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/* -*- 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
#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;
nsCString file;
EventOrString msgOrEvent;
Optional<nsACString> 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;
}