/**
 * Copyright (c) 2006-2015, JGraph Ltd
 * Copyright (c) 2006-2015, Gaudenz Alder
 */
/**
 * Class: mxCompositeLayout
 * 
 * Allows to compose multiple layouts into a single layout. The master layout
 * is the layout that handles move operations if another layout than the first
 * element in <layouts> should be used. The <master> layout is not executed as
 * the code assumes that it is part of <layouts>.
 * 
 * Example:
 * (code)
 * var first = new mxFastOrganicLayout(graph);
 * var second = new mxParallelEdgeLayout(graph);
 * var layout = new mxCompositeLayout(graph, [first, second], first);
 * layout.execute(graph.getDefaultParent());
 * (end)
 * 
 * Constructor: mxCompositeLayout
 *
 * Constructs a new layout using the given layouts. The graph instance is
 * required for creating the transaction that contains all layouts.
 *
 * Arguments:
 * 
 * graph - Reference to the enclosing <mxGraph>.
 * layouts - Array of <mxGraphLayouts>.
 * master - Optional layout that handles moves. If no layout is given then
 * the first layout of the above array is used to handle moves.
 */
function mxCompositeLayout(graph, layouts, master)
{
	mxGraphLayout.call(this, graph);
	this.layouts = layouts;
	this.master = master;
};

/**
 * Extends mxGraphLayout.
 */
mxCompositeLayout.prototype = new mxGraphLayout();
mxCompositeLayout.prototype.constructor = mxCompositeLayout;
	
/**
 * Variable: layouts
 * 
 * Holds the array of <mxGraphLayouts> that this layout contains.
 */
mxCompositeLayout.prototype.layouts = null;

/**
 * Variable: master
 * 
 * Reference to the <mxGraphLayouts> that handles moves. If this is null
 * then the first layout in <layouts> is used.
 */
mxCompositeLayout.prototype.master = null;

/**
 * Function: moveCell
 * 
 * Implements <mxGraphLayout.moveCell> by calling move on <master> or the first
 * layout in <layouts>.
 */
mxCompositeLayout.prototype.moveCell = function(cell, x, y)
{
	if (this.master != null)
	{
		this.master.moveCell.apply(this.master, arguments);
	}
	else
	{
		this.layouts[0].moveCell.apply(this.layouts[0], arguments);
	}
};

/**
 * Function: execute
 * 
 * Implements <mxGraphLayout.execute> by executing all <layouts> in a
 * single transaction.
 */
mxCompositeLayout.prototype.execute = function(parent)
{
	var model = this.graph.getModel();
	
	model.beginUpdate();
	try
	{
		for (var i = 0; i < this.layouts.length; i++)
		{
			this.layouts[i].execute.apply(this.layouts[i], arguments);
		}
	}
	finally
	{
		model.endUpdate();
	}
};