1// Copyright (c) 2013 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_BROWSER_ITERATOR_H_
6#define CHROME_BROWSER_UI_BROWSER_ITERATOR_H_
7
8#include "chrome/browser/ui/browser_list.h"
9#include "chrome/browser/ui/host_desktop.h"
10
11class Browser;
12
13namespace chrome {
14
15// Iterates over all existing browsers (potentially across multiple desktops).
16// Note: to iterate only over the browsers of a specific desktop, use the
17// const_iterator of a given BrowserList instead.
18//
19// Example:
20//   for (BrowserIterator iterator; !iterator.done(); iterator.Next()) {
21//     Browser* cur = *iterator;
22//     -or-
23//     iterator->OperationOnBrowser();
24//     ...
25//   }
26class BrowserIterator {
27 public:
28  BrowserIterator();
29  ~BrowserIterator();
30
31  // Returns true if this iterator is past the last Browser.
32  bool done() const {
33    // |current_iterator_| is never at the end of a list unless it is done (it
34    // immediately moves to the next browser list upon hitting the end of the
35    // current list unless there are no remaining empty browser lists).
36    return current_iterator_ == current_browser_list_->end();
37  }
38
39  // Returns the current Browser, valid as long as !done().
40  Browser* operator->() const {
41    return *current_iterator_;
42  }
43  Browser* operator*() const {
44    return *current_iterator_;
45  }
46
47  // Advances |current_iterator_| to the next browser.
48  void Next();
49
50 private:
51  // If |current_iterator_| is at |current_browser_list_->end()|, advance to the
52  // next non-empty browser list. After a call to this method: either
53  // |current_iterator_| is valid or done().
54  void NextBrowserListIfAtEnd();
55
56  // The BrowserList currently being iterated over. Instances of this class do
57  // not own this pointer.
58  BrowserList* current_browser_list_;
59
60  // The underlying iterator over browsers in |current_browser_list_|.
61  BrowserList::const_iterator current_iterator_;
62
63  // The next HostDesktopType to iterate over when |current_iterator_| reaches
64  // |current_browser_list_->end()|.
65  HostDesktopType next_desktop_type_;
66
67  DISALLOW_COPY_AND_ASSIGN(BrowserIterator);
68};
69
70}  // namespace chrome
71
72#endif  // CHROME_BROWSER_UI_BROWSER_ITERATOR_H_
73