chrome/browser/ui/tabs/tab_strip

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This source file includes following definitions.
ShouldForgetOpenersForTransition
parent_
WebContentsDestroyed
HasNext
Next
OnWebContentsDestroyed
web_contents
group
set_group
opener
set_opener
reset_group_on_select
set_reset_group_on_select
pinned
set_pinned
blocked
set_blocked
discarded
set_discarded
discarded_
SetWebContents
WebContentsDestroyed
in_notify_
AddObserver
RemoveObserver
ContainsIndex
AppendWebContents
InsertWebContentsAt
ReplaceWebContentsAt
DiscardWebContentsAt
DetachWebContentsAt
ActivateTabAt
AddTabAtToSelection
MoveWebContentsAt
MoveSelectedTabsTo
GetActiveWebContents
GetWebContentsAt
GetIndexOfWebContents
UpdateWebContentsStateAt
CloseAllTabs
CloseWebContentsAt
TabsAreLoading
GetOpenerOfWebContentsAt
SetOpenerOfWebContentsAt
GetIndexOfNextWebContentsOpenedBy
GetIndexOfLastWebContentsOpenedBy
TabNavigating
ForgetAllOpeners
ForgetGroup
ShouldResetGroupOnSelect
SetTabBlocked
SetTabPinned
IsTabPinned
IsMiniTab
IsAppTab
IsTabBlocked
IsTabDiscarded
IndexOfFirstNonMiniTab
ConstrainInsertionIndex
ExtendSelectionTo
ToggleSelectionAt
AddSelectionFromAnchorTo
IsTabSelected
SetSelectionFromModel
AddWebContents
CloseSelectedTabs
SelectNextTab
SelectPreviousTab
SelectLastTab
MoveTabNext
MoveTabPrevious
IsContextMenuCommandEnabled
ExecuteContextMenuCommand
GetIndicesClosedByCommand
WillContextMenuPin
ContextMenuCommandToBrowserCommand
GetWebContentsFromIndices
GetIndicesWithSameDomain
GetIndicesWithSameOpener
GetIndicesForCommand
IsNewTabAtEndOfTabStrip
InternalCloseTabs
InternalCloseTab
GetWebContentsAtImpl
NotifyIfTabDeactivated
NotifyIfActiveTabChanged
NotifyIfActiveOrSelectionChanged
SetSelection
SelectRelativeTab
MoveWebContentsAtImpl
MoveSelectedTabsToImpl
OpenerMatches
ForgetOpenersAndGroupsReferencing
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/ui/tabs/tab_strip_model.h"

#include <algorithm>
#include <map>
#include <string>

#include "base/metrics/histogram.h"
#include "base/stl_util.h"
#include "chrome/app/chrome_command_ids.h"
#include "chrome/browser/browser_shutdown.h"
#include "chrome/browser/defaults.h"
#include "chrome/browser/extensions/tab_helper.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/ui/tab_contents/core_tab_helper.h"
#include "chrome/browser/ui/tab_contents/core_tab_helper_delegate.h"
#include "chrome/browser/ui/tabs/tab_strip_model_delegate.h"
#include "chrome/browser/ui/tabs/tab_strip_model_order_controller.h"
#include "chrome/common/url_constants.h"
#include "components/web_modal/web_contents_modal_dialog_manager.h"
#include "content/public/browser/render_process_host.h"
#include "content/public/browser/user_metrics.h"
#include "content/public/browser/web_contents.h"
#include "content/public/browser/web_contents_observer.h"
#include "content/public/browser/web_contents_view.h"

using base::UserMetricsAction;
using content::WebContents;

namespace {

// Returns true if the specified transition is one of the types that cause the
// opener relationships for the tab in which the transition occurred to be
// forgotten. This is generally any navigation that isn't a link click (i.e.
// any navigation that can be considered to be the start of a new task distinct
// from what had previously occurred in that tab).
bool ShouldForgetOpenersForTransition(content::PageTransition transition) {
  return transition == content::PAGE_TRANSITION_TYPED ||
      transition == content::PAGE_TRANSITION_AUTO_BOOKMARK ||
      transition == content::PAGE_TRANSITION_GENERATED ||
      transition == content::PAGE_TRANSITION_KEYWORD ||
      transition == content::PAGE_TRANSITION_AUTO_TOPLEVEL;
}

// CloseTracker is used when closing a set of WebContents. It listens for
// deletions of the WebContents and removes from the internal set any time one
// is deleted.
class CloseTracker {
 public:
  typedef std::vector<WebContents*> Contents;

  explicit CloseTracker(const Contents& contents);
  virtual ~CloseTracker();

  // Returns true if there is another WebContents in the Tracker.
  bool HasNext() const;

  // Returns the next WebContents, or NULL if there are no more.
  WebContents* Next();

 private:
  class DeletionObserver : public content::WebContentsObserver {
   public:
    DeletionObserver(CloseTracker* parent, WebContents* web_contents)
        : WebContentsObserver(web_contents),
          parent_(parent) {
    }

    // Expose web_contents() publicly.
    using content::WebContentsObserver::web_contents;

   private:
    // WebContentsObserver:
    virtual void WebContentsDestroyed(WebContents* web_contents) OVERRIDE {
      parent_->OnWebContentsDestroyed(this);
    }

    CloseTracker* parent_;

    DISALLOW_COPY_AND_ASSIGN(DeletionObserver);
  };

  void OnWebContentsDestroyed(DeletionObserver* observer);

  typedef std::vector<DeletionObserver*> Observers;
  Observers observers_;

  DISALLOW_COPY_AND_ASSIGN(CloseTracker);
};

CloseTracker::CloseTracker(const Contents& contents) {
  for (size_t i = 0; i < contents.size(); ++i)
    observers_.push_back(new DeletionObserver(this, contents[i]));
}

CloseTracker::~CloseTracker() {
  DCHECK(observers_.empty());
}

bool CloseTracker::HasNext() const {
  return !observers_.empty();
}

WebContents* CloseTracker::Next() {
  if (observers_.empty())
    return NULL;

  DeletionObserver* observer = observers_[0];
  WebContents* web_contents = observer->web_contents();
  observers_.erase(observers_.begin());
  delete observer;
  return web_contents;
}

void CloseTracker::OnWebContentsDestroyed(DeletionObserver* observer) {
  Observers::iterator i =
      std::find(observers_.begin(), observers_.end(), observer);
  if (i != observers_.end()) {
    delete *i;
    observers_.erase(i);
    return;
  }
  NOTREACHED() << "WebContents destroyed that wasn't in the list";
}

