chrome/browser/ui/toolbar/back_forward_menu_model.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_TOOLBAR_BACK_FORWARD_MENU_MODEL_H_
   6 #define CHROME_BROWSER_UI_TOOLBAR_BACK_FORWARD_MENU_MODEL_H_
   7
   8 #include <set>
   9 #include <string>
  10
  11 #include "base/basictypes.h"
  12 #include "base/gtest_prod_util.h"
  13 #include "base/strings/string16.h"
  14 #include "base/task/cancelable_task_tracker.h"
  15 #include "chrome/browser/favicon/favicon_service.h"
  16 #include "ui/base/models/menu_model.h"
  17 #include "ui/base/window_open_disposition.h"
  18
  19 class Browser;
  20
  21 namespace favicon_base {
  22 struct FaviconImageResult;
  23 }
  24
  25 namespace content {
  26 class NavigationEntry;
  27 class WebContents;
  28 }
  29
  30 namespace gfx {
  31 class Image;
  32 }
  33
  34 ///////////////////////////////////////////////////////////////////////////////
  35 //
  36 // BackForwardMenuModel
  37 //
  38 // Interface for the showing of the dropdown menu for the Back/Forward buttons.
  39 // Actual implementations are platform-specific.
  40 ///////////////////////////////////////////////////////////////////////////////
  41 class BackForwardMenuModel : public ui::MenuModel {
  42  public:
  43   // These are IDs used to identify individual UI elements within the
  44   // browser window using View::GetViewByID.
  45   enum ModelType {
  46     FORWARD_MENU = 1,
  47     BACKWARD_MENU = 2
  48   };
  49
  50   BackForwardMenuModel(Browser* browser, ModelType model_type);
  51   virtual ~BackForwardMenuModel();
  52
  53   // MenuModel implementation.
  54   virtual bool HasIcons() const OVERRIDE;
  55   // Returns how many items the menu should show, including history items,
  56   // chapter-stops, separators and the Show Full History link. This function
  57   // uses GetHistoryItemCount() and GetChapterStopCount() internally to figure
  58   // out the total number of items to show.
  59   virtual int GetItemCount() const OVERRIDE;
  60   virtual ItemType GetTypeAt(int index) const OVERRIDE;
  61   virtual ui::MenuSeparatorType GetSeparatorTypeAt(int index) const OVERRIDE;
  62   virtual int GetCommandIdAt(int index) const OVERRIDE;
  63   virtual base::string16 GetLabelAt(int index) const OVERRIDE;
  64   virtual bool IsItemDynamicAt(int index) const OVERRIDE;
  65   virtual bool GetAcceleratorAt(int index,
  66                                 ui::Accelerator* accelerator) const OVERRIDE;
  67   virtual bool IsItemCheckedAt(int index) const OVERRIDE;
  68   virtual int GetGroupIdAt(int index) const OVERRIDE;
  69   virtual bool GetIconAt(int index, gfx::Image* icon) OVERRIDE;
  70   virtual ui::ButtonMenuItemModel* GetButtonMenuItemAt(
  71       int index) const OVERRIDE;
  72   virtual bool IsEnabledAt(int index) const OVERRIDE;
  73   virtual MenuModel* GetSubmenuModelAt(int index) const OVERRIDE;
  74   virtual void HighlightChangedTo(int index) OVERRIDE;
  75   virtual void ActivatedAt(int index) OVERRIDE;
  76   virtual void ActivatedAt(int index, int event_flags) OVERRIDE;
  77   virtual void MenuWillShow() OVERRIDE;
  78
  79   // Is the item at |index| a separator?
  80   bool IsSeparator(int index) const;
  81
  82   // Set the delegate for triggering OnIconChanged.
  83   virtual void SetMenuModelDelegate(
  84       ui::MenuModelDelegate* menu_model_delegate) OVERRIDE;
  85   virtual ui::MenuModelDelegate* GetMenuModelDelegate() const OVERRIDE;
  86
  87  protected:
  88    ui::MenuModelDelegate* menu_model_delegate() { return menu_model_delegate_; }
  89
  90  private:
  91   friend class BackFwdMenuModelTest;
  92   FRIEND_TEST_ALL_PREFIXES(BackFwdMenuModelTest, BasicCase);
  93   FRIEND_TEST_ALL_PREFIXES(BackFwdMenuModelTest, MaxItemsTest);
  94   FRIEND_TEST_ALL_PREFIXES(BackFwdMenuModelTest, ChapterStops);
  95   FRIEND_TEST_ALL_PREFIXES(BackFwdMenuModelTest, EscapeLabel);
  96   FRIEND_TEST_ALL_PREFIXES(BackFwdMenuModelTest, FaviconLoadTest);
  97
  98   // Requests a favicon from the FaviconService. Called by GetIconAt if the
  99   // NavigationEntry has an invalid favicon.
 100   void FetchFavicon(content::NavigationEntry* entry);
 101
 102   // Callback from the favicon service.
 103   void OnFavIconDataAvailable(
 104       int navigation_entry_unique_id,
 105       const favicon_base::FaviconImageResult& image_result);
 106
 107   // Allows the unit test to use its own dummy tab contents.
