1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/dom/events/JSEventHandler.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,252 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +#include "nsJSUtils.h"
1.9 +#include "nsString.h"
1.10 +#include "nsIServiceManager.h"
1.11 +#include "nsIScriptSecurityManager.h"
1.12 +#include "nsIScriptContext.h"
1.13 +#include "nsIScriptGlobalObject.h"
1.14 +#include "nsIXPConnect.h"
1.15 +#include "nsIMutableArray.h"
1.16 +#include "nsVariant.h"
1.17 +#include "nsIDOMBeforeUnloadEvent.h"
1.18 +#include "nsGkAtoms.h"
1.19 +#include "xpcpublic.h"
1.20 +#include "nsJSEnvironment.h"
1.21 +#include "nsDOMJSUtils.h"
1.22 +#include "WorkerPrivate.h"
1.23 +#include "mozilla/ContentEvents.h"
1.24 +#include "mozilla/CycleCollectedJSRuntime.h"
1.25 +#include "mozilla/HoldDropJSObjects.h"
1.26 +#include "mozilla/JSEventHandler.h"
1.27 +#include "mozilla/Likely.h"
1.28 +#include "mozilla/dom/ErrorEvent.h"
1.29 +#include "mozilla/dom/UnionTypes.h"
1.30 +
1.31 +namespace mozilla {
1.32 +
1.33 +using namespace dom;
1.34 +
1.35 +JSEventHandler::JSEventHandler(nsISupports* aTarget,
1.36 + nsIAtom* aType,
1.37 + const TypedEventHandler& aTypedHandler)
1.38 + : mEventName(aType)
1.39 + , mTypedHandler(aTypedHandler)
1.40 +{
1.41 + nsCOMPtr<nsISupports> base = do_QueryInterface(aTarget);
1.42 + mTarget = base.get();
1.43 + // Note, we call HoldJSObjects to get CanSkip called before CC.
1.44 + HoldJSObjects(this);
1.45 +}
1.46 +
1.47 +JSEventHandler::~JSEventHandler()
1.48 +{
1.49 + NS_ASSERTION(!mTarget, "Should have called Disconnect()!");
1.50 + DropJSObjects(this);
1.51 +}
1.52 +
1.53 +NS_IMPL_CYCLE_COLLECTION_CLASS(JSEventHandler)
1.54 +
1.55 +NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(JSEventHandler)
1.56 + tmp->mTypedHandler.ForgetHandler();
1.57 +NS_IMPL_CYCLE_COLLECTION_UNLINK_END
1.58 +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(JSEventHandler)
1.59 + if (MOZ_UNLIKELY(cb.WantDebugInfo()) && tmp->mEventName) {
1.60 + nsAutoCString name;
1.61 + name.AppendLiteral("JSEventHandler handlerName=");
1.62 + name.Append(
1.63 + NS_ConvertUTF16toUTF8(nsDependentAtomString(tmp->mEventName)).get());
1.64 + cb.DescribeRefCountedNode(tmp->mRefCnt.get(), name.get());
1.65 + } else {
1.66 + NS_IMPL_CYCLE_COLLECTION_DESCRIBE(JSEventHandler, tmp->mRefCnt.get())
1.67 + }
1.68 + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_RAWPTR(mTypedHandler.Ptr())
1.69 + NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
1.70 +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
1.71 +
1.72 +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(JSEventHandler)
1.73 + if (tmp->IsBlackForCC()) {
1.74 + return true;
1.75 + }
1.76 + // If we have a target, it is the one which has tmp as onfoo handler.
1.77 + if (tmp->mTarget) {
1.78 + nsXPCOMCycleCollectionParticipant* cp = nullptr;
1.79 + CallQueryInterface(tmp->mTarget, &cp);
1.80 + nsISupports* canonical = nullptr;
1.81 + tmp->mTarget->QueryInterface(NS_GET_IID(nsCycleCollectionISupports),
1.82 + reinterpret_cast<void**>(&canonical));
1.83 + // Usually CanSkip ends up unmarking the event listeners of mTarget,
1.84 + // so tmp may become black.