}  // namespace

///////////////////////////////////////////////////////////////////////////////
// WebContentsData

// An object to hold a reference to a WebContents that is in a tabstrip, as
// well as other various properties it has.
class TabStripModel::WebContentsData : public content::WebContentsObserver {
 public:
  WebContentsData(TabStripModel* tab_strip_model, WebContents* a_contents);

  // Changes the WebContents that this WebContentsData tracks.
  void SetWebContents(WebContents* contents);
  WebContents* web_contents() { return contents_; }

  // Create a relationship between this WebContentsData and other
  // WebContentses. Used to identify which WebContents to select next after
  // one is closed.
  WebContents* group() const { return group_; }
  void set_group(WebContents* value) { group_ = value; }
  WebContents* opener() const { return opener_; }
  void set_opener(WebContents* value) { opener_ = value; }

  // Alters the properties of the WebContents.
  bool reset_group_on_select() const { return reset_group_on_select_; }
  void set_reset_group_on_select(bool value) { reset_group_on_select_ = value; }
  bool pinned() const { return pinned_; }
  void set_pinned(bool value) { pinned_ = value; }
  bool blocked() const { return blocked_; }
  void set_blocked(bool value) { blocked_ = value; }
  bool discarded() const { return discarded_; }
  void set_discarded(bool value) { discarded_ = value; }

 private:
  // Make sure that if someone deletes this WebContents out from under us, it
  // is properly removed from the tab strip.
  virtual void WebContentsDestroyed(WebContents* web_contents) OVERRIDE;

  // The WebContents being tracked by this WebContentsData. The
  // WebContentsObserver does keep a reference, but when the WebContents is
  // deleted, the WebContentsObserver reference is NULLed and thus inaccessible.
  WebContents* contents_;

  // The TabStripModel containing this WebContents.
  TabStripModel* tab_strip_model_;

  // The group is used to model a set of tabs spawned from a single parent
  // tab. This value is preserved for a given tab as long as the tab remains
  // navigated to the link it was initially opened at or some navigation from
  // that page (i.e. if the user types or visits a bookmark or some other
  // navigation within that tab, the group relationship is lost). This
  // property can safely be used to implement features that depend on a
  // logical group of related tabs.
  WebContents* group_;

  // The owner models the same relationship as group, except it is more
  // easily discarded, e.g. when the user switches to a tab not part of the
  // same group. This property is used to determine what tab to select next
  // when one is closed.
  WebContents* opener_;

  // True if our group should be reset the moment selection moves away from
  // this tab. This is the case for tabs opened in the foreground at the end
  // of the TabStrip while viewing another Tab. If these tabs are closed
  // before selection moves elsewhere, their opener is selected. But if
  // selection shifts to _any_ tab (including their opener), the group
  // relationship is reset to avoid confusing close sequencing.
  bool reset_group_on_select_;

  // Is the tab pinned?
  bool pinned_;

  // Is the tab interaction blocked by a modal dialog?
  bool blocked_;

  // Has the tab data been discarded to save memory?
  bool discarded_;

  DISALLOW_COPY_AND_ASSIGN(WebContentsData);
};

TabStripModel::WebContentsData::WebContentsData(TabStripModel* tab_strip_model,
                                                WebContents* contents)
    : content::WebContentsObserver(contents),
      contents_(contents),
      tab_strip_model_(tab_strip_model),
      group_(NULL),
      opener_(NULL),
      reset_group_on_select_(false),
      pinned_(false),
      blocked_(false),
      discarded_(false) {
}

void TabStripModel::WebContentsData::SetWebContents(WebContents* contents) {
  contents_ = contents;
  Observe(contents);
}

void TabStripModel::WebContentsData::WebContentsDestroyed(
    WebContents* web_contents) {
  DCHECK_EQ(contents_, web_contents);

  // Note that we only detach the contents here, not close it - it's
  // already been closed. We just want to undo our bookkeeping.
  int index = tab_strip_model_->GetIndexOfWebContents(web_contents);
  DCHECK_NE(TabStripModel::kNoTab, index);
  tab_strip_model_->DetachWebContentsAt(index);
}

///////////////////////////////////////////////////////////////////////////////
// TabStripModel, public:

TabStripModel::TabStripModel(TabStripModelDelegate* delegate, Profile* profile)
    : delegate_(delegate),
      profile_(profile),
      closing_all_(false),
      in_notify_(false) {
  DCHECK(delegate_);
  order_controller_.reset(new TabStripModelOrderController(this));
}

TabStripModel::~TabStripModel() {
  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                    TabStripModelDeleted());
  STLDeleteElements(&contents_data_);
  order_controller_.reset();
}

void TabStripModel::AddObserver(TabStripModelObserver* observer) {
  observers_.AddObserver(observer);
}

void TabStripModel::RemoveObserver(TabStripModelObserver* observer) {
  observers_.RemoveObserver(observer);
}

bool TabStripModel::ContainsIndex(int index) const {
  return index >= 0 && index < count();
}

void TabStripModel::AppendWebContents(WebContents* contents,
                                      bool foreground) {
  InsertWebContentsAt(count(), contents,
                      foreground ? (ADD_INHERIT_GROUP | ADD_ACTIVE) :
                                   ADD_NONE);
}

void TabStripModel::InsertWebContentsAt(int index,
                                        WebContents* contents,
                                        int add_types) {
  delegate_->WillAddWebContents(contents);

  bool active = add_types & ADD_ACTIVE;
  // Force app tabs to be pinned.
  extensions::TabHelper* extensions_tab_helper =
      extensions::TabHelper::FromWebContents(contents);
  bool pin = extensions_tab_helper->is_app() || add_types & ADD_PINNED;
  index = ConstrainInsertionIndex(index, pin);

  // In tab dragging situations, if the last tab in the window was detached
  // then the user aborted the drag, we will have the |closing_all_| member
  // set (see DetachWebContentsAt) which will mess with our mojo here. We need
  // to clear this bit.
  closing_all_ = false;

