using System.Windows;
using System.Windows.Media;

namespace SHJX.Service.WorkFlowEdit
{
    public class LinkAdorner : DragAdorner
    {
        private Pen _pen;

        private IPort _port;
        public IPort Port
        {
            get { return _port; }
            set
            {
                if (_port != value)
                {
                    _port = value;
                    InvalidateVisual();
                }
            }
        }

        public LinkAdorner(DiagramView view, Point start)
            : base(view, start)
        {
            _pen = new Pen(new SolidColorBrush(Colors.Red), 1);
        }

        protected override bool DoDrag()
        {
            View.LinkTool.DragTo(End - Start);
            return View.LinkTool.CanDrop();
        }

        protected override void EndDrag()
        {
            View.LinkTool.EndDrag(DoCommit);
        }

        protected override void OnRender(DrawingContext drawingContext)
        {
            if (Port != null)
            {
                var p = Port.Center;
                drawingContext.DrawLine(_pen, new Point(p.X, p.Y - 3.5), new Point(p.X, p.Y + 3.5));
                drawingContext.DrawLine(_pen, new Point(p.X - 3.5, p.Y), new Point(p.X + 3.5, p.Y));
            }
        }
    }
}