gecko/dom/events/nsJSEventListener.cpp
Boris Zbarsky 9eb56076b1 Bug 958576 part 2. Move FakeDependentString to the binding_detail namespace. r=peterv
I took the opportunity to move away from the NonNull<nsAString> hack
we had for string arguments, since just passing in a
FakeDependentString works fine and callees are now less likely to
declare their arg as being of that type.

In the process of doing that, I ran into what looks like a substantive
bug in the "owning union with string default value" case: We were
doing mValue.mString.Value() without ever having constructed
mValue.mString!
2014-01-22 14:37:10 -05:00

272 lines
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 "nsJSEventListener.h"
#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 "mozilla/ContentEvents.h"
#include "mozilla/Likely.h"
#include "mozilla/dom/UnionTypes.h"
#include "nsDOMEvent.h"
#ifdef DEBUG
#include "nspr.h" // PR_fprintf
class EventListenerCounter
{
public:
~EventListenerCounter() {
}
};
static EventListenerCounter sEventListenerCounter;
#endif
using namespace mozilla;
using namespace mozilla::dom;
/*
* nsJSEventListener implementation
*/
nsJSEventListener::nsJSEventListener(JSObject* aScopeObject,
nsISupports *aTarget,
nsIAtom* aType,
const nsEventHandler& aHandler)
: nsIJSEventListener(aScopeObject, aTarget, aType, aHandler)
{
if (mScopeObject) {
mozilla::HoldJSObjects(this);
}
}
nsJSEventListener::~nsJSEventListener()
{
if (mScopeObject) {
mScopeObject = nullptr;
mozilla::DropJSObjects(this);
}
}
/* virtual */
void
nsJSEventListener::UpdateScopeObject(JS::Handle<JSObject*> aScopeObject)
{
if (mScopeObject && !aScopeObject) {
mScopeObject = nullptr;
mozilla::DropJSObjects(this);
} else if (aScopeObject && !mScopeObject) {
mozilla::HoldJSObjects(this);
}
mScopeObject = aScopeObject;
}
NS_IMPL_CYCLE_COLLECTION_CLASS(nsJSEventListener)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsJSEventListener)
if (tmp->mScopeObject) {
tmp->mScopeObject = nullptr;
mozilla::DropJSObjects(tmp);
}
tmp->mHandler.ForgetHandler();
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(nsJSEventListener)
if (MOZ_UNLIKELY(cb.WantDebugInfo()) && tmp->mEventName) {
nsAutoCString name;
name.AppendLiteral("nsJSEventListener handlerName=");
name.Append(
NS_ConvertUTF16toUTF8(nsDependentAtomString(tmp->mEventName)).get());
cb.DescribeRefCountedNode(tmp->mRefCnt.get(), name.get());
} else {
NS_IMPL_CYCLE_COLLECTION_DESCRIBE(nsJSEventListener, tmp->mRefCnt.get())
}
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_RAWPTR(mHandler.Ptr())
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsJSEventListener)
NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mScopeObject)
NS_IMPL_CYCLE_COLLECTION_TRACE_END
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(nsJSEventListener)
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(nsJSEventListener)
return tmp->IsBlackForCC();
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(nsJSEventListener)
return tmp->IsBlackForCC();
NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END
NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(nsJSEventListener)
NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener)
NS_INTERFACE_MAP_ENTRY(nsIJSEventListener)
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
NS_IMPL_CYCLE_COLLECTING_ADDREF(nsJSEventListener)
NS_IMPL_CYCLE_COLLECTING_RELEASE(nsJSEventListener)
bool
nsJSEventListener::IsBlackForCC()
{
// We can claim to be black if all the things we reference are
// effectively black already.
if ((!mScopeObject || !xpc_IsGrayGCThing(mScopeObject)) &&
(!mHandler.HasEventHandler() ||
!mHandler.Ptr()->HasGrayCallable())) {
return true;
}
return false;
}
nsresult
nsJSEventListener::HandleEvent(nsIDOMEvent* aEvent)
{
nsCOMPtr<EventTarget> target = do_QueryInterface(mTarget);
if (!target || !mHandler.HasEventHandler())
return NS_ERROR_FAILURE;
if (mHandler.Type() == nsEventHandler::eOnError) {
MOZ_ASSERT_IF(mEventName, mEventName == nsGkAtoms::onerror);
nsString errorMsg, file;
EventOrString msgOrEvent;
Optional<nsAString> fileName;
Optional<uint32_t> lineNumber;
Optional<uint32_t> columnNumber;
NS_ENSURE_TRUE(aEvent, NS_ERROR_UNEXPECTED);
InternalScriptErrorEvent* scriptEvent =
aEvent->GetInternalNSEvent()->AsScriptErrorEvent();
if (scriptEvent &&
(scriptEvent->message == NS_LOAD_ERROR ||
scriptEvent->typeString.EqualsLiteral("error"))) {
errorMsg = scriptEvent->errorMsg;
msgOrEvent.SetAsString().SetData(errorMsg.Data(), errorMsg.Length());
file = scriptEvent->fileName;
fileName = &file;
lineNumber.Construct();
lineNumber.Value() = scriptEvent->lineNr;
} else {
msgOrEvent.SetAsEvent() = aEvent->InternalDOMEvent();
}
nsRefPtr<OnErrorEventHandlerNonNull> handler =
mHandler.OnErrorEventHandler();
ErrorResult rv;
bool handled = handler->Call(mTarget, msgOrEvent, fileName, lineNumber,
columnNumber, rv);
if (rv.Failed()) {
return rv.ErrorCode();
}
if (handled) {
aEvent->PreventDefault();
}
return NS_OK;
}
if (mHandler.Type() == nsEventHandler::eOnBeforeUnload) {
MOZ_ASSERT(mEventName == nsGkAtoms::onbeforeunload);
nsRefPtr<OnBeforeUnloadEventHandlerNonNull> handler =
mHandler.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)) {
aEvent->PreventDefault();
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(mHandler.Type() == nsEventHandler::eNormal);
ErrorResult rv;
nsRefPtr<EventHandlerNonNull> handler = mHandler.EventHandler();
JS::Value retval =
handler->Call(mTarget, *(aEvent->InternalDOMEvent()), 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)) {
aEvent->PreventDefault();
}
return NS_OK;
}
/*
* Factory functions
*/
nsresult
NS_NewJSEventListener(JSObject* aScopeObject,
nsISupports*aTarget, nsIAtom* aEventType,
const nsEventHandler& aHandler,
nsIJSEventListener** aReturn)
{
NS_ENSURE_ARG(aEventType || !NS_IsMainThread());
nsJSEventListener* it =
new nsJSEventListener(aScopeObject, aTarget, aEventType, aHandler);
NS_ADDREF(*aReturn = it);
return NS_OK;
}