diff --git a/.gitignore b/.gitignore
index d86b573..022f031 100644
--- a/.gitignore
+++ b/.gitignore
@@ -123,3 +123,5 @@ app.*.symbols
 pubspec.lock
 **/*.evc
 **/pubspec_overrides.yaml
+
+flutter_eval.json
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8767e43..d3ee20a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,13 @@
+## 0.4.6
+- Add Builder
+- Add AlignmentGeometry, Alignment, and BoxConstraints
+- Add alignment, margin, constraints, and transformAlignment on Container
+- Add widthFactor and heightFactor on Center
+- Add TextDirection, VerticalDirection, and TextBaseline
+- Add textDirection and verticalDirection on Row
+- Add verticalDirection and textBaseline on Column
+- Documentation improvements
+
 ## 0.4.5
 - Support for Flutter 3.3
 - Update example to the Flutter counter example
diff --git a/README.md b/README.md
index 2a868ad..2a81658 100644
--- a/README.md
+++ b/README.md
@@ -105,6 +105,22 @@ Your project structure should look like this:
     └── main.dart
 ```
 
+You'll also have to change your entrypoint a bit. flutter_eval does not support 
+`runApp()` as it runs inside an existing Flutter app, which already calls runApp().
+Instead, you can change your main() function to look like this:
+
+```dart
+Widget main() {
+  // do any setup, then
+  return MyApp();
+}
+```
+
+Alternatively, you can simply comment out runApp() and reference Widget
+constructors directly from RuntimeWidget. This is recommended if your project
+has multiple widgets which are displayed at different times or in different
+parts of the app.
+
 Finally, in the root of your project, run:
 ```bash
 dart_eval compile -o program.evc
@@ -122,6 +138,37 @@ The resulting `program.evc` file will be in the root of your project and you can
 in flutter_eval, as an asset or from a URL. The package name will be automatically inferred
 from your pubspec.yaml file.
 
+## Calling functions and passing arguments
+
+To instantiate a class with its default constructor, append a '.' to the class name.
+
+When calling a dart_eval function or constructor externally, you must specify *all* 
+arguments - even optional and named ones - in order, using null to indicate the absence
+of an argument (whereas `$null()` indicates a null value).
+
+E.g. for the following class:
+
+```dart
+class MyApp extends SomeWidget {
+  MyApp(this.name, {Key? key, Color? color}) : super(key: key, color: color);
+
+  final String name;
+}
+```
+
+You could instantiate it in `RuntimeWidget` with:
+
+```dart
+return RuntimeWidget(
+  uri: Uri.parse('asset:assets/program.evc'),
+  library: 'package:example/main.dart',
+  function: 'MyApp.',
+  args: [$String('Jessica'), null, null]
+);
+```
+
+You can also pass callbacks with `$Function`.
+
 ## Supported widgets and classes
 
 Currently supported widgets and classes include:
@@ -130,10 +177,12 @@ Currently supported widgets and classes include:
 - `WidgetsApp`, `Container`, `Column`, `Row`, `Center`;
 - `Padding`, `EdgeInsetsGeometry`, `EdgeInsets`;
 - `MainAxisAlignment`, `MainAxisSize`, `CrossAxisAlignment`;
+- `AlignmentGeometry`, `Alignment`, `Constraints`, `BoxConstraints`;
 - `Color`,  `ColorSwatch`, `Colors`, `FontWeight`, `FontStyle`;
 - `MaterialApp`, `MaterialColor`, `MaterialAccentColor`;
 - `Theme`, `ThemeData`, `TextTheme`;
 - `Text`, `TextStyle`, `TextEditingController`, `TextField`;
+- `TextDirection`, `VerticalDirection`, `TextBaseline`
 - `Scaffold`, `ScaffoldMessenger`, `AppBar`, `SnackBar`, `FloatingActionButton`;
 - `TextButton`, `ElevatedButton`;
 - `Navigator`, `NavigatorState`;
diff --git a/lib/flutter_eval.dart b/lib/flutter_eval.dart
index a4fa7ac..a866081 100644
--- a/lib/flutter_eval.dart
+++ b/lib/flutter_eval.dart
@@ -21,12 +21,15 @@ import 'package:flutter_eval/src/material/text_theme.dart';
 import 'package:flutter_eval/src/material/theme.dart';
 import 'package:flutter_eval/src/material/theme_data.dart';
 import 'package:flutter_eval/src/painting.dart';
+import 'package:flutter_eval/src/painting/alignment.dart';
 import 'package:flutter_eval/src/painting/basic_types.dart';
 import 'package:flutter_eval/src/painting/colors.dart';
 import 'package:flutter_eval/src/painting/edge_insets.dart';
 import 'package:flutter_eval/src/painting/text_style.dart';
 import 'package:flutter_eval/src/rendering.dart';
+import 'package:flutter_eval/src/rendering/box.dart';
 import 'package:flutter_eval/src/rendering/flex.dart';
+import 'package:flutter_eval/src/rendering/object.dart';
 import 'package:flutter_eval/src/sky_engine/ui/painting.dart';
 import 'package:flutter_eval/src/sky_engine/ui/text.dart';
 import 'package:flutter_eval/src/sky_engine/ui/ui.dart';
@@ -78,7 +81,12 @@ void setupFlutterForCompile(Compiler compiler) {
     $TextButton.$declaration,
     $ThemeData.$declaration,
     $Theme.$declaration,
-    $ElevatedButton.$declaration
+    $ElevatedButton.$declaration,
+    $Builder.$declaration,
+    $AlignmentGeometry.$declaration,
+    $Alignment.$declaration,
+    $Constraints.$declaration,
+    $BoxConstraints.$declaration
   ];
 
