chrome/browser/sessions/tab_restore_service_helper.h

   1 // Copyright 2012 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_TAB_RESTORE_SERVICE_HELPER_H_
   6 #define CHROME_BROWSER_SESSIONS_TAB_RESTORE_SERVICE_HELPER_H_
   7
   8 #include <set>
   9 #include <vector>
  10
  11 #include "base/basictypes.h"
  12 #include "base/observer_list.h"
  13 #include "base/time/time.h"
  14 #include "chrome/browser/sessions/tab_restore_service.h"
  15 #include "chrome/browser/ui/host_desktop.h"
  16 #include "components/sessions/session_id.h"
  17 #include "components/sessions/session_types.h"
  18
  19 class Profile;
  20 class TabRestoreService;
  21 class TabRestoreServiceDelegate;
  22 class TabRestoreServiceObserver;
  23 class TimeFactory;
  24
  25 namespace content {
  26 class NavigationController;
  27 class WebContents;
  28 }
  29
  30 // Helper class used to implement InMemoryTabRestoreService and
  31 // PersistentTabRestoreService. See tab_restore_service.h for method-level
  32 // comments.
  33 class TabRestoreServiceHelper {
  34  public:
  35   typedef TabRestoreService::Entries Entries;
  36   typedef TabRestoreService::Entry Entry;
  37   typedef TabRestoreService::Tab Tab;
  38   typedef TabRestoreService::TimeFactory TimeFactory;
  39   typedef TabRestoreService::Window Window;
  40
  41   // Provides a way for the client to add behavior to the tab restore service
  42   // helper (e.g. implementing tabs persistence).
  43   class Observer {
  44    public:
  45     // Invoked before the entries are cleared.
  46     virtual void OnClearEntries();
  47
  48     // Invoked before the entry is restored. |entry_iterator| points to the
  49     // entry corresponding to the session identified by |id|.
  50     virtual void OnRestoreEntryById(SessionID::id_type id,
  51                                     Entries::const_iterator entry_iterator);
  52
  53     // Invoked after an entry was added.
  54     virtual void OnAddEntry();
  55
  56    protected:
  57     virtual ~Observer();
  58   };
  59
  60   enum {
  61     // Max number of entries we'll keep around.
  62     kMaxEntries = 25,
  63   };
  64
  65   // Creates a new TabRestoreServiceHelper and provides an object that provides
  66   // the current time. The TabRestoreServiceHelper does not take ownership of
  67   // |time_factory| and |observer|. Note that |observer| can also be NULL.
  68   TabRestoreServiceHelper(TabRestoreService* tab_restore_service,
  69                           Observer* observer,
  70                           Profile* profile,
  71                           TimeFactory* time_factory);
  72
  73   ~TabRestoreServiceHelper();
  74
  75   // Helper methods used to implement TabRestoreService.
  76   void AddObserver(TabRestoreServiceObserver* observer);
  77   void RemoveObserver(TabRestoreServiceObserver* observer);
  78   void CreateHistoricalTab(content::WebContents* contents, int index);
  79   void BrowserClosing(TabRestoreServiceDelegate* delegate);
  80   void BrowserClosed(TabRestoreServiceDelegate* delegate);
  81   void ClearEntries();
  82   const Entries& entries() const;
  83   std::vector<content::WebContents*> RestoreMostRecentEntry(
  84       TabRestoreServiceDelegate* delegate,
  85       chrome::HostDesktopType host_desktop_type);
  86   Tab* RemoveTabEntryById(SessionID::id_type id);
  87   std::vector<content::WebContents*> RestoreEntryById(
  88       TabRestoreServiceDelegate* delegate,
  89       SessionID::id_type id,
  90       chrome::HostDesktopType host_desktop_type,
  91       WindowOpenDisposition disposition);
  92
  93   // Notifies observers the tabs have changed.
  94   void NotifyTabsChanged();
  95
  96   // Notifies observers the service has loaded.
  97   void NotifyLoaded();
  98
  99   // Adds |entry| to the list of entries and takes ownership. If |prune| is true
 100   // |PruneAndNotify| is invoked. If |to_front| is true the entry is added to
 101   // the front, otherwise the back. Normal closes go to the front, but
 102   // tab/window closes from the previous session are added to the back.
