예제 #1
0
EventListenerManager::Listener*
EventListenerManager::SetEventHandlerInternal(
                        nsIAtom* aName,
                        const nsAString& aTypeString,
                        const TypedEventHandler& aTypedHandler,
                        bool aPermitUntrustedEvents)
{
  MOZ_ASSERT(aName || !aTypeString.IsEmpty());

  uint32_t eventType = nsContentUtils::GetEventId(aName);
  Listener* listener = FindEventHandler(eventType, aName, aTypeString);

  if (!listener) {
    // If we didn't find a script listener or no listeners existed
    // create and add a new one.
    EventListenerFlags flags;
    flags.mListenerIsJSListener = true;

    nsCOMPtr<JSEventHandler> jsEventHandler;
    NS_NewJSEventHandler(mTarget, aName,
                         aTypedHandler, getter_AddRefs(jsEventHandler));
    EventListenerHolder listenerHolder(jsEventHandler);
    AddEventListenerInternal(listenerHolder, eventType, aName, aTypeString,
                             flags, true);

    listener = FindEventHandler(eventType, aName, aTypeString);
  } else {
    JSEventHandler* jsEventHandler = listener->GetJSEventHandler();
    MOZ_ASSERT(jsEventHandler,
               "How can we have an event handler with no JSEventHandler?");

    bool same = jsEventHandler->GetTypedEventHandler() == aTypedHandler;
    // Possibly the same listener, but update still the context and scope.
    jsEventHandler->SetHandler(aTypedHandler);
    if (mTarget && !same && aName) {
      mTarget->EventListenerRemoved(aName);
      mTarget->EventListenerAdded(aName);
    }
    if (mIsMainThreadELM && mTarget) {
      EventListenerService::NotifyAboutMainThreadListenerChange(mTarget);
    }
  }

  // Set flag to indicate possible need for compilation later
  listener->mHandlerIsString = !aTypedHandler.HasEventHandler();
  if (aPermitUntrustedEvents) {
    listener->mFlags.mAllowUntrustedEvents = true;
  }

  return listener;
}
size_t
EventListenerManager::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const
{
  size_t n = aMallocSizeOf(this);
  n += mListeners.SizeOfExcludingThis(aMallocSizeOf);
  uint32_t count = mListeners.Length();
  for (uint32_t i = 0; i < count; ++i) {
    JSEventHandler* jsEventHandler =
      mListeners.ElementAt(i).GetJSEventHandler();
    if (jsEventHandler) {
      n += jsEventHandler->SizeOfIncludingThis(aMallocSizeOf);
    }
  }
  return n;
}
void
EventListenerManager::TraceListeners(JSTracer* aTrc)
{
  uint32_t count = mListeners.Length();
  for (uint32_t i = 0; i < count; ++i) {
    const Listener& listener = mListeners.ElementAt(i);
    JSEventHandler* jsEventHandler = listener.GetJSEventHandler();
    if (jsEventHandler) {
      const TypedEventHandler& typedHandler =
        jsEventHandler->GetTypedEventHandler();
      if (typedHandler.HasEventHandler()) {
        mozilla::TraceScriptHolder(typedHandler.Ptr(), aTrc);
      }
    } else if (listener.mListenerType == Listener::eWebIDLListener) {
      mozilla::TraceScriptHolder(listener.mListener.GetWebIDLCallback(), aTrc);
    }
    // We might have eWrappedJSListener, but that is the legacy type for
    // JS implemented event listeners, and trickier to handle here.
  }
}
const TypedEventHandler*
EventListenerManager::GetTypedEventHandler(nsIAtom* aEventName,
                                           const nsAString& aTypeString)
{
  uint32_t eventType = nsContentUtils::GetEventId(aEventName);
  Listener* listener = FindEventHandler(eventType, aEventName, aTypeString);

  if (!listener) {
    return nullptr;
  }

  JSEventHandler* jsEventHandler = listener->GetJSEventHandler();

  if (listener->mHandlerIsString) {
    CompileEventHandlerInternal(listener, nullptr, nullptr);
  }

