1// Copyright (c) 2010 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef CHROME_BROWSER_TABS_TAB_STRIP_MODEL_ORDER_CONTROLLER_H_
6#define CHROME_BROWSER_TABS_TAB_STRIP_MODEL_ORDER_CONTROLLER_H_
7#pragma once
8
9#include "chrome/browser/tabs/tab_strip_model.h"
10#include "content/common/page_transition_types.h"
11
12class TabContentsWrapper;
13
14///////////////////////////////////////////////////////////////////////////////
15// TabStripModelOrderController
16//
17//  An object that allows different types of ordering and reselection to be
18//  heuristics plugged into a TabStripModel.
19//
20class TabStripModelOrderController : public TabStripModelObserver {
21 public:
22  explicit TabStripModelOrderController(TabStripModel* tabstrip);
23  virtual ~TabStripModelOrderController();
24
25  // Sets the insertion policy. Default is INSERT_AFTER.
26  void set_insertion_policy(TabStripModel::InsertionPolicy policy) {
27    insertion_policy_ = policy;
28  }
29  TabStripModel::InsertionPolicy insertion_policy() const {
30    return insertion_policy_;
31  }
32
33  // Determine where to place a newly opened tab by using the supplied
34  // transition and foreground flag to figure out how it was opened.
35  int DetermineInsertionIndex(TabContentsWrapper* new_contents,
36                              PageTransition::Type transition,
37                              bool foreground);
38
39  // Returns the index to append tabs at.
40  int DetermineInsertionIndexForAppending();
41
42  // Determine where to shift selection after a tab is closed.
43  int DetermineNewSelectedIndex(int removed_index) const;
44
45  // Overridden from TabStripModelObserver:
46  virtual void TabSelectedAt(TabContentsWrapper* old_contents,
47                             TabContentsWrapper* new_contents,
48                             int index,
49                             bool user_gesture);
50
51 private:
52  // Returns a valid index to be selected after the tab at |removing_index| is
53  // closed. If |index| is after |removing_index|, |index| is adjusted to
54  // reflect the fact that |removing_index| is going away.
55  int GetValidIndex(int index, int removing_index) const;
56
57  TabStripModel* tabstrip_;
58
59  TabStripModel::InsertionPolicy insertion_policy_;
60
61  DISALLOW_COPY_AND_ASSIGN(TabStripModelOrderController);
62};
63
64#endif  // CHROME_BROWSER_TABS_TAB_STRIP_MODEL_ORDER_CONTROLLER_H_
65