 103   void AddEntry(Entry* entry, bool prune, bool to_front);
 104
 105   // Prunes |entries_| to contain only kMaxEntries, and removes uninteresting
 106   // entries.
 107   void PruneEntries();
 108
 109   // Returns an iterator into |entries_| whose id matches |id|. If |id|
 110   // identifies a Window, then its iterator position will be returned. If it
 111   // identifies a tab, then the iterator position of the Window in which the Tab
 112   // resides is returned.
 113   Entries::iterator GetEntryIteratorById(SessionID::id_type id);
 114
 115   // Calls either ValidateTab or ValidateWindow as appropriate.
 116   static bool ValidateEntry(Entry* entry);
 117
 118  private:
 119   friend class PersistentTabRestoreService;
 120
 121   // Populates the tab's navigations from the NavigationController, and its
 122   // browser_id and pinned state from the browser.
 123   void PopulateTab(Tab* tab,
 124                    int index,
 125                    TabRestoreServiceDelegate* delegate,
 126                    content::NavigationController* controller);
 127
 128   // This is a helper function for RestoreEntryById() for restoring a single
 129   // tab. If |delegate| is NULL, this creates a new window for the entry. This
 130   // returns the TabRestoreServiceDelegate into which the tab was restored.
 131   // |disposition| will be respected, but if it is UNKNOWN then the tab's
 132   // original attributes will be respected instead. If a new browser needs to be
 133   // created for this tab, it will be created on the desktop specified by
 134   // |host_desktop_type|. If present, |contents| will be populated with the
 135   // WebContents of the restored tab.
 136   TabRestoreServiceDelegate* RestoreTab(
 137       const Tab& tab,
 138       TabRestoreServiceDelegate* delegate,
 139       chrome::HostDesktopType host_desktop_type,
 140       WindowOpenDisposition disposition,
 141       content::WebContents** contents);
 142
 143   // Returns true if |tab| has more than one navigation. If |tab| has more
 144   // than one navigation |tab->current_navigation_index| is constrained based
 145   // on the number of navigations.
 146   static bool ValidateTab(Tab* tab);
 147
 148   // Validates all the tabs in a window, plus the window's active tab index.
 149   static bool ValidateWindow(Window* window);
 150
 151   // Returns true if |tab| is one we care about restoring.
 152   static bool IsTabInteresting(const Tab* tab);
 153
 154   // Checks whether |window| is interesting --- if it only contains a single,
 155   // uninteresting tab, it's not interesting.
 156   static bool IsWindowInteresting(const Window* window);
 157
 158   // Validates and checks |entry| for interesting.
 159   static bool FilterEntry(Entry* entry);
 160
 161   // Finds tab entries with the old browser_id and sets it to the new one.
 162   void UpdateTabBrowserIDs(SessionID::id_type old_id,
 163                            SessionID::id_type new_id);
 164
 165   // Gets the current time. This uses the time_factory_ if there is one.
 166   base::Time TimeNow() const;
 167
 168   TabRestoreService* const tab_restore_service_;
 169
 170   Observer* const observer_;
 171
 172   Profile* const profile_;
 173
 174   // Set of entries. They are ordered from most to least recent.
 175   Entries entries_;
 176
 177   // Are we restoring a tab? If this is true we ignore requests to create a
 178   // historical tab.
 179   bool restoring_;
 180
 181   ObserverList<TabRestoreServiceObserver> observer_list_;
 182
 183   // Set of delegates that we've received a BrowserClosing method for but no
 184   // corresponding BrowserClosed. We cache the set of delegates closing to
 185   // avoid creating historical tabs for them.
 186   std::set<TabRestoreServiceDelegate*> closing_delegates_;
 187
 188   TimeFactory* const time_factory_;
 189
 190   DISALLOW_COPY_AND_ASSIGN(TabRestoreServiceHelper);
 191 };
 192
 193 #endif  // CHROME_BROWSER_SESSIONS_TAB_RESTORE_SERVICE_HELPER_H_