private void GridColumnWidthChanged(object?sender, EventArgs?e)
{
if (!_loaded)
{
return;
}
if (sender is GridViewColumn 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.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();
}
private void ThumbPreviewMouseMove(object sender, MouseEventArgs e)
{
var thumb = sender as Thumb;
if (thumb is null)
{
return;
}
var gridViewColumn = FindParentColumn(thumb);
if (gridViewColumn is null)
{
return;
}
// suppress column resizing for proportional, fixed and range fill columns
if (ProportionalColumn.IsProportionalColumn(gridViewColumn) || FixedColumn.IsFixedColumn(gridViewColumn) || IsFillColumn(gridViewColumn))
{
thumb.SetCurrentValue(FrameworkElement.CursorProperty, null);
return;
}
// check range column bounds
if (thumb.IsMouseCaptured && RangeColumn.IsRangeColumn(gridViewColumn))
{
var minWidth = RangeColumn.GetRangeMinWidth(gridViewColumn);
var maxWidth = RangeColumn.GetRangeMaxWidth(gridViewColumn);
if (minWidth.HasValue && maxWidth.HasValue && (minWidth > maxWidth))
{
return; // invalid case
}
if (_resizeCursor is null)
{
_resizeCursor = thumb.Cursor; // save the resize cursor
}
if (minWidth.HasValue && gridViewColumn.Width <= minWidth.Value)
{
thumb.SetCurrentValue(FrameworkElement.CursorProperty, Cursors.No);
}
else if (maxWidth.HasValue && gridViewColumn.Width >= maxWidth.Value)
{
thumb.SetCurrentValue(FrameworkElement.CursorProperty, Cursors.No);
}
else
{
thumb.SetCurrentValue(FrameworkElement.CursorProperty, _resizeCursor); // between valid min/max
}
}
}
private void InitColumns()
{
if (!(ListView.View is GridView gridView))
{
return;
}
foreach (var gridViewColumn in gridView.Columns)
{
if (!RangeColumn.IsRangeColumn(gridViewColumn))
{
continue;
}
var minWidth = RangeColumn.GetRangeMinWidth(gridViewColumn);
var maxWidth = RangeColumn.GetRangeMaxWidth(gridViewColumn);
if (!minWidth.HasValue && !maxWidth.HasValue)
{
continue;
}
var columnHeader = FindColumnHeader(ListView, gridViewColumn);
if (columnHeader is null)
{
continue;
}
var actualWidth = columnHeader.ActualWidth;
if (minWidth.HasValue)
{
columnHeader.SetCurrentValue(FrameworkElement.MinWidthProperty, minWidth.Value);
if (!double.IsInfinity(actualWidth) && actualWidth < columnHeader.MinWidth)
{
gridViewColumn.SetCurrentValue(GridViewColumn.WidthProperty, columnHeader.MinWidth);
}
}
if (maxWidth.HasValue)
{
columnHeader.SetCurrentValue(FrameworkElement.MaxWidthProperty, maxWidth.Value);
if (!double.IsInfinity(actualWidth) && actualWidth > columnHeader.MaxWidth)
{
gridViewColumn.SetCurrentValue(GridViewColumn.WidthProperty, columnHeader.MaxWidth);
}
}
}
}
private bool IsFillColumn(GridViewColumn?gridViewColumn)
{
if (gridViewColumn is null)
{
return(false);
}
var view = ListView.View as GridView;
if (view is null || view.Columns.Count == 0)
{
return(false);
}
var isFillColumn = RangeColumn.GetRangeIsFillColumn(gridViewColumn);
return(isFillColumn.HasValue && isFillColumn.Value);
}
// returns the delta
private double SetRangeColumnToBounds(GridViewColumn gridViewColumn)
{
var startWidth = gridViewColumn.Width;
var minWidth = RangeColumn.GetRangeMinWidth(gridViewColumn);
var maxWidth = RangeColumn.GetRangeMaxWidth(gridViewColumn);
if (minWidth.HasValue && maxWidth.HasValue && (minWidth > maxWidth))
{
return(0); // invalid case
}
if (minWidth.HasValue && gridViewColumn.Width < minWidth.Value)
{
gridViewColumn.SetCurrentValue(GridViewColumn.WidthProperty, minWidth.Value);
}
else if (maxWidth.HasValue && gridViewColumn.Width > maxWidth.Value)
{
gridViewColumn.SetCurrentValue(GridViewColumn.WidthProperty, maxWidth.Value);
}
return(gridViewColumn.Width - startWidth);
}
private void ResizeColumns()
{
var view = ListView.View as GridView;
if (view is null || view.Columns.Count == 0)
{
return;
}
var 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 (var gridViewColumn in view.Columns)
{
if (ProportionalColumn.IsProportionalColumn(gridViewColumn))
{
var 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.SetCurrentValue(ScrollViewer.HorizontalScrollBarVisibilityProperty, ScrollBarVisibility.Auto);
}
// search the first fill column
GridViewColumn?fillColumn = null;
for (var i = 0; i < view.Columns.Count; i++)
{
var gridViewColumn = view.Columns[i];
if (IsFillColumn(gridViewColumn))
{
fillColumn = gridViewColumn;
break;
}
}
if (fillColumn != null)
{
var otherColumnsWithoutFillWidth = otherColumnsWidth - fillColumn.ActualWidth;
var fillWidth = actualWidth - otherColumnsWithoutFillWidth;
if (fillWidth > 0)
{
var minWidth = RangeColumn.GetRangeMinWidth(fillColumn);
var maxWidth = RangeColumn.GetRangeMaxWidth(fillColumn);
var setWidth = !(minWidth.HasValue && fillWidth < minWidth.Value);
if (maxWidth.HasValue && fillWidth > maxWidth.Value)
{
setWidth = false;
}
if (setWidth)
{
if (_scrollViewer != null)
{
_scrollViewer.SetCurrentValue(ScrollViewer.HorizontalScrollBarVisibilityProperty, ScrollBarVisibility.Hidden);
}
fillColumn.SetCurrentValue(GridViewColumn.WidthProperty, fillWidth);
}
}
}
return;
}
var resizeableColumnsWidth = actualWidth - otherColumnsWidth;
if (resizeableColumnsWidth <= 0)
{
return;
}
// resize columns
var resizeableRegionWidth = resizeableColumnsWidth / resizeableRegionCount;
foreach (var gridViewColumn in view.Columns)
{
if (ProportionalColumn.IsProportionalColumn(gridViewColumn))
{
var proportionalWidth = ProportionalColumn.GetProportionalWidth(gridViewColumn);
if (proportionalWidth != null)
{
gridViewColumn.SetCurrentValue(GridViewColumn.WidthProperty, proportionalWidth.Value * resizeableRegionWidth);
}
}
}
}