Line data    Source code

       1             : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
       2             : /* vim: set ts=8 sts=4 et sw=4 tw=99: */
       3             : /* This Source Code Form is subject to the terms of the Mozilla Public
       4             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       5             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
       6             : 
       7             : #include "xpcprivate.h"
       8             : #include "XPCJSWeakReference.h"
       9             : 
      10             : #include "nsContentUtils.h"
      11             : 
      12             : using namespace JS;
      13             : 
      14           0 : xpcJSWeakReference::xpcJSWeakReference()
      15             : {
      16           0 : }
      17             : 
      18           0 : NS_IMPL_ISUPPORTS(xpcJSWeakReference, xpcIJSWeakReference)
      19             : 
      20           0 : nsresult xpcJSWeakReference::Init(JSContext* cx, const JS::Value& object)
      21             : {
      22           0 :     if (!object.isObject())
      23           0 :         return NS_OK;
      24             : 
      25           0 :     JS::RootedObject obj(cx, &object.toObject());
      26             : 
      27           0 :     XPCCallContext ccx(cx);
      28             : 
      29             :     // See if the object is a wrapped native that supports weak references.
      30           0 :     nsCOMPtr<nsISupports> supports = xpc::UnwrapReflectorToISupports(obj);
      31             :     nsCOMPtr<nsISupportsWeakReference> supportsWeakRef =
      32           0 :         do_QueryInterface(supports);
      33           0 :     if (supportsWeakRef) {
      34           0 :         supportsWeakRef->GetWeakReference(getter_AddRefs(mReferent));
      35           0 :         if (mReferent) {
      36           0 :             return NS_OK;
      37             :         }
      38             :     }
      39             :     // If it's not a wrapped native, or it is a wrapped native that does not
      40             :     // support weak references, fall back to getting a weak ref to the object.
      41             : 
      42             :     // See if object is a wrapped JSObject.
      43           0 :     RefPtr<nsXPCWrappedJS> wrapped;
      44           0 :     nsresult rv = nsXPCWrappedJS::GetNewOrUsed(obj,
      45             :                                                NS_GET_IID(nsISupports),
      46           0 :                                                getter_AddRefs(wrapped));
      47           0 :     if (!wrapped) {
      48           0 :         NS_ERROR("can't get nsISupportsWeakReference wrapper for obj");
      49           0 :         return rv;
      50             :     }
      51             : 
      52           0 :     return wrapped->GetWeakReference(getter_AddRefs(mReferent));
      53             : }
      54             : 
      55             : NS_IMETHODIMP
      56           0 : xpcJSWeakReference::Get(JSContext* aCx, MutableHandleValue aRetval)
      57             : {
      58           0 :     aRetval.setNull();
      59             : 
      60           0 :     if (!mReferent) {
      61           0 :         return NS_OK;
      62             :     }
      63             : 
      64           0 :     nsCOMPtr<nsISupports> supports = do_QueryReferent(mReferent);
      65           0 :     if (!supports) {
      66           0 :         return NS_OK;
      67             :     }
      68             : 
      69           0 :     nsCOMPtr<nsIXPConnectWrappedJS> wrappedObj = do_QueryInterface(supports);
      70           0 :     if (!wrappedObj) {
      71             :         // We have a generic XPCOM object that supports weak references here.
      72             :         // Wrap it and pass it out.
      73           0 :         return nsContentUtils::WrapNative(aCx, supports,
      74             :                                           &NS_GET_IID(nsISupports),
      75           0 :                                           aRetval);
      76             :     }
      77             : 
      78           0 :     JS::RootedObject obj(aCx, wrappedObj->GetJSObject());
      79           0 :     if (!obj) {
      80           0 :         return NS_OK;
      81             :     }
      82             : 
      83             :     // Most users of XPCWrappedJS don't need to worry about
      84             :     // re-wrapping because things are implicitly rewrapped by
      85             :     // xpcconvert. However, because we're doing this directly
      86             :     // through the native call context, we need to call
      87             :     // JS_WrapObject().
      88           0 :     if (!JS_WrapObject(aCx, &obj)) {
      89           0 :         return NS_ERROR_FAILURE;
      90             :     }
      91             : 
      92           0 :     aRetval.setObject(*obj);
      93           0 :     return NS_OK;
      94             : }