tab_strip_model.cc revision f2477e01787aa58f445919b809d89e252beef54f 
1// Copyright (c) 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#include "chrome/browser/ui/tabs/tab_strip_model.h"
6
7#include <algorithm>
8#include <map>
9#include <string>
10
11#include "base/metrics/histogram.h"
12#include "base/stl_util.h"
13#include "chrome/app/chrome_command_ids.h"
14#include "chrome/browser/browser_shutdown.h"
15#include "chrome/browser/defaults.h"
16#include "chrome/browser/extensions/tab_helper.h"
17#include "chrome/browser/profiles/profile.h"
18#include "chrome/browser/ui/tab_contents/core_tab_helper.h"
19#include "chrome/browser/ui/tab_contents/core_tab_helper_delegate.h"
20#include "chrome/browser/ui/tabs/tab_strip_model_delegate.h"
21#include "chrome/browser/ui/tabs/tab_strip_model_order_controller.h"
22#include "chrome/common/url_constants.h"
23#include "components/web_modal/web_contents_modal_dialog_manager.h"
24#include "content/public/browser/render_process_host.h"
25#include "content/public/browser/user_metrics.h"
26#include "content/public/browser/web_contents.h"
27#include "content/public/browser/web_contents_observer.h"
28#include "content/public/browser/web_contents_view.h"
29
30using content::UserMetricsAction;
31using content::WebContents;
32
33namespace {
34
35// Returns true if the specified transition is one of the types that cause the
36// opener relationships for the tab in which the transition occurred to be
37// forgotten. This is generally any navigation that isn't a link click (i.e.
38// any navigation that can be considered to be the start of a new task distinct
39// from what had previously occurred in that tab).
40bool ShouldForgetOpenersForTransition(content::PageTransition transition) {
41  return transition == content::PAGE_TRANSITION_TYPED ||
42      transition == content::PAGE_TRANSITION_AUTO_BOOKMARK ||
43      transition == content::PAGE_TRANSITION_GENERATED ||
44      transition == content::PAGE_TRANSITION_KEYWORD ||
45      transition == content::PAGE_TRANSITION_AUTO_TOPLEVEL;
46}
47
48// CloseTracker is used when closing a set of WebContents. It listens for
49// deletions of the WebContents and removes from the internal set any time one
50// is deleted.
51class CloseTracker {
52 public:
53  typedef std::vector<WebContents*> Contents;
54
55  explicit CloseTracker(const Contents& contents);
56  virtual ~CloseTracker();
57
58  // Returns true if there is another WebContents in the Tracker.
59  bool HasNext() const;
60
61  // Returns the next WebContents, or NULL if there are no more.
62  WebContents* Next();
63
64 private:
65  class DeletionObserver : public content::WebContentsObserver {
66   public:
67    DeletionObserver(CloseTracker* parent, WebContents* web_contents)
68        : WebContentsObserver(web_contents),
69          parent_(parent) {
70    }
71
72    // Expose web_contents() publicly.
73    using content::WebContentsObserver::web_contents;
74
75   private:
76    // WebContentsObserver:
77    virtual void WebContentsDestroyed(WebContents* web_contents) OVERRIDE {
78      parent_->OnWebContentsDestroyed(this);
79    }
80
81    CloseTracker* parent_;
82
83    DISALLOW_COPY_AND_ASSIGN(DeletionObserver);
84  };
85
86  void OnWebContentsDestroyed(DeletionObserver* observer);
87
88  typedef std::vector<DeletionObserver*> Observers;
89  Observers observers_;
90
91  DISALLOW_COPY_AND_ASSIGN(CloseTracker);
92};
93
94CloseTracker::CloseTracker(const Contents& contents) {
95  for (size_t i = 0; i < contents.size(); ++i)
96    observers_.push_back(new DeletionObserver(this, contents[i]));
97}
98
99CloseTracker::~CloseTracker() {
100  DCHECK(observers_.empty());
101}
102
103bool CloseTracker::HasNext() const {
104  return !observers_.empty();
105}
106
107WebContents* CloseTracker::Next() {
108  if (observers_.empty())
109    return NULL;
110
111  DeletionObserver* observer = observers_[0];
112  WebContents* web_contents = observer->web_contents();
113  observers_.erase(observers_.begin());
114  delete observer;
115  return web_contents;
116}
117
118void CloseTracker::OnWebContentsDestroyed(DeletionObserver* observer) {
119  Observers::iterator i =
120      std::find(observers_.begin(), observers_.end(), observer);
121  if (i != observers_.end()) {
122    delete *i;
123    observers_.erase(i);
124    return;
125  }
126  NOTREACHED() << "WebContents destroyed that wasn't in the list";
127}
128
129}  // namespace
130
131///////////////////////////////////////////////////////////////////////////////
132// WebContentsData
133
134// An object to hold a reference to a WebContents that is in a tabstrip, as
135// well as other various properties it has.
136class TabStripModel::WebContentsData : public content::WebContentsObserver {
137 public:
138  WebContentsData(TabStripModel* tab_strip_model, WebContents* a_contents);
139
140  // Changes the WebContents that this WebContentsData tracks.
141  void SetWebContents(WebContents* contents);
142  WebContents* web_contents() { return contents_; }
143
144  // Create a relationship between this WebContentsData and other
145  // WebContentses. Used to identify which WebContents to select next after
146  // one is closed.
147  WebContents* group() const { return group_; }
148  void set_group(WebContents* value) { group_ = value; }
149  WebContents* opener() const { return opener_; }
150  void set_opener(WebContents* value) { opener_ = value; }
151
152  // Alters the properties of the WebContents.
153  bool reset_group_on_select() const { return reset_group_on_select_; }
154  void set_reset_group_on_select(bool value) { reset_group_on_select_ = value; }
155  bool pinned() const { return pinned_; }
156  void set_pinned(bool value) { pinned_ = value; }
157  bool blocked() const { return blocked_; }
158  void set_blocked(bool value) { blocked_ = value; }
159  bool discarded() const { return discarded_; }
160  void set_discarded(bool value) { discarded_ = value; }
161
162 private:
163  // Make sure that if someone deletes this WebContents out from under us, it
164  // is properly removed from the tab strip.
165  virtual void WebContentsDestroyed(WebContents* web_contents) OVERRIDE;
166
167  // The WebContents being tracked by this WebContentsData. The
168  // WebContentsObserver does keep a reference, but when the WebContents is
169  // deleted, the WebContentsObserver reference is NULLed and thus inaccessible.
170  WebContents* contents_;
171
172  // The TabStripModel containing this WebContents.
173  TabStripModel* tab_strip_model_;
174
175  // The group is used to model a set of tabs spawned from a single parent
176  // tab. This value is preserved for a given tab as long as the tab remains
177  // navigated to the link it was initially opened at or some navigation from
178  // that page (i.e. if the user types or visits a bookmark or some other
179  // navigation within that tab, the group relationship is lost). This
180  // property can safely be used to implement features that depend on a
181  // logical group of related tabs.
