protected virtual void ProcessDragOnCurrentDropTarget(IDropTarget dropTarget)
{
if (dropTarget != this.CurrentDropTarget)
{
if (this.CurrentDropTarget != null)
{
this.CurrentDropTarget.DragLeave(this.DraggedElement);
this.CurrentDropTarget = null;
}
if (dropTarget != null)
{
if (dropTarget.CanDropElement(this.DraggedElement))
{
this.CurrentDropTarget = dropTarget;
this.CurrentDropTarget.DragEnter(this.DraggedElement);
}
}
}
if (this.CurrentDropTarget != null)
{
// Always use the Mouse Position relative to DraggedElement and not the DraggedContainer
this.CurrentDropTarget.DragOver(this.DraggedElement, Mouse.GetPosition(this.CurrentDropTarget as IInputElement));
}
}
private void SetCurrentDropTarget(IDropTarget value, RelativePoint mousePosition, bool raiseDragEvents)
{
if (value == m_currentDropTarget)
{
return;
}
var element = this.DraggedElement;
if (m_currentDropTarget != null)
{
if (raiseDragEvents)
{
m_currentDropTarget.DragLeave(element);
}
m_currentDropTarget = null;
}
if ((value != null) && value.CanDropElement(element, mousePosition))
{
m_currentDropTarget = value;
if (raiseDragEvents)
{
m_currentDropTarget.DragEnter(element);
}
}
this.OnPropertyChanged("CurrentDropTarget");
}
public static IDropTarget GetDropTargetAtPoint(
UIElement draggedElement,
UIElement dragContainer,
MouseEventArgs e,
out Nullable <Point> dropTargetPosition,
out IDropTarget lastFoundDropTarget)
{
dropTargetPosition = null;
lastFoundDropTarget = null;
if (dragContainer == null)
{
return(null);
}
IDropTarget dropTarget = null;
Point pointToDragContainer = e.GetPosition(dragContainer);
IInputElement hitTest = dragContainer.InputHitTest(pointToDragContainer);
if (hitTest != null)
{
DependencyObject parent = hitTest as DependencyObject;
while (parent != null)
{
dropTarget = parent as IDropTarget;
if (dropTarget != null)
{
lastFoundDropTarget = dropTarget;
if (dropTarget.CanDropElement(draggedElement))
{
dropTargetPosition = pointToDragContainer;
break;
}
}
dropTarget = null;
parent = Xceed.Utils.Wpf.TreeHelper.GetParent(parent);
}
}
return(dropTarget);
}
protected virtual void ProcessDragOnCurrentDropTarget( IDropTarget dropTarget )
{
if( dropTarget != this.CurrentDropTarget )
{
if( this.CurrentDropTarget != null )
{
this.CurrentDropTarget.DragLeave( this.DraggedElement );
this.CurrentDropTarget = null;
}
if( dropTarget != null )
{
if( dropTarget.CanDropElement( this.DraggedElement ) )
{
this.CurrentDropTarget = dropTarget;
this.CurrentDropTarget.DragEnter( this.DraggedElement );
}
}
}
if( this.CurrentDropTarget != null )
{
// Always use the Mouse Position relative to DraggedElement and not the DraggedContainer
this.CurrentDropTarget.DragOver( this.DraggedElement, Mouse.GetPosition( this.CurrentDropTarget as IInputElement ) );
}
}
