Add generic TreeView class

EstusShots.Gtk/Controls/BindableListView.cs

@@ -0,0 +1,135 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using Gtk;
+
+namespace EstusShots.Gtk.Controls
+{
+    public class SelectionChangedEventArgs : EventArgs
+    {
+        public object Selection { get; }
+
+        public SelectionChangedEventArgs(object selection)
+        {
+            Selection = selection;
+        }
+    }
+    
+    public delegate void SelectionChangedEventHandler(object o, SelectionChangedEventArgs args);
+    
+    public class BindableListView<T>
+    {
+        public ListStore ListStore { get; internal set; }
+
+        public TreeView TreeView { get; }
+
+        public string KeyField { get; }
+
+        public IEnumerable<T> Items { get; set; }
+
+        public T SelectedItem { get; set; }
+        
+        public List<DataColumn> Columns { get; }
+
+        public event SelectionChangedEventHandler OnSelectionChanged;
+
+        /// <summary>
+        /// Initialize a new BindableListView with an existing TreeView Widget
+        /// </summary>
+        /// <param name="columns">The columns of the grid</param>
+        /// <param name="keyField">Unique key field in the item sources type</param>
+        /// <param name="treeView">An instance of an existing TreeView Widget</param>
+        public BindableListView(List<DataColumn> columns, string keyField, TreeView treeView = null)
+        {
+            TreeView = treeView ?? new TreeView();
+            Columns = columns;
+            KeyField = keyField;
+            InitTreeViewColumns();
+            InitListStore();
+            TreeView.Model = ListStore;
+            Items = new List<T>();
+            
+            TreeView.Selection.Changed += TreeView_SelectionChanged;
+        }
+
+        private void TreeView_SelectionChanged(object sender, EventArgs e)
+        {
+            if (!(sender is TreeSelection selection)) return;
+            selection.GetSelected(out var model, out var iter);
+            var key = model.GetValue(iter, 0);
+            var item  = Items.FirstOrDefault(x =>
+            {
+                var prop = x.GetType().GetProperty(KeyField);
+                var value = prop?.GetValue(x);
+                return value != null && value.Equals(key);
+            });
+            
+            if (item == null)
+            {
+                Console.WriteLine($"No item for key '{key}' found in data store");
+                return;
+            }
+
+            SelectedItem = item;
+            OnSelectionChanged?.Invoke(this, new SelectionChangedEventArgs(SelectedItem));
+        }
+
+        public void DataBind()
+        {
+            ListStore.Clear();
+            foreach (var item in Items)
+            {
+                var row = new List<object>();
+                foreach (var column in Columns)
+                {
+                    var prop = item.GetType().GetProperty(column.PropertyName);
+                    
+                    if (prop == null)
+                        throw new TypeLoadException(
+                            $"Property '{column.PropertyName}' does not exist on Type '{item.GetType()}'");
+                    
+                    row.Add(prop.GetValue(item));
+                }
+                
+                // The key value must be the first value in the row
+                var key = item.GetType().GetProperty(KeyField)?.GetValue(item);
+                row.Insert(0, key);
+                
+                try
+                {
+                    ListStore.AppendValues(row.ToArray());
+                }
+                catch (Exception e)
+                {
+                    Console.WriteLine(e);
+                }
+            }
+        }
+
+        private void InitTreeViewColumns()
+        {
+            foreach (var dataColumn in Columns)
+            {
+                // Offset by one, because the first column in the data store is fixed to the key value of the row
+                var index = Columns.IndexOf(dataColumn) + 1;
+                var column = new TreeViewColumn(
+                    dataColumn.Title,
+                    new CellRendererText(),
+                    "text", index);
+                TreeView.AppendColumn(column);
+            }
+        }
+
+        private void InitListStore()
+        {
+            var types = Columns
+                .Select(x => typeof(T).GetProperty(x.PropertyName)?.PropertyType);
+
+            // The first column in the data store is always the key field.
+            var columns = new List<Type> {typeof(T).GetProperty(KeyField)?.PropertyType};
+            columns.AddRange(types);
+            
+            ListStore = new ListStore(columns.ToArray());
+        }
+    }
+}

EstusShots.Gtk/Controls/DataColumn.cs

@@ -0,0 +1,16 @@
+namespace EstusShots.Gtk.Controls
+{
+    public class DataColumn
+    {
+        public string PropertyName { get; set; }
+        
+        public string Title { get; set; }
+
+        public DataColumn()  { }
+
+        public DataColumn(string propertyName)
+        {
+            PropertyName = propertyName;
+        }
+    }
+}