/**
* Function: createRoot
*
* Creates a new root cell with a default layer (child 0).
*/
function createRoot()
{
$root = new mxCell();
$root->insert(new mxCell());
return $root;
}
/**
* Function: createEdge
*
* Creates the edge to be used in <insertEdge>. This implementation does
* not set the source and target of the edge, these are set when the edge
* is added to the model.
*/
function &createEdge($parent, $id = null, $value = null, $source = null, $target = null, $style = null)
{
$geometry = new mxGeometry();
$edge = new mxCell($value, $geometry, $style);
$edge->setId($id);
$edge->setEdge(true);
$edge->geometry->relative = true;
return $edge;
}