  // Have to get the active contents before we monkey with the contents
  // otherwise we run into problems when we try to change the active contents
  // since the old contents and the new contents will be the same...
  WebContents* active_contents = GetActiveWebContents();
  WebContentsData* data = new WebContentsData(this, contents);
  data->set_pinned(pin);
  if ((add_types & ADD_INHERIT_GROUP) && active_contents) {
    if (active) {
      // Forget any existing relationships, we don't want to make things too
      // confusing by having multiple groups active at the same time.
      ForgetAllOpeners();
    }
    // Anything opened by a link we deem to have an opener.
    data->set_group(active_contents);
    data->set_opener(active_contents);
  } else if ((add_types & ADD_INHERIT_OPENER) && active_contents) {
    if (active) {
      // Forget any existing relationships, we don't want to make things too
      // confusing by having multiple groups active at the same time.
      ForgetAllOpeners();
    }
    data->set_opener(active_contents);
  }

  web_modal::WebContentsModalDialogManager* modal_dialog_manager =
      web_modal::WebContentsModalDialogManager::FromWebContents(contents);
  if (modal_dialog_manager)
    data->set_blocked(modal_dialog_manager->IsDialogActive());

  contents_data_.insert(contents_data_.begin() + index, data);

  selection_model_.IncrementFrom(index);

  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                    TabInsertedAt(contents, index, active));
  if (active) {
    ui::ListSelectionModel new_model;
    new_model.Copy(selection_model_);
    new_model.SetSelectedIndex(index);
    SetSelection(new_model, NOTIFY_DEFAULT);
  }
}

WebContents* TabStripModel::ReplaceWebContentsAt(int index,
                                                 WebContents* new_contents) {
  delegate_->WillAddWebContents(new_contents);

  DCHECK(ContainsIndex(index));
  WebContents* old_contents = GetWebContentsAtImpl(index);

  ForgetOpenersAndGroupsReferencing(old_contents);

  contents_data_[index]->SetWebContents(new_contents);

  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                    TabReplacedAt(this, old_contents, new_contents, index));

  // When the active WebContents is replaced send out a selection notification
  // too. We do this as nearly all observers need to treat a replacement of the
  // selected contents as the selection changing.
  if (active_index() == index) {
    FOR_EACH_OBSERVER(
        TabStripModelObserver,
        observers_,
        ActiveTabChanged(old_contents,
                         new_contents,
                         active_index(),
                         TabStripModelObserver::CHANGE_REASON_REPLACED));
  }
  return old_contents;
}

WebContents* TabStripModel::DiscardWebContentsAt(int index) {
  DCHECK(ContainsIndex(index));
  // Do not discard active tab.
  if (active_index() == index)
    return NULL;

  WebContents* null_contents =
      WebContents::Create(WebContents::CreateParams(profile()));
  WebContents* old_contents = GetWebContentsAtImpl(index);
  // Copy over the state from the navigation controller so we preserve the
  // back/forward history and continue to display the correct title/favicon.
  null_contents->GetController().CopyStateFrom(old_contents->GetController());
  // Replace the tab we're discarding with the null version.
  ReplaceWebContentsAt(index, null_contents);
  // Mark the tab so it will reload when we click.
  contents_data_[index]->set_discarded(true);
  // Discard the old tab's renderer.
  // TODO(jamescook): This breaks script connections with other tabs.
  // We need to find a different approach that doesn't do that, perhaps based
  // on navigation to swappedout://.
  delete old_contents;
  return null_contents;
}

WebContents* TabStripModel::DetachWebContentsAt(int index) {
  CHECK(!in_notify_);
  if (contents_data_.empty())
    return NULL;

  DCHECK(ContainsIndex(index));

  WebContents* removed_contents = GetWebContentsAtImpl(index);
  bool was_selected = IsTabSelected(index);
  int next_selected_index = order_controller_->DetermineNewSelectedIndex(index);
  delete contents_data_[index];
  contents_data_.erase(contents_data_.begin() + index);
  ForgetOpenersAndGroupsReferencing(removed_contents);
  if (empty())
    closing_all_ = true;
  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                    TabDetachedAt(removed_contents, index));
  if (empty()) {
    selection_model_.Clear();
    // TabDetachedAt() might unregister observers, so send |TabStripEmpty()| in
    // a second pass.
    FOR_EACH_OBSERVER(TabStripModelObserver, observers_, TabStripEmpty());
  } else {
    int old_active = active_index();
    selection_model_.DecrementFrom(index);
    ui::ListSelectionModel old_model;
    old_model.Copy(selection_model_);
    if (index == old_active) {
      NotifyIfTabDeactivated(removed_contents);
      if (!selection_model_.empty()) {
        // The active tab was removed, but there is still something selected.
        // Move the active and anchor to the first selected index.
        selection_model_.set_active(selection_model_.selected_indices()[0]);
        selection_model_.set_anchor(selection_model_.active());
      } else {
        // The active tab was removed and nothing is selected. Reset the
        // selection and send out notification.
        selection_model_.SetSelectedIndex(next_selected_index);
      }
      NotifyIfActiveTabChanged(removed_contents, NOTIFY_DEFAULT);
    }

    // Sending notification in case the detached tab was selected. Using
    // NotifyIfActiveOrSelectionChanged() here would not guarantee that a
    // notification is sent even though the tab selection has changed because
    // |old_model| is stored after calling DecrementFrom().
    if (was_selected) {
      FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                        TabSelectionChanged(this, old_model));
    }
  }
  return removed_contents;
}

void TabStripModel::ActivateTabAt(int index, bool user_gesture) {
  DCHECK(ContainsIndex(index));
  ui::ListSelectionModel new_model;
  new_model.Copy(selection_model_);
  new_model.SetSelectedIndex(index);
  SetSelection(new_model, user_gesture ? NOTIFY_USER_GESTURE : NOTIFY_DEFAULT);
}

void TabStripModel::AddTabAtToSelection(int index) {
  DCHECK(ContainsIndex(index));
  ui::ListSelectionModel new_model;
  new_model.Copy(selection_model_);
  new_model.AddIndexToSelection(index);
  SetSelection(new_model, NOTIFY_DEFAULT);
}

void TabStripModel::MoveWebContentsAt(int index,
                                      int to_position,
                                      bool select_after_move) {
  DCHECK(ContainsIndex(index));
  if (index == to_position)
    return;

  int first_non_mini_tab = IndexOfFirstNonMiniTab();
  if ((index < first_non_mini_tab && to_position >= first_non_mini_tab) ||
      (to_position < first_non_mini_tab && index >= first_non_mini_tab)) {
    // This would result in mini tabs mixed with non-mini tabs. We don't allow
    // that.
    return;
  }

  MoveWebContentsAtImpl(index, to_position, select_after_move);
}

void TabStripModel::MoveSelectedTabsTo(int index) {
  int total_mini_count = IndexOfFirstNonMiniTab();
  int selected_mini_count = 0;
  int selected_count =
      static_cast<int>(selection_model_.selected_indices().size());
  for (int i = 0; i < selected_count &&
           IsMiniTab(selection_model_.selected_indices()[i]); ++i) {
    selected_mini_count++;
  }

