Show offline interstitial page when offline and reload when reconnected to network.

chrome/browser/chromeos/offline/offline_load_service.cc

+// Copyright (c) 2010 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/chromeos/offline/offline_load_service.h"
+
+#include "base/singleton.h"
+#include "base/ref_counted.h"
+#include "chrome/common/notification_service.h"
+#include "chrome/browser/chrome_thread.h"
+#include "chrome/browser/tab_contents/tab_contents.h"
+#include "chrome/browser/tab_contents/tab_util.h"
+#include "chrome/browser/tab_contents/navigation_controller.h"
+
+namespace chromeos {
+
+// A utility class that serves a singleton instance of OfflineLoadService.
+// OfflineLoadSerivce itself cannot be a singleton as it implements
+// RefCount interface.
+class OfflineLoadServiceSingleton {
+ public:
+  chromeos::OfflineLoadService* offline_load_service() {
+    return offline_load_service_.get();
+  }
+
+ private:
+  friend struct DefaultSingletonTraits<OfflineLoadServiceSingleton>;
+  OfflineLoadServiceSingleton()
+      : offline_load_service_(new chromeos::OfflineLoadService()) {}
+  virtual ~OfflineLoadServiceSingleton() {}
+
+  scoped_refptr<chromeos::OfflineLoadService> offline_load_service_;
+
+  DISALLOW_COPY_AND_ASSIGN(OfflineLoadServiceSingleton);
+};
+
+// static
+OfflineLoadService* OfflineLoadService::Get() {
+  return Singleton<OfflineLoadServiceSingleton>::get()->offline_load_service();
+}
+
+void OfflineLoadService::Observe(NotificationType type,
+                                 const NotificationSource& source,
+                                 const NotificationDetails& details) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
+  if (type.value == NotificationType::TAB_CLOSED) {
+    registrar_.Remove(this, NotificationType::TAB_CLOSED, source);
+    NavigationController* tab = Source<NavigationController>(source).ptr();
+    ChromeThread::PostTask(
+        ChromeThread::IO, FROM_HERE,
+        NewRunnableMethod(this,
+                          &OfflineLoadService::RemoveTabContents,
+                          tab->tab_contents()));
+  }
+}
+
+bool OfflineLoadService::ShouldProceed(int process_host_id,
+                                       int render_view_id,
+                                       const GURL& url) const {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
+  TabContents* tab_contents = tab_util::GetTabContentsByID(
+      process_host_id, render_view_id);
+  DCHECK(tab_contents);
+  bool proceed = tabs_.find(tab_contents) != tabs_.end();
+  DLOG(INFO) << "ShouldProceed:" << proceed << ", url=" << url.spec()
+             << ", tab_contents=" << tab_contents;
+  return proceed;
+}
+
+void OfflineLoadService::Proceeded(int process_host_id,
+                                   int render_view_id,
+                                   const GURL& url) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
+  TabContents* tab_contents = tab_util::GetTabContentsByID(
+      process_host_id, render_view_id);
+  DCHECK(tab_contents);
+  if (tabs_.find(tab_contents) == tabs_.end()) {
+    DLOG(INFO) << "Proceeded: url=" << url.spec()
+               << ", tab_contents=" << tab_contents;
+    tabs_.insert(tab_contents);
+    ChromeThread::PostTask(
+        ChromeThread::UI, FROM_HERE,
+        NewRunnableMethod(this,
+                          &OfflineLoadService::RegisterNotification,
+                          &tab_contents->controller()));
+  } else {
+    DLOG(WARNING) << "Proceeded: ignoring duplicate";
+  }
+}
+
+void OfflineLoadService::RemoveTabContents(TabContents* tab_contents) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
+  tabs_.erase(tabs_.find(tab_contents));
+}
+
+void OfflineLoadService::RegisterNotification(
+    NavigationController* navigation_controller) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
+  registrar_.Add(this, NotificationType::TAB_CLOSED,
+                   Source<NavigationController>(
+                       navigation_controller));
+}
+
+}  // namespace chromeos