refactor<*>: rewrite all codes...

src/Views/Controls/TreeItem.cs

@@ -0,0 +1,41 @@
+using System.Windows;
+using System.Windows.Controls;
+
+namespace SourceGit.Views.Controls {
+
+    /// <summary>
+    ///     树节点
+    /// </summary>
+    public class TreeItem : TreeViewItem {
+
+        public static readonly DependencyProperty IsCheckedProperty = DependencyProperty.Register(
+            "IsChecked", 
+            typeof(bool), 
+            typeof(TreeItem), 
+            new PropertyMetadata(false));
+
+        public bool IsChecked {
+            get { return (bool)GetValue(IsCheckedProperty); }
+            set { SetValue(IsCheckedProperty, value); }
+        }
+
+        private int depth = 0;
+        private double indent = 16;
+
+        public TreeItem(int depth, double indent) {
+            this.depth = depth;
+            this.indent = indent;
+
+            Padding = new Thickness(indent * depth, 0, 0, 0);
+            RequestBringIntoView += (o, e) => e.Handled = true;
+        }
+
+        protected override DependencyObject GetContainerForItemOverride() {
+            return new TreeItem(depth + 1, indent);
+        }
+
+        protected override bool IsItemItsOwnContainerOverride(object item) {
+            return item is TreeItem;
+        }
+    }
+}