private void EndDrag(bool processDrop)
{
// This prevents the mouse up event or the end drag event firing more than once from causing the
// events to bubble up and the drop be handled more than once.
if (this.HasProcessedEndDrag)
{
return;
}
this.HasProcessedEndDrag = true;
// Reshow the cursor and hide the source image.
this.Host.Cursor = Cursors.Arrow;
// Hide the drag cursor.
if (this.DragCursor != null)
{
this.DragCursor.Visibility = Visibility.Collapsed;
this.DragCursor.MouseLeftButtonUp -= new MouseButtonEventHandler(OnDragCursorMouseLeftButtonUp);
this.DragCursor.MouseMove -= new MouseEventHandler(OnDragCursorMouseMove);
}
if (processDrop)
{
// Find a destination slot, using the search elements to find a Slot that intersects with the current
// mouse position.
Slot destSlot = null;
UIElement destElement = null;
// Foreach of the search elements attempt to find a slot at the x and y position.
foreach (var element in this.SearchElements.Where(se => se.Visibility == Visibility.Visible))
{
var slot = (from v in VisualTreeHelper.FindElementsInHostCoordinates(this.MousePosition, element)
where (v as Slot) != null
select v as Slot).FirstOrDefault();
if (slot != null)
{
destElement = element;
destSlot = slot;
break;
}
}
if (destSlot != null)
{
// Just use the first available, unless it is the same as the source slot.
if (destSlot != this.SourceSlot && this.SourceSlot.IsDraggable && destSlot.IsDroppable)
{
SlotItem destItem = destSlot.Item;
SlotItem sourceItem = this.SourceSlot.Item;
SlotItemChangeEventArgs args = new SlotItemChangeEventArgs(destElement, this.SourceSlot, destSlot, sourceItem, destItem);
this.SlotItemChange(args);
// Only continue this processing if the change was not handled.
if (!args.Handled)
{
// Clear the source slot item.
this.SourceSlot.Item = null;
// If the destination slot is not empty then swap the two items.
if (destItem != null)
{
SlotItemChangingEventArgs srcArgs = new SlotItemChangingEventArgs(this.SourceSlot, sourceItem, destItem);
this.SlotItemChanging(srcArgs);
if (!srcArgs.Cancel)
{
this.SourceSlot.Item = destItem;
}
}
SlotItemChangingEventArgs destArgs = new SlotItemChangingEventArgs(destSlot, destItem, sourceItem);
this.SlotItemChanging(destArgs);
if (!destArgs.Cancel)
{
destSlot.Item = sourceItem;
}
}
}
}
}
}
public SlotItemChangingEventArgs(Slot slot, SlotItem oldValue, SlotItem newValue)
{
this.Slot = slot;
this.OldValue = oldValue;
this.NewValue = NewValue;
}
public SlotItemChangeEventArgs(UIElement destinationElement, Slot sourceSlot, Slot destinationSlot, SlotItem sourceValue, SlotItem destinationValue)
{
this.DestinationElement = destinationElement;
this.SourceSlot = sourceSlot;
this.DestinationSlot = destinationSlot;
this.SourceValue = sourceValue;
this.DestinationValue = destinationValue;
}
