src/chrome/browser/ui/browser_tab_restorer.cc

   1 // Copyright 2014 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 #include "base/metrics/user_metrics_action.h"
   6 #include "base/supports_user_data.h"
   7 #include "chrome/browser/profiles/profile.h"
   8 #include "chrome/browser/sessions/tab_restore_service.h"
   9 #include "chrome/browser/sessions/tab_restore_service_factory.h"
  10 #include "chrome/browser/sessions/tab_restore_service_observer.h"
  11 #include "chrome/browser/ui/browser.h"
  12 #include "chrome/browser/ui/browser_commands.h"
  13 #include "chrome/browser/ui/browser_list.h"
  14 #include "chrome/browser/ui/browser_list_observer.h"
  15 #include "chrome/browser/ui/browser_tab_restore_service_delegate.h"
  16 #include "content/public/browser/user_metrics.h"
  17
  18 namespace chrome {
  19 namespace {
  20
  21 const char kBrowserTabRestorerKey[] = "BrowserTabRestorer";
  22
  23 // BrowserTabRestorer is responsible for restoring a tab when the
  24 // TabRestoreService finishes loading. A TabRestoreService is associated with a
  25 // single Browser and deletes itself if the Browser is destroyed.
  26 // BrowserTabRestorer is installed on the Profile (by way of user data), only
  27 // one instance is created per profile at a time.
  28 class BrowserTabRestorer : public TabRestoreServiceObserver,
  29                            public chrome::BrowserListObserver,
  30                            public base::SupportsUserData::Data {
  31  public:
  32   virtual ~BrowserTabRestorer();
  33
  34   static void CreateIfNecessary(Browser* browser);
  35
  36  private:
  37   explicit BrowserTabRestorer(Browser* browser);
  38
  39   // TabRestoreServiceObserver:
  40   virtual void TabRestoreServiceChanged(TabRestoreService* service) OVERRIDE;
  41   virtual void TabRestoreServiceDestroyed(TabRestoreService* service) OVERRIDE;
  42   virtual void TabRestoreServiceLoaded(TabRestoreService* service) OVERRIDE;
  43
  44   // BrowserListObserver:
  45   virtual void OnBrowserRemoved(Browser* browser) OVERRIDE;
  46
  47   Browser* browser_;
  48   TabRestoreService* tab_restore_service_;
  49
  50   DISALLOW_COPY_AND_ASSIGN(BrowserTabRestorer);
  51 };
  52
  53 BrowserTabRestorer::~BrowserTabRestorer() {
  54   tab_restore_service_->RemoveObserver(this);
  55   BrowserList::GetInstance(browser_->host_desktop_type())->RemoveObserver(this);
  56 }
  57
  58 // static
  59 void BrowserTabRestorer::CreateIfNecessary(Browser* browser) {
  60   DCHECK(browser);
  61   if (browser->profile()->GetUserData(kBrowserTabRestorerKey))
  62     return;  // Only allow one restore for a given profile at a time.
  63
  64   // BrowserTabRestorer is deleted at the appropriate time.
  65   new BrowserTabRestorer(browser);
  66 }
  67
  68 BrowserTabRestorer::BrowserTabRestorer(Browser* browser)
  69     : browser_(browser),
  70       tab_restore_service_(
  71           TabRestoreServiceFactory::GetForProfile(browser->profile())) {
  72   DCHECK(tab_restore_service_);
  73   DCHECK(!tab_restore_service_->IsLoaded());
  74   tab_restore_service_->AddObserver(this);
  75   BrowserList::GetInstance(browser->host_desktop_type())->AddObserver(this);
  76   browser_->profile()->SetUserData(kBrowserTabRestorerKey, this);
  77   tab_restore_service_->LoadTabsFromLastSession();
  78 }
  79
  80 void BrowserTabRestorer::TabRestoreServiceChanged(TabRestoreService* service) {
  81 }
  82
  83 void BrowserTabRestorer::TabRestoreServiceDestroyed(
  84     TabRestoreService* service) {
  85 }
  86
  87 void BrowserTabRestorer::TabRestoreServiceLoaded(TabRestoreService* service) {
  88   RestoreTab(browser_);
  89   // This deletes us.
  90   browser_->profile()->SetUserData(kBrowserTabRestorerKey, NULL);
  91 }
  92
  93 void BrowserTabRestorer::OnBrowserRemoved(Browser* browser) {
  94   // This deletes us.
  95   browser_->profile()->SetUserData(kBrowserTabRestorerKey, NULL);
  96 }
  97
  98 }  // namespace
  99
 100 void RestoreTab(Browser* browser) {
 101   content::RecordAction(base::UserMetricsAction("RestoreTab"));
 102   TabRestoreService* service =
 103       TabRestoreServiceFactory::GetForProfile(browser->profile());
 104   if (!service)
 105     return;
 106
 107   if (service->IsLoaded()) {
 108     service->RestoreMostRecentEntry(browser->tab_restore_service_delegate(),
 109                                     browser->host_desktop_type());
 110     return;
 111   }
 112
 113   BrowserTabRestorer::CreateIfNecessary(browser);
 114 }
 115
 116 }  // namespace chrome