Back to index

lightning-sunbird  0.9+nobinonly
nsJavaXPTCStubWeakRef.cpp
Go to the documentation of this file.
00001 /* ***** BEGIN LICENSE BLOCK *****
00002  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
00003  *
00004  * The contents of this file are subject to the Mozilla Public License Version
00005  * 1.1 (the "License"); you may not use this file except in compliance with
00006  * the License. You may obtain a copy of the License at
00007  * http://www.mozilla.org/MPL/
00008  *
00009  * Software distributed under the License is distributed on an "AS IS" basis,
00010  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
00011  * for the specific language governing rights and limitations under the
00012  * License.
00013  *
00014  * The Original Code is Java XPCOM Bindings.
00015  *
00016  * The Initial Developer of the Original Code is
00017  * IBM Corporation.
00018  * Portions created by the Initial Developer are Copyright (C) 2005
00019  * IBM Corporation. All Rights Reserved.
00020  *
00021  * Contributor(s):
00022  *   Javier Pedemonte (jhpedemonte@gmail.com)
00023  *
00024  * Alternatively, the contents of this file may be used under the terms of
00025  * either the GNU General Public License Version 2 or later (the "GPL"), or
00026  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
00027  * in which case the provisions of the GPL or the LGPL are applicable instead
00028  * of those above. If you wish to allow use of your version of this file only
00029  * under the terms of either the GPL or the LGPL, and not to allow others to
00030  * use your version of this file under the terms of the MPL, indicate your
00031  * decision by deleting the provisions above and replace them with the notice
00032  * and other provisions required by the GPL or the LGPL. If you do not delete
00033  * the provisions above, a recipient may use your version of this file under
00034  * the terms of any one of the MPL, the GPL or the LGPL.
00035  *
00036  * ***** END LICENSE BLOCK ***** */
00037 
00038 #include "jni.h"
00039 #include "nsJavaXPTCStubWeakRef.h"
00040 #include "nsJavaXPTCStub.h"
00041 #include "nsJavaXPCOMBindingUtils.h"
00042 #include "nsIInterfaceInfoManager.h"
00043 
00044 
00059 nsJavaXPTCStubWeakRef::nsJavaXPTCStubWeakRef(jobject aJavaObject,
00060                                              nsJavaXPTCStub* aXPTCStub)
00061   : mXPTCStub(aXPTCStub)
00062 {
00063   JNIEnv* env = GetJNIEnv();
00064   jobject weakref = env->NewObject(weakReferenceClass,
00065                                    weakReferenceConstructorMID, aJavaObject);
00066   mWeakRef = env->NewGlobalRef(weakref);
00067 }
00068 
00069 nsJavaXPTCStubWeakRef::~nsJavaXPTCStubWeakRef()
00070 {
00071   JNIEnv* env = GetJNIEnv();
00072   env->CallVoidMethod(mWeakRef, clearReferentMID);
00073   env->DeleteGlobalRef(mWeakRef);
00074   mXPTCStub->ReleaseWeakRef();
00075 }
00076 
00077 NS_IMPL_ADDREF(nsJavaXPTCStubWeakRef)
00078 NS_IMPL_RELEASE(nsJavaXPTCStubWeakRef)
00079 
00080 NS_IMPL_QUERY_INTERFACE1(nsJavaXPTCStubWeakRef, nsIWeakReference)
00081 
00082 NS_IMETHODIMP
00083 nsJavaXPTCStubWeakRef::QueryReferent(const nsIID& aIID, void** aInstancePtr)
00084 {
00085   LOG(("nsJavaXPTCStubWeakRef::QueryReferent()\n"));
00086 
00087   // Is weak ref still valid?
00088   // We create a strong local ref to make sure Java object isn't garbage
00089   // collected during this call.
00090   JNIEnv* env = GetJNIEnv();
00091   jobject javaObject = env->CallObjectMethod(mWeakRef, getReferentMID);
00092   if (env->IsSameObject(javaObject, NULL))
00093     return NS_ERROR_NULL_POINTER;
00094 
00095   // Java object has not been garbage collected, so return QI from XPTCStub.
00096   return mXPTCStub->QueryInterface(aIID, aInstancePtr);
00097 }
00098