1.85 + if (cp && canonical && cp->CanSkip(canonical, true)) {
1.86 + return tmp->IsBlackForCC();
1.87 + }
1.88 + }
1.89 +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END
1.90 +
1.91 +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(JSEventHandler)
1.92 + return tmp->IsBlackForCC();
1.93 +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END
1.94 +
1.95 +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(JSEventHandler)
1.96 + return tmp->IsBlackForCC();
1.97 +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END
1.98 +
1.99 +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(JSEventHandler)
1.100 + NS_INTERFACE_MAP_ENTRY(nsIDOMEventListener)
1.101 + NS_INTERFACE_MAP_ENTRY(nsISupports)
1.102 + NS_INTERFACE_MAP_ENTRY(JSEventHandler)
1.103 +NS_INTERFACE_MAP_END
1.104 +
1.105 +NS_IMPL_CYCLE_COLLECTING_ADDREF(JSEventHandler)
1.106 +NS_IMPL_CYCLE_COLLECTING_RELEASE(JSEventHandler)
1.107 +
1.108 +bool
1.109 +JSEventHandler::IsBlackForCC()
1.110 +{
1.111 + // We can claim to be black if all the things we reference are
1.112 + // effectively black already.
1.113 + return !mTypedHandler.HasEventHandler() ||
1.114 + !mTypedHandler.Ptr()->HasGrayCallable();
1.115 +}
1.116 +
1.117 +nsresult
1.118 +JSEventHandler::HandleEvent(nsIDOMEvent* aEvent)
1.119 +{
1.120 + nsCOMPtr<EventTarget> target = do_QueryInterface(mTarget);
1.121 + if (!target || !mTypedHandler.HasEventHandler() ||
1.122 + !GetTypedEventHandler().Ptr()->CallbackPreserveColor()) {
1.123 + return NS_ERROR_FAILURE;
1.124 + }
1.125 +
1.126 + Event* event = aEvent->InternalDOMEvent();
1.127 + bool isMainThread = event->IsMainThreadEvent();
1.128 + bool isChromeHandler =
1.129 + isMainThread ?
1.130 + nsContentUtils::GetObjectPrincipal(
1.131 + GetTypedEventHandler().Ptr()->CallbackPreserveColor()) ==
1.132 + nsContentUtils::GetSystemPrincipal() :
1.133 + mozilla::dom::workers::IsCurrentThreadRunningChromeWorker();
1.134 +
1.135 + if (mTypedHandler.Type() == TypedEventHandler::eOnError) {
1.136 + MOZ_ASSERT_IF(mEventName, mEventName == nsGkAtoms::onerror);
1.137 +
1.138 + nsString errorMsg, file;
1.139 + EventOrString msgOrEvent;
1.140 + Optional<nsAString> fileName;
1.141 + Optional<uint32_t> lineNumber;
1.142 + Optional<uint32_t> columnNumber;
1.143 + Optional<JS::Handle<JS::Value>> error;
1.144 +
1.145 + NS_ENSURE_TRUE(aEvent, NS_ERROR_UNEXPECTED);
1.146 + ErrorEvent* scriptEvent = aEvent->InternalDOMEvent()->AsErrorEvent();
1.147 + if (scriptEvent) {
1.148 + scriptEvent->GetMessage(errorMsg);
1.149 + msgOrEvent.SetAsString().SetData(errorMsg.Data(), errorMsg.Length());
1.150 +
1.151 + scriptEvent->GetFilename(file);
1.152 + fileName = &file;
1.153 +
1.154 + lineNumber.Construct();
1.155 + lineNumber.Value() = scriptEvent->Lineno();
1.156 +
1.157 + columnNumber.Construct();
1.158 + columnNumber.Value() = scriptEvent->Colno();
1.159 +
1.160 + ThreadsafeAutoJSContext cx;
1.161 + error.Construct(cx);
1.162 + scriptEvent->GetError(cx, &error.Value());
1.163 + } else {
1.164 + msgOrEvent.SetAsEvent() = aEvent->InternalDOMEvent();
