SelectedItemsManager.prototype._count = 0;
SelectedItemsManager.prototype._items = null;
SelectedItemsManager.prototype._firstItemID = null;
SelectedItemsManager.prototype._currentView = null;
SelectedItemsManager.prototype._callback = null;

function SelectedItemsManager() {
    this._count = 0;
    this._firstItemID = null;
    this._items = new Array();  // initialise our map of items
}

SelectedItemsManager.prototype.AddItem = function(ItemID, Value)
{
    // adds the item to our map (if it doesn't already exist)
    if (getTopAppWindow)
    {
        this._currentView = getTopAppWindow().gCurrentView;
    }

    if (Value == undefined)
    {
        Value = ItemID; // no map value specified so we'll make it the same as the key.
    }

    if (!this.ItemExists(ItemID))
    {
        if (this._count == 0)
        {
            this._firstItemID = ItemID;
        }

        this._items[ItemID] = Value;
        this._count++;
        return 1;
    }

    return 0;
};

SelectedItemsManager.prototype.GetItem = function(ItemID)
{
    if (this.ItemExists(ItemID))
        return this._items[ItemID];
    
    return null;
};

SelectedItemsManager.prototype.GetItems = function() {
    // returns an associative array
    return this._items;
};

SelectedItemsManager.prototype.GetItemsArray = function() {
    // returns an array of all the items in our map
    var items = new Array();
    for (var id in this._items) {
        items.push(this._items[id]);
    }
    return items;
};

SelectedItemsManager.prototype.RemoveItem = function(ItemID) {

    if (!this.ItemExists(ItemID)) {
        return; // bail
    }

    delete this._items[ItemID];

    if (this._count > 0)
        this._count--;
};

SelectedItemsManager.prototype.ItemExists = function(ItemID) {
    var item = this._items[ItemID];
    if (!item || item == undefined)
        return false;

    return true;
};

SelectedItemsManager.prototype.Clear = function() {
    this._items = new Array();
    this._firstItemID = null;
    this._count = 0;
};

SelectedItemsManager.prototype.GetSize = function() {
    return this._count;
};

SelectedItemsManager.prototype.GetFirstSelectedItem = function() {
    if (!this.ItemExists(this._firstItemID)) {
        return "";
    }

    return this._items[this._firstItemID];
};

SelectedItemsManager.prototype.GetView = function() {
    return this._currentView;
};

SelectedItemsManager.prototype.GetNumSelectedItems = function() {
    return this._count;
};

SelectedItemsManager.prototype.SetCallback = function(CallbackFn) {
    this._callback = CallbackFn;
};

SelectedItemsManager.prototype.GetCallback = function() {
    return this._callback;
};

SelectedItemsManager.prototype.ExecuteCallback = function() {
    if (this._callback != null)
        this._callback();
};

SelectedItemsManager.prototype.CallbackExists = function() {
    if (this._callback != null)
        return true;

    return false;
};

//SelectedItemsManager.prototype._iterator = null;
//SelectedItemsManager.prototype.GetFirstNItems = function(MaxItems) {
//    // this function returns a string of the first N items in our map
//    // and stores the position of the iterator for the next batch
//    // request.

//    // note: the Iterator object is NOT supported in IE
//    var it = Iterator(this._items, true);   // true; just iterate over the keys
//    return this.GetIteratorItems(it, MaxItems);
//};

//SelectedItemsManager.prototype.GetNextNItems = function(MaxItems) {
//    return this.GetIteratorItems(this._iterator, MaxItems);
//};

//SelectedItemsManager.prototype.GetIteratorItems = function(MyIterator, MaxItems) {
//    var it = MyIterator;
//    var items = "";
//    var count = 0;

//    if (!it)
//        return "";

//    for (var key in it) {
//        if (count > 0)
//            items += ",";
//        items += key;
//        count++;

//        if (count == MaxItems) {
//            // store our iterator
//            this._iterator = it;
//            break;
//        }
//    }
//};