ui/app_list/app_list_item_list.h

   1 // Copyright (c) 2013 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 UI_APP_LIST_APP_LIST_ITEM_LIST_H_
   6 #define UI_APP_LIST_APP_LIST_ITEM_LIST_H_
   7
   8 #include <string>
   9
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/scoped_vector.h"
  12 #include "base/observer_list.h"
  13 #include "sync/api/string_ordinal.h"
  14 #include "ui/app_list/app_list_export.h"
  15 #include "ui/app_list/app_list_item_list_observer.h"
  16
  17 namespace app_list {
  18
  19 class AppListItem;
  20
  21 // Class to manage items in the app list. Used both by AppListModel and
  22 // AppListFolderItem. Manages the position ordinal of items in the list, and
  23 // notifies observers when items in the list are added / deleted / moved.
  24 class APP_LIST_EXPORT AppListItemList {
  25  public:
  26   AppListItemList();
  27   virtual ~AppListItemList();
  28
  29   void AddObserver(AppListItemListObserver* observer);
  30   void RemoveObserver(AppListItemListObserver* observer);
  31
  32   // Finds item matching |id|. NOTE: Requires a linear search.
  33   // Generally this should not be used directly, AppListModel::FindItem
  34   // should be used instead.
  35   AppListItem* FindItem(const std::string& id);
  36
  37   // Finds the |index| of the the item matching |id| in |app_list_items_|.
  38   // Returns true if the matching item is found.
  39   // Note: Requires a linear search.
  40   bool FindItemIndex(const std::string& id, size_t* index);
  41
  42   // Moves item at |from_index| to |to_index|.
  43   // Triggers observers_.OnListItemMoved().
  44   void MoveItem(size_t from_index, size_t to_index);
  45
  46   // Sets the position of |item| which is expected to be a member of
  47   // |app_list_items_| and sorts the list accordingly. If |new_position| is
  48   // invalid, move the item to the end of the list.
  49   void SetItemPosition(AppListItem* item, syncer::StringOrdinal new_position);
  50
  51   AppListItem* item_at(size_t index) {
  52     DCHECK_LT(index, app_list_items_.size());
  53     return app_list_items_[index];
  54   }
  55   const AppListItem* item_at(size_t index) const {
  56     DCHECK_LT(index, app_list_items_.size());
  57     return app_list_items_[index];
  58   }
  59   size_t item_count() const { return app_list_items_.size(); }
  60
  61  private:
  62   friend class AppListItemListTest;
  63   friend class AppListModel;
  64
  65   // Returns a unique, valid StringOrdinal immediately before |position| or at
  66   // the end of the list if |position| is invalid.
  67   syncer::StringOrdinal CreatePositionBefore(
  68       const syncer::StringOrdinal& position);
  69
  70   // Adds |item| to the end of |app_list_items_|. Takes ownership of |item|.
  71   // Triggers observers_.OnListItemAdded(). Returns a pointer to the added item
  72   // that is safe to use (e.g. after releasing a scoped ptr).
  73   AppListItem* AddItem(scoped_ptr<AppListItem> item_ptr);
  74
  75   // Finds item matching |id| in |app_list_items_| (linear search) and deletes
  76   // it. Triggers observers_.OnListItemRemoved() after removing the item from
  77   // the list and before deleting it.
  78   void DeleteItem(const std::string& id);
  79
  80   // Removes the item with matching |id| in |app_list_items_| without deleting
  81   // it. Returns a scoped pointer containing the removed item.
  82   scoped_ptr<AppListItem> RemoveItem(const std::string& id);
  83
  84   // Removes the item at |index| from |app_list_items_| without deleting it.
  85   // Returns a scoped pointer containing the removed item.
  86   scoped_ptr<AppListItem> RemoveItemAt(size_t index);
  87
  88   // Deletes item at |index| and signals observers.
  89   void DeleteItemAt(size_t index);
  90
  91   // If |item|->position() is not a valid ordinal, sets |item|->position()
  92   // to a valid ordinal after the last item in the list.
  93   void EnsureValidItemPosition(AppListItem* item);
  94
  95   // Returns the index at which to insert an item in |app_list_items_| based on
  96   // |position| (which must be valid) and |id| (if the positions are equal).
  97   size_t GetItemSortOrderIndex(const syncer::StringOrdinal& position,
  98                                const std::string& id);
  99
 100   // Fixes the position of the item at |index| when the position matches the
 101   // previous item's position. |index| must be > 0.
 102   void FixItemPosition(size_t index);
 103
 104   ScopedVector<AppListItem> app_list_items_;
 105   ObserverList<AppListItemListObserver> observers_;
 106
 107   DISALLOW_COPY_AND_ASSIGN(AppListItemList);
 108 };
 109
 110 }  // namespace app_list
 111
 112 #endif  // UI_APP_LIST_APP_LIST_ITEM_LIST_H_