1.165 + }
1.166 +
1.167 + nsRefPtr<OnErrorEventHandlerNonNull> handler =
1.168 + mTypedHandler.OnErrorEventHandler();
1.169 + ErrorResult rv;
1.170 + bool handled = handler->Call(mTarget, msgOrEvent, fileName, lineNumber,
1.171 + columnNumber, error, rv);
1.172 + if (rv.Failed()) {
1.173 + return rv.ErrorCode();
1.174 + }
1.175 +
1.176 + if (handled) {
1.177 + event->PreventDefaultInternal(isChromeHandler);
1.178 + }
1.179 + return NS_OK;
1.180 + }
1.181 +
1.182 + if (mTypedHandler.Type() == TypedEventHandler::eOnBeforeUnload) {
1.183 + MOZ_ASSERT(mEventName == nsGkAtoms::onbeforeunload);
1.184 +
1.185 + nsRefPtr<OnBeforeUnloadEventHandlerNonNull> handler =
1.186 + mTypedHandler.OnBeforeUnloadEventHandler();
1.187 + ErrorResult rv;
1.188 + nsString retval;
1.189 + handler->Call(mTarget, *(aEvent->InternalDOMEvent()), retval, rv);
1.190 + if (rv.Failed()) {
1.191 + return rv.ErrorCode();
1.192 + }
1.193 +
1.194 + nsCOMPtr<nsIDOMBeforeUnloadEvent> beforeUnload = do_QueryInterface(aEvent);
1.195 + NS_ENSURE_STATE(beforeUnload);
1.196 +
1.197 + if (!DOMStringIsNull(retval)) {
1.198 + event->PreventDefaultInternal(isChromeHandler);
1.199 +
1.200 + nsAutoString text;
1.201 + beforeUnload->GetReturnValue(text);
1.202 +
1.203 + // Set the text in the beforeUnload event as long as it wasn't
1.204 + // already set (through event.returnValue, which takes
1.205 + // precedence over a value returned from a JS function in IE)
1.206 + if (text.IsEmpty()) {
1.207 + beforeUnload->SetReturnValue(retval);
1.208 + }
1.209 + }
1.210 +
1.211 + return NS_OK;
1.212 + }
1.213 +
1.214 + MOZ_ASSERT(mTypedHandler.Type() == TypedEventHandler::eNormal);
1.215 + ErrorResult rv;
1.216 + nsRefPtr<EventHandlerNonNull> handler = mTypedHandler.NormalEventHandler();
1.217 + JS::Rooted<JS::Value> retval(CycleCollectedJSRuntime::Get()->Runtime());
1.218 + handler->Call(mTarget, *(aEvent->InternalDOMEvent()), &retval, rv);
1.219 + if (rv.Failed()) {
1.220 + return rv.ErrorCode();
1.221 + }
1.222 +
1.223 + // If the handler returned false and its sense is not reversed,
1.224 + // or the handler returned true and its sense is reversed from
1.225 + // the usual (false means cancel), then prevent default.
1.226 + if (retval.isBoolean() &&
1.227 + retval.toBoolean() == (mEventName == nsGkAtoms::onerror ||
1.228 + mEventName == nsGkAtoms::onmouseover)) {
1.229 + event->PreventDefaultInternal(isChromeHandler);
1.230 + }
1.231 +
1.232 + return NS_OK;
1.233 +}
1.234 +
1.235 +} // namespace mozilla
1.236 +
1.237 +using namespace mozilla;
1.238 +
1.239 +/*
1.240 + * Factory functions
1.241 + */
1.242 +
1.243 +nsresult
1.244 +NS_NewJSEventHandler(nsISupports* aTarget,
1.245 + nsIAtom* aEventType,
1.246 + const TypedEventHandler& aTypedHandler,
1.247 + JSEventHandler** aReturn)
1.248 +{
1.249 + NS_ENSURE_ARG(aEventType || !NS_IsMainThread());
1.250 + JSEventHandler* it =
1.251 + new JSEventHandler(aTarget, aEventType, aTypedHandler);
1.252 + NS_ADDREF(*aReturn = it);
1.253 +
1.254 + return NS_OK;
1.255 +}
