(nsISupports *aHandler,
00132                                          nsISupports *aTargetObject,
00133                                          void * aArgs,
00134                                          PRUint32 aArgCount)
00135 {
00136   nsCOMPtr<nsIScriptEventHandler> handler(do_QueryInterface(aHandler));
00137 
00138   if (!handler) {
00139     return NS_ERROR_FAILURE;
00140   }
00141 
00142   return handler->Invoke(aTargetObject, aArgs, aArgCount);
00143 }