private void AssociatedObject_QueryContinueDrag(object sender, QueryContinueDragEventArgs e)
{
var element = GetSenderDiagram(sender) ?? sender as UIElement;
if (element == null)
{
return;
}
DrawLineAdorner adorner = GetDraggingLineAdorner(element);
Point point = WPFUtility.GetMousePosition(element);
if (adorner != null)
{
adorner.Position = point;
}
}
private void AssociatedObject_PreviewMouseMove(object sender, MouseEventArgs e)
{
if (e.LeftButton == MouseButtonState.Released)
{
return;
}
//use the connection object base on ConnectionDiagramBase
var element = GetSenderDiagram(sender) ?? sender as UIElement;
if (element == null)
{
return;
}
Point point = e.GetPosition(element as UIElement);
Point startPoint = (element as ConnectionDiagramBase)?.CenterPosition ?? new Point(0, 0);
//change the draw line center position
int centerradius = (element as ConnectionDiagramBase)?.CenterPositionRadius ?? 0;
if (!WPFUtility.IsCenterDragging(startPoint, point, centerradius))
{
return;
}
if (!WPFUtility.IsDragging(startPoint, point))
{
return;
}
DrawLineAdorner adorner = new DrawLineAdorner(element, 0.7, point);
SetDraggingLineAdorner(element, adorner);
DataObject data = new DataObject();
//set the adorner for drop action and create the clone element.
data.SetData(typeof(UIElement), element);
data.SetData(typeof(DrawLineAdorner), adorner);
ICommand dragcommand = GetDragLineCommand(element);
//cann't drag without command
if (dragcommand != null)
{
object parameter = GetDragLineCommandParameter(element); //?? this.AssociatedObject.DataContext;
if (parameter != null)
{
data.SetData(DataFormats.Serializable, parameter);
}
if (dragcommand.CanExecute(parameter))
{
dragcommand.Execute(parameter);
DragDrop.DoDragDrop(element, data, DragDropEffects.Copy | DragDropEffects.Move);
}
}
adorner.Remove();
SetDraggingLineAdorner(element, null);
}
/// <summary>
/// Sets the value of the DraggingLineAdorner attached property
/// for a given dependency object.
/// </summary>
/// <param name="obj">The object to which the property value
/// is written.</param>
/// <param name="value">Sets the DraggingLineAdorner value of the specified object.</param>
public static void SetDraggingLineAdorner(DependencyObject obj, DrawLineAdorner value)
{
obj.SetValue(DraggingLineAdornerProperty, value);
}