   compiler.defineBridgeClasses(classes);
@@ -88,6 +96,9 @@ void setupFlutterForCompile(Compiler compiler) {
   compiler.defineBridgeEnum($MainAxisSize.$declaration);
   compiler.defineBridgeEnum($FontWeight.$declaration);
   compiler.defineBridgeEnum($FontStyle.$declaration);
+  compiler.defineBridgeEnum($TextDirection.$declaration);
+  compiler.defineBridgeEnum($VerticalDirection.$declaration);
+  compiler.defineBridgeEnum($TextBaseline.$declaration);
 
   compiler.addSource(DartSource('dart:ui', dartUiSource));
 
@@ -105,7 +116,7 @@ void setupFlutterForCompile(Compiler compiler) {
   compiler.addSource(DartSource('package:flutter/src/widgets/framework.dart', widgetsFrameworkSource));
   compiler.addSource(DartSource('package:flutter/src/widgets/basic.dart', widgetsBasicSource));
 
-  /*final outJson = json.encode({
+  /* final outJson = json.encode({
     'classes': classes.map((c) => c.toJson()).toList(),
     'enums': [
       $MainAxisAlignment.$declaration.toJson(),
@@ -128,7 +139,7 @@ void setupFlutterForCompile(Compiler compiler) {
     ]
   });
 
-  File('flutter_eval.json').writeAsStringSync(outJson);*/
+  File('flutter_eval.json').writeAsStringSync(outJson); */
 }
 
