Code (Javascript)

this.diagram.addEventListener(MindFusion.Diagramming.Events.hitTestAdjustmentHandles, this.onHitTestHandles);

// ...

// hitTestAdjustmentHandles handler
private onHitTestHandles(sender, args) {
    var node = args.node;
    var mousePosition = args.mousePosition;

    var bounds = new Rect(node.bounds.x + 3, node.bounds.y + 3, node.bounds.width - 6, node.bounds.height - 6)
    if (bounds.containsPoint(mousePosition))
        return args.setAdjustmentHandle(8 /* move handle */);
}

//...

private createCompositeNode(diagramElement: DiagramElement): CompositeNode {

    // ...

    node.setHandlesStyle(common.Diagramming.HandlesStyle.Custom);

    // ...
} 

Code (Javascript)

function onHitTestHandles(sender, args)
{
    var node = args.node;
    var mousePosition = args.mousePosition;

    if (node.isAnchorPatternVisible && node.anchorPointVisuals)
    {
        for (var i = 0; i < node.anchorPointVisuals.length; i++)
        {
            var p = node.anchorPointVisuals[i];
            if (p.containsPoint(mousePosition))
            {
                node.parent.removeElement(p);
                p.pen = "red";
                node.parent.addElement(p);
            }
            else
            {
                if (p.pen != node.anchorPattern.getPoints()[i].getColor())
                {
                    node.parent.removeElement(p);
                    p.pen = node.anchorPattern.getPoints()[i].getColor();
                    node.parent.addElement(p);
                }
            }
        }
    }

    var bounds = new Rect(node.bounds.x + 3, node.bounds.y + 3, node.bounds.width - 6, node.bounds.height - 6)
    if (bounds.containsPoint(mousePosition))
        return args.setAdjustmentHandle(8);
} 

Code (Javascript)

var bounds = new Rect(node.bounds.x + 3, node.bounds.y + 3, node.bounds.width - 6, node.bounds.height - 6)