gecko-dev/dom/events/JSEventHandler.cpp

253 строки
8.0 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "nsIServiceManager.h"
#include "nsIScriptSecurityManager.h"
#include "nsIScriptContext.h"
#include "nsIScriptGlobalObject.h"
#include "nsIXPConnect.h"
#include "nsIMutableArray.h"
#include "nsVariant.h"
#include "nsIDOMBeforeUnloadEvent.h"
#include "nsGkAtoms.h"
#include "xpcpublic.h"
#include "nsJSEnvironment.h"
#include "nsDOMJSUtils.h"
#include "WorkerPrivate.h"
#include "mozilla/ContentEvents.h"
#include "mozilla/CycleCollectedJSRuntime.h"
#include "mozilla/HoldDropJSObjects.h"
#include "mozilla/JSEventHandler.h"
#include "mozilla/Likely.h"
#include "mozilla/dom/ErrorEvent.h"
#include "mozilla/dom/UnionTypes.h"
namespace mozilla {
using namespace dom;
JSEventHandler::JSEventHandler(nsISupports* aTarget,
nsIAtom* aType,
const TypedEventHandler& aTypedHandler)
: mEventName(aType)
, mTypedHandler(aTypedHandler)
{
nsCOMPtr<nsISupports> base = do_QueryInterface(aTarget);
mTarget = base.get();
// 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_SCRIPT_OBJECTS
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()->HasGrayCallable();
}
nsresult
JSEventHandler::HandleEvent(nsIDOMEvent* aEvent)
{
nsCOMPtr<EventTarget> target = do_QueryInterface(mTarget);
if (!target || !mTypedHandler.HasEventHandler() ||
!GetTypedEventHandler().Ptr()->CallbackPreserveColor()) {
return NS_ERROR_FAILURE;
}
Event* event = aEvent->InternalDOMEvent();
bool isMainThread = event->IsMainThreadEvent();
bool isChromeHandler =
isMainThread ?
nsContentUtils::ObjectPrincipal(
GetTypedEventHandler().Ptr()->CallbackPreserveColor()) ==
nsContentUtils::GetSystemPrincipal() :
mozilla::dom::workers::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->InternalDOMEvent()->AsErrorEvent();
if (scriptEvent) {
scriptEvent->GetMessage(errorMsg);
msgOrEvent.SetAsString().SetData(errorMsg.Data(), errorMsg.Length());
scriptEvent->GetFilename(file);
fileName = &file;
lineNumber.Construct();
lineNumber.Value() = scriptEvent->Lineno();
columnNumber.Construct();
columnNumber.Value() = scriptEvent->Colno();
ThreadsafeAutoJSContext cx;
error.Construct(cx);
scriptEvent->GetError(cx, &error.Value());
} else {
msgOrEvent.SetAsEvent() = aEvent->InternalDOMEvent();
}
nsRefPtr<OnErrorEventHandlerNonNull> handler =
mTypedHandler.OnErrorEventHandler();
ErrorResult rv;
bool handled = handler->Call(mTarget, msgOrEvent, fileName, lineNumber,
columnNumber, error, rv);
if (rv.Failed()) {
return rv.ErrorCode();
}
if (handled) {
event->PreventDefaultInternal(isChromeHandler);
}
return NS_OK;
}
if (mTypedHandler.Type() == TypedEventHandler::eOnBeforeUnload) {
MOZ_ASSERT(mEventName == nsGkAtoms::onbeforeunload);
nsRefPtr<OnBeforeUnloadEventHandlerNonNull> handler =
mTypedHandler.OnBeforeUnloadEventHandler();
ErrorResult rv;
nsString retval;
handler->Call(mTarget, *(aEvent->InternalDOMEvent()), retval, rv);
if (rv.Failed()) {
return rv.ErrorCode();
}
nsCOMPtr<nsIDOMBeforeUnloadEvent> beforeUnload = do_QueryInterface(aEvent);
NS_ENSURE_STATE(beforeUnload);
if (!DOMStringIsNull(retval)) {
event->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;
nsRefPtr<EventHandlerNonNull> handler = mTypedHandler.NormalEventHandler();
JS::Rooted<JS::Value> retval(CycleCollectedJSRuntime::Get()->Runtime());
handler->Call(mTarget, *(aEvent->InternalDOMEvent()), &retval, rv);
if (rv.Failed()) {
return rv.ErrorCode();
}
// If the handler returned false and its sense is not reversed,
// or the handler returned true and its sense is reversed from
// the usual (false means cancel), then prevent default.
if (retval.isBoolean() &&
retval.toBoolean() == (mEventName == nsGkAtoms::onerror ||
mEventName == nsGkAtoms::onmouseover)) {
event->PreventDefaultInternal(isChromeHandler);
}
return NS_OK;
}
} // namespace mozilla
using namespace mozilla;
/*
* Factory functions
*/
nsresult
NS_NewJSEventHandler(nsISupports* aTarget,
nsIAtom* 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;
}