1 files changed, 112 insertions, 0 deletions
diff --git a/toolkit/components/sessionstore/RestoreTabContentObserver.cpp b/toolkit/components/sessionstore/RestoreTabContentObserver.cpp
new file mode 100644
index 0000000000..b0dda66ff0
--- /dev/null
+++ b/toolkit/components/sessionstore/RestoreTabContentObserver.cpp
@@ -0,0 +1,112 @@
+/* -*- 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 "mozilla/dom/BrowsingContext.h"
+#include "mozilla/dom/CanonicalBrowsingContext.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/WindowGlobalChild.h"
+#include "mozilla/dom/WindowGlobalParent.h"
+#include "mozilla/Services.h"
+#include "nsIObserverService.h"
+#include "nsIURI.h"
+#include "nsNetUtil.h"
+#include "nsPIDOMWindow.h"
+#include "nsReadableUtils.h"
+#include "nsThreadUtils.h"
+#include "RestoreTabContentObserver.h"
+
+using namespace mozilla::dom;
+
+NS_IMPL_ISUPPORTS(RestoreTabContentObserver, nsIObserver)
+
+const char* const kAboutReaderTopic = "AboutReader:Ready";
+const char* const kContentDocumentLoaded = "content-document-loaded";
+const char* const kChromeDocumentLoaded = "chrome-document-loaded";
+
+/* static */
+void RestoreTabContentObserver::Initialize() {
+  MOZ_ASSERT(!gRestoreTabContentObserver);
+  MOZ_ASSERT(NS_IsMainThread());
+
+  RefPtr<RestoreTabContentObserver> observer = new RestoreTabContentObserver();
+
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (NS_WARN_IF(!obs)) {
+    return;
+  }
+
+  obs->AddObserver(observer, kAboutReaderTopic, false);
+  obs->AddObserver(observer, kContentDocumentLoaded, false);
+  obs->AddObserver(observer, kChromeDocumentLoaded, false);
+
+  gRestoreTabContentObserver = observer;
+}
+
+/* static */
+void RestoreTabContentObserver::Shutdown() {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  if (!gRestoreTabContentObserver) {
+    return;
+  }
+
+  RefPtr<RestoreTabContentObserver> observer = gRestoreTabContentObserver;
+  gRestoreTabContentObserver = nullptr;
+
+  nsCOMPtr<nsIObserverService> obs = mozilla::services::GetObserverService();
+  if (!obs) {
+    return;
+  }
+
+  obs->RemoveObserver(observer, kAboutReaderTopic);
+  obs->RemoveObserver(observer, kContentDocumentLoaded);
+  obs->RemoveObserver(observer, kChromeDocumentLoaded);
+}
+
+NS_IMETHODIMP
+RestoreTabContentObserver::Observe(nsISupports* aSubject, const char* aTopic,
+                                   const char16_t* aData) {
+  nsCOMPtr<nsPIDOMWindowInner> inner;
+  if (!strcmp(aTopic, kAboutReaderTopic)) {
+    inner = do_QueryInterface(aSubject);
+  } else if (!strcmp(aTopic, kContentDocumentLoaded) ||
+             !strcmp(aTopic, kChromeDocumentLoaded)) {
+    nsCOMPtr<Document> doc = do_QueryInterface(aSubject);
+    inner = doc ? doc->GetInnerWindow() : nullptr;
+  }
+  if (!inner) {
+    return NS_OK;
+  }
+
+  nsCOMPtr<nsIURI> uri = inner->GetDocumentURI();
+  if (!uri) {
+    return NS_OK;
+  }
+
+  // We'll handle loading about:reader with "AboutReader:Ready"
+  // rather than "content-document-loaded".
+  if (uri->SchemeIs("about") &&
+      StringBeginsWith(uri->GetSpecOrDefault(), "about:reader"_ns) &&
+      strcmp(aTopic, kAboutReaderTopic) != 0) {
+    return NS_OK;
+  }
+
+  RefPtr<BrowsingContext> bc = inner->GetBrowsingContext();
+  if (!bc || !bc->Top()->GetHasRestoreData()) {
+    return NS_OK;
+  }
+  if (XRE_IsParentProcess()) {
+    if (WindowGlobalParent* wgp = bc->Canonical()->GetCurrentWindowGlobal()) {
+      bc->Canonical()->Top()->RequestRestoreTabContent(wgp);
+    }
+  } else if (WindowContext* windowContext = bc->GetCurrentWindowContext()) {
+    if (WindowGlobalChild* wgc = windowContext->GetWindowGlobalChild()) {
+      wgc->SendRequestRestoreTabContent();
+    }
+  }
+  return NS_OK;
+}
+
+mozilla::StaticRefPtr<RestoreTabContentObserver>
+    RestoreTabContentObserver::gRestoreTabContentObserver;