  const TypedEventHandler& typedHandler =
    jsEventHandler->GetTypedEventHandler();
  return typedHandler.HasEventHandler() ? &typedHandler : nullptr;
}
void
EventListenerManager::MarkForCC()
{
  uint32_t count = mListeners.Length();
  for (uint32_t i = 0; i < count; ++i) {
    const Listener& listener = mListeners.ElementAt(i);
    JSEventHandler* jsEventHandler = listener.GetJSEventHandler();
    if (jsEventHandler) {
      const TypedEventHandler& typedHandler =
        jsEventHandler->GetTypedEventHandler();
      if (typedHandler.HasEventHandler()) {
        JS::ExposeObjectToActiveJS(typedHandler.Ptr()->Callable());
      }
    } else if (listener.mListenerType == Listener::eWrappedJSListener) {
      xpc_TryUnmarkWrappedGrayObject(listener.mListener.GetXPCOMCallback());
    } else if (listener.mListenerType == Listener::eWebIDLListener) {
      // Callback() unmarks gray
      listener.mListener.GetWebIDLCallback()->Callback();
    }
  }
  if (mRefCnt.IsPurple()) {
    mRefCnt.RemovePurple();
  }
}
nsresult
EventListenerManager::CompileEventHandlerInternal(Listener* aListener,
                                                  const nsAString* aBody,
                                                  Element* aElement)
{
  MOZ_ASSERT(aListener->GetJSEventHandler());
  MOZ_ASSERT(aListener->mHandlerIsString, "Why are we compiling a non-string JS listener?");
  JSEventHandler* jsEventHandler = aListener->GetJSEventHandler();
  MOZ_ASSERT(!jsEventHandler->GetTypedEventHandler().HasEventHandler(),
             "What is there to compile?");

  nsresult result = NS_OK;
  nsCOMPtr<nsIDocument> doc;
  nsCOMPtr<nsIScriptGlobalObject> global =
    GetScriptGlobalAndDocument(getter_AddRefs(doc));
  NS_ENSURE_STATE(global);

  // Activate JSAPI, and make sure that exceptions are reported on the right
  // Window.
  AutoJSAPI jsapi;
  if (NS_WARN_IF(!jsapi.InitWithLegacyErrorReporting(global))) {
    return NS_ERROR_UNEXPECTED;
  }
  JSContext* cx = jsapi.cx();

  nsCOMPtr<nsIAtom> typeAtom = aListener->mTypeAtom;
  nsIAtom* attrName = typeAtom;

  // Flag us as not a string so we don't keep trying to compile strings which
  // can't be compiled.
  aListener->mHandlerIsString = false;

  // mTarget may not be an Element if it's a window and we're
  // getting an inline event listener forwarded from <html:body> or
  // <html:frameset> or <xul:window> or the like.
  // XXX I don't like that we have to reference content from
  // here. The alternative is to store the event handler string on
  // the JSEventHandler itself, and that still doesn't address
  // the arg names issue.
  nsCOMPtr<Element> element = do_QueryInterface(mTarget);
  MOZ_ASSERT(element || aBody, "Where will we get our body?");
  nsAutoString handlerBody;
  const nsAString* body = aBody;
  if (!aBody) {
    if (aListener->mTypeAtom == nsGkAtoms::onSVGLoad) {
      attrName = nsGkAtoms::onload;
    } else if (aListener->mTypeAtom == nsGkAtoms::onSVGUnload) {
      attrName = nsGkAtoms::onunload;
    } else if (aListener->mTypeAtom == nsGkAtoms::onSVGResize) {
      attrName = nsGkAtoms::onresize;
    } else if (aListener->mTypeAtom == nsGkAtoms::onSVGScroll) {
      attrName = nsGkAtoms::onscroll;
    } else if (aListener->mTypeAtom == nsGkAtoms::onSVGZoom) {
      attrName = nsGkAtoms::onzoom;
    } else if (aListener->mTypeAtom == nsGkAtoms::onbeginEvent) {
      attrName = nsGkAtoms::onbegin;
    } else if (aListener->mTypeAtom == nsGkAtoms::onrepeatEvent) {
      attrName = nsGkAtoms::onrepeat;
    } else if (aListener->mTypeAtom == nsGkAtoms::onendEvent) {
      attrName = nsGkAtoms::onend;
    }

    element->GetAttr(kNameSpaceID_None, attrName, handlerBody);
    body = &handlerBody;
    aElement = element;
  }
  aListener = nullptr;

  uint32_t lineNo = 0;
  nsAutoCString url (NS_LITERAL_CSTRING("-moz-evil:lying-event-listener"));
  MOZ_ASSERT(body);
  MOZ_ASSERT(aElement);
  nsIURI *uri = aElement->OwnerDoc()->GetDocumentURI();
  if (uri) {
    uri->GetSpec(url);
    lineNo = 1;
  }

  nsCOMPtr<nsPIDOMWindow> win = do_QueryInterface(mTarget);
  uint32_t argCount;
  const char **argNames;
  nsContentUtils::GetEventArgNames(aElement->GetNameSpaceID(),
                                   typeAtom, win,
                                   &argCount, &argNames);