 /// Setup Flutter classes for use in a dart_eval [Runtime]. After
@@ -144,14 +155,35 @@ void setupFlutterForRuntime(Runtime runtime) {
     ..registerBridgeFunc('package:flutter/src/widgets/framework.dart', 'StatefulWidget.', $StatefulWidget$bridge.$new,
         isBridge: true)
     ..registerBridgeFunc('package:flutter/src/widgets/framework.dart', 'State.', $State$bridge.$new, isBridge: true)
+    ..registerBridgeFunc('package:flutter/src/painting/alignment.dart', 'Alignment.', $Alignment.$new)
+    ..registerBridgeFunc('package:flutter/src/painting/alignment.dart', 'Alignment.topLeft*g', $Alignment.$topLeft)
+    ..registerBridgeFunc('package:flutter/src/painting/alignment.dart', 'Alignment.topCenter*g', $Alignment.$topCenter)
+    ..registerBridgeFunc('package:flutter/src/painting/alignment.dart', 'Alignment.topRight*g', $Alignment.$topRight)
+    ..registerBridgeFunc(
+        'package:flutter/src/painting/alignment.dart', 'Alignment.centerLeft*g', $Alignment.$centerLeft)
+    ..registerBridgeFunc('package:flutter/src/painting/alignment.dart', 'Alignment.center*g', $Alignment.$center)
+    ..registerBridgeFunc(
+        'package:flutter/src/painting/alignment.dart', 'Alignment.centerRight*g', $Alignment.$centerRight)
+    ..registerBridgeFunc(
+        'package:flutter/src/painting/alignment.dart', 'Alignment.bottomLeft*g', $Alignment.$bottomLeft)
+    ..registerBridgeFunc(
+        'package:flutter/src/painting/alignment.dart', 'Alignment.bottomCenter*g', $Alignment.$bottomCenter)
+    ..registerBridgeFunc(
+        'package:flutter/src/painting/alignment.dart', 'Alignment.bottomRight*g', $Alignment.$bottomRight)
     ..registerBridgeFunc('package:flutter/src/painting/edge_insets.dart', 'EdgeInsets.fromLTRB', $EdgeInsets.$fromLTRB)
     ..registerBridgeFunc('package:flutter/src/painting/edge_insets.dart', 'EdgeInsets.all', $EdgeInsets.$all)
     ..registerBridgeFunc('package:flutter/src/painting/text_style.dart', 'TextStyle.', $TextStyle.$new)
+    ..registerBridgeFunc('package:flutter/src/rendering/box.dart', 'BoxConstraints.', $BoxConstraints.$new)
+    ..registerBridgeFunc('package:flutter/src/rendering/box.dart', 'BoxConstraints.tightFor', $BoxConstraints.$tightFor)
+    ..registerBridgeFunc(
+        'package:flutter/src/rendering/box.dart', 'BoxConstraints.tightForFinite', $BoxConstraints.$tightForFinite)
+    ..registerBridgeFunc('package:flutter/src/rendering/box.dart', 'BoxConstraints.expand', $BoxConstraints.$expand)
     ..registerBridgeFunc('package:flutter/src/widgets/app.dart', 'WidgetsApp.', $WidgetsApp.$new)
     ..registerBridgeFunc('package:flutter/src/widgets/basic.dart', 'Padding.', $Padding.$new)
     ..registerBridgeFunc('package:flutter/src/widgets/basic.dart', 'Column.', $Column.$new)
     ..registerBridgeFunc('package:flutter/src/widgets/basic.dart', 'Row.', $Row.$new)
     ..registerBridgeFunc('package:flutter/src/widgets/basic.dart', 'Center.', $Center.$new)
+    ..registerBridgeFunc('package:flutter/src/widgets/basic.dart', 'Builder.', $Builder.$new)
     ..registerBridgeFunc('package:flutter/src/widgets/text.dart', 'Text.', $Text.$new)
     ..registerBridgeFunc('package:flutter/src/widgets/container.dart', 'Container.', $Container.$new)
     ..registerBridgeFunc(
diff --git a/lib/src/painting.dart b/lib/src/painting.dart
index 19cc4cc..166ee18 100644
--- a/lib/src/painting.dart
+++ b/lib/src/painting.dart
@@ -1,6 +1,7 @@
 const paintingSource = '''
 library painting;
 