182  WebContents* group_;
183
184  // The owner models the same relationship as group, except it is more
185  // easily discarded, e.g. when the user switches to a tab not part of the
186  // same group. This property is used to determine what tab to select next
187  // when one is closed.
188  WebContents* opener_;
189
190  // True if our group should be reset the moment selection moves away from
191  // this tab. This is the case for tabs opened in the foreground at the end
192  // of the TabStrip while viewing another Tab. If these tabs are closed
193  // before selection moves elsewhere, their opener is selected. But if
194  // selection shifts to _any_ tab (including their opener), the group
195  // relationship is reset to avoid confusing close sequencing.
196  bool reset_group_on_select_;
197
198  // Is the tab pinned?
199  bool pinned_;
200
201  // Is the tab interaction blocked by a modal dialog?
202  bool blocked_;
203
204  // Has the tab data been discarded to save memory?
205  bool discarded_;
206
207  DISALLOW_COPY_AND_ASSIGN(WebContentsData);
208};
209
210TabStripModel::WebContentsData::WebContentsData(TabStripModel* tab_strip_model,
211                                                WebContents* contents)
212    : content::WebContentsObserver(contents),
213      contents_(contents),
214      tab_strip_model_(tab_strip_model),
215      group_(NULL),
216      opener_(NULL),
217      reset_group_on_select_(false),
218      pinned_(false),
219      blocked_(false),
220      discarded_(false) {
221}
222
223void TabStripModel::WebContentsData::SetWebContents(WebContents* contents) {
224  contents_ = contents;
225  Observe(contents);
226}
227
228void TabStripModel::WebContentsData::WebContentsDestroyed(
229    WebContents* web_contents) {
230  DCHECK_EQ(contents_, web_contents);
231
232  // Note that we only detach the contents here, not close it - it's
233  // already been closed. We just want to undo our bookkeeping.
234  int index = tab_strip_model_->GetIndexOfWebContents(web_contents);
235  DCHECK_NE(TabStripModel::kNoTab, index);
236  tab_strip_model_->DetachWebContentsAt(index);
237}
238
239///////////////////////////////////////////////////////////////////////////////
240// TabStripModel, public:
241
242TabStripModel::TabStripModel(TabStripModelDelegate* delegate, Profile* profile)
243    : delegate_(delegate),
244      profile_(profile),
245      closing_all_(false),
246      in_notify_(false) {
247  DCHECK(delegate_);
248  order_controller_.reset(new TabStripModelOrderController(this));
249}
250
251TabStripModel::~TabStripModel() {
252  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
253                    TabStripModelDeleted());
254  STLDeleteElements(&contents_data_);
255  order_controller_.reset();
256}
257
258void TabStripModel::AddObserver(TabStripModelObserver* observer) {
259  observers_.AddObserver(observer);
260}
261
262void TabStripModel::RemoveObserver(TabStripModelObserver* observer) {
263  observers_.RemoveObserver(observer);
264}
265
266bool TabStripModel::ContainsIndex(int index) const {
267  return index >= 0 && index < count();
268}
269
270void TabStripModel::AppendWebContents(WebContents* contents,
271                                      bool foreground) {
272  InsertWebContentsAt(count(), contents,
273                      foreground ? (ADD_INHERIT_GROUP | ADD_ACTIVE) :
274                                   ADD_NONE);
275}
276
277void TabStripModel::InsertWebContentsAt(int index,
278                                        WebContents* contents,
279                                        int add_types) {
280  delegate_->WillAddWebContents(contents);
281
282  bool active = add_types & ADD_ACTIVE;
283  // Force app tabs to be pinned.
284  extensions::TabHelper* extensions_tab_helper =
285      extensions::TabHelper::FromWebContents(contents);
286  bool pin = extensions_tab_helper->is_app() || add_types & ADD_PINNED;
287  index = ConstrainInsertionIndex(index, pin);
288
289  // In tab dragging situations, if the last tab in the window was detached
290  // then the user aborted the drag, we will have the |closing_all_| member
291  // set (see DetachWebContentsAt) which will mess with our mojo here. We need
292  // to clear this bit.
293  closing_all_ = false;
294
295  // Have to get the active contents before we monkey with the contents
296  // otherwise we run into problems when we try to change the active contents
297  // since the old contents and the new contents will be the same...
298  WebContents* active_contents = GetActiveWebContents();
299  WebContentsData* data = new WebContentsData(this, contents);
300  data->set_pinned(pin);
301  if ((add_types & ADD_INHERIT_GROUP) && active_contents) {
302    if (active) {
303      // Forget any existing relationships, we don't want to make things too
304      // confusing by having multiple groups active at the same time.
305      ForgetAllOpeners();
306    }
307    // Anything opened by a link we deem to have an opener.
308    data->set_group(active_contents);
309    data->set_opener(active_contents);
310  } else if ((add_types & ADD_INHERIT_OPENER) && active_contents) {
311    if (active) {
312      // Forget any existing relationships, we don't want to make things too
313      // confusing by having multiple groups active at the same time.
314      ForgetAllOpeners();
315    }
316    data->set_opener(active_contents);
317  }
318
319  web_modal::WebContentsModalDialogManager* modal_dialog_manager =
320      web_modal::WebContentsModalDialogManager::FromWebContents(contents);
321  if (modal_dialog_manager)
322    data->set_blocked(modal_dialog_manager->IsDialogActive());
323
324  contents_data_.insert(contents_data_.begin() + index, data);
325
326  selection_model_.IncrementFrom(index);
327
328  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
329                    TabInsertedAt(contents, index, active));
330  if (active) {
331    ui::ListSelectionModel new_model;
332    new_model.Copy(selection_model_);
333    new_model.SetSelectedIndex(index);
334    SetSelection(new_model, NOTIFY_DEFAULT);
335  }
336}
337
338WebContents* TabStripModel::ReplaceWebContentsAt(int index,
339                                                 WebContents* new_contents) {
340  delegate_->WillAddWebContents(new_contents);
341
342  DCHECK(ContainsIndex(index));
343  WebContents* old_contents = GetWebContentsAtImpl(index);
344
345  ForgetOpenersAndGroupsReferencing(old_contents);
346
347  contents_data_[index]->SetWebContents(new_contents);
348
349  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
350                    TabReplacedAt(this, old_contents, new_contents, index));
351
352  // When the active WebContents is replaced send out a selection notification
353  // too. We do this as nearly all observers need to treat a replacement of the
354  // selected contents as the selection changing.
355  if (active_index() == index) {
356    FOR_EACH_OBSERVER(
357        TabStripModelObserver,
358        observers_,
359        ActiveTabChanged(old_contents,
360                         new_contents,
361                         active_index(),
362                         TabStripModelObserver::CHANGE_REASON_REPLACED));
363  }
364  return old_contents;
365}
366
367WebContents* TabStripModel::DiscardWebContentsAt(int index) {
368  DCHECK(ContainsIndex(index));
369  // Do not discard active tab.
