1 files changed, 147 insertions, 0 deletions
diff --git a/dom/debugger/DebuggerNotificationObserver.cpp b/dom/debugger/DebuggerNotificationObserver.cpp
new file mode 100644
index 0000000000..b821003070
--- /dev/null
+++ b/dom/debugger/DebuggerNotificationObserver.cpp
@@ -0,0 +1,147 @@
+/* -*- 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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "DebuggerNotificationObserver.h"
+
+#include "DebuggerNotification.h"
+#include "nsIGlobalObject.h"
+#include "WrapperFactory.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(DebuggerNotificationObserver,
+                                      mOwnerGlobal, mEventListenerCallbacks)
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(DebuggerNotificationObserver)
+NS_IMPL_CYCLE_COLLECTING_RELEASE(DebuggerNotificationObserver)
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(DebuggerNotificationObserver)
+  NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
+NS_INTERFACE_MAP_END
+
+/* static */ already_AddRefed<DebuggerNotificationObserver>
+DebuggerNotificationObserver::Constructor(GlobalObject& aGlobal,
+                                          ErrorResult& aRv) {
+  nsCOMPtr<nsIGlobalObject> globalInterface(
+      do_QueryInterface(aGlobal.GetAsSupports()));
+  if (NS_WARN_IF(!globalInterface)) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+
+  RefPtr<DebuggerNotificationObserver> observer(
+      new DebuggerNotificationObserver(globalInterface));
+  return observer.forget();
+}
+
+DebuggerNotificationObserver::DebuggerNotificationObserver(
+    nsIGlobalObject* aOwnerGlobal)
+    : mEventListenerCallbacks(), mOwnerGlobal(aOwnerGlobal) {}
+
+JSObject* DebuggerNotificationObserver::WrapObject(
+    JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
+  return DebuggerNotificationObserver_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+static already_AddRefed<DebuggerNotificationManager> GetManager(
+    JSContext* aCx, JS::Handle<JSObject*> aDebuggeeGlobal) {
+  // The debuggee global here is likely a debugger-compartment cross-compartment
+  // wrapper for the debuggee global object, so we need to unwrap it to get
+  // the real debuggee-compartment global object.
+  JS::Rooted<JSObject*> debuggeeGlobalRooted(
+      aCx, js::UncheckedUnwrap(aDebuggeeGlobal, false));
+
+  if (!debuggeeGlobalRooted) {
+    return nullptr;
+  }
+
+  nsCOMPtr<nsIGlobalObject> debuggeeGlobalObject(
+      xpc::NativeGlobal(debuggeeGlobalRooted));
+  if (!debuggeeGlobalObject) {
+    return nullptr;
+  }
+
+  RefPtr<DebuggerNotificationManager> manager(
+      debuggeeGlobalObject->GetOrCreateDebuggerNotificationManager());
+  return manager.forget();
+}
+
+bool DebuggerNotificationObserver::Connect(
+    JSContext* aCx, JS::Handle<JSObject*> aDebuggeeGlobal, ErrorResult& aRv) {
+  RefPtr<DebuggerNotificationManager> manager(GetManager(aCx, aDebuggeeGlobal));
+
+  if (!manager) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return false;
+  }
+
+  return manager->Attach(this);
+}
+
+bool DebuggerNotificationObserver::Disconnect(
+    JSContext* aCx, JS::Handle<JSObject*> aDebuggeeGlobal, ErrorResult& aRv) {
+  RefPtr<DebuggerNotificationManager> manager(GetManager(aCx, aDebuggeeGlobal));
+
+  if (!manager) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return false;
+  }
+
+  return manager->Detach(this);
+}
+
+bool DebuggerNotificationObserver::AddListener(
+    DebuggerNotificationCallback& aHandlerFn) {
+  const auto [begin, end] = mEventListenerCallbacks.NonObservingRange();
+  if (std::any_of(begin, end,
+                  [&](const RefPtr<DebuggerNotificationCallback>& callback) {
+                    return *callback == aHandlerFn;
+                  })) {
+    return false;
+  }
+
+  RefPtr<DebuggerNotificationCallback> handlerFn(&aHandlerFn);
+  mEventListenerCallbacks.AppendElement(handlerFn);
+  return true;
+}
+
+bool DebuggerNotificationObserver::RemoveListener(
+    DebuggerNotificationCallback& aHandlerFn) {
+  for (nsTObserverArray<RefPtr<DebuggerNotificationCallback>>::ForwardIterator
+           iter(mEventListenerCallbacks);
+       iter.HasMore();) {
+    if (*iter.GetNext().get() == aHandlerFn) {
+      iter.Remove();
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool DebuggerNotificationObserver::HasListeners() {
+  return !mEventListenerCallbacks.IsEmpty();
+}
+
+void DebuggerNotificationObserver::NotifyListeners(
+    DebuggerNotification* aNotification) {
+  if (!HasListeners()) {
+    return;
+  }
+
+  // Since we want the notification objects to live in the same compartment
+  // as the observer, we create a new instance of the notification before
+  // an observer dispatches the event listeners.
+  RefPtr<DebuggerNotification> debuggerNotification(
+      aNotification->CloneInto(mOwnerGlobal));
+
+  for (RefPtr<DebuggerNotificationCallback> callback :
+       mEventListenerCallbacks.ForwardRange()) {
+    callback->Call(*debuggerNotification);
+  }
+}
+
+}  // namespace mozilla::dom