  // To maintain that all mini-tabs occur before non-mini-tabs we move them
  // first.
  if (selected_mini_count > 0) {
    MoveSelectedTabsToImpl(
        std::min(total_mini_count - selected_mini_count, index), 0u,
        selected_mini_count);
    if (index > total_mini_count - selected_mini_count) {
      // We're being told to drag mini-tabs to an invalid location. Adjust the
      // index such that non-mini-tabs end up at a location as though we could
      // move the mini-tabs to index. See description in header for more
      // details.
      index += selected_mini_count;
    }
  }
  if (selected_mini_count == selected_count)
    return;

  // Then move the non-pinned tabs.
  MoveSelectedTabsToImpl(std::max(index, total_mini_count),
                         selected_mini_count,
                         selected_count - selected_mini_count);
}

WebContents* TabStripModel::GetActiveWebContents() const {
  return GetWebContentsAt(active_index());
}

WebContents* TabStripModel::GetWebContentsAt(int index) const {
  if (ContainsIndex(index))
    return GetWebContentsAtImpl(index);
  return NULL;
}

int TabStripModel::GetIndexOfWebContents(const WebContents* contents) const {
  for (size_t i = 0; i < contents_data_.size(); ++i) {
    if (contents_data_[i]->web_contents() == contents)
      return i;
  }
  return kNoTab;
}

void TabStripModel::UpdateWebContentsStateAt(int index,
    TabStripModelObserver::TabChangeType change_type) {
  DCHECK(ContainsIndex(index));

  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
      TabChangedAt(GetWebContentsAtImpl(index), index, change_type));
}

void TabStripModel::CloseAllTabs() {
  // Set state so that observers can adjust their behavior to suit this
  // specific condition when CloseWebContentsAt causes a flurry of
  // Close/Detach/Select notifications to be sent.
  closing_all_ = true;
  std::vector<int> closing_tabs;
  for (int i = count() - 1; i >= 0; --i)
    closing_tabs.push_back(i);
  InternalCloseTabs(closing_tabs, CLOSE_CREATE_HISTORICAL_TAB);
}

bool TabStripModel::CloseWebContentsAt(int index, uint32 close_types) {
  DCHECK(ContainsIndex(index));
  std::vector<int> closing_tabs;
  closing_tabs.push_back(index);
  return InternalCloseTabs(closing_tabs, close_types);
}

bool TabStripModel::TabsAreLoading() const {
  for (WebContentsDataVector::const_iterator iter = contents_data_.begin();
       iter != contents_data_.end(); ++iter) {
    if ((*iter)->web_contents()->IsLoading())
      return true;
  }
  return false;
}

WebContents* TabStripModel::GetOpenerOfWebContentsAt(int index) {
  DCHECK(ContainsIndex(index));
  return contents_data_[index]->opener();
}

void TabStripModel::SetOpenerOfWebContentsAt(int index,
                                             WebContents* opener) {
  DCHECK(ContainsIndex(index));
  DCHECK(opener);
  contents_data_[index]->set_opener(opener);
}

int TabStripModel::GetIndexOfNextWebContentsOpenedBy(const WebContents* opener,
                                                     int start_index,
                                                     bool use_group) const {
  DCHECK(opener);
  DCHECK(ContainsIndex(start_index));

  // Check tabs after start_index first.
  for (int i = start_index + 1; i < count(); ++i) {
    if (OpenerMatches(contents_data_[i], opener, use_group))
      return i;
  }
  // Then check tabs before start_index, iterating backwards.
  for (int i = start_index - 1; i >= 0; --i) {
    if (OpenerMatches(contents_data_[i], opener, use_group))
      return i;
  }
  return kNoTab;
}

int TabStripModel::GetIndexOfLastWebContentsOpenedBy(const WebContents* opener,
                                                     int start_index) const {
  DCHECK(opener);
  DCHECK(ContainsIndex(start_index));

  for (int i = contents_data_.size() - 1; i > start_index; --i) {
    if (contents_data_[i]->opener() == opener)
      return i;
  }
  return kNoTab;
}

void TabStripModel::TabNavigating(WebContents* contents,
                                  content::PageTransition transition) {
  if (ShouldForgetOpenersForTransition(transition)) {
    // Don't forget the openers if this tab is a New Tab page opened at the
    // end of the TabStrip (e.g. by pressing Ctrl+T). Give the user one
    // navigation of one of these transition types before resetting the
    // opener relationships (this allows for the use case of opening a new
    // tab to do a quick look-up of something while viewing a tab earlier in
    // the strip). We can make this heuristic more permissive if need be.
    if (!IsNewTabAtEndOfTabStrip(contents)) {
      // If the user navigates the current tab to another page in any way
      // other than by clicking a link, we want to pro-actively forget all
      // TabStrip opener relationships since we assume they're beginning a
      // different task by reusing the current tab.
      ForgetAllOpeners();
      // In this specific case we also want to reset the group relationship,
      // since it is now technically invalid.
      ForgetGroup(contents);
    }
  }
}

void TabStripModel::ForgetAllOpeners() {
  // Forget all opener memories so we don't do anything weird with tab
  // re-selection ordering.
  for (WebContentsDataVector::const_iterator iter = contents_data_.begin();
       iter != contents_data_.end(); ++iter)
    (*iter)->set_opener(NULL);
}

void TabStripModel::ForgetGroup(WebContents* contents) {
  int index = GetIndexOfWebContents(contents);
  DCHECK(ContainsIndex(index));
  contents_data_[index]->set_group(NULL);
  contents_data_[index]->set_opener(NULL);
}

bool TabStripModel::ShouldResetGroupOnSelect(WebContents* contents) const {
  int index = GetIndexOfWebContents(contents);
  DCHECK(ContainsIndex(index));
  return contents_data_[index]->reset_group_on_select();
}

void TabStripModel::SetTabBlocked(int index, bool blocked) {
  DCHECK(ContainsIndex(index));
  if (contents_data_[index]->blocked() == blocked)
    return;
  contents_data_[index]->set_blocked(blocked);
  FOR_EACH_OBSERVER(
      TabStripModelObserver, observers_,
      TabBlockedStateChanged(contents_data_[index]->web_contents(),
                             index));
}

void TabStripModel::SetTabPinned(int index, bool pinned) {
  DCHECK(ContainsIndex(index));
  if (contents_data_[index]->pinned() == pinned)
    return;

  if (IsAppTab(index)) {
    if (!pinned) {
      // App tabs should always be pinned.
      NOTREACHED();
      return;
    }
    // Changing the pinned state of an app tab doesn't affect its mini-tab
    // status.
    contents_data_[index]->set_pinned(pinned);
  } else {
    // The tab is not an app tab, its position may have to change as the
    // mini-tab state is changing.
    int non_mini_tab_index = IndexOfFirstNonMiniTab();
    contents_data_[index]->set_pinned(pinned);
    if (pinned && index != non_mini_tab_index) {
      MoveWebContentsAtImpl(index, non_mini_tab_index, false);
      index = non_mini_tab_index;
    } else if (!pinned && index + 1 != non_mini_tab_index) {
      MoveWebContentsAtImpl(index, non_mini_tab_index - 1, false);
      index = non_mini_tab_index - 1;
    }

    FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                      TabMiniStateChanged(contents_data_[index]->web_contents(),
                                          index));
  }

  // else: the tab was at the boundary and its position doesn't need to change.
  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                    TabPinnedStateChanged(contents_data_[index]->web_contents(),
                                          index));
}

bool TabStripModel::IsTabPinned(int index) const {
  DCHECK(ContainsIndex(index));
  return contents_data_[index]->pinned();
}

bool TabStripModel::IsMiniTab(int index) const {
  return IsTabPinned(index) || IsAppTab(index);
}

bool TabStripModel::IsAppTab(int index) const {
  WebContents* contents = GetWebContentsAt(index);
  return contents && extensions::TabHelper::FromWebContents(contents)->is_app();
}

bool TabStripModel::IsTabBlocked(int index) const {
  return contents_data_[index]->blocked();
}

bool TabStripModel::IsTabDiscarded(int index) const {
  return contents_data_[index]->discarded();
}

int TabStripModel::IndexOfFirstNonMiniTab() const {
  for (size_t i = 0; i < contents_data_.size(); ++i) {
    if (!IsMiniTab(static_cast<int>(i)))
      return static_cast<int>(i);
  }
  // No mini-tabs.
  return count();
}

int TabStripModel::ConstrainInsertionIndex(int index, bool mini_tab) {
  return mini_tab ? std::min(std::max(0, index), IndexOfFirstNonMiniTab()) :
      std::min(count(), std::max(index, IndexOfFirstNonMiniTab()));
}

void TabStripModel::ExtendSelectionTo(int index) {
  DCHECK(ContainsIndex(index));
  ui::ListSelectionModel new_model;
  new_model.Copy(selection_model_);
  new_model.SetSelectionFromAnchorTo(index);
  SetSelection(new_model, NOTIFY_DEFAULT);
}

void TabStripModel::ToggleSelectionAt(int index) {
  DCHECK(ContainsIndex(index));
  ui::ListSelectionModel new_model;
  new_model.Copy(selection_model());
  if (selection_model_.IsSelected(index)) {
    if (selection_model_.size() == 1) {
      // One tab must be selected and this tab is currently selected so we can't
      // unselect it.
      return;
    }
    new_model.RemoveIndexFromSelection(index);
    new_model.set_anchor(index);
    if (new_model.active() == index ||
        new_model.active() == ui::ListSelectionModel::kUnselectedIndex)
      new_model.set_active(new_model.selected_indices()[0]);
  } else {
    new_model.AddIndexToSelection(index);
    new_model.set_anchor(index);
    new_model.set_active(index);
  }
  SetSelection(new_model, NOTIFY_DEFAULT);
}

void TabStripModel::AddSelectionFromAnchorTo(int index) {
  ui::ListSelectionModel new_model;
  new_model.Copy(selection_model_);
  new_model.AddSelectionFromAnchorTo(index);
  SetSelection(new_model, NOTIFY_DEFAULT);
}

bool TabStripModel::IsTabSelected(int index) const {
  DCHECK(ContainsIndex(index));
  return selection_model_.IsSelected(index);
}

void TabStripModel::SetSelectionFromModel(
    const ui::ListSelectionModel& source) {
  DCHECK_NE(ui::ListSelectionModel::kUnselectedIndex, source.active());
  SetSelection(source, NOTIFY_DEFAULT);
}

void TabStripModel::AddWebContents(WebContents* contents,
                                   int index,
                                   content::PageTransition transition,
                                   int add_types) {
  // If the newly-opened tab is part of the same task as the parent tab, we want
  // to inherit the parent's "group" attribute, so that if this tab is then
  // closed we'll jump back to the parent tab.
  bool inherit_group = (add_types & ADD_INHERIT_GROUP) == ADD_INHERIT_GROUP;

  if (transition == content::PAGE_TRANSITION_LINK &&
      (add_types & ADD_FORCE_INDEX) == 0) {
    // We assume tabs opened via link clicks are part of the same task as their
    // parent.  Note that when |force_index| is true (e.g. when the user
    // drag-and-drops a link to the tab strip), callers aren't really handling
    // link clicks, they just want to score the navigation like a link click in
    // the history backend, so we don't inherit the group in this case.
    index = order_controller_->DetermineInsertionIndex(transition,
                                                       add_types & ADD_ACTIVE);
    inherit_group = true;
  } else {
    // For all other types, respect what was passed to us, normalizing -1s and
    // values that are too large.
    if (index < 0 || index > count())
      index = count();
  }

  if (transition == content::PAGE_TRANSITION_TYPED && index == count()) {
    // Also, any tab opened at the end of the TabStrip with a "TYPED"
    // transition inherit group as well. This covers the cases where the user
    // creates a New Tab (e.g. Ctrl+T, or clicks the New Tab button), or types
    // in the address bar and presses Alt+Enter. This allows for opening a new
    // Tab to quickly look up something. When this Tab is closed, the old one
    // is re-selected, not the next-adjacent.
    inherit_group = true;
  }
  InsertWebContentsAt(index, contents,
                      add_types | (inherit_group ? ADD_INHERIT_GROUP : 0));
  // Reset the index, just in case insert ended up moving it on us.
  index = GetIndexOfWebContents(contents);

  if (inherit_group && transition == content::PAGE_TRANSITION_TYPED)
    contents_data_[index]->set_reset_group_on_select(true);

