ash/shelf/shelf_model.h

   1 // Copyright 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 ASH_SHELF_SHELF_MODEL_H_
   6 #define ASH_SHELF_SHELF_MODEL_H_
   7
   8 #include "ash/ash_export.h"
   9 #include "ash/launcher/launcher_types.h"
  10 #include "base/basictypes.h"
  11 #include "base/observer_list.h"
  12
  13 namespace ash {
  14
  15 class ShelfModelObserver;
  16
  17 // Model used by ShelfView.
  18 class ASH_EXPORT ShelfModel {
  19  public:
  20   enum Status {
  21     STATUS_NORMAL,
  22     // A status that indicates apps are syncing/loading.
  23     STATUS_LOADING,
  24   };
  25
  26   ShelfModel();
  27   ~ShelfModel();
  28
  29   // Adds a new item to the model. Returns the resulting index.
  30   int Add(const LauncherItem& item);
  31
  32   // Adds the item. |index| is the requested insertion index, which may be
  33   // modified to meet type-based ordering. Returns the actual insertion index.
  34   int AddAt(int index, const LauncherItem& item);
  35
  36   // Removes the item at |index|.
  37   void RemoveItemAt(int index);
  38
  39   // Moves the item at |index| to |target_index|. |target_index| is in terms
  40   // of the model *after* the item at |index| is removed.
  41   void Move(int index, int target_index);
  42
  43   // Resets the item at the specified index. The item maintains its existing
  44   // id and type.
  45   void Set(int index, const LauncherItem& item);
  46
  47   // Returns the index of the item by id.
  48   int ItemIndexByID(LauncherID id) const;
  49
  50   // Returns the |index| of the item matching |type| in |items_|.
  51   // Returns -1 if the matching item is not found.
  52   // Note: Requires a linear search.
  53   int GetItemIndexForType(LauncherItemType type);
  54
  55   // Returns the index of the first panel or the index where the first panel
  56   // would go if there are no panels.
  57   int FirstPanelIndex() const;
  58
  59   // Returns the id assigned to the next item added.
  60   LauncherID next_id() const { return next_id_; }
  61
  62   // Returns a reserved id which will not be used by the |ShelfModel|.
  63   LauncherID reserve_external_id() { return next_id_++; }
  64
  65   // Returns an iterator into items() for the item with the specified id, or
  66   // items().end() if there is no item with the specified id.
  67   LauncherItems::const_iterator ItemByID(LauncherID id) const;
  68
  69   const LauncherItems& items() const { return items_; }
  70   int item_count() const { return static_cast<int>(items_.size()); }
  71
  72   void SetStatus(Status status);
  73   Status status() const { return status_; }
  74
  75   void AddObserver(ShelfModelObserver* observer);
  76   void RemoveObserver(ShelfModelObserver* observer);
  77
  78  private:
  79   // Makes sure |index| is in line with the type-based order of items. If that
  80   // is not the case, adjusts index by shifting it to the valid range and
  81   // returns the new value.
  82   int ValidateInsertionIndex(LauncherItemType type, int index) const;
  83
  84   // ID assigned to the next item.
  85   LauncherID next_id_;
  86
  87   LauncherItems items_;
  88   Status status_;
  89   ObserverList<ShelfModelObserver> observers_;
  90
  91   DISALLOW_COPY_AND_ASSIGN(ShelfModel);
  92 };
  93
  94 }  // namespace ash
  95
  96 #endif  // ASH_SHELF_SHELF_MODEL_H_