}         // ThumbPreviewMouseLeftButtonDown

        // ----------------------------------------------------------------------
        private void GridColumnWidthChanged(object sender, EventArgs e)
        {
            if (!loaded)
            {
                return;
            }

            GridViewColumn gridViewColumn = sender as GridViewColumn;

            // suppress column resizing for proportional and fixed columns
            if (ProportionalColumn.IsProportionalColumn(gridViewColumn) || FixedColumn.IsFixedColumn(gridViewColumn))
            {
                return;
            }

            // ensure range column within the bounds
            if (RangeColumn.IsRangeColumn(gridViewColumn))
            {
                // special case: auto column width - maybe conflicts with min/max range
                if (gridViewColumn != null && gridViewColumn.Width.Equals(double.NaN))
                {
                    autoSizedColumn = gridViewColumn;
                    return;                     // handled by the change header size event
                }

                // ensure column bounds
                if (Math.Abs(SetRangeColumnToBounds(gridViewColumn) - 0) > zeroWidthRange)
                {
                    return;
                }
            }

            DoResizeColumns();
        }         // GridColumnWidthChanged
        }         // ListViewUnloaded

        // ----------------------------------------------------------------------
        private void ThumbPreviewMouseMove(object sender, MouseEventArgs e)
        {
            Thumb thumb = sender as Thumb;

            if (thumb == null)
            {
                return;
            }
            GridViewColumn gridViewColumn = FindParentColumn(thumb);

            if (gridViewColumn == null)
            {
                return;
            }

            // suppress column resizing for proportional, fixed and range fill columns
            if (ProportionalColumn.IsProportionalColumn(gridViewColumn) ||
                FixedColumn.IsFixedColumn(gridViewColumn) ||
                IsFillColumn(gridViewColumn))
            {
                thumb.Cursor = null;
                return;
            }

            // check range column bounds
            if (thumb.IsMouseCaptured && RangeColumn.IsRangeColumn(gridViewColumn))
            {
                double?minWidth = RangeColumn.GetRangeMinWidth(gridViewColumn);
                double?maxWidth = RangeColumn.GetRangeMaxWidth(gridViewColumn);

                if ((minWidth.HasValue && maxWidth.HasValue) && (minWidth > maxWidth))
                {
                    return;                     // invalid case
                }

                if (resizeCursor == null)
                {
                    resizeCursor = thumb.Cursor;                     // save the resize cursor
                }

                if (minWidth.HasValue && gridViewColumn.Width <= minWidth.Value)
                {
                    thumb.Cursor = Cursors.No;
                }
                else if (maxWidth.HasValue && gridViewColumn.Width >= maxWidth.Value)
                {
                    thumb.Cursor = Cursors.No;
                }
                else
                {
                    thumb.Cursor = resizeCursor;                     // between valid min/max
                }
            }
        }         // ThumbPreviewMouseMove
        }         // ThumbPreviewMouseMove

        // ----------------------------------------------------------------------
        private void ThumbPreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            Thumb          thumb          = sender as Thumb;
            GridViewColumn gridViewColumn = FindParentColumn(thumb);

            // suppress column resizing for proportional, fixed and range fill columns
            if (ProportionalColumn.IsProportionalColumn(gridViewColumn) ||
                FixedColumn.IsFixedColumn(gridViewColumn) ||
                IsFillColumn(gridViewColumn))
            {
                e.Handled = true;
            }
        }         // ThumbPreviewMouseLeftButtonDown
        }         // Refresh

        // ----------------------------------------------------------------------
        private void RegisterEvents(DependencyObject start)
        {
            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(start); i++)
            {
                Visual childVisual = VisualTreeHelper.GetChild(start, i) as Visual;
                if (childVisual is Thumb)
                {
                    GridViewColumn gridViewColumn = FindParentColumn(childVisual);
                    if (gridViewColumn != null)
                    {
                        Thumb thumb = childVisual as Thumb;
                        if (ProportionalColumn.IsProportionalColumn(gridViewColumn) ||
                            FixedColumn.IsFixedColumn(gridViewColumn) || IsFillColumn(gridViewColumn))
                        {
                            //thumb.IsHitTestVisible = false;
                        }
                        else
                        {
                            thumb.PreviewMouseMove           += new MouseEventHandler(ThumbPreviewMouseMove);
                            thumb.PreviewMouseLeftButtonDown += new MouseButtonEventHandler(ThumbPreviewMouseLeftButtonDown);
                            DependencyPropertyDescriptor.FromProperty(
                                GridViewColumn.WidthProperty,
                                typeof(GridViewColumn)).AddValueChanged(gridViewColumn, GridColumnWidthChanged);
                        }
                    }
                }
                else if (childVisual is GridViewColumnHeader)
                {
                    GridViewColumnHeader columnHeader = childVisual as GridViewColumnHeader;
                    columnHeader.SizeChanged += new SizeChangedEventHandler(GridColumnHeaderSizeChanged);
                }
                else if (scrollViewer == null && childVisual is ScrollViewer)
                {
                    scrollViewer = childVisual as ScrollViewer;
                    scrollViewer.ScrollChanged += new ScrollChangedEventHandler(ScrollViewerScrollChanged);
                    // assume we do the regulation of the horizontal scrollbar
                    scrollViewer.HorizontalScrollBarVisibility = HorizontalScrollBarVisibility;
                    scrollViewer.VerticalScrollBarVisibility   = VerticalScrollBarVisibility;
                }

                RegisterEvents(childVisual); // recursive
            }
        }                                    // RegisterEvents
        }                                    // RegisterEvents

        // ----------------------------------------------------------------------
        private void UnregisterEvents(DependencyObject start)
        {
            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(start); i++)
            {
                Visual childVisual = VisualTreeHelper.GetChild(start, i) as Visual;
                if (childVisual is Thumb)
                {
                    GridViewColumn gridViewColumn = FindParentColumn(childVisual);
                    if (gridViewColumn != null)
                    {
                        Thumb thumb = childVisual as Thumb;
                        if (ProportionalColumn.IsProportionalColumn(gridViewColumn) ||
                            FixedColumn.IsFixedColumn(gridViewColumn) || IsFillColumn(gridViewColumn))
                        {
                            thumb.IsHitTestVisible = true;
                        }
                        else
                        {
                            thumb.PreviewMouseMove           -= new MouseEventHandler(ThumbPreviewMouseMove);
                            thumb.PreviewMouseLeftButtonDown -= new MouseButtonEventHandler(ThumbPreviewMouseLeftButtonDown);
                            DependencyPropertyDescriptor.FromProperty(
                                GridViewColumn.WidthProperty,
                                typeof(GridViewColumn)).RemoveValueChanged(gridViewColumn, GridColumnWidthChanged);
                        }
                    }
                }
                else if (childVisual is GridViewColumnHeader)
                {
                    GridViewColumnHeader columnHeader = childVisual as GridViewColumnHeader;
                    columnHeader.SizeChanged -= new SizeChangedEventHandler(GridColumnHeaderSizeChanged);
                }
                else if (scrollViewer == null && childVisual is ScrollViewer)
                {
                    scrollViewer = childVisual as ScrollViewer;
                    scrollViewer.ScrollChanged -= new ScrollChangedEventHandler(ScrollViewerScrollChanged);
                }

                UnregisterEvents(childVisual); // recursive
            }
        }                                      // UnregisterEvents