  // TODO(sky): figure out why this is here and not in InsertWebContentsAt. When
  // here we seem to get failures in startup perf tests.
  // Ensure that the new WebContentsView begins at the same size as the
  // previous WebContentsView if it existed.  Otherwise, the initial WebKit
  // layout will be performed based on a width of 0 pixels, causing a
  // very long, narrow, inaccurate layout.  Because some scripts on pages (as
  // well as WebKit's anchor link location calculation) are run on the
  // initial layout and not recalculated later, we need to ensure the first
  // layout is performed with sane view dimensions even when we're opening a
  // new background tab.
  if (WebContents* old_contents = GetActiveWebContents()) {
    if ((add_types & ADD_ACTIVE) == 0) {
      contents->GetView()->SizeContents(
          old_contents->GetView()->GetContainerSize());
    }
  }
}

void TabStripModel::CloseSelectedTabs() {
  InternalCloseTabs(selection_model_.selected_indices(),
                    CLOSE_CREATE_HISTORICAL_TAB | CLOSE_USER_GESTURE);
}

void TabStripModel::SelectNextTab() {
  SelectRelativeTab(true);
}

void TabStripModel::SelectPreviousTab() {
  SelectRelativeTab(false);
}

void TabStripModel::SelectLastTab() {
  ActivateTabAt(count() - 1, true);
}

void TabStripModel::MoveTabNext() {
  // TODO: this likely needs to be updated for multi-selection.
  int new_index = std::min(active_index() + 1, count() - 1);
  MoveWebContentsAt(active_index(), new_index, true);
}

void TabStripModel::MoveTabPrevious() {
  // TODO: this likely needs to be updated for multi-selection.
  int new_index = std::max(active_index() - 1, 0);
  MoveWebContentsAt(active_index(), new_index, true);
}

// Context menu functions.
bool TabStripModel::IsContextMenuCommandEnabled(
    int context_index, ContextMenuCommand command_id) const {
  DCHECK(command_id > CommandFirst && command_id < CommandLast);
  switch (command_id) {
    case CommandNewTab:
    case CommandCloseTab:
      return true;

    case CommandReload: {
      std::vector<int> indices = GetIndicesForCommand(context_index);
      for (size_t i = 0; i < indices.size(); ++i) {
        WebContents* tab = GetWebContentsAt(indices[i]);
        if (tab) {
          CoreTabHelperDelegate* core_delegate =
              CoreTabHelper::FromWebContents(tab)->delegate();
          if (!core_delegate || core_delegate->CanReloadContents(tab))
            return true;
        }
      }
      return false;
    }

    case CommandCloseOtherTabs:
    case CommandCloseTabsToRight:
      return !GetIndicesClosedByCommand(context_index, command_id).empty();

    case CommandDuplicate: {
      std::vector<int> indices = GetIndicesForCommand(context_index);
      for (size_t i = 0; i < indices.size(); ++i) {
        if (delegate_->CanDuplicateContentsAt(indices[i]))
          return true;
      }
      return false;
    }

    case CommandRestoreTab:
      return delegate_->GetRestoreTabType() !=
          TabStripModelDelegate::RESTORE_NONE;

    case CommandTogglePinned: {
      std::vector<int> indices = GetIndicesForCommand(context_index);
      for (size_t i = 0; i < indices.size(); ++i) {
        if (!IsAppTab(indices[i]))
          return true;
      }
      return false;
    }

    case CommandBookmarkAllTabs:
      return browser_defaults::bookmarks_enabled &&
          delegate_->CanBookmarkAllTabs();

    case CommandSelectByDomain:
    case CommandSelectByOpener:
      return true;

    default:
      NOTREACHED();
  }
  return false;
}

void TabStripModel::ExecuteContextMenuCommand(
    int context_index, ContextMenuCommand command_id) {
  DCHECK(command_id > CommandFirst && command_id < CommandLast);
  switch (command_id) {
    case CommandNewTab:
      content::RecordAction(UserMetricsAction("TabContextMenu_NewTab"));
      UMA_HISTOGRAM_ENUMERATION("Tab.NewTab",
                                TabStripModel::NEW_TAB_CONTEXT_MENU,
                                TabStripModel::NEW_TAB_ENUM_COUNT);
      delegate()->AddTabAt(GURL(), context_index + 1, true);
      break;

    case CommandReload: {
      content::RecordAction(UserMetricsAction("TabContextMenu_Reload"));
      std::vector<int> indices = GetIndicesForCommand(context_index);
      for (size_t i = 0; i < indices.size(); ++i) {
        WebContents* tab = GetWebContentsAt(indices[i]);
        if (tab) {
          CoreTabHelperDelegate* core_delegate =
              CoreTabHelper::FromWebContents(tab)->delegate();
          if (!core_delegate || core_delegate->CanReloadContents(tab))
            tab->GetController().Reload(true);
        }
      }
      break;
    }

    case CommandDuplicate: {
      content::RecordAction(UserMetricsAction("TabContextMenu_Duplicate"));
      std::vector<int> indices = GetIndicesForCommand(context_index);
      // Copy the WebContents off as the indices will change as tabs are
      // duplicated.
      std::vector<WebContents*> tabs;
      for (size_t i = 0; i < indices.size(); ++i)
        tabs.push_back(GetWebContentsAt(indices[i]));
      for (size_t i = 0; i < tabs.size(); ++i) {
        int index = GetIndexOfWebContents(tabs[i]);
        if (index != -1 && delegate_->CanDuplicateContentsAt(index))
          delegate_->DuplicateContentsAt(index);
      }
      break;
    }

    case CommandCloseTab: {
      content::RecordAction(UserMetricsAction("TabContextMenu_CloseTab"));
      InternalCloseTabs(GetIndicesForCommand(context_index),
                        CLOSE_CREATE_HISTORICAL_TAB | CLOSE_USER_GESTURE);
      break;
    }

    case CommandCloseOtherTabs: {
      content::RecordAction(
          UserMetricsAction("TabContextMenu_CloseOtherTabs"));
      InternalCloseTabs(GetIndicesClosedByCommand(context_index, command_id),
                        CLOSE_CREATE_HISTORICAL_TAB);
      break;
    }

    case CommandCloseTabsToRight: {
      content::RecordAction(
          UserMetricsAction("TabContextMenu_CloseTabsToRight"));
      InternalCloseTabs(GetIndicesClosedByCommand(context_index, command_id),
                        CLOSE_CREATE_HISTORICAL_TAB);
      break;
    }

    case CommandRestoreTab: {
      content::RecordAction(UserMetricsAction("TabContextMenu_RestoreTab"));
      delegate_->RestoreTab();
      break;
    }

    case CommandTogglePinned: {
      content::RecordAction(
          UserMetricsAction("TabContextMenu_TogglePinned"));
      std::vector<int> indices = GetIndicesForCommand(context_index);
      bool pin = WillContextMenuPin(context_index);
      if (pin) {
        for (size_t i = 0; i < indices.size(); ++i) {
          if (!IsAppTab(indices[i]))
            SetTabPinned(indices[i], true);
        }
      } else {
        // Unpin from the back so that the order is maintained (unpinning can
        // trigger moving a tab).
        for (size_t i = indices.size(); i > 0; --i) {
          if (!IsAppTab(indices[i - 1]))
            SetTabPinned(indices[i - 1], false);
        }
      }
      break;
    }

