mxConnectionHandler.prototype.mouseDown=function(a,b){this.mouseDownCounter++;this.isEnabled()&&this.graph.isEnabled()&&!b.isConsumed()&&!this.isConnecting()&&this.isStartEvent(b)&&(null!=this.constraintHandler.currentConstraint&&null!=this.constraintHandler.currentFocus&&null!=this.constraintHandler.currentPoint?(this.sourceConstraint=this.constraintHandler.currentConstraint,this.previous=this.constraintHandler.currentFocus,this.first=this.constraintHandler.currentPoint.clone()):this.first=new mxPoint(b.getGraphX(),