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      1 // Copyright (c) 2011 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_TOOLBAR_BACK_FORWARD_MENU_MODEL_H_
      6 #define CHROME_BROWSER_UI_TOOLBAR_BACK_FORWARD_MENU_MODEL_H_
      7 #pragma once
      8 
      9 #include <set>
     10 #include <string>
     11 
     12 #include "base/basictypes.h"
     13 #include "base/gtest_prod_util.h"
     14 #include "base/string16.h"
     15 #include "chrome/browser/favicon_service.h"
     16 #include "ui/base/models/menu_model.h"
     17 #include "webkit/glue/window_open_disposition.h"
     18 
     19 class Browser;
     20 class SkBitmap;
     21 class TabContents;
     22 class NavigationEntry;
     23 
     24 ///////////////////////////////////////////////////////////////////////////////
     25 //
     26 // BackForwardMenuModel
     27 //
     28 // Interface for the showing of the dropdown menu for the Back/Forward buttons.
     29 // Actual implementations are platform-specific.
     30 ///////////////////////////////////////////////////////////////////////////////
     31 class BackForwardMenuModel : public ui::MenuModel {
     32  public:
     33   // These are IDs used to identify individual UI elements within the
     34   // browser window using View::GetViewByID.
     35   enum ModelType {
     36     FORWARD_MENU = 1,
     37     BACKWARD_MENU = 2
     38   };
     39 
     40   BackForwardMenuModel(Browser* browser, ModelType model_type);
     41   virtual ~BackForwardMenuModel();
     42 
     43   // MenuModel implementation.
     44   virtual bool HasIcons() const;
     45   // Returns how many items the menu should show, including history items,
     46   // chapter-stops, separators and the Show Full History link. This function
     47   // uses GetHistoryItemCount() and GetChapterStopCount() internally to figure
     48   // out the total number of items to show.
     49   virtual int GetItemCount() const;
     50   virtual ItemType GetTypeAt(int index) const;
     51   virtual int GetCommandIdAt(int index) const;
     52   virtual string16 GetLabelAt(int index) const;
     53   virtual bool IsItemDynamicAt(int index) const;
     54   virtual bool GetAcceleratorAt(int index,
     55                                 ui::Accelerator* accelerator) const;
     56   virtual bool IsItemCheckedAt(int index) const;
     57   virtual int GetGroupIdAt(int index) const;
     58   virtual bool GetIconAt(int index, SkBitmap* icon);
     59   virtual ui::ButtonMenuItemModel* GetButtonMenuItemAt(int index) const;
     60   virtual bool IsEnabledAt(int index) const;
     61   virtual MenuModel* GetSubmenuModelAt(int index) const;
     62   virtual void HighlightChangedTo(int index);
     63   virtual void ActivatedAt(int index);
     64   virtual void ActivatedAtWithDisposition(int index, int disposition);
     65   virtual void MenuWillShow();
     66 
     67   // Is the item at |index| a separator?
     68   bool IsSeparator(int index) const;
     69 
     70   // Set the delegate for triggering OnIconChanged.
     71   virtual void SetMenuModelDelegate(ui::MenuModelDelegate* menu_model_delegate);
     72 
     73  protected:
     74    ui::MenuModelDelegate* menu_model_delegate() { return menu_model_delegate_; }
     75 
     76  private:
     77   friend class BackFwdMenuModelTest;
     78   FRIEND_TEST_ALL_PREFIXES(BackFwdMenuModelTest, BasicCase);
     79   FRIEND_TEST_ALL_PREFIXES(BackFwdMenuModelTest, MaxItemsTest);
     80   FRIEND_TEST_ALL_PREFIXES(BackFwdMenuModelTest, ChapterStops);
     81   FRIEND_TEST_ALL_PREFIXES(BackFwdMenuModelTest, EscapeLabel);
     82   FRIEND_TEST_ALL_PREFIXES(BackFwdMenuModelTest, FaviconLoadTest);
     83 
     84   // Requests a favicon from the FaviconService. Called by GetIconAt if the
     85   // NavigationEntry has an invalid favicon.
     86   void FetchFavicon(NavigationEntry* entry);
     87 
     88   // Callback from the favicon service.
     89   void OnFavIconDataAvailable(FaviconService::Handle handle,
     90                               history::FaviconData favicon);
     91 
     92   // Allows the unit test to use its own dummy tab contents.
     93   void set_test_tab_contents(TabContents* test_tab_contents) {
     94     test_tab_contents_ = test_tab_contents;
     95   }
     96 
     97   // Returns how many history items the menu should show. For example, if the
     98   // navigation controller of the current tab has a current entry index of 5 and
     99   // forward_direction_ is false (we are the back button delegate) then this
    100   // function will return 5 (representing 0-4). If forward_direction_ is
    101   // true (we are the forward button delegate), then this function will return
    102   // the number of entries after 5. Note, though, that in either case it will
    103   // not report more than kMaxHistoryItems. The number returned also does not
    104   // include the separator line after the history items (nor the separator for
    105   // the "Show Full History" link).
