/// <summary>
        /// Selects the first polygon point.
        /// </summary>
        public void SelectFirstPolygonPoint()
        {
            Logger.Instance.Log(LogPriority.DEBUG, this, "[NOTICE]\t[INTERACTION]\t[NAVIGATION]\t" + "first poly point");

            if (LastSelectedShapePolygonPoints == null && LastSelectedShape != null)
            {
                var pObs = LastSelectedShape.GetPolygonPointsObserver();
                if (pObs != null)
                {
                    LastSelectedShapePolygonPoints = pObs;
                }
            }

            if (LastSelectedShapePolygonPoints != null)
            {
                PolyPointDescriptor point;
                if (LastSelectedShapePolygonPoints.HasPoints())
                {
                    point = LastSelectedShapePolygonPoints.First();
                }
                else
                {
                    point = new PolyPointDescriptor();
                }

                SpeakPolygonPoint(LastSelectedShapePolygonPoints);
                fire_PolygonPointSelected(LastSelectedShapePolygonPoints, point);
            }
            else
            {
                fire_PolygonPointSelected_Reset();
            }
        }
        /// <summary>
        /// Selects the previous polygon point.
        /// </summary>
        public void SelectPreviousPolygonPoint(bool ignoreLastDuplicate = true)
        {
            Logger.Instance.Log(LogPriority.DEBUG, this, "[NOTICE]\t[INTERACTION]\t[NAVIGATION]\t" + "previous poly point");

            if (LastSelectedShapePolygonPoints == null && LastSelectedShape != null)
            {
                var pObs = LastSelectedShape.GetPolygonPointsObserver();
                if (pObs != null)
                {
                    LastSelectedShapePolygonPoints = pObs;
                }
            }

            if (LastSelectedShapePolygonPoints != null)
            {
                PolyPointDescriptor point;
                if (LastSelectedShapePolygonPoints.HasPoints())
                {
                    if (LastSelectedShapePolygonPoints.HasPrevious())
                    {
                        point = LastSelectedShapePolygonPoints.Previous();
                    }
                    else
                    {
                        point = LastSelectedShapePolygonPoints.Last();
                        if (ignoreLastDuplicate && LastSelectedShapePolygonPoints.HasPrevious())
                        {
                            point = LastSelectedShapePolygonPoints.Previous();
                        }
                    }
                }
                else
                {
                    point = new PolyPointDescriptor();
                }

                SpeakPolygonPoint(LastSelectedShapePolygonPoints);
                fire_PolygonPointSelected(LastSelectedShapePolygonPoints, point);
            }
            else
            {
                fire_PolygonPointSelected_Reset();
            }
        }
        /// <summary>
        /// Selects the first available polygon point.
        /// </summary>
        public void SelectPolygonPoint()
        {
            Logger.Instance.Log(LogPriority.DEBUG, this, "[NOTICE]\t[INTERACTION]\t[NAVIGATION]\t" + "select poly point");

            if (LastSelectedShapePolygonPoints == null && LastSelectedShape != null)
            {
                LastSelectedShapePolygonPoints = LastSelectedShape.GetPolygonPointsObserver();
                UpdateLastSelectedPolygonPoints();
            }
            if (LastSelectedShapePolygonPoints != null)
            {
                SpeakPolygonPoint(LastSelectedShapePolygonPoints);
                int i;
                fire_PolygonPointSelected(LastSelectedShapePolygonPoints, LastSelectedShapePolygonPoints.Current(out i));
            }
            else
            {
                fire_PolygonPointSelected_Reset();
            }
        }
        /// <summary>
        /// Selects the next following polygon point.
        /// </summary>
        /// <param name="ignoreLastDuplicate">if set to <c>true</c> to ignore the last point of an closed bezier,
        /// because it's the same as the first point..</param>
        public void SelectNextPolygonPoint(bool ignoreLastDuplicate = true)
        {
            // check if the shape is closed or not


            Logger.Instance.Log(LogPriority.DEBUG, this, "[NOTICE]\t[INTERACTION]\t[NAVIGATION]\t" + "next poly point");

            if (LastSelectedShapePolygonPoints == null && LastSelectedShape != null)
            {
                LastSelectedShapePolygonPoints = LastSelectedShape.GetPolygonPointsObserver();
                UpdateLastSelectedPolygonPoints();
            }
            if (LastSelectedShapePolygonPoints != null)
            {
                PolyPointDescriptor point;
                if (LastSelectedShapePolygonPoints.HasPoints())
                {
                    if (!LastSelectedShapePolygonPoints.HasNext(ignoreLastDuplicate))
                    {
                        LastSelectedShapePolygonPoints.ResetIterator();
                    }
                    point = LastSelectedShapePolygonPoints.Next();
                }
                else
                {
                    point = new PolyPointDescriptor();
                }

                SpeakPolygonPoint(LastSelectedShapePolygonPoints);
                fire_PolygonPointSelected(LastSelectedShapePolygonPoints, point);
            }
            else
            {
                fire_PolygonPointSelected_Reset();
            }
        }