chrome/browser/ui/browser_iterator.h

   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
  11 class Browser;
  12
  13 namespace 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 //   }
  26 class 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_