370  if (active_index() == index)
371    return NULL;
372
373  WebContents* null_contents =
374      WebContents::Create(WebContents::CreateParams(profile()));
375  WebContents* old_contents = GetWebContentsAtImpl(index);
376  // Copy over the state from the navigation controller so we preserve the
377  // back/forward history and continue to display the correct title/favicon.
378  null_contents->GetController().CopyStateFrom(old_contents->GetController());
379  // Replace the tab we're discarding with the null version.
380  ReplaceWebContentsAt(index, null_contents);
381  // Mark the tab so it will reload when we click.
382  contents_data_[index]->set_discarded(true);
383  // Discard the old tab's renderer.
384  // TODO(jamescook): This breaks script connections with other tabs.
385  // We need to find a different approach that doesn't do that, perhaps based
386  // on navigation to swappedout://.
387  delete old_contents;
388  return null_contents;
389}
390
391WebContents* TabStripModel::DetachWebContentsAt(int index) {
392  CHECK(!in_notify_);
393  if (contents_data_.empty())
394    return NULL;
395
396  DCHECK(ContainsIndex(index));
397
398  WebContents* removed_contents = GetWebContentsAtImpl(index);
399  bool was_selected = IsTabSelected(index);
400  int next_selected_index = order_controller_->DetermineNewSelectedIndex(index);
401  delete contents_data_[index];
402  contents_data_.erase(contents_data_.begin() + index);
403  ForgetOpenersAndGroupsReferencing(removed_contents);
404  if (empty())
405    closing_all_ = true;
406  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
407                    TabDetachedAt(removed_contents, index));
408  if (empty()) {
409    selection_model_.Clear();
410    // TabDetachedAt() might unregister observers, so send |TabStripEmpty()| in
411    // a second pass.
412    FOR_EACH_OBSERVER(TabStripModelObserver, observers_, TabStripEmpty());
413  } else {
414    int old_active = active_index();
415    selection_model_.DecrementFrom(index);
416    ui::ListSelectionModel old_model;
417    old_model.Copy(selection_model_);
418    if (index == old_active) {
419      NotifyIfTabDeactivated(removed_contents);
420      if (!selection_model_.empty()) {
421        // The active tab was removed, but there is still something selected.
422        // Move the active and anchor to the first selected index.
423        selection_model_.set_active(selection_model_.selected_indices()[0]);
424        selection_model_.set_anchor(selection_model_.active());
425      } else {
426        // The active tab was removed and nothing is selected. Reset the
427        // selection and send out notification.
428        selection_model_.SetSelectedIndex(next_selected_index);
429      }
430      NotifyIfActiveTabChanged(removed_contents, NOTIFY_DEFAULT);
431    }
432
433    // Sending notification in case the detached tab was selected. Using
434    // NotifyIfActiveOrSelectionChanged() here would not guarantee that a
435    // notification is sent even though the tab selection has changed because
436    // |old_model| is stored after calling DecrementFrom().
437    if (was_selected) {
438      FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
439                        TabSelectionChanged(this, old_model));
440    }
441  }
442  return removed_contents;
443}
444
445void TabStripModel::ActivateTabAt(int index, bool user_gesture) {
446  DCHECK(ContainsIndex(index));
447  ui::ListSelectionModel new_model;
448  new_model.Copy(selection_model_);
449  new_model.SetSelectedIndex(index);
450  SetSelection(new_model, user_gesture ? NOTIFY_USER_GESTURE : NOTIFY_DEFAULT);
451}
452
453void TabStripModel::AddTabAtToSelection(int index) {
454  DCHECK(ContainsIndex(index));
455  ui::ListSelectionModel new_model;
456  new_model.Copy(selection_model_);
457  new_model.AddIndexToSelection(index);
458  SetSelection(new_model, NOTIFY_DEFAULT);
459}
460
461void TabStripModel::MoveWebContentsAt(int index,
462                                      int to_position,
463                                      bool select_after_move) {
464  DCHECK(ContainsIndex(index));
465  if (index == to_position)
466    return;
467
468  int first_non_mini_tab = IndexOfFirstNonMiniTab();
469  if ((index < first_non_mini_tab && to_position >= first_non_mini_tab) ||
470      (to_position < first_non_mini_tab && index >= first_non_mini_tab)) {
471    // This would result in mini tabs mixed with non-mini tabs. We don't allow
472    // that.
473    return;
474  }
475
476  MoveWebContentsAtImpl(index, to_position, select_after_move);
477}
478
479void TabStripModel::MoveSelectedTabsTo(int index) {
480  int total_mini_count = IndexOfFirstNonMiniTab();
481  int selected_mini_count = 0;
482  int selected_count =
483      static_cast<int>(selection_model_.selected_indices().size());
484  for (int i = 0; i < selected_count &&
485           IsMiniTab(selection_model_.selected_indices()[i]); ++i) {
486    selected_mini_count++;
487  }
488
489  // To maintain that all mini-tabs occur before non-mini-tabs we move them
490  // first.
491  if (selected_mini_count > 0) {
492    MoveSelectedTabsToImpl(
493        std::min(total_mini_count - selected_mini_count, index), 0u,
494        selected_mini_count);
495    if (index > total_mini_count - selected_mini_count) {
496      // We're being told to drag mini-tabs to an invalid location. Adjust the
497      // index such that non-mini-tabs end up at a location as though we could
498      // move the mini-tabs to index. See description in header for more
499      // details.
500      index += selected_mini_count;
501    }
502  }
503  if (selected_mini_count == selected_count)
504    return;
505
506  // Then move the non-pinned tabs.
507  MoveSelectedTabsToImpl(std::max(index, total_mini_count),
508                         selected_mini_count,
509                         selected_count - selected_mini_count);
510}
511
512WebContents* TabStripModel::GetActiveWebContents() const {
513  return GetWebContentsAt(active_index());
514}
515
516WebContents* TabStripModel::GetWebContentsAt(int index) const {
517  if (ContainsIndex(index))
518    return GetWebContentsAtImpl(index);
519  return NULL;
520}
521
522int TabStripModel::GetIndexOfWebContents(const WebContents* contents) const {
523  for (size_t i = 0; i < contents_data_.size(); ++i) {
524    if (contents_data_[i]->web_contents() == contents)
525      return i;
526  }
527  return kNoTab;
528}
529
530void TabStripModel::UpdateWebContentsStateAt(int index,
531    TabStripModelObserver::TabChangeType change_type) {
532  DCHECK(ContainsIndex(index));
533
534  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
535      TabChangedAt(GetWebContentsAtImpl(index), index, change_type));
536}
537
538void TabStripModel::CloseAllTabs() {
539  // Set state so that observers can adjust their behavior to suit this
540  // specific condition when CloseWebContentsAt causes a flurry of
541  // Close/Detach/Select notifications to be sent.
