} // 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 = ScrollBarVisibility.Hidden;
                    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
        } // InitColumns

        // ----------------------------------------------------------------------
        protected virtual void ResizeColumns()
        {
            GridView view = listView.View as GridView;

            if (view == null || view.Columns.Count == 0)
            {
                return;
            }

            // listview width
            double actualWidth = double.PositiveInfinity;

            if (scrollViewer != null)
            {
                actualWidth = scrollViewer.ViewportWidth;
            }
            if (double.IsInfinity(actualWidth))
            {
                actualWidth = listView.ActualWidth;
            }
            if (double.IsInfinity(actualWidth) || actualWidth <= 0)
            {
                return;
            }

            double resizeableRegionCount = 0;
            double otherColumnsWidth     = 0;

            // determine column sizes
            foreach (GridViewColumn gridViewColumn in view.Columns)
            {
                if (ProportionalColumn.IsProportionalColumn(gridViewColumn))
                {
                    double?proportionalWidth = ProportionalColumn.GetProportionalWidth(gridViewColumn);
                    if (proportionalWidth != null)
                    {
                        resizeableRegionCount += proportionalWidth.Value;
                    }
                }
                else
                {
                    otherColumnsWidth += gridViewColumn.ActualWidth;
                }
            }

            if (resizeableRegionCount <= 0)
            {
                // no proportional columns present: commit the regulation to the scroll viewer
                if (scrollViewer != null)
                {
                    scrollViewer.HorizontalScrollBarVisibility = ScrollBarVisibility.Auto;
                }

                // search the first fill column
                GridViewColumn fillColumn = null;
                for (int i = 0; i < view.Columns.Count; i++)
                {
                    GridViewColumn gridViewColumn = view.Columns[i];
                    if (IsFillColumn(gridViewColumn))
                    {
                        fillColumn = gridViewColumn;
                        break;
                    }
                }

                if (fillColumn != null)
                {
                    double otherColumnsWithoutFillWidth = otherColumnsWidth - fillColumn.ActualWidth;
                    double fillWidth = actualWidth - otherColumnsWithoutFillWidth;
                    if (fillWidth > 0)
                    {
                        double?minWidth = RangeColumn.GetRangeMinWidth(fillColumn);
                        double?maxWidth = RangeColumn.GetRangeMaxWidth(fillColumn);

                        bool setWidth = !(minWidth.HasValue && fillWidth < minWidth.Value);
                        if (maxWidth.HasValue && fillWidth > maxWidth.Value)
                        {
                            setWidth = false;
                        }
                        if (setWidth)
                        {
                            if (scrollViewer != null)
                            {
                                scrollViewer.HorizontalScrollBarVisibility = ScrollBarVisibility.Hidden;
                            }
                            fillColumn.Width = fillWidth;
                        }
                    }
                }
                return;
            }

            double resizeableColumnsWidth = actualWidth - otherColumnsWidth;

            if (resizeableColumnsWidth <= 0)
            {
                return; // missing space
            }

            // resize columns
            double resizeableRegionWidth = resizeableColumnsWidth / resizeableRegionCount;

            foreach (GridViewColumn gridViewColumn in view.Columns)
            {
                if (ProportionalColumn.IsProportionalColumn(gridViewColumn))
                {
                    double?proportionalWidth = ProportionalColumn.GetProportionalWidth(gridViewColumn);
                    if (proportionalWidth != null)
                    {
                        gridViewColumn.Width = proportionalWidth.Value * resizeableRegionWidth;
                    }
                }
            }
        } // ResizeColumns