chrome/browser/sessions/session_tab_helper.h

   1 // Copyright (c) 2011 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 CHROME_BROWSER_SESSIONS_SESSION_TAB_HELPER_H_
   6 #define CHROME_BROWSER_SESSIONS_SESSION_TAB_HELPER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "components/sessions/session_id.h"
  10 #include "content/public/browser/web_contents_observer.h"
  11 #include "content/public/browser/web_contents_user_data.h"
  12
  13 // This class keeps the extension API's windowID up-to-date with the current
  14 // window of the tab.
  15 class SessionTabHelper : public content::WebContentsObserver,
  16                          public content::WebContentsUserData<SessionTabHelper> {
  17  public:
  18   ~SessionTabHelper() override;
  19
  20   // Returns the identifier used by session restore for this tab.
  21   const SessionID& session_id() const { return session_id_; }
  22
  23   // Identifier of the window the tab is in.
  24   void SetWindowID(const SessionID& id);
  25   const SessionID& window_id() const { return window_id_; }
  26
  27   // If the specified WebContents has a SessionTabHelper (probably because it
  28   // was used as the contents of a tab), returns a tab id. This value is
  29   // immutable for a given tab. It will be unique across Chrome within the
  30   // current session, but may be re-used across sessions. Returns -1
  31   // for a NULL WebContents or if the WebContents has no SessionTabHelper.
  32   static SessionID::id_type IdForTab(const content::WebContents* tab);
  33
  34   // If the specified WebContents has a SessionTabHelper (probably because it
  35   // was used as the contents of a tab), and has ever been attached to a Browser
  36   // window, returns Browser::session_id().id() for that Browser. If the tab is
  37   // being dragged between Browser windows, returns the old window's id value.
  38   // If the WebContents has a SessionTabHelper but has never been attached to a
  39   // Browser window, returns an id value that is different from that of any
  40   // Browser. Returns -1 for a NULL WebContents or if the WebContents has no
  41   // SessionTabHelper.
  42   static SessionID::id_type IdForWindowContainingTab(
  43       const content::WebContents* tab);
  44
  45   // content::WebContentsObserver:
  46   void UserAgentOverrideSet(const std::string& user_agent) override;
  47
  48  private:
  49   explicit SessionTabHelper(content::WebContents* contents);
  50   friend class content::WebContentsUserData<SessionTabHelper>;
  51
  52   // Unique identifier of the tab for session restore. This id is only unique
  53   // within the current session, and is not guaranteed to be unique across
  54   // sessions.
  55   const SessionID session_id_;
  56
  57   // Unique identifier of the window the tab is in.
  58   SessionID window_id_;
  59
  60   DISALLOW_COPY_AND_ASSIGN(SessionTabHelper);
  61 };
  62
  63 #endif  // CHROME_BROWSER_SESSIONS_SESSION_TAB_HELPER_H_