port from perforce

intromat/NodeNetworkToolkit/NodeList/NodeListViewModel.cs

@@ -0,0 +1,130 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reactive;
+using System.Reactive.Linq;
+using DynamicData;
+using NodeNetwork.ViewModels;
+using ReactiveUI;
+
+namespace NodeNetwork.Toolkit.NodeList
+{
+    /// <summary>
+    /// A viewmodel for a UI List component that contains NodeViewModels
+    /// and can be used to let the user add new nodes to a network.
+    /// </summary>
+    public class NodeListViewModel : ReactiveObject
+    {
+        static NodeListViewModel()
+        {
+            NNViewRegistrar.AddRegistration(() => new NodeListView(), typeof(IViewFor<NodeListViewModel>));
+        }
+
+        /// <summary>
+        /// The formatting mode of the list.
+        /// </summary>
+        public enum DisplayMode
+        {
+            /// <summary>
+            /// The nodes are displayed graphically in a grid.
+            /// </summary>
+            Tiles,
+            /// <summary>
+            /// The node names are displayed as text in a list.
+            /// </summary>
+            List
+        }
+
+        #region Title
+        /// <summary>
+        /// The string that is displayed at the top of the list
+        /// </summary>
+        public string Title
+        {
+            get => _title;
+            set => this.RaiseAndSetIfChanged(ref _title, value);
+        }
+        private string _title;
+        #endregion
+
+        #region EmptyLabel
+        /// <summary>
+        /// The string that is displayed when VisibleNodes is empty.
+        /// </summary>
+        public string EmptyLabel
+        {
+            get => _emptyLabel;
+            set => this.RaiseAndSetIfChanged(ref _emptyLabel, value);
+        }
+        private string _emptyLabel = "";
+        #endregion
+
+        #region DisplayMode
+        /// <summary>
+        /// The way the list of available nodes is formatted.
+        /// </summary>
+        public DisplayMode Display
+        {
+            get => _display;
+            set => this.RaiseAndSetIfChanged(ref _display, value);
+        }
+        private DisplayMode _display;
+        #endregion
+
+        #region NodeTemplates
+        /// <summary>
+        /// List of all the available nodes in the list.
+        /// </summary>
+        public ISourceList<NodeTemplate> NodeTemplates { get; } = new SourceList<NodeTemplate>();
+        #endregion
+
+        #region VisibleNodes
+        /// <summary>
+        /// List of nodes that are actually visible in the list.
+        /// This list is based on Nodes and SearchQuery.
+        /// </summary>
+        public IObservableList<NodeViewModel> VisibleNodes { get; }
+        #endregion
+
+        #region SearchQuery
+        /// <summary>
+        /// The current search string that is used to filter Nodes into VisibleNodes.
+        /// </summary>
+        public string SearchQuery
+        {
+            get => _searchQuery;
+            set => this.RaiseAndSetIfChanged(ref _searchQuery, value);
+        }
+        private string _searchQuery = "";
+        #endregion
+
+        public NodeListViewModel()
+        {
+            Title = "Add node";
+            EmptyLabel = "No matching nodes found.";
+            Display = DisplayMode.Tiles;
+
+	        var onQueryChanged = this.WhenAnyValue(vm => vm.SearchQuery)
+		        .Throttle(TimeSpan.FromMilliseconds(200), RxApp.MainThreadScheduler)
+		        .Publish();
+	        onQueryChanged.Connect();
+	        VisibleNodes = NodeTemplates.Connect()
+		        .AutoRefreshOnObservable(_ => onQueryChanged)
+                .Transform(t => t.Instance)
+		        .AutoRefresh(node => node.Name)
+		        .Filter(n => (n.Name ?? "").ToUpper().Contains(SearchQuery?.ToUpper() ?? ""))
+		        .AsObservableList();
+        }
+
+        /// <summary>
+        /// Adds a new node type to the list.
+        /// Every time a node is added to a network from this list, the factory function will be called to create a new instance of the viewmodel type.
+        /// </summary>
+        /// <typeparam name="T">The subtype of NodeViewModel to add to the list.</typeparam>
+        /// <param name="factory">The factory function to create a new instance of T</param>
+        public void AddNodeType<T>(Func<T> factory) where T : NodeViewModel
+        {
+            NodeTemplates.Add(new NodeTemplate(factory));
+        }
+    }
+}