    106   int GetHistoryItemCount() const;
    107 
    108   // Returns how many chapter-stop items the menu should show. For the
    109   // definition of a chapter-stop, see GetIndexOfNextChapterStop(). The number
    110   // returned does not include the separator lines before and after the
    111   // chapter-stops.
    112   int GetChapterStopCount(int history_items) const;
    113 
    114   // Finds the next chapter-stop in the NavigationEntryList starting from
    115   // the index specified in |start_from| and continuing in the direction
    116   // specified (|forward|) until either a chapter-stop is found or we reach the
    117   // end, in which case -1 is returned. If |start_from| is out of bounds, -1
    118   // will also be returned. A chapter-stop is defined as the last page the user
    119   // browsed to within the same domain. For example, if the user's homepage is
    120   // Google and she navigates to Google pages G1, G2 and G3 before heading over
    121   // to WikiPedia for pages W1 and W2 and then back to Google for pages G4 and
    122   // G5 then G3, W2 and G5 are considered chapter-stops. The return value from
    123   // this function is an index into the NavigationEntryList vector.
    124   int GetIndexOfNextChapterStop(int start_from, bool forward) const;
    125 
    126   // Finds a given chapter-stop starting at the currently active entry in the
    127   // NavigationEntryList vector advancing first forward or backward by |offset|
    128   // (depending on the direction specified in parameter |forward|). It also
    129   // allows you to skip chapter-stops by specifying a positive value for |skip|.
    130   // Example: FindChapterStop(5, false, 3) starts with the currently active
    131   // index, subtracts 5 from it and then finds the fourth chapter-stop before
    132   // that index (skipping the first 3 it finds).
    133   // Example: FindChapterStop(0, true, 0) is functionally equivalent to
    134   // calling GetIndexOfNextChapterStop(GetCurrentEntryIndex(), true).
    135   //
    136   // NOTE: Both |offset| and |skip| must be non-negative. The return value from
    137   // this function is an index into the NavigationEntryList vector. If |offset|
    138   // is out of bounds or if we skip too far (run out of chapter-stops) this
    139   // function returns -1.
    140   int FindChapterStop(int offset, bool forward, int skip) const;
    141 
    142   // How many items (max) to show in the back/forward history menu dropdown.
    143   static const int kMaxHistoryItems;
    144 
    145   // How many chapter-stops (max) to show in the back/forward dropdown list.
    146   static const int kMaxChapterStops;
    147 
    148   // Takes a menu item index as passed in through one of the menu delegate
    149   // functions and converts it into an index into the NavigationEntryList
    150   // vector. |index| can point to a separator, or the
    151   // "Show Full History" link in which case this function returns -1.
    152   int MenuIndexToNavEntryIndex(int index) const;
    153 
    154   // Does the item have a command associated with it?
    155   bool ItemHasCommand(int index) const;
    156 
    157   // Returns true if there is an icon for this menu item.
    158   bool ItemHasIcon(int index) const;
    159 
    160   // Allow the unit test to use the "Show Full History" label.
    161   string16 GetShowFullHistoryLabel() const;
    162 
    163   // Looks up a NavigationEntry by menu id.
    164   NavigationEntry* GetNavigationEntry(int index) const;
    165 
    166   // Retrieves the TabContents pointer to use, which is either the one that
    167   // the unit test sets (using SetTabContentsForUnitTest) or the one from
    168   // the browser window.
    169   TabContents* GetTabContents() const;
    170 
    171   // Build a string version of a user action on this menu, used as an
    172   // identifier for logging user behavior.
    173   // E.g. BuildActionName("Click", 2) returns "BackMenu_Click2".
    174   // An index of -1 means no index.
    175   std::string BuildActionName(const std::string& name, int index) const;
    176 
    177   Browser* browser_;
    178 
    179   // The unit tests will provide their own TabContents to use.
    180   TabContents* test_tab_contents_;
    181 
    182   // Represents whether this is the delegate for the forward button or the
    183   // back button.
    184   ModelType model_type_;
    185 
    186   // Keeps track of which favicons have already been requested from the history
    187   // to prevent duplicate requests, identified by NavigationEntry->unique_id().
    188   std::set<int> requested_favicons_;
    189 
    190   // Used for loading favicons from history.
    191   CancelableRequestConsumerTSimple<int> load_consumer_;
    192 
    193   // Used for receiving notifications when an icon is changed.
    194   ui::MenuModelDelegate* menu_model_delegate_;
    195 
    196   DISALLOW_COPY_AND_ASSIGN(BackForwardMenuModel);
    197 };
    198 
    199 #endif  // CHROME_BROWSER_UI_TOOLBAR_BACK_FORWARD_MENU_MODEL_H_
    200