542  closing_all_ = true;
543  std::vector<int> closing_tabs;
544  for (int i = count() - 1; i >= 0; --i)
545    closing_tabs.push_back(i);
546  InternalCloseTabs(closing_tabs, CLOSE_CREATE_HISTORICAL_TAB);
547}
548
549bool TabStripModel::CloseWebContentsAt(int index, uint32 close_types) {
550  DCHECK(ContainsIndex(index));
551  std::vector<int> closing_tabs;
552  closing_tabs.push_back(index);
553  return InternalCloseTabs(closing_tabs, close_types);
554}
555
556bool TabStripModel::TabsAreLoading() const {
557  for (WebContentsDataVector::const_iterator iter = contents_data_.begin();
558       iter != contents_data_.end(); ++iter) {
559    if ((*iter)->web_contents()->IsLoading())
560      return true;
561  }
562  return false;
563}
564
565WebContents* TabStripModel::GetOpenerOfWebContentsAt(int index) {
566  DCHECK(ContainsIndex(index));
567  return contents_data_[index]->opener();
568}
569
570void TabStripModel::SetOpenerOfWebContentsAt(int index,
571                                             WebContents* opener) {
572  DCHECK(ContainsIndex(index));
573  DCHECK(opener);
574  contents_data_[index]->set_opener(opener);
575}
576
577int TabStripModel::GetIndexOfNextWebContentsOpenedBy(const WebContents* opener,
578                                                     int start_index,
579                                                     bool use_group) const {
580  DCHECK(opener);
581  DCHECK(ContainsIndex(start_index));
582
583  // Check tabs after start_index first.
584  for (int i = start_index + 1; i < count(); ++i) {
585    if (OpenerMatches(contents_data_[i], opener, use_group))
586      return i;
587  }
588  // Then check tabs before start_index, iterating backwards.
589  for (int i = start_index - 1; i >= 0; --i) {
590    if (OpenerMatches(contents_data_[i], opener, use_group))
591      return i;
592  }
593  return kNoTab;
594}
595
596int TabStripModel::GetIndexOfLastWebContentsOpenedBy(const WebContents* opener,
597                                                     int start_index) const {
598  DCHECK(opener);
599  DCHECK(ContainsIndex(start_index));
600
601  for (int i = contents_data_.size() - 1; i > start_index; --i) {
602    if (contents_data_[i]->opener() == opener)
603      return i;
604  }
605  return kNoTab;
606}
607
608void TabStripModel::TabNavigating(WebContents* contents,
609                                  content::PageTransition transition) {
610  if (ShouldForgetOpenersForTransition(transition)) {
611    // Don't forget the openers if this tab is a New Tab page opened at the
612    // end of the TabStrip (e.g. by pressing Ctrl+T). Give the user one
613    // navigation of one of these transition types before resetting the
614    // opener relationships (this allows for the use case of opening a new
615    // tab to do a quick look-up of something while viewing a tab earlier in
616    // the strip). We can make this heuristic more permissive if need be.
617    if (!IsNewTabAtEndOfTabStrip(contents)) {
618      // If the user navigates the current tab to another page in any way
619      // other than by clicking a link, we want to pro-actively forget all
620      // TabStrip opener relationships since we assume they're beginning a
621      // different task by reusing the current tab.
622      ForgetAllOpeners();
623      // In this specific case we also want to reset the group relationship,
624      // since it is now technically invalid.
625      ForgetGroup(contents);
626    }
627  }
628}
629
630void TabStripModel::ForgetAllOpeners() {
631  // Forget all opener memories so we don't do anything weird with tab
632  // re-selection ordering.
633  for (WebContentsDataVector::const_iterator iter = contents_data_.begin();
634       iter != contents_data_.end(); ++iter)
635    (*iter)->set_opener(NULL);
636}
637
638void TabStripModel::ForgetGroup(WebContents* contents) {
639  int index = GetIndexOfWebContents(contents);
640  DCHECK(ContainsIndex(index));
641  contents_data_[index]->set_group(NULL);
642  contents_data_[index]->set_opener(NULL);
643}
644
645bool TabStripModel::ShouldResetGroupOnSelect(WebContents* contents) const {
646  int index = GetIndexOfWebContents(contents);
647  DCHECK(ContainsIndex(index));
648  return contents_data_[index]->reset_group_on_select();
649}
650
651void TabStripModel::SetTabBlocked(int index, bool blocked) {
652  DCHECK(ContainsIndex(index));
653  if (contents_data_[index]->blocked() == blocked)
654    return;
655  contents_data_[index]->set_blocked(blocked);
656  FOR_EACH_OBSERVER(
657      TabStripModelObserver, observers_,
658      TabBlockedStateChanged(contents_data_[index]->web_contents(),
659                             index));
660}
661
662void TabStripModel::SetTabPinned(int index, bool pinned) {
663  DCHECK(ContainsIndex(index));
664  if (contents_data_[index]->pinned() == pinned)
665    return;
666
667  if (IsAppTab(index)) {
668    if (!pinned) {
669      // App tabs should always be pinned.
670      NOTREACHED();
671      return;
672    }
673    // Changing the pinned state of an app tab doesn't affect its mini-tab
674    // status.
675    contents_data_[index]->set_pinned(pinned);
676  } else {
677    // The tab is not an app tab, its position may have to change as the
678    // mini-tab state is changing.
679    int non_mini_tab_index = IndexOfFirstNonMiniTab();
680    contents_data_[index]->set_pinned(pinned);
681    if (pinned && index != non_mini_tab_index) {
682      MoveWebContentsAtImpl(index, non_mini_tab_index, false);
683      index = non_mini_tab_index;
684    } else if (!pinned && index + 1 != non_mini_tab_index) {
685      MoveWebContentsAtImpl(index, non_mini_tab_index - 1, false);
686      index = non_mini_tab_index - 1;
687    }
688
689    FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
690                      TabMiniStateChanged(contents_data_[index]->web_contents(),
691                                          index));
692  }
693
694  // else: the tab was at the boundary and its position doesn't need to change.
695  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
696                    TabPinnedStateChanged(contents_data_[index]->web_contents(),
697                                          index));
698}
699
700bool TabStripModel::IsTabPinned(int index) const {
701  DCHECK(ContainsIndex(index));
702  return contents_data_[index]->pinned();
703}
704
705bool TabStripModel::IsMiniTab(int index) const {
706  return IsTabPinned(index) || IsAppTab(index);
707}
708
709bool TabStripModel::IsAppTab(int index) const {
710  WebContents* contents = GetWebContentsAt(index);
711  return contents && extensions::TabHelper::FromWebContents(contents)->is_app();
712}
713
714bool TabStripModel::IsTabBlocked(int index) const {
715  return contents_data_[index]->blocked();
716}
717
718bool TabStripModel::IsTabDiscarded(int index) const {
719  return contents_data_[index]->discarded();
720}
721
722int TabStripModel::IndexOfFirstNonMiniTab() const {
723  for (size_t i = 0; i < contents_data_.size(); ++i) {
724    if (!IsMiniTab(static_cast<int>(i)))
725      return static_cast<int>(i);
726  }
727  // No mini-tabs.