  JSAddonId *addonId = MapURIToAddonID(uri);

  // Wrap the event target, so that we can use it as the scope for the event
  // handler. Note that mTarget is different from aElement in the <body> case,
  // where mTarget is a Window.
  //
  // The wrapScope doesn't really matter here, because the target will create
  // its reflector in the proper scope, and then we'll enter that compartment.
  JS::Rooted<JSObject*> wrapScope(cx, global->GetGlobalJSObject());
  JS::Rooted<JS::Value> v(cx);
  {
    JSAutoCompartment ac(cx, wrapScope);
    nsresult rv = nsContentUtils::WrapNative(cx, mTarget, &v,
                                             /* aAllowWrapping = */ false);
    if (NS_WARN_IF(NS_FAILED(rv))) {
      return rv;
    }
  }
  if (addonId) {
    JS::Rooted<JSObject*> vObj(cx, &v.toObject());
    JS::Rooted<JSObject*> addonScope(cx, xpc::GetAddonScope(cx, vObj, addonId));
    if (!addonScope) {
      return NS_ERROR_FAILURE;
    }
    JSAutoCompartment ac(cx, addonScope);
    if (!JS_WrapValue(cx, &v)) {
      return NS_ERROR_FAILURE;
    }
  }
  JS::Rooted<JSObject*> target(cx, &v.toObject());
  JSAutoCompartment ac(cx, target);

  nsDependentAtomString str(attrName);
  // Most of our names are short enough that we don't even have to malloc
  // the JS string stuff, so don't worry about playing games with
  // refcounting XPCOM stringbuffers.
  JS::Rooted<JSString*> jsStr(cx, JS_NewUCStringCopyN(cx,
                                                      str.BeginReading(),
                                                      str.Length()));
  NS_ENSURE_TRUE(jsStr, NS_ERROR_OUT_OF_MEMORY);

  // Get the reflector for |aElement|, so that we can pass to setElement.
  if (NS_WARN_IF(!WrapNewBindingObject(cx, target, aElement, &v))) {
    return NS_ERROR_FAILURE;
  }
  JS::CompileOptions options(cx);
  options.setIntroductionType("eventHandler")
         .setFileAndLine(url.get(), lineNo)
         .setVersion(JSVERSION_DEFAULT)
         .setElement(&v.toObject())
         .setElementAttributeName(jsStr)
         .setDefineOnScope(false);

  JS::Rooted<JSObject*> handler(cx);
  result = nsJSUtils::CompileFunction(cx, target, options,
                                      nsAtomCString(typeAtom),
                                      argCount, argNames, *body, handler.address());
  NS_ENSURE_SUCCESS(result, result);
  NS_ENSURE_TRUE(handler, NS_ERROR_FAILURE);

  if (jsEventHandler->EventName() == nsGkAtoms::onerror && win) {
    nsRefPtr<OnErrorEventHandlerNonNull> handlerCallback =
      new OnErrorEventHandlerNonNull(handler, /* aIncumbentGlobal = */ nullptr);
    jsEventHandler->SetHandler(handlerCallback);
  } else if (jsEventHandler->EventName() == nsGkAtoms::onbeforeunload && win) {
    nsRefPtr<OnBeforeUnloadEventHandlerNonNull> handlerCallback =
      new OnBeforeUnloadEventHandlerNonNull(handler, /* aIncumbentGlobal = */ nullptr);
    jsEventHandler->SetHandler(handlerCallback);
  } else {
    nsRefPtr<EventHandlerNonNull> handlerCallback =
      new EventHandlerNonNull(handler, /* aIncumbentGlobal = */ nullptr);
    jsEventHandler->SetHandler(handlerCallback);
  }

  return result;
}