    case CommandBookmarkAllTabs: {
      content::RecordAction(
          UserMetricsAction("TabContextMenu_BookmarkAllTabs"));

      delegate_->BookmarkAllTabs();
      break;
    }

    case CommandSelectByDomain:
    case CommandSelectByOpener: {
      std::vector<int> indices;
      if (command_id == CommandSelectByDomain)
        GetIndicesWithSameDomain(context_index, &indices);
      else
        GetIndicesWithSameOpener(context_index, &indices);
      ui::ListSelectionModel selection_model;
      selection_model.SetSelectedIndex(context_index);
      for (size_t i = 0; i < indices.size(); ++i)
        selection_model.AddIndexToSelection(indices[i]);
      SetSelectionFromModel(selection_model);
      break;
    }

    default:
      NOTREACHED();
  }
}

std::vector<int> TabStripModel::GetIndicesClosedByCommand(
    int index,
    ContextMenuCommand id) const {
  DCHECK(ContainsIndex(index));
  DCHECK(id == CommandCloseTabsToRight || id == CommandCloseOtherTabs);
  bool is_selected = IsTabSelected(index);
  int start;
  if (id == CommandCloseTabsToRight) {
    if (is_selected) {
      start = selection_model_.selected_indices()[
          selection_model_.selected_indices().size() - 1] + 1;
    } else {
      start = index + 1;
    }
  } else {
    start = 0;
  }
  // NOTE: callers expect the vector to be sorted in descending order.
  std::vector<int> indices;
  for (int i = count() - 1; i >= start; --i) {
    if (i != index && !IsMiniTab(i) && (!is_selected || !IsTabSelected(i)))
      indices.push_back(i);
  }
  return indices;
}

bool TabStripModel::WillContextMenuPin(int index) {
  std::vector<int> indices = GetIndicesForCommand(index);
  // If all tabs are pinned, then we unpin, otherwise we pin.
  bool all_pinned = true;
  for (size_t i = 0; i < indices.size() && all_pinned; ++i) {
    if (!IsAppTab(index))  // We never change app tabs.
      all_pinned = IsTabPinned(indices[i]);
  }
  return !all_pinned;
}

// static
bool TabStripModel::ContextMenuCommandToBrowserCommand(int cmd_id,
                                                       int* browser_cmd) {
  switch (cmd_id) {
    case CommandNewTab:
      *browser_cmd = IDC_NEW_TAB;
      break;
    case CommandReload:
      *browser_cmd = IDC_RELOAD;
      break;
    case CommandDuplicate:
      *browser_cmd = IDC_DUPLICATE_TAB;
      break;
    case CommandCloseTab:
      *browser_cmd = IDC_CLOSE_TAB;
      break;
    case CommandRestoreTab:
      *browser_cmd = IDC_RESTORE_TAB;
      break;
    case CommandBookmarkAllTabs:
      *browser_cmd = IDC_BOOKMARK_ALL_TABS;
      break;
    default:
      *browser_cmd = 0;
      return false;
  }

  return true;
}

///////////////////////////////////////////////////////////////////////////////
// TabStripModel, private:

std::vector<WebContents*> TabStripModel::GetWebContentsFromIndices(
    const std::vector<int>& indices) const {
  std::vector<WebContents*> contents;
  for (size_t i = 0; i < indices.size(); ++i)
    contents.push_back(GetWebContentsAtImpl(indices[i]));
  return contents;
}

void TabStripModel::GetIndicesWithSameDomain(int index,
                                             std::vector<int>* indices) {
  std::string domain = GetWebContentsAt(index)->GetURL().host();
  if (domain.empty())
    return;
  for (int i = 0; i < count(); ++i) {
    if (i == index)
      continue;
    if (GetWebContentsAt(i)->GetURL().host() == domain)
      indices->push_back(i);
  }
}

void TabStripModel::GetIndicesWithSameOpener(int index,
                                             std::vector<int>* indices) {
  WebContents* opener = contents_data_[index]->group();
  if (!opener) {
    // If there is no group, find all tabs with the selected tab as the opener.
    opener = GetWebContentsAt(index);
    if (!opener)
      return;
  }
  for (int i = 0; i < count(); ++i) {
    if (i == index)
      continue;
    if (contents_data_[i]->group() == opener ||
        GetWebContentsAtImpl(i) == opener) {
      indices->push_back(i);
    }
  }
}

std::vector<int> TabStripModel::GetIndicesForCommand(int index) const {
  if (!IsTabSelected(index)) {
    std::vector<int> indices;
    indices.push_back(index);
    return indices;
  }
  return selection_model_.selected_indices();
}

bool TabStripModel::IsNewTabAtEndOfTabStrip(WebContents* contents) const {
  const GURL& url = contents->GetURL();
  return url.SchemeIs(content::kChromeUIScheme) &&
         url.host() == chrome::kChromeUINewTabHost &&
         contents == GetWebContentsAtImpl(count() - 1) &&
         contents->GetController().GetEntryCount() == 1;
}

bool TabStripModel::InternalCloseTabs(const std::vector<int>& indices,
                                      uint32 close_types) {
  if (indices.empty())
    return true;

  CloseTracker close_tracker(GetWebContentsFromIndices(indices));

  // We only try the fast shutdown path if the whole browser process is *not*
  // shutting down. Fast shutdown during browser termination is handled in
  // BrowserShutdown.
  if (browser_shutdown::GetShutdownType() == browser_shutdown::NOT_VALID) {
    // Construct a map of processes to the number of associated tabs that are
    // closing.
    std::map<content::RenderProcessHost*, size_t> processes;
    for (size_t i = 0; i < indices.size(); ++i) {
      WebContents* closing_contents = GetWebContentsAtImpl(indices[i]);
      if (delegate_->ShouldRunUnloadListenerBeforeClosing(closing_contents))
        continue;
      content::RenderProcessHost* process =
          closing_contents->GetRenderProcessHost();
      ++processes[process];
    }

    // Try to fast shutdown the tabs that can close.
    for (std::map<content::RenderProcessHost*, size_t>::iterator iter =
         processes.begin(); iter != processes.end(); ++iter) {
      iter->first->FastShutdownForPageCount(iter->second);
    }
  }

