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#ifndef CHROME_BROWSER_UI_TABS_TAB_STRIP_MODEL_ORDER_CONTROLLER_H_
6#define CHROME_BROWSER_UI_TABS_TAB_STRIP_MODEL_ORDER_CONTROLLER_H_
7
8#include "chrome/browser/ui/tabs/tab_strip_model.h"
9#include "ui/base/page_transition_types.h"
10
11///////////////////////////////////////////////////////////////////////////////
12// TabStripModelOrderController
13//
14//  An object that allows different types of ordering and reselection to be
15//  heuristics plugged into a TabStripModel.
16//
17class TabStripModelOrderController : public TabStripModelObserver {
18 public:
19  explicit TabStripModelOrderController(TabStripModel* tabstrip);
20  virtual ~TabStripModelOrderController();
21
22  // Determine where to place a newly opened tab by using the supplied
23  // transition and foreground flag to figure out how it was opened.
24  int DetermineInsertionIndex(ui::PageTransition transition,
25                              bool foreground);
26
27  // Determine where to shift selection after a tab is closed.
28  int DetermineNewSelectedIndex(int removed_index) const;
29
30  // Overridden from TabStripModelObserver:
31  virtual void ActiveTabChanged(content::WebContents* old_contents,
32                                content::WebContents* new_contents,
33                                int index,
34                                int reason) OVERRIDE;
35
36 private:
37  // Returns a valid index to be selected after the tab at |removing_index| is
38  // closed. If |index| is after |removing_index|, |index| is adjusted to
39  // reflect the fact that |removing_index| is going away.
40  int GetValidIndex(int index, int removing_index) const;
41
42  TabStripModel* tabstrip_;
43
44  DISALLOW_COPY_AND_ASSIGN(TabStripModelOrderController);
45};
46
47#endif  // CHROME_BROWSER_UI_TABS_TAB_STRIP_MODEL_ORDER_CONTROLLER_H_
48