Home | History | Annotate | Download | only in ui 
      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
    117