/**
 * @module gallery-checkboxgroups
 */

/**********************************************************************
 * All checkboxes can be selected and a select-all checkbox is available
 * to check all. This check-all box is automatically changed if any other
 * checkbox changes state.
 * 
 * @class SelectAllCheckboxGroup
 * @extends CheckboxGroup
 * @constructor
 * @param select_all_cb {String|Object} The checkbox that triggers "select all"
 * @param cb_list {String|Node|NodeList} The list of checkboxes to manage
 */

function SelectAllCheckboxGroup(
	/* string/Node */			select_all_cb,
	/* string/Node/NodeList */	cb_list)
{
	this.select_all_cb = Y.one(select_all_cb);
	this.select_all_cb.on('click', updateSelectAll, this);

	SelectAllCheckboxGroup.superclass.constructor.call(this, cb_list);
	this.enforceConstraints(this.cb_list, 0);
}

function updateSelectAll()
{
	var checked = this.select_all_cb.get('checked');
	var count   = this.cb_list.size();
	for (var i=0; i<count; i++)
	{
		var cb = this.cb_list.item(i);
		if (!cb.get('disabled'))
		{
			cb.set('checked', checked);
		}
	}
};

Y.extend(SelectAllCheckboxGroup, CheckboxGroup,
{
	/**
	 * @method getSelectAllCheckbox
	 * @return {Node} checkbox that controls "select all"
	 */
	getSelectAllCheckbox: function()
	{
		return this.select_all_cb;
	},

	/**
	 * Toggle the setting of the "select all" checkbox.
	 *
	 * @method toggleSelectAll
	 */
	toggleSelectAll: function()
	{
		this.select_all_cb.set('checked', !this.select_all_cb.get('checked'));
		updateSelectAll.call(this);
	},

	/**
	 * @method enforceConstraints
	 * @param cb_list {String|Object|Array} The list of checkboxes
	 * @param index {Int} The index of the checkbox that changed
	 */
	enforceConstraints: function(
		/* NodeList */	cb_list,
		/* int */		index)
	{
		this.select_all_cb.set('checked', this.allChecked());
	}
});

Y.SelectAllCheckboxGroup = SelectAllCheckboxGroup;