728  return count();
729}
730
731int TabStripModel::ConstrainInsertionIndex(int index, bool mini_tab) {
732  return mini_tab ? std::min(std::max(0, index), IndexOfFirstNonMiniTab()) :
733      std::min(count(), std::max(index, IndexOfFirstNonMiniTab()));
734}
735
736void TabStripModel::ExtendSelectionTo(int index) {
737  DCHECK(ContainsIndex(index));
738  ui::ListSelectionModel new_model;
739  new_model.Copy(selection_model_);
740  new_model.SetSelectionFromAnchorTo(index);
741  SetSelection(new_model, NOTIFY_DEFAULT);
742}
743
744void TabStripModel::ToggleSelectionAt(int index) {
745  DCHECK(ContainsIndex(index));
746  ui::ListSelectionModel new_model;
747  new_model.Copy(selection_model());
748  if (selection_model_.IsSelected(index)) {
749    if (selection_model_.size() == 1) {
750      // One tab must be selected and this tab is currently selected so we can't
751      // unselect it.
752      return;
753    }
754    new_model.RemoveIndexFromSelection(index);
755    new_model.set_anchor(index);
756    if (new_model.active() == index ||
757        new_model.active() == ui::ListSelectionModel::kUnselectedIndex)
758      new_model.set_active(new_model.selected_indices()[0]);
759  } else {
760    new_model.AddIndexToSelection(index);
761    new_model.set_anchor(index);
762    new_model.set_active(index);
763  }
764  SetSelection(new_model, NOTIFY_DEFAULT);
765}
766
767void TabStripModel::AddSelectionFromAnchorTo(int index) {
768  ui::ListSelectionModel new_model;
769  new_model.Copy(selection_model_);
770  new_model.AddSelectionFromAnchorTo(index);
771  SetSelection(new_model, NOTIFY_DEFAULT);
772}
773
774bool TabStripModel::IsTabSelected(int index) const {
775  DCHECK(ContainsIndex(index));
776  return selection_model_.IsSelected(index);
777}
778
779void TabStripModel::SetSelectionFromModel(
780    const ui::ListSelectionModel& source) {
781  DCHECK_NE(ui::ListSelectionModel::kUnselectedIndex, source.active());
782  SetSelection(source, NOTIFY_DEFAULT);
783}
784
785void TabStripModel::AddWebContents(WebContents* contents,
786                                   int index,
787                                   content::PageTransition transition,
788                                   int add_types) {
789  // If the newly-opened tab is part of the same task as the parent tab, we want
790  // to inherit the parent's "group" attribute, so that if this tab is then
791  // closed we'll jump back to the parent tab.
792  bool inherit_group = (add_types & ADD_INHERIT_GROUP) == ADD_INHERIT_GROUP;
793
794  if (transition == content::PAGE_TRANSITION_LINK &&
795      (add_types & ADD_FORCE_INDEX) == 0) {
796    // We assume tabs opened via link clicks are part of the same task as their
797    // parent.  Note that when |force_index| is true (e.g. when the user
798    // drag-and-drops a link to the tab strip), callers aren't really handling
799    // link clicks, they just want to score the navigation like a link click in
800    // the history backend, so we don't inherit the group in this case.
801    index = order_controller_->DetermineInsertionIndex(transition,
802                                                       add_types & ADD_ACTIVE);
803    inherit_group = true;
804  } else {
805    // For all other types, respect what was passed to us, normalizing -1s and
806    // values that are too large.
807    if (index < 0 || index > count())
808      index = count();
809  }
810
811  if (transition == content::PAGE_TRANSITION_TYPED && index == count()) {
812    // Also, any tab opened at the end of the TabStrip with a "TYPED"
813    // transition inherit group as well. This covers the cases where the user
814    // creates a New Tab (e.g. Ctrl+T, or clicks the New Tab button), or types
815    // in the address bar and presses Alt+Enter. This allows for opening a new
816    // Tab to quickly look up something. When this Tab is closed, the old one
817    // is re-selected, not the next-adjacent.
818    inherit_group = true;
819  }
820  InsertWebContentsAt(index, contents,
821                      add_types | (inherit_group ? ADD_INHERIT_GROUP : 0));
822  // Reset the index, just in case insert ended up moving it on us.
823  index = GetIndexOfWebContents(contents);
824
825  if (inherit_group && transition == content::PAGE_TRANSITION_TYPED)
826    contents_data_[index]->set_reset_group_on_select(true);
827
828  // TODO(sky): figure out why this is here and not in InsertWebContentsAt. When
829  // here we seem to get failures in startup perf tests.
830  // Ensure that the new WebContentsView begins at the same size as the
831  // previous WebContentsView if it existed.  Otherwise, the initial WebKit
832  // layout will be performed based on a width of 0 pixels, causing a
833  // very long, narrow, inaccurate layout.  Because some scripts on pages (as
834  // well as WebKit's anchor link location calculation) are run on the
835  // initial layout and not recalculated later, we need to ensure the first
836  // layout is performed with sane view dimensions even when we're opening a
837  // new background tab.
838  if (WebContents* old_contents = GetActiveWebContents()) {
839    if ((add_types & ADD_ACTIVE) == 0) {
840      contents->GetView()->SizeContents(
841          old_contents->GetView()->GetContainerSize());
842    }
843  }
844}
845
846void TabStripModel::CloseSelectedTabs() {
847  InternalCloseTabs(selection_model_.selected_indices(),
848                    CLOSE_CREATE_HISTORICAL_TAB | CLOSE_USER_GESTURE);
849}
850
851void TabStripModel::SelectNextTab() {
852  SelectRelativeTab(true);
853}
854
855void TabStripModel::SelectPreviousTab() {
856  SelectRelativeTab(false);
857}
858
859void TabStripModel::SelectLastTab() {
860  ActivateTabAt(count() - 1, true);
861}
862
863void TabStripModel::MoveTabNext() {
864  // TODO: this likely needs to be updated for multi-selection.
865  int new_index = std::min(active_index() + 1, count() - 1);
866  MoveWebContentsAt(active_index(), new_index, true);
867}
868
869void TabStripModel::MoveTabPrevious() {
870  // TODO: this likely needs to be updated for multi-selection.
871  int new_index = std::max(active_index() - 1, 0);
872  MoveWebContentsAt(active_index(), new_index, true);
873}
874
875// Context menu functions.