  // We now return to our regularly scheduled shutdown procedure.
  bool retval = true;
  while (close_tracker.HasNext()) {
    WebContents* closing_contents = close_tracker.Next();
    int index = GetIndexOfWebContents(closing_contents);
    // Make sure we still contain the tab.
    if (index == kNoTab)
      continue;

    CoreTabHelper* core_tab_helper =
        CoreTabHelper::FromWebContents(closing_contents);
    core_tab_helper->OnCloseStarted();

    // Update the explicitly closed state. If the unload handlers cancel the
    // close the state is reset in Browser. We don't update the explicitly
    // closed state if already marked as explicitly closed as unload handlers
    // call back to this if the close is allowed.
    if (!closing_contents->GetClosedByUserGesture()) {
      closing_contents->SetClosedByUserGesture(
          close_types & CLOSE_USER_GESTURE);
    }

    if (delegate_->RunUnloadListenerBeforeClosing(closing_contents)) {
      retval = false;
      continue;
    }

    InternalCloseTab(closing_contents, index,
                     (close_types & CLOSE_CREATE_HISTORICAL_TAB) != 0);
  }

  return retval;
}

void TabStripModel::InternalCloseTab(WebContents* contents,
                                     int index,
                                     bool create_historical_tabs) {
  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                    TabClosingAt(this, contents, index));

  // Ask the delegate to save an entry for this tab in the historical tab
  // database if applicable.
  if (create_historical_tabs)
    delegate_->CreateHistoricalTab(contents);

  // Deleting the WebContents will call back to us via
  // WebContentsData::WebContentsDestroyed and detach it.
  delete contents;
}

WebContents* TabStripModel::GetWebContentsAtImpl(int index) const {
  CHECK(ContainsIndex(index)) <<
      "Failed to find: " << index << " in: " << count() << " entries.";
  return contents_data_[index]->web_contents();
}

void TabStripModel::NotifyIfTabDeactivated(WebContents* contents) {
  if (contents) {
    FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                      TabDeactivated(contents));
  }
}

void TabStripModel::NotifyIfActiveTabChanged(WebContents* old_contents,
                                             NotifyTypes notify_types) {
  WebContents* new_contents = GetWebContentsAtImpl(active_index());
  if (old_contents != new_contents) {
    int reason = notify_types == NOTIFY_USER_GESTURE
                 ? TabStripModelObserver::CHANGE_REASON_USER_GESTURE
                 : TabStripModelObserver::CHANGE_REASON_NONE;
    CHECK(!in_notify_);
    in_notify_ = true;
    FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
        ActiveTabChanged(old_contents,
                         new_contents,
                         active_index(),
                         reason));
    in_notify_ = false;
    // Activating a discarded tab reloads it, so it is no longer discarded.
    contents_data_[active_index()]->set_discarded(false);
  }
}

void TabStripModel::NotifyIfActiveOrSelectionChanged(
    WebContents* old_contents,
    NotifyTypes notify_types,
    const ui::ListSelectionModel& old_model) {
  NotifyIfActiveTabChanged(old_contents, notify_types);

  if (!selection_model().Equals(old_model)) {
    FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                      TabSelectionChanged(this, old_model));
  }
}

void TabStripModel::SetSelection(
    const ui::ListSelectionModel& new_model,
    NotifyTypes notify_types) {
  WebContents* old_contents = GetActiveWebContents();
  ui::ListSelectionModel old_model;
  old_model.Copy(selection_model_);
  if (new_model.active() != selection_model_.active())
    NotifyIfTabDeactivated(old_contents);
  selection_model_.Copy(new_model);
  NotifyIfActiveOrSelectionChanged(old_contents, notify_types, old_model);
}

void TabStripModel::SelectRelativeTab(bool next) {
  // This may happen during automated testing or if a user somehow buffers
  // many key accelerators.
  if (contents_data_.empty())
    return;

  int index = active_index();
  int delta = next ? 1 : -1;
  index = (index + count() + delta) % count();
  ActivateTabAt(index, true);
}

void TabStripModel::MoveWebContentsAtImpl(int index,
                                          int to_position,
                                          bool select_after_move) {
  WebContentsData* moved_data = contents_data_[index];
  contents_data_.erase(contents_data_.begin() + index);
  contents_data_.insert(contents_data_.begin() + to_position, moved_data);

  selection_model_.Move(index, to_position);
  if (!selection_model_.IsSelected(select_after_move) && select_after_move) {
    // TODO(sky): why doesn't this code notify observers?
    selection_model_.SetSelectedIndex(to_position);
  }

  ForgetOpenersAndGroupsReferencing(moved_data->web_contents());

  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
                    TabMoved(moved_data->web_contents(), index, to_position));
}

void TabStripModel::MoveSelectedTabsToImpl(int index,
                                           size_t start,
                                           size_t length) {
  DCHECK(start < selection_model_.selected_indices().size() &&
         start + length <= selection_model_.selected_indices().size());
  size_t end = start + length;
  int count_before_index = 0;
  for (size_t i = start; i < end &&
       selection_model_.selected_indices()[i] < index + count_before_index;
       ++i) {
    count_before_index++;
  }

  // First move those before index. Any tabs before index end up moving in the
  // selection model so we use start each time through.
  int target_index = index + count_before_index;
  size_t tab_index = start;
  while (tab_index < end &&
         selection_model_.selected_indices()[start] < index) {
    MoveWebContentsAt(selection_model_.selected_indices()[start],
                      target_index - 1, false);
    tab_index++;
  }

  // Then move those after the index. These don't result in reordering the
  // selection.
  while (tab_index < end) {
    if (selection_model_.selected_indices()[tab_index] != target_index) {
      MoveWebContentsAt(selection_model_.selected_indices()[tab_index],
                        target_index, false);
    }
    tab_index++;
    target_index++;
  }
}

// static
bool TabStripModel::OpenerMatches(const WebContentsData* data,
                                  const WebContents* opener,
                                  bool use_group) {
  return data->opener() == opener || (use_group && data->group() == opener);
}

void TabStripModel::ForgetOpenersAndGroupsReferencing(
    const WebContents* tab) {
  for (WebContentsDataVector::const_iterator i = contents_data_.begin();
       i != contents_data_.end(); ++i) {
    if ((*i)->group() == tab)
      (*i)->set_group(NULL);
    if ((*i)->opener() == tab)
      (*i)->set_opener(NULL);
  }
}
/* [<][>][^][v][top][bottom][index][help] */
root/chrome/browser/ui/tabs/tab_strip_model.cc

DEFINITIONS
