components/sessions/core/tab_restore_service_client.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_SESSIONS_CORE_TAB_RESTORE_SERVICE_CLIENT_H_
   6 #define COMPONENTS_SESSIONS_CORE_TAB_RESTORE_SERVICE_CLIENT_H_
   7
   8 #include "base/callback.h"
   9 #include "base/memory/scoped_vector.h"
  10 #include "components/sessions/session_id.h"
  11
  12 namespace base {
  13 class CancelableTaskTracker;
  14 }
  15
  16 namespace sessions {
  17 struct SessionWindow;
  18 }
  19
  20 namespace sessions {
  21
  22 struct SessionWindow;
  23
  24 // Callback from TabRestoreServiceClient::GetLastSession.
  25 // The second parameter is the id of the window that was last active.
  26 typedef base::Callback<void(ScopedVector<SessionWindow>, SessionID::id_type)>
  27     GetLastSessionCallback;
  28
  29 // A client interface that needs to be supplied to the tab restore service by
  30 // the embedder.
  31 class TabRestoreServiceClient {
  32  public:
  33   virtual ~TabRestoreServiceClient() {}
  34
  35   // Returns whether there is a previous session to load.
  36   virtual bool HasLastSession() = 0;
  37
  38   // Fetches the contents of the last session, notifying the callback when
  39   // done. If the callback is supplied an empty vector of SessionWindows
  40   // it means the session could not be restored.
  41   virtual void GetLastSession(const GetLastSessionCallback& callback,
  42                               base::CancelableTaskTracker* tracker) = 0;
  43 };
  44
  45 }  // namespace sessions
  46
  47 #endif  // COMPONENTS_SESSIONS_CORE_TAB_RESTORE_SERVICE_CLIENT_H_