dom/debugger/DebuggerNotificationObserver.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "DebuggerNotificationObserver.h"
   8
   9 #include "DebuggerNotification.h"
  10 #include "nsIGlobalObject.h"
  11 #include "WrapperFactory.h"
  12
  13 namespace mozilla::dom {
  14
  15 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DebuggerNotificationObserver,
  16                                       mOwnerGlobal, mEventListenerCallbacks)
  17
  18 NS_IMPL_CYCLE_COLLECTING_ADDREF(DebuggerNotificationObserver)
  19 NS_IMPL_CYCLE_COLLECTING_RELEASE(DebuggerNotificationObserver)
  20
  21 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DebuggerNotificationObserver)
  22   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
  23 NS_INTERFACE_MAP_END
  24
  25 /* static */ already_AddRefed<DebuggerNotificationObserver>
  26 DebuggerNotificationObserver::Constructor(GlobalObject& aGlobal,
  27                                           ErrorResult& aRv) {
  28   nsCOMPtr<nsIGlobalObject> globalInterface(
  29       do_QueryInterface(aGlobal.GetAsSupports()));
  30   if (NS_WARN_IF(!globalInterface)) {
  31     aRv.Throw(NS_ERROR_FAILURE);
  32     return nullptr;
  33   }
  34
  35   RefPtr<DebuggerNotificationObserver> observer(
  36       new DebuggerNotificationObserver(globalInterface));
  37   return observer.forget();
  38 }
  39
  40 DebuggerNotificationObserver::DebuggerNotificationObserver(
  41     nsIGlobalObject* aOwnerGlobal)
  42     : mEventListenerCallbacks(), mOwnerGlobal(aOwnerGlobal) {}
  43
  44 JSObject* DebuggerNotificationObserver::WrapObject(
  45     JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
  46   return DebuggerNotificationObserver_Binding::Wrap(aCx, this, aGivenProto);
  47 }
  48
  49 static already_AddRefed<DebuggerNotificationManager> GetManager(
  50     JSContext* aCx, JS::Handle<JSObject*> aDebuggeeGlobal) {
  51   // The debuggee global here is likely a debugger-compartment cross-compartment
  52   // wrapper for the debuggee global object, so we need to unwrap it to get
  53   // the real debuggee-compartment global object.
  54   JS::Rooted<JSObject*> debuggeeGlobalRooted(
  55       aCx, js::UncheckedUnwrap(aDebuggeeGlobal, false));
  56
  57   if (!debuggeeGlobalRooted) {
  58     return nullptr;
  59   }
  60
  61   nsCOMPtr<nsIGlobalObject> debuggeeGlobalObject(
  62       xpc::NativeGlobal(debuggeeGlobalRooted));
  63   if (!debuggeeGlobalObject) {
  64     return nullptr;
  65   }
  66
  67   RefPtr<DebuggerNotificationManager> manager(
  68       debuggeeGlobalObject->GetOrCreateDebuggerNotificationManager());
  69   return manager.forget();
  70 }
  71
  72 bool DebuggerNotificationObserver::Connect(
  73     JSContext* aCx, JS::Handle<JSObject*> aDebuggeeGlobal, ErrorResult& aRv) {
  74   RefPtr<DebuggerNotificationManager> manager(GetManager(aCx, aDebuggeeGlobal));
  75
  76   if (!manager) {
  77     aRv.Throw(NS_ERROR_FAILURE);
  78     return false;
  79   }
  80
  81   return manager->Attach(this);
  82 }
  83
  84 bool DebuggerNotificationObserver::Disconnect(
  85     JSContext* aCx, JS::Handle<JSObject*> aDebuggeeGlobal, ErrorResult& aRv) {
  86   RefPtr<DebuggerNotificationManager> manager(GetManager(aCx, aDebuggeeGlobal));
  87
  88   if (!manager) {
  89     aRv.Throw(NS_ERROR_FAILURE);
  90     return false;
  91   }
  92
  93   return manager->Detach(this);
  94 }
  95
  96 bool DebuggerNotificationObserver::AddListener(
  97     DebuggerNotificationCallback& aHandlerFn) {
  98   const auto [begin, end] = mEventListenerCallbacks.NonObservingRange();
  99   if (std::any_of(begin, end,
 100                   [&](const RefPtr<DebuggerNotificationCallback>& callback) {
 101                     return *callback == aHandlerFn;
 102                   })) {
 103     return false;
 104   }
 105
 106   RefPtr<DebuggerNotificationCallback> handlerFn(&aHandlerFn);
 107   mEventListenerCallbacks.AppendElement(handlerFn);
 108   return true;
 109 }
 110
 111 bool DebuggerNotificationObserver::RemoveListener(
 112     DebuggerNotificationCallback& aHandlerFn) {
 113   for (nsTObserverArray<RefPtr<DebuggerNotificationCallback>>::ForwardIterator
 114            iter(mEventListenerCallbacks);
 115        iter.HasMore();) {
 116     if (*iter.GetNext().get() == aHandlerFn) {
 117       iter.Remove();
 118       return true;
 119     }
 120   }
 121
 122   return false;
 123 }
 124
 125 bool DebuggerNotificationObserver::HasListeners() {
 126   return !mEventListenerCallbacks.IsEmpty();
 127 }
 128
 129 void DebuggerNotificationObserver::NotifyListeners(
 130     DebuggerNotification* aNotification) {
 131   if (!HasListeners()) {
 132     return;
 133   }
 134
 135   // Since we want the notification objects to live in the same compartment
 136   // as the observer, we create a new instance of the notification before
 137   // an observer dispatches the event listeners.
 138   RefPtr<DebuggerNotification> debuggerNotification(
 139       aNotification->CloneInto(mOwnerGlobal));
 140
 141   for (RefPtr<DebuggerNotificationCallback> callback :
 142        mEventListenerCallbacks.ForwardRange()) {
 143     callback->Call(*debuggerNotification);
 144   }
 145 }
 146
 147 }  // namespace mozilla::dom