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