876bool TabStripModel::IsContextMenuCommandEnabled(
877    int context_index, ContextMenuCommand command_id) const {
878  DCHECK(command_id > CommandFirst && command_id < CommandLast);
879  switch (command_id) {
880    case CommandNewTab:
881    case CommandCloseTab:
882      return true;
883
884    case CommandReload: {
885      std::vector<int> indices = GetIndicesForCommand(context_index);
886      for (size_t i = 0; i < indices.size(); ++i) {
887        WebContents* tab = GetWebContentsAt(indices[i]);
888        if (tab) {
889          CoreTabHelperDelegate* core_delegate =
890              CoreTabHelper::FromWebContents(tab)->delegate();
891          if (!core_delegate || core_delegate->CanReloadContents(tab))
892            return true;
893        }
894      }
895      return false;
896    }
897
898    case CommandCloseOtherTabs:
899    case CommandCloseTabsToRight:
900      return !GetIndicesClosedByCommand(context_index, command_id).empty();
901
902    case CommandDuplicate: {
903      std::vector<int> indices = GetIndicesForCommand(context_index);
904      for (size_t i = 0; i < indices.size(); ++i) {
905        if (delegate_->CanDuplicateContentsAt(indices[i]))
906          return true;
907      }
908      return false;
909    }
910
911    case CommandRestoreTab:
912      return delegate_->GetRestoreTabType() !=
913          TabStripModelDelegate::RESTORE_NONE;
914
915    case CommandTogglePinned: {
916      std::vector<int> indices = GetIndicesForCommand(context_index);
917      for (size_t i = 0; i < indices.size(); ++i) {
918        if (!IsAppTab(indices[i]))
919          return true;
920      }
921      return false;
922    }
923
924    case CommandBookmarkAllTabs:
925      return browser_defaults::bookmarks_enabled &&
926          delegate_->CanBookmarkAllTabs();
927
928    case CommandSelectByDomain:
929    case CommandSelectByOpener:
930      return true;
931
932    default:
933      NOTREACHED();
934  }
935  return false;
936}
937
938void TabStripModel::ExecuteContextMenuCommand(
939    int context_index, ContextMenuCommand command_id) {
940  DCHECK(command_id > CommandFirst && command_id < CommandLast);
941  switch (command_id) {
942    case CommandNewTab:
943      content::RecordAction(UserMetricsAction("TabContextMenu_NewTab"));
944      UMA_HISTOGRAM_ENUMERATION("Tab.NewTab",
945                                TabStripModel::NEW_TAB_CONTEXT_MENU,
946                                TabStripModel::NEW_TAB_ENUM_COUNT);
947      delegate()->AddTabAt(GURL(), context_index + 1, true);
948      break;
949
950    case CommandReload: {
951      content::RecordAction(UserMetricsAction("TabContextMenu_Reload"));
952      std::vector<int> indices = GetIndicesForCommand(context_index);
953      for (size_t i = 0; i < indices.size(); ++i) {
954        WebContents* tab = GetWebContentsAt(indices[i]);
955        if (tab) {
956          CoreTabHelperDelegate* core_delegate =
957              CoreTabHelper::FromWebContents(tab)->delegate();
958          if (!core_delegate || core_delegate->CanReloadContents(tab))
959            tab->GetController().Reload(true);
960        }
961      }
962      break;
963    }
964
965    case CommandDuplicate: {
966      content::RecordAction(UserMetricsAction("TabContextMenu_Duplicate"));
967      std::vector<int> indices = GetIndicesForCommand(context_index);
968      // Copy the WebContents off as the indices will change as tabs are
969      // duplicated.
970      std::vector<WebContents*> tabs;
971      for (size_t i = 0; i < indices.size(); ++i)
972        tabs.push_back(GetWebContentsAt(indices[i]));
973      for (size_t i = 0; i < tabs.size(); ++i) {
974        int index = GetIndexOfWebContents(tabs[i]);
975        if (index != -1 && delegate_->CanDuplicateContentsAt(index))
976          delegate_->DuplicateContentsAt(index);
977      }
978      break;
979    }
980
981    case CommandCloseTab: {
982      content::RecordAction(UserMetricsAction("TabContextMenu_CloseTab"));
983      InternalCloseTabs(GetIndicesForCommand(context_index),
984                        CLOSE_CREATE_HISTORICAL_TAB | CLOSE_USER_GESTURE);
985      break;
986    }
987
988    case CommandCloseOtherTabs: {
989      content::RecordAction(
990          UserMetricsAction("TabContextMenu_CloseOtherTabs"));
991      InternalCloseTabs(GetIndicesClosedByCommand(context_index, command_id),
992                        CLOSE_CREATE_HISTORICAL_TAB);
993      break;
994    }
995
996    case CommandCloseTabsToRight: {
997      content::RecordAction(
998          UserMetricsAction("TabContextMenu_CloseTabsToRight"));
999      InternalCloseTabs(GetIndicesClosedByCommand(context_index, command_id),
1000                        CLOSE_CREATE_HISTORICAL_TAB);
1001      break;
1002    }
1003
1004    case CommandRestoreTab: {
1005      content::RecordAction(UserMetricsAction("TabContextMenu_RestoreTab"));
1006      delegate_->RestoreTab();
1007      break;
1008    }
1009
1010    case CommandTogglePinned: {
1011      content::RecordAction(
1012          UserMetricsAction("TabContextMenu_TogglePinned"));
1013      std::vector<int> indices = GetIndicesForCommand(context_index);
1014      bool pin = WillContextMenuPin(context_index);
1015      if (pin) {
1016        for (size_t i = 0; i < indices.size(); ++i) {
1017          if (!IsAppTab(indices[i]))
1018            SetTabPinned(indices[i], true);
1019        }
1020      } else {
1021        // Unpin from the back so that the order is maintained (unpinning can
1022        // trigger moving a tab).
1023        for (size_t i = indices.size(); i > 0; --i) {
1024          if (!IsAppTab(indices[i - 1]))
1025            SetTabPinned(indices[i - 1], false);
1026        }
1027      }
1028      break;
1029    }
1030
1031    case CommandBookmarkAllTabs: {
1032      content::RecordAction(
1033          UserMetricsAction("TabContextMenu_BookmarkAllTabs"));
1034
1035      delegate_->BookmarkAllTabs();
1036      break;
1037    }
1038
1039    case CommandSelectByDomain:
1040    case CommandSelectByOpener: {
1041      std::vector<int> indices;
1042      if (command_id == CommandSelectByDomain)
1043        GetIndicesWithSameDomain(context_index, &indices);
1044      else
1045        GetIndicesWithSameOpener(context_index, &indices);
1046      ui::ListSelectionModel selection_model;
1047      selection_model.SetSelectedIndex(context_index);
1048      for (size_t i = 0; i < indices.size(); ++i)
1049        selection_model.AddIndexToSelection(indices[i]);
1050      SetSelectionFromModel(selection_model);
1051      break;
1052    }
1053
1054    default:
1055      NOTREACHED();
1056  }
1057}
1058
1059std::vector<int> TabStripModel::GetIndicesClosedByCommand(
1060    int index,
1061    ContextMenuCommand id) const {
1062  DCHECK(ContainsIndex(index));
1063  DCHECK(id == CommandCloseTabsToRight || id == CommandCloseOtherTabs);
1064  bool is_selected = IsTabSelected(index);
1065  int start;
1066  if (id == CommandCloseTabsToRight) {
1067    if (is_selected) {
1068      start = selection_model_.selected_indices()[
1069          selection_model_.selected_indices().size() - 1] + 1;
1070    } else {
1071      start = index + 1;
1072    }
1073  } else {
1074    start = 0;
1075  }
1076  // NOTE: callers expect the vector to be sorted in descending order.
