internal void ProcessDrop(ColumnManagerCell draggedCell, RelativePoint mousePosition)
{
var manager = default(ColumnReorderingDragSourceManager);
if (draggedCell != null)
{
manager = draggedCell.DragSourceManager as ColumnReorderingDragSourceManager;
}
if ((manager != null) && (manager.IsAnimatedColumnReorderingEnabled))
{
manager.CommitReordering();
}
else
{
this.HideDropMark();
var dataGridContext = this.DataGridContext;
Debug.Assert(dataGridContext != null);
if (dataGridContext != null)
{
var targetColumn = draggedCell.ParentColumn;
var pivotColumn = this.ParentColumn;
Debug.Assert(targetColumn != null);
Debug.Assert(pivotColumn != null);
var relativePosition = mousePosition.GetPoint(this);
var offset = Point.Subtract(mousePosition.GetPoint(draggedCell), relativePosition);
var moveBefore = true;
// We assumme the cells are layouted horizontally.
if (Math.Abs(offset.X) >= Math.Abs(offset.Y))
{
// Consider the case where the columns are layouted from left to right in reverse order.
var reverse = ((offset.X > 0d) == (targetColumn.VisiblePosition >= pivotColumn.VisiblePosition));
moveBefore = ((relativePosition.X < this.ActualWidth / 2d) != reverse);
}
// We assume the cells are layouted vertically.
else
{
// Consider the case where the columns are layouted from top to bottom in reverse order.
var reverse = ((offset.Y > 0d) == (targetColumn.VisiblePosition >= pivotColumn.VisiblePosition));
moveBefore = ((relativePosition.Y < this.ActualHeight / 2d) != reverse);
}
var success = (moveBefore)
? dataGridContext.MoveColumnBefore(targetColumn, pivotColumn)
: dataGridContext.MoveColumnAfter(targetColumn, pivotColumn);
Debug.Assert(success);
}
}
}
bool IDropTarget.CanDropElement(UIElement draggedElement, RelativePoint mousePosition)
{
var draggedCell = draggedElement as ColumnManagerCell;
if (draggedCell == null)
{
return(false);
}
var manager = draggedCell.DragSourceManager as ColumnReorderingDragSourceManager;
if ((manager != null) && manager.IsAnimatedColumnReorderingEnabled && draggedCell.IsBeingDragged)
{
var dataGridContext = DataGridControl.GetDataGridContext(this);
if ((dataGridContext == null) || !dataGridContext.Columns.Contains(draggedCell.ParentColumn))
{
return(false);
}
// We are not interested by the y-axis.
var relativePoint = mousePosition.GetPoint(this);
var xPosition = new RelativePoint(this, new Point(relativePoint.X, this.ActualHeight / 2d));
var targetCell = (from dropTarget in manager.GetDropTargetsAtPoint(xPosition)
let dropCell = dropTarget as ColumnManagerCell
where (dropCell != null)
select dropCell).FirstOrDefault();
if ((targetCell == null) || (targetCell == draggedCell) || (( IDropTarget )targetCell).CanDropElement(draggedElement, xPosition))
{
return(true);
}
}
return(false);
}
internal void UpdateAlignment(RelativePoint mousePosition)
{
var relativePosition = mousePosition.GetPoint(this.AdornedElement);
var elementSize = this.AdornedElement.RenderSize;
if (m_orientation == DropMarkOrientation.Horizontal)
{
this.Alignment = (relativePosition.Y < elementSize.Height / 2d) ? DropMarkAlignment.Near : DropMarkAlignment.Far;
}
else
{
this.Alignment = (relativePosition.X < elementSize.Width / 2d) ? DropMarkAlignment.Near : DropMarkAlignment.Far;
}
}
bool IDropTarget.CanDropElement(UIElement draggedElement, RelativePoint mousePosition)
{
var draggedCell = draggedElement as ColumnManagerCell;
if ((draggedCell == null) || (this == draggedCell))
{
return(false);
}
var parentRow = this.ParentRow as ColumnManagerRow;
if ((parentRow == null) || !parentRow.AllowColumnReorder)
{
return(false);
}
var draggedDetailContext = draggedCell.DataGridContext;
var sourceDetailContext = this.DataGridContext;
Debug.Assert((draggedDetailContext != null) && (sourceDetailContext != null));
if ((sourceDetailContext.SourceDetailConfiguration != draggedDetailContext.SourceDetailConfiguration) ||
(sourceDetailContext.GroupLevelDescriptions != draggedDetailContext.GroupLevelDescriptions))
{
return(false);
}
if (!ColumnManagerCell.CanMove(draggedCell))
{
return(false);
}
var manager = draggedCell.DragSourceManager as ColumnReorderingDragSourceManager;
if ((manager != null) && (manager.IsAnimatedColumnReorderingEnabled))
{
if (!manager.CanReorder(draggedCell, this, mousePosition))
{
return(false);
}
}
else
{
var relativePosition = mousePosition.GetPoint(this);
var moveBefore = (relativePosition.X <= this.ActualWidth / 2d);
if (moveBefore)
{
if (!draggedCell.CanMoveBefore(this.ParentColumn))
{
return(false);
}
}
else
{
if (!draggedCell.CanMoveAfter(this.ParentColumn))
{
return(false);
}
}
}
return(true);
}