Fire a notification in Windows 8 metro chrome which informs the user about a completed download. Th…

chrome/browser/download/download_completion_observer_win.cc

+// Copyright (c) 2012 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 "chrome/browser/download/download_completion_observer_win.h"
+
+#include <string>
+
+#include "base/logging.h"
+#include "base/string_number_conversions.h"
+#include "base/win/metro.h"
+#include "googleurl/src/gurl.h"
+#include "grit/generated_resources.h"
+#include "ui/base/l10n/l10n_util.h"
+
+using content::DownloadItem;
+using content::DownloadManager;
+
+static const char kDownloadNotificationPrefix[] = "DownloadNotification";
+int g_next_notification_id = 0;
+
+void DownloadCompletionObserver::Initialize(DownloadManager* manager) {
+  manager->AddObserver(this);
+}
+
+void DownloadCompletionObserver::OnDownloadCreated(DownloadManager* manager,
+                                                   DownloadItem* item) {
+  if (item->IsInProgress())
+    item->AddObserver(this);
+}
+
+void DownloadCompletionObserver::ManagerGoingDown(DownloadManager* manager) {
+  manager->RemoveObserver(this);

[asanka, 2012/08/07 19:05:15]

There are some lifetime issues here. Notably, it would be great if we can delete
|this| when we get the ManagerGoingDown() notification. Unfortunately,
ManagerGoingDown() is received prior to OnDownloadUpdate() notifications from
any active downloads that are being torn down as a result of the download
manager going down.

So for proper cleanup, you might have to keep a list of DownloadItems that are
being observed and call RemoveObserver() on them during ManagerGoingDown(). Then
you can properly dispose of |this| here.

[ananta, 2012/08/07 21:40:31]

Done. Maintained the list of items in a set.

+}
+
+void DownloadCompletionObserver::OnDownloadUpdated(DownloadItem* download) {
+  if (!base::win::IsMetroProcess())
+    return;
+
+  switch (download->GetState()) {
+    case DownloadItem::COMPLETE: {
+      if (!download->GetOpenWhenComplete() &&
+          !download->ShouldOpenFileBasedOnExtension() &&
+          !download->IsTemporary() &&
+          !download->GetAutoOpened()) {
+        // In Windows 8 metro mode display a metro style notification which
+        // informs the user that the download is complete.
+        HMODULE metro = base::win::GetMetroModule();
+        base::win::MetroNotification display_notification =
+            reinterpret_cast< base::win::MetroNotification>(
+                ::GetProcAddress(metro, "DisplayNotification"));
+        DCHECK(display_notification);
+        if (display_notification) {
+          string16 title = l10n_util::GetStringUTF16(
+              IDS_METRO_DOWNLOAD_COMPLETE_NOTIFICATION_TITLE);
+          string16 body = l10n_util::GetStringUTF16(
+              IDS_METRO_DOWNLOAD_COMPLETE_NOTIFICATION);
+
+          // Dummy notification id. Every metro style notification needs a
+          // unique notification id.
+          std::string notification_id = kDownloadNotificationPrefix;
+          notification_id += base::IntToString(g_next_notification_id++);
+
+          display_notification(download->GetURL().spec().c_str(),
+                                "",

[asanka, 2012/08/07 19:05:15]

Nit: Indent

[ananta, 2012/08/07 21:40:31]

Done.

+                                title.c_str(),
+                                body.c_str(),
+                                L"",
+                                notification_id.c_str());
+        }
+      }
+      download->RemoveObserver(this);
+      break;
+    }
+
+    case DownloadItem::REMOVING:
+    case DownloadItem::INTERRUPTED:
+    case DownloadItem::CANCELLED: {
+      download->RemoveObserver(this);
+      break;
+    }
+
+    default:
+      break;
+  }
+}