1077  std::vector<int> indices;
1078  for (int i = count() - 1; i >= start; --i) {
1079    if (i != index && !IsMiniTab(i) && (!is_selected || !IsTabSelected(i)))
1080      indices.push_back(i);
1081  }
1082  return indices;
1083}
1084
1085bool TabStripModel::WillContextMenuPin(int index) {
1086  std::vector<int> indices = GetIndicesForCommand(index);
1087  // If all tabs are pinned, then we unpin, otherwise we pin.
1088  bool all_pinned = true;
1089  for (size_t i = 0; i < indices.size() && all_pinned; ++i) {
1090    if (!IsAppTab(index))  // We never change app tabs.
1091      all_pinned = IsTabPinned(indices[i]);
1092  }
1093  return !all_pinned;
1094}
1095
1096// static
1097bool TabStripModel::ContextMenuCommandToBrowserCommand(int cmd_id,
1098                                                       int* browser_cmd) {
1099  switch (cmd_id) {
1100    case CommandNewTab:
1101      *browser_cmd = IDC_NEW_TAB;
1102      break;
1103    case CommandReload:
1104      *browser_cmd = IDC_RELOAD;
1105      break;
1106    case CommandDuplicate:
1107      *browser_cmd = IDC_DUPLICATE_TAB;
1108      break;
1109    case CommandCloseTab:
1110      *browser_cmd = IDC_CLOSE_TAB;
1111      break;
1112    case CommandRestoreTab:
1113      *browser_cmd = IDC_RESTORE_TAB;
1114      break;
1115    case CommandBookmarkAllTabs:
1116      *browser_cmd = IDC_BOOKMARK_ALL_TABS;
1117      break;
1118    default:
1119      *browser_cmd = 0;
1120      return false;
1121  }
1122
1123  return true;
1124}
1125
1126///////////////////////////////////////////////////////////////////////////////
1127// TabStripModel, private:
1128
1129std::vector<WebContents*> TabStripModel::GetWebContentsFromIndices(
1130    const std::vector<int>& indices) const {
1131  std::vector<WebContents*> contents;
1132  for (size_t i = 0; i < indices.size(); ++i)
1133    contents.push_back(GetWebContentsAtImpl(indices[i]));
1134  return contents;
1135}
1136
1137void TabStripModel::GetIndicesWithSameDomain(int index,
1138                                             std::vector<int>* indices) {
1139  std::string domain = GetWebContentsAt(index)->GetURL().host();
1140  if (domain.empty())
1141    return;
1142  for (int i = 0; i < count(); ++i) {
1143    if (i == index)
1144      continue;
1145    if (GetWebContentsAt(i)->GetURL().host() == domain)
1146      indices->push_back(i);
1147  }
1148}
1149
1150void TabStripModel::GetIndicesWithSameOpener(int index,
1151                                             std::vector<int>* indices) {
1152  WebContents* opener = contents_data_[index]->group();
1153  if (!opener) {
1154    // If there is no group, find all tabs with the selected tab as the opener.
1155    opener = GetWebContentsAt(index);
1156    if (!opener)
1157      return;
1158  }
1159  for (int i = 0; i < count(); ++i) {
1160    if (i == index)
1161      continue;
1162    if (contents_data_[i]->group() == opener ||
1163        GetWebContentsAtImpl(i) == opener) {
1164      indices->push_back(i);
1165    }
1166  }
1167}
1168
1169std::vector<int> TabStripModel::GetIndicesForCommand(int index) const {
1170  if (!IsTabSelected(index)) {
1171    std::vector<int> indices;
1172    indices.push_back(index);
1173    return indices;
1174  }
1175  return selection_model_.selected_indices();
1176}
1177
1178bool TabStripModel::IsNewTabAtEndOfTabStrip(WebContents* contents) const {
1179  const GURL& url = contents->GetURL();
1180  return url.SchemeIs(chrome::kChromeUIScheme) &&
1181         url.host() == chrome::kChromeUINewTabHost &&
1182         contents == GetWebContentsAtImpl(count() - 1) &&
1183         contents->GetController().GetEntryCount() == 1;
1184}
1185
1186bool TabStripModel::InternalCloseTabs(const std::vector<int>& indices,
1187                                      uint32 close_types) {
1188  if (indices.empty())
1189    return true;
1190
1191  CloseTracker close_tracker(GetWebContentsFromIndices(indices));
1192
1193  // We only try the fast shutdown path if the whole browser process is *not*
1194  // shutting down. Fast shutdown during browser termination is handled in
1195  // BrowserShutdown.
1196  if (browser_shutdown::GetShutdownType() == browser_shutdown::NOT_VALID) {
1197    // Construct a map of processes to the number of associated tabs that are
1198    // closing.
1199    std::map<content::RenderProcessHost*, size_t> processes;
1200    for (size_t i = 0; i < indices.size(); ++i) {
1201      WebContents* closing_contents = GetWebContentsAtImpl(indices[i]);
1202      if (delegate_->ShouldRunUnloadListenerBeforeClosing(closing_contents))
1203        continue;
1204      content::RenderProcessHost* process =
1205          closing_contents->GetRenderProcessHost();
1206      ++processes[process];
1207    }
1208
1209    // Try to fast shutdown the tabs that can close.
1210    for (std::map<content::RenderProcessHost*, size_t>::iterator iter =
1211         processes.begin(); iter != processes.end(); ++iter) {
1212      iter->first->FastShutdownForPageCount(iter->second);
1213    }
1214  }
1215
1216  // We now return to our regularly scheduled shutdown procedure.
1217  bool retval = true;
1218  while (close_tracker.HasNext()) {
1219    WebContents* closing_contents = close_tracker.Next();
1220    int index = GetIndexOfWebContents(closing_contents);
1221    // Make sure we still contain the tab.
1222    if (index == kNoTab)
1223      continue;
1224
1225    CoreTabHelper* core_tab_helper =
1226        CoreTabHelper::FromWebContents(closing_contents);
1227    core_tab_helper->OnCloseStarted();
1228
1229    // Update the explicitly closed state. If the unload handlers cancel the
1230    // close the state is reset in Browser. We don't update the explicitly
1231    // closed state if already marked as explicitly closed as unload handlers
1232    // call back to this if the close is allowed.
