A weak reference implementation. Not part of default build.

This file was copied in CVS from the following location:
mozilla/extensions/java/xpcom/nsJavaXPTCStubWeakRef.cpp
Original committer: pedemont%us.ibm.com
Original revision: 1.1
Original date: 2004/09/15 21:50:41

extensions/java/xpcom/src/nsJavaXPTCStubWeakRef.cpp

@@ -0,0 +1,98 @@
+/* ***** 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 Java XPCOM Bindings.
+ *
+ * The Initial Developer of the Original Code is
+ * IBM Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 2004
+ * IBM Corporation. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Javier Pedemonte (jhpedemonte@gmail.com)
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either 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 "jni.h"
+#include "nsJavaXPTCStubWeakRef.h"
+#include "nsJavaXPTCStub.h"
+#include "nsJavaXPCOMBindingUtils.h"
+#include "nsIInterfaceInfoManager.h"
+
+
+nsJavaXPTCStubWeakRef::nsJavaXPTCStubWeakRef(JNIEnv* env, jobject aJavaObject)
+{
+  mJavaEnv = env;
+  mWeakRef = mJavaEnv->NewWeakGlobalRef(aJavaObject);
+}
+
+nsJavaXPTCStubWeakRef::~nsJavaXPTCStubWeakRef()
+{
+  mJavaEnv->DeleteWeakGlobalRef(mWeakRef);
+}
+
+NS_IMPL_ADDREF(nsJavaXPTCStubWeakRef)
+NS_IMPL_RELEASE(nsJavaXPTCStubWeakRef)
+
+NS_IMPL_THREADSAFE_QUERY_INTERFACE1(nsJavaXPTCStubWeakRef, nsIWeakReference)
+
+NS_IMETHODIMP
+nsJavaXPTCStubWeakRef::QueryReferent(const nsIID& aIID, void** aInstancePtr)
+{
+  // Is weak ref still valid?
+  // We create a strong local ref to make sure Java object isn't garbage
+  // collected during this call.
+  jobject javaObject = mJavaEnv->NewLocalRef(mWeakRef);
+  if (!javaObject)
+    return NS_ERROR_NULL_POINTER;
+
+  // Java object has not been garbage collected.  Do we have an
+  // associated nsJavaXPTCStub?
+  void* inst = GetMatchingXPCOMObject(mJavaEnv, javaObject);
+  NS_ASSERTION(IsXPTCStub(inst), "Found xpcom object was not an XPTCStub");
+
+  if (!inst) {
+    // No XPTCStub exists, so create one
+
+    // Get interface info for class
+    nsCOMPtr<nsIInterfaceInfoManager> iim = XPTI_GetInterfaceInfoManager();
+    nsCOMPtr<nsIInterfaceInfo> iinfo;
+    iim->GetInfoForIID(&aIID, getter_AddRefs(iinfo));
+
+    // Create XPCOM stub
+    nsJavaXPTCStub* xpcomStub = new nsJavaXPTCStub(mJavaEnv, javaObject, iinfo);
+    NS_ADDREF(xpcomStub);
+    AddJavaXPCOMBinding(mJavaEnv, javaObject, SetAsXPTCStub(xpcomStub));
+
+    // return created stub
+    *aInstancePtr = (void*) xpcomStub;
+    return NS_OK;
+  }
+
+  // We have an exising XPTCStub, so return QI result
+  nsJavaXPTCStub* xpcomStub = GetXPTCStubAddr(inst);
+  return xpcomStub->QueryInterface(aIID, aInstancePtr);
+}
+