New controls, main view

src/Library/TerminalUI/Extensions/Binding.cs

@@ -6,20 +6,44 @@ namespace TerminalUI.Extensions;
 
 public static class Binding
 {
-    public static Binding<TDataContext, TResult> Bind<TView, TDataContext, TResult>(
+    public static Binding<TDataContext, TResult, TResult> Bind<TView, TDataContext, TResult>(
         this TView targetView,
         IView<TDataContext> dataSourceView,
         Expression<Func<TDataContext?, TResult>> dataContextExpression,
-        Expression<Func<TView, TResult>> propertyExpression)
+        Expression<Func<TView, TResult>> propertyExpression,
+        TResult? fallbackValue = default)
     {
         if (propertyExpression.Body is not MemberExpression {Member: PropertyInfo propertyInfo})
             throw new AggregateException(nameof(propertyExpression) + " must be a property expression");
 
-        return new Binding<TDataContext, TResult>(
-            dataSourceView, 
-            dataContextExpression, 
-            targetView, 
-            propertyInfo
+        return new Binding<TDataContext, TResult, TResult>(
+            dataSourceView,
+            dataContextExpression,
+            targetView,
+            propertyInfo,
+            value => value,
+            fallbackValue
+        );
+    }
+
+    public static Binding<TDataContext, TExpressionResult, TResult> Bind<TView, TDataContext, TExpressionResult, TResult>(
+        this TView targetView,
+        IView<TDataContext> dataSourceView,
+        Expression<Func<TDataContext?, TExpressionResult>> dataContextExpression,
+        Expression<Func<TView, TResult>> propertyExpression,
+        Func<TExpressionResult, TResult> converter,
+        TResult? fallbackValue = default)
+    {
+        if (propertyExpression.Body is not MemberExpression {Member: PropertyInfo propertyInfo})
+            throw new AggregateException(nameof(propertyExpression) + " must be a property expression");
+
+        return new Binding<TDataContext, TExpressionResult, TResult>(
+            dataSourceView,
+            dataContextExpression,
+            targetView,
+            propertyInfo,
+            converter,
+            fallbackValue
         );
     }
 }