code: function(x, y) {
          this.line.geometry.addComponent(
              new OpenLayers.Geometry.Point(x, y), 
              this.getCurrentPointIndex()
          );
          this.drawFeature();
          delete this.redoStack;
      }
docs: Method: insertXY
  Insert a point in the current sketch given x & y coordinates.  The new
  point is inserted immediately before the most recently drawn point.
  
  Parameters:
  x - {Number} The x-coordinate of the point.
  y - {Number} The y-coordinate of the point.