 108   void set_test_web_contents(content::WebContents* test_web_contents) {
 109     test_web_contents_ = test_web_contents;
 110   }
 111
 112   // Returns how many history items the menu should show. For example, if the
 113   // navigation controller of the current tab has a current entry index of 5 and
 114   // forward_direction_ is false (we are the back button delegate) then this
 115   // function will return 5 (representing 0-4). If forward_direction_ is
 116   // true (we are the forward button delegate), then this function will return
 117   // the number of entries after 5. Note, though, that in either case it will
 118   // not report more than kMaxHistoryItems. The number returned also does not
 119   // include the separator line after the history items (nor the separator for
 120   // the "Show Full History" link).
 121   int GetHistoryItemCount() const;
 122
 123   // Returns how many chapter-stop items the menu should show. For the
 124   // definition of a chapter-stop, see GetIndexOfNextChapterStop(). The number
 125   // returned does not include the separator lines before and after the
 126   // chapter-stops.
 127   int GetChapterStopCount(int history_items) const;
 128
 129   // Finds the next chapter-stop in the NavigationEntryList starting from
 130   // the index specified in |start_from| and continuing in the direction
 131   // specified (|forward|) until either a chapter-stop is found or we reach the
 132   // end, in which case -1 is returned. If |start_from| is out of bounds, -1
 133   // will also be returned. A chapter-stop is defined as the last page the user
 134   // browsed to within the same domain. For example, if the user's homepage is
 135   // Google and she navigates to Google pages G1, G2 and G3 before heading over
 136   // to WikiPedia for pages W1 and W2 and then back to Google for pages G4 and
 137   // G5 then G3, W2 and G5 are considered chapter-stops. The return value from
 138   // this function is an index into the NavigationEntryList vector.
 139   int GetIndexOfNextChapterStop(int start_from, bool forward) const;
 140
 141   // Finds a given chapter-stop starting at the currently active entry in the
 142   // NavigationEntryList vector advancing first forward or backward by |offset|
 143   // (depending on the direction specified in parameter |forward|). It also
 144   // allows you to skip chapter-stops by specifying a positive value for |skip|.
 145   // Example: FindChapterStop(5, false, 3) starts with the currently active
 146   // index, subtracts 5 from it and then finds the fourth chapter-stop before
 147   // that index (skipping the first 3 it finds).
 148   // Example: FindChapterStop(0, true, 0) is functionally equivalent to
 149   // calling GetIndexOfNextChapterStop(GetCurrentEntryIndex(), true).
 150   //
 151   // NOTE: Both |offset| and |skip| must be non-negative. The return value from
 152   // this function is an index into the NavigationEntryList vector. If |offset|
 153   // is out of bounds or if we skip too far (run out of chapter-stops) this
 154   // function returns -1.
 155   int FindChapterStop(int offset, bool forward, int skip) const;
 156
 157   // How many items (max) to show in the back/forward history menu dropdown.
 158   static const int kMaxHistoryItems;
 159
 160   // How many chapter-stops (max) to show in the back/forward dropdown list.
 161   static const int kMaxChapterStops;
 162
 163   // Takes a menu item index as passed in through one of the menu delegate
 164   // functions and converts it into an index into the NavigationEntryList
 165   // vector. |index| can point to a separator, or the
 166   // "Show Full History" link in which case this function returns -1.
 167   int MenuIndexToNavEntryIndex(int index) const;
 168
 169   // Does the item have a command associated with it?
 170   bool ItemHasCommand(int index) const;
 171
 172   // Returns true if there is an icon for this menu item.
 173   bool ItemHasIcon(int index) const;
 174
 175   // Allow the unit test to use the "Show Full History" label.
 176   base::string16 GetShowFullHistoryLabel() const;
 177
 178   // Looks up a NavigationEntry by menu id.
 179   content::NavigationEntry* GetNavigationEntry(int index) const;
 180
 181   // Retrieves the WebContents pointer to use, which is either the one that
 182   // the unit test sets (using set_test_web_contents) or the one from
 183   // the browser window.
 184   content::WebContents* GetWebContents() const;
 185
 186   // Build a string version of a user action on this menu, used as an
 187   // identifier for logging user behavior.
 188   // E.g. BuildActionName("Click", 2) returns "BackMenu_Click2".
 189   // An index of -1 means no index.
 190   std::string BuildActionName(const std::string& name, int index) const;
 191
 192   Browser* browser_;
 193
 194   // The unit tests will provide their own WebContents to use.
 195   content::WebContents* test_web_contents_;
 196
 197   // Represents whether this is the delegate for the forward button or the
 198   // back button.
 199   ModelType model_type_;
 200
 201   // Keeps track of which favicons have already been requested from the history
 202   // to prevent duplicate requests, identified by
 203   // NavigationEntry->GetUniqueID().
 204   std::set<int> requested_favicons_;
 205
 206   // Used for loading favicons.
 207   base::CancelableTaskTracker cancelable_task_tracker_;
 208
 209   // Used for receiving notifications when an icon is changed.
 210   ui::MenuModelDelegate* menu_model_delegate_;
 211
 212   DISALLOW_COPY_AND_ASSIGN(BackForwardMenuModel);
 213 };
 214
 215 #endif  // CHROME_BROWSER_UI_TOOLBAR_BACK_FORWARD_MENU_MODEL_H_