diff options
Diffstat (limited to 'dom/events/JSEventHandler.cpp')
| -rw-r--r-- | dom/events/JSEventHandler.cpp | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/dom/events/JSEventHandler.cpp b/dom/events/JSEventHandler.cpp new file mode 100644 index 0000000000..8304ec6582 --- /dev/null +++ b/dom/events/JSEventHandler.cpp @@ -0,0 +1,229 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ +#include "nsJSUtils.h" +#include "nsString.h" +#include "nsIScriptContext.h" +#include "nsIScriptGlobalObject.h" +#include "nsVariant.h" +#include "nsGkAtoms.h" +#include "xpcpublic.h" +#include "nsJSEnvironment.h" +#include "nsDOMJSUtils.h" +#include "mozilla/ContentEvents.h" +#include "mozilla/CycleCollectedJSContext.h" +#include "mozilla/HoldDropJSObjects.h" +#include "mozilla/JSEventHandler.h" +#include "mozilla/Likely.h" +#include "mozilla/dom/BeforeUnloadEvent.h" +#include "mozilla/dom/ErrorEvent.h" +#include "mozilla/dom/WorkerPrivate.h" + +namespace mozilla { + +using namespace dom; + +JSEventHandler::JSEventHandler(EventTarget* aTarget, nsAtom* aType, + const TypedEventHandler& aTypedHandler) + : mTarget(aTarget), mEventName(aType), mTypedHandler(aTypedHandler) { + // Note, we call HoldJSObjects to get CanSkip called before CC. + HoldJSObjects(this); +} + +JSEventHandler::~JSEventHandler() { + NS_ASSERTION(!mTarget, "Should have called Disconnect()!"); + DropJSObjects(this); +} + +NS_IMPL_CYCLE_COLLECTION_CLASS(JSEventHandler) + +NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(JSEventHandler) + tmp->mTypedHandler.ForgetHandler(); +NS_IMPL_CYCLE_COLLECTION_UNLINK_END +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(JSEventHandler) + if (MOZ_UNLIKELY(cb.WantDebugInfo()) && tmp->mEventName) { + nsAutoCString name; + name.AppendLiteral("JSEventHandler handlerName="); + name.Append( + NS_ConvertUTF16toUTF8(nsDependentAtomString(tmp->mEventName)).get()); + cb.DescribeRefCountedNode(tmp->mRefCnt.get(), name.get()); + } else { + NS_IMPL_CYCLE_COLLECTION_DESCRIBE(JSEventHandler, tmp->mRefCnt.get()) + } + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_RAWPTR(mTypedHandler.Ptr()) +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END + +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(JSEventHandler) + if (tmp->IsBlackForCC()) { + return true; + } + // If we have a target, it is the one which has tmp as onfoo handler. + if (tmp->mTarget) { + nsXPCOMCycleCollectionParticipant* cp = nullptr; + CallQueryInterface(tmp->mTarget, &cp); + nsISupports* canonical = nullptr; + tmp->mTarget->QueryInterface(NS_GET_IID(nsCycleCollectionISupports), + reinterpret_cast<void**>(&canonical)); + // Usually CanSkip ends up unmarking the event listeners of mTarget, + // so tmp may become black. + if (cp && canonical && cp->CanSkip(canonical, true)) { + return tmp->IsBlackForCC(); + } + } +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END + +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(JSEventHandler) + return tmp->IsBlackForCC(); +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END + +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(JSEventHandler) + return tmp->IsBlackForCC(); +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END + +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(JSEventHandler) + NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener) + NS_INTERFACE_MAP_ENTRY(nsISupports) + NS_INTERFACE_MAP_ENTRY(JSEventHandler) +NS_INTERFACE_MAP_END + +NS_IMPL_CYCLE_COLLECTING_ADDREF(JSEventHandler) +NS_IMPL_CYCLE_COLLECTING_RELEASE(JSEventHandler) + +bool JSEventHandler::IsBlackForCC() { + // We can claim to be black if all the things we reference are + // effectively black already. + return !mTypedHandler.HasEventHandler() || + mTypedHandler.Ptr()->IsBlackForCC(); +} + +nsresult JSEventHandler::HandleEvent(Event* aEvent) { + nsCOMPtr<EventTarget> target = mTarget; + if (!target || !mTypedHandler.HasEventHandler() || + !GetTypedEventHandler().Ptr()->CallbackPreserveColor()) { + return NS_ERROR_FAILURE; + } + + bool isMainThread = aEvent->IsMainThreadEvent(); + bool isChromeHandler = + isMainThread + ? nsContentUtils::ObjectPrincipal( + GetTypedEventHandler().Ptr()->CallbackGlobalOrNull()) == + nsContentUtils::GetSystemPrincipal() + : mozilla::dom::IsCurrentThreadRunningChromeWorker(); + + if (mTypedHandler.Type() == TypedEventHandler::eOnError) { + MOZ_ASSERT_IF(mEventName, mEventName == nsGkAtoms::onerror); + + nsString errorMsg, file; + EventOrString msgOrEvent; + Optional<nsAString> fileName; + Optional<uint32_t> lineNumber; + Optional<uint32_t> columnNumber; + Optional<JS::Handle<JS::Value>> error; + + NS_ENSURE_TRUE(aEvent, NS_ERROR_UNEXPECTED); + ErrorEvent* scriptEvent = aEvent->AsErrorEvent(); + if (scriptEvent) { + scriptEvent->GetMessage(errorMsg); + msgOrEvent.SetAsString().ShareOrDependUpon(errorMsg); + + scriptEvent->GetFilename(file); + fileName = &file; + + lineNumber.Construct(); + lineNumber.Value() = scriptEvent->Lineno(); + + columnNumber.Construct(); + columnNumber.Value() = scriptEvent->Colno(); + + error.Construct(RootingCx()); + scriptEvent->GetError(&error.Value()); + } else { + msgOrEvent.SetAsEvent() = aEvent; + } + + RefPtr<OnErrorEventHandlerNonNull> handler = + mTypedHandler.OnErrorEventHandler(); + ErrorResult rv; + JS::Rooted<JS::Value> retval(RootingCx()); + handler->Call(target, msgOrEvent, fileName, lineNumber, columnNumber, error, + &retval, rv); + if (rv.Failed()) { + return rv.StealNSResult(); + } + + if (retval.isBoolean() && retval.toBoolean() == bool(scriptEvent)) { + aEvent->PreventDefaultInternal(isChromeHandler); + } + return NS_OK; + } + + if (mTypedHandler.Type() == TypedEventHandler::eOnBeforeUnload) { + MOZ_ASSERT(mEventName == nsGkAtoms::onbeforeunload); + + RefPtr<OnBeforeUnloadEventHandlerNonNull> handler = + mTypedHandler.OnBeforeUnloadEventHandler(); + ErrorResult rv; + nsString retval; + handler->Call(target, *aEvent, retval, rv); + if (rv.Failed()) { + return rv.StealNSResult(); + } + + BeforeUnloadEvent* beforeUnload = aEvent->AsBeforeUnloadEvent(); + NS_ENSURE_STATE(beforeUnload); + + if (!DOMStringIsNull(retval)) { + aEvent->PreventDefaultInternal(isChromeHandler); + + nsAutoString text; + beforeUnload->GetReturnValue(text); + + // Set the text in the beforeUnload event as long as it wasn't + // already set (through event.returnValue, which takes + // precedence over a value returned from a JS function in IE) + if (text.IsEmpty()) { + beforeUnload->SetReturnValue(retval); + } + } + + return NS_OK; + } + + MOZ_ASSERT(mTypedHandler.Type() == TypedEventHandler::eNormal); + ErrorResult rv; + RefPtr<EventHandlerNonNull> handler = mTypedHandler.NormalEventHandler(); + JS::Rooted<JS::Value> retval(RootingCx()); + handler->Call(target, *aEvent, &retval, rv); + if (rv.Failed()) { + return rv.StealNSResult(); + } + + // If the handler returned false, then prevent default. + if (retval.isBoolean() && !retval.toBoolean()) { + aEvent->PreventDefaultInternal(isChromeHandler); + } + + return NS_OK; +} + +} // namespace mozilla + +using namespace mozilla; + +/* + * Factory functions + */ + +nsresult NS_NewJSEventHandler(mozilla::dom::EventTarget* aTarget, + nsAtom* aEventType, + const TypedEventHandler& aTypedHandler, + JSEventHandler** aReturn) { + NS_ENSURE_ARG(aEventType || !NS_IsMainThread()); + JSEventHandler* it = new JSEventHandler(aTarget, aEventType, aTypedHandler); + NS_ADDREF(*aReturn = it); + + return NS_OK; +} |