1233    if (!closing_contents->GetClosedByUserGesture()) {
1234      closing_contents->SetClosedByUserGesture(
1235          close_types & CLOSE_USER_GESTURE);
1236    }
1237
1238    if (delegate_->RunUnloadListenerBeforeClosing(closing_contents)) {
1239      retval = false;
1240      continue;
1241    }
1242
1243    InternalCloseTab(closing_contents, index,
1244                     (close_types & CLOSE_CREATE_HISTORICAL_TAB) != 0);
1245  }
1246
1247  return retval;
1248}
1249
1250void TabStripModel::InternalCloseTab(WebContents* contents,
1251                                     int index,
1252                                     bool create_historical_tabs) {
1253  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
1254                    TabClosingAt(this, contents, index));
1255
1256  // Ask the delegate to save an entry for this tab in the historical tab
1257  // database if applicable.
1258  if (create_historical_tabs)
1259    delegate_->CreateHistoricalTab(contents);
1260
1261  // Deleting the WebContents will call back to us via
1262  // WebContentsData::WebContentsDestroyed and detach it.
1263  delete contents;
1264}
1265
1266WebContents* TabStripModel::GetWebContentsAtImpl(int index) const {
1267  CHECK(ContainsIndex(index)) <<
1268      "Failed to find: " << index << " in: " << count() << " entries.";
1269  return contents_data_[index]->web_contents();
1270}
1271
1272void TabStripModel::NotifyIfTabDeactivated(WebContents* contents) {
1273  if (contents) {
1274    FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
1275                      TabDeactivated(contents));
1276  }
1277}
1278
1279void TabStripModel::NotifyIfActiveTabChanged(WebContents* old_contents,
1280                                             NotifyTypes notify_types) {
1281  WebContents* new_contents = GetWebContentsAtImpl(active_index());
1282  if (old_contents != new_contents) {
1283    int reason = notify_types == NOTIFY_USER_GESTURE
1284                 ? TabStripModelObserver::CHANGE_REASON_USER_GESTURE
1285                 : TabStripModelObserver::CHANGE_REASON_NONE;
1286    CHECK(!in_notify_);
1287    in_notify_ = true;
1288    FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
1289        ActiveTabChanged(old_contents,
1290                         new_contents,
1291                         active_index(),
1292                         reason));
1293    in_notify_ = false;
1294    // Activating a discarded tab reloads it, so it is no longer discarded.
1295    contents_data_[active_index()]->set_discarded(false);
1296  }
1297}
1298
1299void TabStripModel::NotifyIfActiveOrSelectionChanged(
1300    WebContents* old_contents,
1301    NotifyTypes notify_types,
1302    const ui::ListSelectionModel& old_model) {
1303  NotifyIfActiveTabChanged(old_contents, notify_types);
1304
1305  if (!selection_model().Equals(old_model)) {
1306    FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
1307                      TabSelectionChanged(this, old_model));
1308  }
1309}
1310
1311void TabStripModel::SetSelection(
1312    const ui::ListSelectionModel& new_model,
1313    NotifyTypes notify_types) {
1314  WebContents* old_contents = GetActiveWebContents();
1315  ui::ListSelectionModel old_model;
1316  old_model.Copy(selection_model_);
1317  if (new_model.active() != selection_model_.active())
1318    NotifyIfTabDeactivated(old_contents);
1319  selection_model_.Copy(new_model);
1320  NotifyIfActiveOrSelectionChanged(old_contents, notify_types, old_model);
1321}
1322
1323void TabStripModel::SelectRelativeTab(bool next) {
1324  // This may happen during automated testing or if a user somehow buffers
1325  // many key accelerators.
1326  if (contents_data_.empty())
1327    return;
1328
1329  int index = active_index();
1330  int delta = next ? 1 : -1;
1331  index = (index + count() + delta) % count();
1332  ActivateTabAt(index, true);
1333}
1334
1335void TabStripModel::MoveWebContentsAtImpl(int index,
1336                                          int to_position,
1337                                          bool select_after_move) {
1338  WebContentsData* moved_data = contents_data_[index];
1339  contents_data_.erase(contents_data_.begin() + index);
1340  contents_data_.insert(contents_data_.begin() + to_position, moved_data);
1341
1342  selection_model_.Move(index, to_position);
1343  if (!selection_model_.IsSelected(select_after_move) && select_after_move) {
1344    // TODO(sky): why doesn't this code notify observers?
1345    selection_model_.SetSelectedIndex(to_position);
1346  }
1347
1348  ForgetOpenersAndGroupsReferencing(moved_data->web_contents());
1349
1350  FOR_EACH_OBSERVER(TabStripModelObserver, observers_,
1351                    TabMoved(moved_data->web_contents(), index, to_position));
1352}
1353
1354void TabStripModel::MoveSelectedTabsToImpl(int index,
1355                                           size_t start,
1356                                           size_t length) {
1357  DCHECK(start < selection_model_.selected_indices().size() &&
1358         start + length <= selection_model_.selected_indices().size());
1359  size_t end = start + length;
1360  int count_before_index = 0;
1361  for (size_t i = start; i < end &&
1362       selection_model_.selected_indices()[i] < index + count_before_index;
1363       ++i) {
1364    count_before_index++;
1365  }
1366
1367  // First move those before index. Any tabs before index end up moving in the
1368  // selection model so we use start each time through.
1369  int target_index = index + count_before_index;
1370  size_t tab_index = start;
1371  while (tab_index < end &&
1372         selection_model_.selected_indices()[start] < index) {
1373    MoveWebContentsAt(selection_model_.selected_indices()[start],
1374                      target_index - 1, false);
1375    tab_index++;
1376  }
1377
1378  // Then move those after the index. These don't result in reordering the
1379  // selection.
1380  while (tab_index < end) {
1381    if (selection_model_.selected_indices()[tab_index] != target_index) {
1382      MoveWebContentsAt(selection_model_.selected_indices()[tab_index],
1383                        target_index, false);
1384    }
1385    tab_index++;
1386    target_index++;
1387  }
1388}
1389
1390// static
1391bool TabStripModel::OpenerMatches(const WebContentsData* data,
1392                                  const WebContents* opener,
1393                                  bool use_group) {
1394  return data->opener() == opener || (use_group && data->group() == opener);
1395}
1396
1397void TabStripModel::ForgetOpenersAndGroupsReferencing(
1398    const WebContents* tab) {
1399  for (WebContentsDataVector::const_iterator i = contents_data_.begin();
1400       i != contents_data_.end(); ++i) {
1401    if ((*i)->group() == tab)
1402      (*i)->set_group(NULL);
1403    if ((*i)->opener() == tab)
1404      (*i)->set_opener(NULL);
1405  }
1406}
1407