[Offline pages] Enabling notifications for pages saved later

components/offline_pages/downloads/download_notifying_observer.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/offline_pages/downloads/download_notifying_observer.h"
+
+#include "components/offline_pages/background/request_coordinator.h"
+#include "components/offline_pages/background/save_page_request.h"
+#include "components/offline_pages/downloads/offline_page_download_notifier.h"
+
+namespace offline_pages {
+namespace {
+int kUserDataKey;  // Only address is used.
+}  // namespace
+
+DownloadNotifyingObserver::DownloadNotifyingObserver(
+    std::unique_ptr<OfflinePageDownloadNotifier> notifier)
+    : notifier_(std::move(notifier)) {}
+
+DownloadNotifyingObserver::~DownloadNotifyingObserver() {}
+
+// static
+DownloadNotifyingObserver* DownloadNotifyingObserver::GetFromRequestCoordinator(
+    RequestCoordinator* request_coordinator) {
+  DCHECK(request_coordinator);
+  return static_cast<DownloadNotifyingObserver*>(
+      request_coordinator->GetUserData(&kUserDataKey));
+}
+
+// static
+void DownloadNotifyingObserver::CreateAndStartObserving(
+    RequestCoordinator* request_coordinator,
+    std::unique_ptr<OfflinePageDownloadNotifier> notifier) {
+  DCHECK(request_coordinator);
+  DCHECK(notifier.get());
+  DownloadNotifyingObserver* observer =
+      new DownloadNotifyingObserver(std::move(notifier));
+  request_coordinator->AddObserver(observer);
+  // |request_coordinator| takes ownership of observer here.
+  request_coordinator->SetUserData(&kUserDataKey, observer);
+}
+
+void DownloadNotifyingObserver::OnAdded(const SavePageRequest& request) {
+  DCHECK(notifier_.get());
+  notifier_->NotifyDownloadProgress(DownloadUIItem(request));
+}
+
+void DownloadNotifyingObserver::OnChanged(const SavePageRequest& request) {
+  DCHECK(notifier_.get());
+  if (request.request_state() == SavePageRequest::RequestState::PAUSED)
+    notifier_->NotifyDownloadPaused(DownloadUIItem(request));
+  else
+    notifier_->NotifyDownloadProgress(DownloadUIItem(request));
+}
+
+void DownloadNotifyingObserver::OnCompleted(
+    const SavePageRequest& request,
+    RequestCoordinator::SavePageStatus status) {
+  DCHECK(notifier_.get());
+  if (status == RequestCoordinator::SavePageStatus::SUCCESS)
+    notifier_->NotifyDownloadSuccessful(DownloadUIItem(request));
+  else if (status == RequestCoordinator::SavePageStatus::REMOVED)
+    notifier_->NotifyDownloadCanceled(DownloadUIItem(request));
+  else
+    notifier_->NotifyDownloadFailed(DownloadUIItem(request));
+}
+}  // namespace offline_pages