chrome/browser/ui/tabs/tab_strip_model_order_controller.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_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 //
  17 class TabStripModelOrderController : public TabStripModelObserver {
  18  public:
  19   explicit TabStripModelOrderController(TabStripModel* tabstrip);
  20   ~TabStripModelOrderController() override;
  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   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_