chrome/browser/sessions/tab_restore_service.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_H_
   6 #define CHROME_BROWSER_SESSIONS_TAB_RESTORE_SERVICE_H_
   7
   8 #include <list>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/memory/ref_counted.h"
  13 #include "base/time/time.h"
  14 #include "chrome/browser/ui/host_desktop.h"
  15 #include "components/keyed_service/core/keyed_service.h"
  16 #include "components/sessions/serialized_navigation_entry.h"
  17 #include "components/sessions/session_id.h"
  18 #include "components/sessions/session_types.h"
  19 #include "content/public/browser/session_storage_namespace.h"
  20 #include "ui/base/window_open_disposition.h"
  21
  22 class TabRestoreServiceDelegate;
  23 class TabRestoreServiceObserver;
  24
  25 namespace content {
  26 class SessionStorageNamespace;
  27 class WebContents;
  28 }
  29
  30 // TabRestoreService is responsible for maintaining the most recently closed
  31 // tabs and windows. When a tab is closed
  32 // TabRestoreService::CreateHistoricalTab is invoked and a Tab is created to
  33 // represent the tab. Similarly, when a browser is closed, BrowserClosing is
  34 // invoked and a Window is created to represent the window.
  35 //
  36 // To restore a tab/window from the TabRestoreService invoke RestoreEntryById
  37 // or RestoreMostRecentEntry.
  38 //
  39 // To listen for changes to the set of entries managed by the TabRestoreService
  40 // add an observer.
  41 class TabRestoreService : public KeyedService {
  42  public:
  43   // Interface used to allow the test to provide a custom time.
  44   class TimeFactory {
  45    public:
  46     virtual ~TimeFactory();
  47     virtual base::Time TimeNow() = 0;
  48   };
  49
  50   // The type of entry.
  51   enum Type {
  52     TAB,
  53     WINDOW
  54   };
  55
  56   struct Entry {
  57     Entry();
  58     explicit Entry(Type type);
  59     virtual ~Entry();
  60
  61     // Unique id for this entry. The id is guaranteed to be unique for a
  62     // session.
  63     SessionID::id_type id;
  64
  65     // The type of the entry.
  66     Type type;
  67
  68     // The time when the window or tab was closed.
  69     base::Time timestamp;
  70
  71     // Is this entry from the last session? This is set to true for entries that
  72     // were closed during the last session, and false for entries that were
  73     // closed during this session.
  74     bool from_last_session;
  75   };
  76
  77   // Represents a previously open tab.
  78   struct Tab : public Entry {
  79     Tab();
  80     ~Tab() override;
  81
  82     bool has_browser() const { return browser_id > 0; }
  83
  84     // The navigations.
  85     std::vector<sessions::SerializedNavigationEntry> navigations;
  86
  87     // Index of the selected navigation in navigations.
  88     int current_navigation_index;
  89
  90     // The ID of the browser to which this tab belonged, so it can be restored
  91     // there. May be 0 (an invalid SessionID) when restoring an entire session.
  92     SessionID::id_type browser_id;
  93
  94     // Index within the tab strip. May be -1 for an unknown index.
  95     int tabstrip_index;
  96
  97     // True if the tab was pinned.
  98     bool pinned;
  99
 100     // If non-empty gives the id of the extension for the tab.
 101     std::string extension_app_id;
 102
 103     // The associated session storage namespace (if any).
 104     scoped_refptr<content::SessionStorageNamespace> session_storage_namespace;
 105
 106     // The user agent override used for the tab's navigations (if applicable).
 107     std::string user_agent_override;
 108   };
 109
 110   // Represents a previously open window.
 111   struct Window : public Entry {
 112     Window();
 113     ~Window() override;
 114
 115     // The tabs that comprised the window, in order.
 116     std::vector<Tab> tabs;
 117
 118     // Index of the selected tab.
 119     int selected_tab_index;
 120
 121     // If an application window, the name of the app.
 122     std::string app_name;
 123   };
 124
 125   typedef std::list<Entry*> Entries;
 126
 127   ~TabRestoreService() override;
 128
 129   // Adds/removes an observer. TabRestoreService does not take ownership of
 130   // the observer.
 131   virtual void AddObserver(TabRestoreServiceObserver* observer) = 0;
 132   virtual void RemoveObserver(TabRestoreServiceObserver* observer) = 0;
 133
 134   // Creates a Tab to represent |contents| and notifies observers the list of
 135   // entries has changed.
 136   virtual void CreateHistoricalTab(content::WebContents* contents,
 137                                    int index) = 0;
 138
 139   // Invoked when a browser is closing. If |delegate| is a tabbed browser with
 140   // at least one tab, a Window is created, added to entries and observers are
 141   // notified.
 142   virtual void BrowserClosing(TabRestoreServiceDelegate* delegate) = 0;
 143
 144   // Invoked when the browser is done closing.
 145   virtual void BrowserClosed(TabRestoreServiceDelegate* delegate) = 0;
 146
 147   // Removes all entries from the list and notifies observers the list
 148   // of tabs has changed.
 149   virtual void ClearEntries() = 0;
 150
 151   // Returns the entries, ordered with most recently closed entries at the
 152   // front.
 153   virtual const Entries& entries() const = 0;
 154
 155   // Restores the most recently closed entry. Does nothing if there are no
 156   // entries to restore. If the most recently restored entry is a tab, it is
 157   // added to |delegate|. If a new browser needs to be created for this entry,
 158   // it will be created on the desktop specified by |host_desktop_type|. Returns
 159   // the WebContents of the restored tab(s).
 160   virtual std::vector<content::WebContents*> RestoreMostRecentEntry(
 161       TabRestoreServiceDelegate* delegate,
 162       chrome::HostDesktopType host_desktop_type) = 0;
 163
 164   // Removes the Tab with id |id| from the list and returns it; ownership is
 165   // passed to the caller.
 166   virtual Tab* RemoveTabEntryById(SessionID::id_type id) = 0;
 167
 168   // Restores an entry by id. If there is no entry with an id matching |id|,
 169   // this does nothing. If |delegate| is NULL, this creates a new window for the
 170   // entry. |disposition| is respected, but the attributes (tabstrip index,
 171   // browser window) of the tab when it was closed will be respected if
 172   // disposition is UNKNOWN. If a new browser needs to be created for this
 173   // entry, it will be created on the desktop specified by |host_desktop_type|.
 174   // Returns the WebContents of the restored tab(s).
 175   virtual std::vector<content::WebContents*> RestoreEntryById(
 176       TabRestoreServiceDelegate* delegate,
 177       SessionID::id_type id,
 178       chrome::HostDesktopType host_desktop_type,
 179       WindowOpenDisposition disposition) = 0;
 180
 181   // Loads the tabs and previous session. This does nothing if the tabs
 182   // from the previous session have already been loaded.
 183   virtual void LoadTabsFromLastSession() = 0;
 184
 185   // Returns true if the tab entries have been loaded.
 186   virtual bool IsLoaded() const = 0;
 187
 188   // Deletes the last session.
 189   virtual void DeleteLastSession() = 0;
 190 };
 191
 192 #endif  // CHROME_BROWSER_SESSIONS_TAB_RESTORE_SERVICE_H_