private void Thumb_DragCompleted(object sender, DragCompletedEventArgs e)
{
//need to alter the drop code for new tilegrid behavior
//before snapping back, see if we move to a new column/row
DependencyObject parent = LogicalTreeHelper.GetParent(this);
if (parent is TileGrid tg)
{
Tuple <int, int> rowCol = tg.GetRowColDimensions(new Size(tg.ActualWidth, tg.ActualHeight));
//use relative end positioning to panel rather than to start position.
Point endPos = Mouse.GetPosition(tg);
//we know where the thumb is but really we would like to know where THIS is
Point thumbOffset = Mouse.GetPosition(this);
endPos.X -= thumbOffset.X;
endPos.Y -= thumbOffset.Y;
//get the width and height of each row
double colWidth = tg.ActualWidth / rowCol.Item2;
double rowHeight = tg.ActualHeight / rowCol.Item1;
//get row and column based on position of top-left corner. round off to an integer to snap to nearest
int newCol = (int)Math.Round(endPos.X / colWidth);
int newRow = (int)Math.Round(endPos.Y / rowHeight);
//if the rowspan and columnspan would exceed the number of rows or columns, fix it
newCol = Math.Min(rowCol.Item2 - TileGrid.GetColumnSpan(this), newCol);
newRow = Math.Min(rowCol.Item1 - TileGrid.GetRowSpan(this), newRow);
//snap to the correct row/column
//this doesn't need to change
TileGrid.SetColumn(this, newCol);
TileGrid.SetRow(this, newRow);
AlignAdorner();
//reset back to no margin
//only do this if snapping; presumably we actually want to stay dragged otherwise
Margin = defaultMargin;
}
}
public TileGridlineAdorner(TileGrid adornedElement) : base(adornedElement)
{
target = adornedElement;
}
private void AlignAdorner()
{
//prefer the adorner to be on the left, but move to the right if we're in the first column
menu.HorizontalAlignment = TileGrid.GetColumn(this) == 0 ? HorizontalAlignment.Right : HorizontalAlignment.Left;
}
