EDIT

/**

 * D3 Layout Tree (inspired by http://bl.ocks.org/mbostock/4339083)

 * which displays a list concept relationships between a 'from' taxon 

 * and a number of 'to' taxon

 */

window.eu_etaxonomy_cdm_vaadin_jscomponent_D3ConceptRelationshipTree = function() {

    var connector = this;

    var diagramElement = connector.getElement();

    var margin = {top: 20, right: 120, bottom: 20, left: 120},

    width = 740 - margin.right - margin.left,

    height = 600 - margin.top - margin.bottom;

    var i = 0,

    duration = 750,

    root;

    var tree;

    var diagonal;

    var svg = d3.select(diagramElement).append("svg")

    .attr("width", width + margin.right + margin.left)

    .attr("height", height + margin.top + margin.bottom)

    .append("g")

    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

    var selectedNode;

    var orientations = {

            "topbottom": {

                size: [width, height],

                x: function(d) { return d.x; },

                y: function(d) { return d.y; }

            },

            "rightleft": {

                size: [height, width],

                x: function(d) { return width - d.y; },

                y: function(d) { return d.x; },

                xend: function(d) { return d.y; },

            },

            "bottomtop": {

                size: [width, height],

                x: function(d) { return d.x; },

                y: function(d) { return height - d.y; }

            },

            "leftright": {

                size: [height, width],

                x: function(d) { return d.y; },

                y: function(d) { return d.x; },

                xend: function(d) { return width - d.y; },

            }

    };

    // default setting is left-right

    var orientation = orientations.rightleft;    

    var tAnchorWithChildren = "end";

    var tAnchorWithoutChildren = "start";

    var dirMult = 1;

    this.onStateChange = function() {

        crTree = this.getState().conceptRelationshipTree;

        if(crTree) {

            root = JSON.parse(connector.getState().conceptRelationshipTree);

            if(root.direction === "left-right") {               

                orientation = orientations.leftright;       

                tAnchorWithChildren = "end";

                tAnchorWithoutChildren = "start";

                dirMult = 1;

            }

            if(root.direction === "right-left") {                

                orientation = orientations.rightleft;      

                tAnchorWithChildren = "start";

                tAnchorWithoutChildren = "end";

                dirMult = -1;

            }

            diagonal = d3.svg.diagonal().projection(function(d) { return [orientation.x(d), orientation.y(d)]; });                

            tree = d3.layout.tree().size(orientation.size);

            update(root);

            d3.select(self.frameElement).style("height", "800px");

        }           

    }

    function update(source) {

        // Compute the new tree layout.

        var nodes = tree.nodes(root).reverse(),

        links = tree.links(nodes);

        // Normalize for fixed-depth.

        nodes.forEach(function(d) { d.y = d.depth * 180; });

        // Update the nodes…

        var node = svg.selectAll("g.node")

        .data(nodes, function(d) { return d.id || (d.id = ++i); });

        // Enter any new nodes at the parent's previous position.

        var nodeEnter = node.enter().append("g")

        .attr("class", "node")

        .attr("transform", function(d) { return "translate(" + orientation.x(source) + "," + orientation.y(source) + ")"; })

        .on("click", click);

        nodeEnter.append("circle")

        .attr("r", function(d) { return d.type === "taxon" ? 5 : 10; })

        .style("fill", function(d) { return d === source && d.type === "conceptr" ? "#DF7401" : "#fff"; });

        nodeEnter.append("text")

        .attr("x", function(d) { 

            if(d.type === "conceptr") { 

                return dirMult*50;

            } else {

                return d.children || d._children ? -1*dirMult*10 : dirMult*10; 

            }

        })

        .attr("y", function(d) { return d.type === "conceptr" ? -20 : 0; })

        .attr("dy", ".35em")

        .attr("text-anchor", function(d) { return d.children || d._children ? tAnchorWithChildren : tAnchorWithoutChildren; })

        .text(function(d) { return d.name; })

        .style("fill-opacity", 1e-6);

        // Transition nodes to their new position.

        var nodeUpdate = node.transition()

        .duration(duration)

        .attr("transform", function(d) { return "translate(" + orientation.x(d) + "," + orientation.y(d) + ")"; });

        nodeUpdate.select("circle")

        .attr("r", function(d) { return d.type === "taxon" ? 5 : 10; })

        .style("fill", function(d) { return d === selectedNode && d.type === "conceptr" ? "#DF7401" : "#fff"; });

        nodeUpdate.select("text")

        .style("fill-opacity", 1);

        // Transition exiting nodes to the parent's new position.

        var nodeExit = node.exit().transition()

            .duration(duration)

            .attr("transform", function(d) { return "translate(" + orientation.xend(source) + "," + orientation.y(source) + ")"; })

            .remove();

        nodeExit.select("circle")

            .attr("r", 1e-6);

        nodeExit.select("text")

            .style("fill-opacity", 1e-6);

        // Update the links…

        var link = svg.selectAll("path.link")

        .data(links, function(d) { return d.target.id; });

        // Remove links without transition

        link.exit().remove();

        // Enter any new links at the parent's previous position.

        link.enter().insert("path", "g")

        .attr("class", "link")

        .attr("d", function(d) {

            var o = {x: source.x, y: source.y};

            return diagonal({source: o, target: o});

        });

        // Transition links to their new position.

        link.transition()

        .duration(duration)

        .attr("d", diagonal);

    }

//  Toggle children on click.

    function click(d) {

        //root.children.forEach(collapse);

        if(d.type === "conceptr") {

            connector.select(d.uuid);

        }

        selectedNode = d;

        update(d);

    }

}