port from perforce

intromat/NodeNetwork/ViewModels/ConnectionViewModel.cs

@@ -0,0 +1,100 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reactive.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using DynamicData;
+using DynamicData.Aggregation;
+using NodeNetwork.Views;
+using ReactiveUI;
+
+namespace NodeNetwork.ViewModels
+{
+    /// <summary>
+    /// Represents a connection between a node input and a node output
+    /// </summary>
+    public class ConnectionViewModel : ReactiveObject
+    {
+        static ConnectionViewModel()
+        {
+            NNViewRegistrar.AddRegistration(() => new ConnectionView(), typeof(IViewFor<ConnectionViewModel>));
+        }
+
+        #region Logger
+        private static readonly log4net.ILog log = log4net.LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
+        #endregion
+
+        /// <summary>
+        /// The network that contains this connection
+        /// </summary>
+        public NetworkViewModel Parent { get; }
+
+        /// <summary>
+        /// The viewmodel of the node input that is on one end of the connection.
+        /// </summary>
+        public NodeInputViewModel Input { get; }
+
+        /// <summary>
+        /// The viewmodel of the node output that is on one end of the connection.
+        /// </summary>
+        public NodeOutputViewModel Output { get; }
+        
+        #region CanBeRemovedByUser
+        /// <summary>
+        /// If false, the user cannot delete this connection. True by default.
+        /// </summary>
+        public bool CanBeRemovedByUser
+        {
+            get => _canBeRemovedByUser;
+            set => this.RaiseAndSetIfChanged(ref _canBeRemovedByUser, value);
+        }
+        private bool _canBeRemovedByUser;
+        #endregion
+
+        #region IsHighlighted
+        /// <summary>
+        /// If true, the connection is highlighted.
+        /// </summary>
+        public bool IsHighlighted
+        {
+            get => _isHighlighted;
+            set => this.RaiseAndSetIfChanged(ref _isHighlighted, value);
+        }
+        private bool _isHighlighted;
+        #endregion
+
+        #region IsInErrorState
+        /// <summary>
+        /// If true, the connection is displayed as being in an erroneous state.
+        /// </summary>
+        public bool IsInErrorState
+        {
+            get => _isInErrorState;
+            set => this.RaiseAndSetIfChanged(ref _isInErrorState, value);
+        }
+        private bool _isInErrorState;
+        #endregion
+
+        #region IsMarkedForDelete
+        /// <summary>
+        /// If true, the connection is displayed as being marked for deletion.
+        /// </summary>
+        public bool IsMarkedForDelete => _isMarkedForDelete.Value;
+        private ObservableAsPropertyHelper<bool> _isMarkedForDelete;
+        #endregion
+
+        public ConnectionViewModel(NetworkViewModel parent, NodeInputViewModel input, NodeOutputViewModel output)
+        {
+            Parent = parent;
+            Input = input;
+            Output = output;
+			
+			this.WhenAnyValue(v => v.Parent.CutLine.IntersectingConnections)
+	            .Where(l => l != null)
+	            .Select(list => list.Connect().Filter(c => c == this).Count().Select(c => c > 0))
+	            .Switch()
+	            .ToProperty(this, vm => vm.IsMarkedForDelete, out _isMarkedForDelete);
+        }
+    }
+}