chrome/browser/ui/tab_contents/tab_contents_iterator.h

   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_TAB_CONTENTS_TAB_CONTENTS_ITERATOR_H_
   6 #define CHROME_BROWSER_UI_TAB_CONTENTS_TAB_CONTENTS_ITERATOR_H_
   7
   8 #include <set>
   9
  10 #include "base/basictypes.h"
  11 #include "chrome/browser/ui/browser_iterator.h"
  12
  13 namespace content {
  14 class WebContents;
  15 }
  16
  17 // Iterates through all web view hosts in all browser windows. Because the
  18 // renderers act asynchronously, getting a host through this interface does
  19 // not guarantee that the renderer is ready to go. Doing anything to affect
  20 // browser windows or tabs while iterating may cause incorrect behavior.
  21 //
  22 // Example:
  23 //   for (TabContentsIterator iterator; !iterator.done(); iterator.Next()) {
  24 //     WebContents* cur = *iterator;
  25 //     -or-
  26 //     iterator->OperationOnWebContents();
  27 //     ...
  28 //   }
  29 class TabContentsIterator {
  30  public:
  31   TabContentsIterator();
  32
  33   // Returns true if we are past the last Browser.
  34   bool done() const { return cur_ == NULL; }
  35
  36   // Returns the Browser instance associated with the current
  37   // WebContents. Valid as long as !done().
  38   Browser* browser() const {
  39     if (!browser_iterator_.done())
  40       return *browser_iterator_;
  41     return NULL;
  42   }
  43
  44   // Returns the current WebContents, valid as long as !done().
  45   content::WebContents* operator->() const {
  46     return cur_;
  47   }
  48   content::WebContents* operator*() const {
  49     return cur_;
  50   }
  51
  52   // Loads the next host into |cur_|. This is designed so that for the initial
  53   // call from the constructor, when browser_iterator_ points to the first
  54   // Browser and web_view_index_ is -1, it will fill the first host.
  55   void Next();
  56
  57  private:
  58   // Tab index into the current Browser of the current web view.
  59   int web_view_index_;
  60
  61   // Current WebContents, or NULL if we're at the end of the list. This
  62   // can be extracted given the browser iterator and index, but it's nice to
  63   // cache this since the caller may access the current host many times.
  64   content::WebContents* cur_;
  65
  66   // An iterator over all the browsers.
  67   chrome::BrowserIterator browser_iterator_;
  68
  69   DISALLOW_COPY_AND_ASSIGN(TabContentsIterator);
  70 };
  71
  72 #endif  // CHROME_BROWSER_UI_TAB_CONTENTS_TAB_CONTENTS_ITERATOR_H_