private void grid_SelectionDragDelta(object sender, DataGridSelectionDragEventArgs e)
{
if (_draggingSelection)
{
var currentPoint = e.GetPosition(null);
double offset = currentPoint.Y - _draggingStartPoint.Y;
double rowsOffset = 0;
int from, to, increment = 1;
if (offset > 0)
{
from = grid.Selection.SelectedRows.Max(r => r.Index) + 1;
to = grid.Rows.Count - 1;
}
else
{
from = grid.Selection.SelectedRows.Min(r => r.Index) - 1;
to = 0;
increment = -1;
}
_rowsNumberOffset = 0;
for (int i = from; increment > 0 ? i <= to : i >= to; i += increment)
{
var rowHeight = grid.Rows[i].ActualHeight * increment;
if (increment > 0 ? rowHeight < offset : rowHeight > offset)
{
rowsOffset += rowHeight;
offset -= rowHeight;
_rowsNumberOffset += increment;
continue;
}
break;
}
double selectionHeight = 0;
foreach (var selectedRow in grid.Selection.SelectedRows)
{
selectionHeight += selectedRow.ActualHeight;
}
foreach (var row in grid.Viewport.Rows)
{
double y = 0;
if (grid.Selection.SelectedRows.Contains(row))
{
y = rowsOffset;
System.Windows.Controls.Canvas.SetZIndex(row.Presenter, 1);
System.Windows.Controls.Canvas.SetZIndex(row.HeaderPresenter, 1);
}
else
{
if (increment > 0 ?
row.Index >= from && row.Index < from + _rowsNumberOffset :
row.Index <= from && row.Index > from + _rowsNumberOffset)
{
y = -selectionHeight * increment;
}
System.Windows.Controls.Canvas.SetZIndex(row.Presenter, 0);
System.Windows.Controls.Canvas.SetZIndex(row.HeaderPresenter, 0);
}
var storyboard = row.Presenter.Tag as Storyboard;
var animation = storyboard.Children[0] as DoubleAnimation;
if (animation.To != y)
{
animation.To = y;
storyboard.Begin();
}
var storyboard2 = row.HeaderPresenter.Tag as Storyboard;
var animation2 = storyboard2.Children[0] as DoubleAnimation;
if (animation2.To != y)
{
animation2.To = y;
storyboard2.Begin();
}
}
}
}
private void grid_SelectionDragCompleted(object sender, DataGridSelectionDragEventArgs e)
{
if (_draggingSelection)
{
foreach (var row in grid.Viewport.Rows)
{
var storyboard = row.Presenter.Tag as Storyboard;
storyboard.Stop();
(row.Presenter.RenderTransform as TranslateTransform).Y = 0;
var storyboard2 = row.HeaderPresenter.Tag as Storyboard;
storyboard2.Stop();
(row.HeaderPresenter.RenderTransform as TranslateTransform).Y = 0;
}
_draggingSelection = false;
var selectedItems = grid.Selection.SelectedRows.Select(r => r.DataItem);
var selectionStart = grid.Selection.SelectedRows.Min(r => r.Index);
var selectionEnd = grid.Selection.SelectedRows.Max(r => r.Index);
for (int i = 0; i < Math.Abs(_rowsNumberOffset); i++)
{
if (_rowsNumberOffset > 0)
{
var player = _players[selectionEnd + _rowsNumberOffset];
_players.Remove(player);
_players.Insert(selectionStart, player);
}
else
{
var player = _players[selectionStart + _rowsNumberOffset];
_players.Remove(player);
_players.Insert(selectionEnd, player);
}
}
grid.Selection.BeginUpdate();
grid.Selection.Clear();
foreach (var item in selectedItems)
{
var row = grid.Rows[item];
grid.Selection.Add(row, row);
}
grid.Selection.EndUpdate();
}
}