diff --git a/src/controller.hpp b/src/controller.hpp
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+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/*
+ * Copyright (c) 2013, Regents of the University of California
+ *                     Yingdi Yu
+ *
+ * BSD license, See the LICENSE file for more information
+ *
+ * Author: Yingdi Yu <yingdi@cs.ucla.edu>
+ */
+
+#ifndef CHRONOS_CONTROLLER_HPP
+#define CHRONOS_CONTROLLER_HPP
+
+#include <QDialog>
+#include <QMenu>
+#include <QSystemTrayIcon>
+#include <QtSql/QSqlDatabase>
+
+#include "setting-dialog.hpp"
+#include "start-chat-dialog.hpp"
+#include "profile-editor.hpp"
+#include "invitation-dialog.hpp"
+#include "contact-panel.hpp"
+#include "browse-contact-dialog.hpp"
+#include "add-contact-panel.hpp"
+#include "chat-dialog.hpp"
+
+#ifndef Q_MOC_RUN
+#include "common.hpp"
+#include "contact-manager.hpp"
+#include "validator-invitation.hpp"
+#include <ndn-cxx/security/key-chain.hpp>
+#endif
+
+namespace chronos {
+
+class Controller : public QDialog
+{
+  Q_OBJECT
+
+public: // public methods
+  Controller(shared_ptr<ndn::Face> face, QWidget* parent = 0);
+
+  virtual
+  ~Controller();
+
+private: // private methods
+  std::string
+  getDBName();
+
+  void
+  openDB();
+
+  void
+  initialize();
+
+  void
+  setInvitationListener();
+
+  void
+  loadConf();
+
+  void
+  saveConf();
+
+  void
+  createActions();
+
+  void
+  createTrayIcon();
+
+  void
+  updateMenu();
+
+  void
+  onLocalPrefix(const Interest& interest, Data& data);
+
+  void
+  onLocalPrefixTimeout(const Interest& interest);
+
+  void
+  onInvitationInterestWrapper(const Name& prefix, const Interest& interest,
+                              size_t routingPrefixOffset);
+
+  void
+  onInvitationRegisterFailed(const Name& prefix, const std::string& failInfo);
+
+  void
+  onInvitationValidated(const shared_ptr<const Interest>& interest);
+
+  void
+  onInvitationValidationFailed(const shared_ptr<const Interest>& interest,
+                               std::string failureInfo);
+
+  std::string
+  getRandomString();
+
+  ndn::Name
+  getInvitationRoutingPrefix();
+
+  void
+  addChatDialog(const QString& chatroomName, ChatDialog* chatDialog);
+
+signals:
+  void
+  closeDBModule();
+
+  void
+  localPrefixUpdated(const QString& localPrefix);
+
+  void
+  identityUpdated(const QString& identity);
+
+  void
+  refreshBrowseContact();
+
+  void
+  invitationInterest(const Name& prefix, const Interest& interest, size_t routingPrefixOffset);
+
+private slots:
+  void
+  onIdentityUpdated(const QString& identity);
+
+  void
+  onIdentityUpdatedContinued();
+
+  void
+  onContactIdListReady(const QStringList& list);
+
+  void
+  onNickUpdated(const QString& nick);
+
+  void
+  onLocalPrefixUpdated(const QString& localPrefix);
+
+  void
+  onStartChatAction();
+
+  void
+  onSettingsAction();
+
+  void
+  onProfileEditorAction();
+
+  void
+  onAddContactAction();
+
+  void
+  onContactListAction();
+
+  void
+  onDirectAdd();
+
+  void
+  onUpdateLocalPrefixAction();
+
+  void
+  onMinimizeAction();
+
+  void
+  onQuitAction();
+
+  void
+  onStartChatroom(const QString& chatroom, bool secured);
+
+  void
+  onInvitationResponded(const Name& invitationName, bool accepted);
+
+  void
+  onShowChatMessage(const QString& chatroomName, const QString& from, const QString& data);
+
+  void
+  onResetIcon();
+
+  void
+  onRemoveChatDialog(const QString& chatroom);
+
+  void
+  onWarning(const QString& msg);
+
+  void
+  onError(const QString& msg);
+
+  void
+  onInvitationInterest(const Name& prefix, const Interest& interest, size_t routingPrefixOffset);
+
+private: // private member
+  typedef std::map<std::string, QAction*> ChatActionList;
+  typedef std::map<std::string, ChatDialog*> ChatDialogList;
+
+  // Communication
+  shared_ptr<ndn::Face> m_face;
+  Name m_localPrefix;
+  const ndn::RegisteredPrefixId* m_invitationListenerId;
+
+  // Contact Manager
+  ContactManager m_contactManager;
+
+  // Tray
+  QAction*         m_startChatroom;
+  QAction*         m_minimizeAction;
+  QAction*         m_settingsAction;
+  QAction*         m_editProfileAction;
+  QAction*         m_contactListAction;
+  QAction*         m_addContactAction;
+  QAction*         m_updateLocalPrefixAction;
+  QAction*         m_quitAction;
+  QMenu*           m_trayIconMenu;
+  QMenu*           m_closeMenu;
+  QSystemTrayIcon* m_trayIcon;
+  ChatActionList   m_chatActionList;
+  ChatActionList   m_closeActionList;
+
+  // Dialogs
+  SettingDialog*       m_settingDialog;
+  StartChatDialog*     m_startChatDialog;
+  ProfileEditor*       m_profileEditor;
+  InvitationDialog*    m_invitationDialog;
+  ContactPanel*        m_contactPanel;
+  BrowseContactDialog* m_browseContactDialog;
+  AddContactPanel*     m_addContactPanel;
+  ChatDialogList       m_chatDialogList;
+
+  // Conf
+  Name m_identity;
+  std::string m_nick;
+  QSqlDatabase m_db;
+
+  // Security related;
+  ndn::KeyChain m_keyChain;
+  ValidatorInvitation m_validator;
+};
+
+} // namespace chronos
+
+#endif //CHRONOS_CONTROLLER_HPP