+export 'package:flutter/src/painting/alignment.dart';
 export 'package:flutter/src/painting/basic_types.dart';
 export 'package:flutter/src/painting/edge_insets.dart';
 export 'package:flutter/src/painting/text_style.dart';
diff --git a/lib/src/painting/alignment.dart b/lib/src/painting/alignment.dart
new file mode 100644
index 0000000..407d34e
--- /dev/null
+++ b/lib/src/painting/alignment.dart
@@ -0,0 +1,141 @@
+import 'package:dart_eval/dart_eval.dart';
+import 'package:dart_eval/dart_eval_bridge.dart';
+import 'package:dart_eval/stdlib/core.dart';
+import 'package:flutter/material.dart';
+
+class $AlignmentGeometry implements $Instance {
+  static const $type =
+      BridgeTypeRef.spec(BridgeTypeSpec('package:flutter/src/painting/alignment.dart', 'AlignmentGeometry'));
+
+  static const $declaration = BridgeClassDef(BridgeClassType($type, isAbstract: true),
+      constructors: {}, methods: {}, getters: {}, setters: {}, fields: {}, wrap: true);
+
+  $AlignmentGeometry.wrap(this.$value);
+
+  @override
+  final AlignmentGeometry $value;
+
+  late final $Instance _superclass = $Object($value);
+
+  @override
+  AlignmentGeometry get $reified => $value;
+
+  @override
+  $Value? $getProperty(Runtime runtime, String identifier) {
+    return _superclass.$getProperty(runtime, identifier);
+  }
+
+  @override
+  int get $runtimeType => throw UnimplementedError();
+
+  @override
+  void $setProperty(Runtime runtime, String identifier, $Value value) {
+    return _superclass.$setProperty(runtime, identifier, value);
+  }
+}
+
+class $Alignment implements $Instance {
+  static const $type = BridgeTypeRef.spec(BridgeTypeSpec('package:flutter/src/painting/alignment.dart', 'Alignment'));
+
+  static const _stValueType =
+      BridgeMethodDef(BridgeFunctionDef(returns: BridgeTypeAnnotation($Alignment.$type)), isStatic: true);
+  static const $declaration =
+      BridgeClassDef(BridgeClassType($type, isAbstract: false, $extends: $AlignmentGeometry.$type),
+          constructors: {
+            '': BridgeConstructorDef(BridgeFunctionDef(returns: BridgeTypeAnnotation($type), namedParams: [
+              BridgeParameter('x', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)), false),
+              BridgeParameter('y', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)), false),
+            ]))
+          },
+          methods: {},
+          getters: {
+            'x': BridgeMethodDef(
+                BridgeFunctionDef(returns: BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)))),
+            'y': BridgeMethodDef(
+                BridgeFunctionDef(returns: BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)))),
+            'topLeft': _stValueType,
+            'topCenter': _stValueType,
+            'topRight': _stValueType,
+            'centerLeft': _stValueType,
+            'center': _stValueType,
+            'centerRight': _stValueType,
+            'bottomLeft': _stValueType,
+            'bottomCenter': _stValueType,
+            'bottomRight': _stValueType,
+          },
+          setters: {},
+          fields: {},
+          wrap: true);
+
+  static $Value? $new(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $Alignment.wrap(Alignment(
+      args[0]!.$value,
+      args[1]!.$value,
+    ));
+  }
+
+  static $Value? $topLeft(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $Alignment.wrap(Alignment.topLeft);
+  }
+
+  static $Value? $topCenter(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $Alignment.wrap(Alignment.topCenter);
+  }
+
+  static $Value? $topRight(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $Alignment.wrap(Alignment.topRight);
+  }
+
+  static $Value? $centerLeft(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $Alignment.wrap(Alignment.centerLeft);
+  }
+
+  static $Value? $center(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $Alignment.wrap(Alignment.center);
+  }
+
+  static $Value? $centerRight(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $Alignment.wrap(Alignment.centerRight);
+  }
+
+  static $Value? $bottomLeft(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $Alignment.wrap(Alignment.bottomLeft);
+  }
+
+  static $Value? $bottomCenter(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $Alignment.wrap(Alignment.bottomCenter);
+  }
+
+  static $Value? $bottomRight(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $Alignment.wrap(Alignment.bottomRight);
+  }
+
+  $Alignment.wrap(this.$value);
+
+  @override
+  final Alignment $value;
+
+  late final $Instance _superclass = $AlignmentGeometry.wrap($value);
+
+  @override
+  get $reified => $value;
+
+  @override
+  $Value? $getProperty(Runtime runtime, String identifier) {
+    switch (identifier) {
+      case 'x':
+        return $double($value.x);
+      case 'y':
+        return $double($value.y);
+    }
+    return _superclass.$getProperty(runtime, identifier);
+  }
+
+  @override
+  int get $runtimeType => throw UnimplementedError();
+
+  @override
+  void $setProperty(Runtime runtime, String identifier, $Value value) {
+    throw UnimplementedError();
+  }
+}
diff --git a/lib/src/painting/basic_types.dart b/lib/src/painting/basic_types.dart
index 9fba658..29ddb89 100644
--- a/lib/src/painting/basic_types.dart
+++ b/lib/src/painting/basic_types.dart
@@ -1,3 +1,7 @@
+import 'package:dart_eval/dart_eval.dart';
+import 'package:dart_eval/dart_eval_bridge.dart';
+import 'package:flutter/material.dart';
+
 const paintingBasicTypesSource = '''
 export 'dart:ui' show
   BlendMode,
@@ -43,3 +47,37 @@ export 'dart:ui' show
 
 export 'package:flutter/foundation.dart' show VoidCallback;
  ''';
+
+class $VerticalDirection implements $Instance {
+  static const $type =
+      BridgeTypeRef.spec(BridgeTypeSpec('package:flutter/src/painting/basic_types.dart', 'VerticalDirection'));
+
+  static const $declaration =
+      BridgeEnumDef($type, methods: {}, getters: {}, setters: {}, values: ['rtl', 'ltr'], fields: {});
+
+  static final $values = {
+    'up': $VerticalDirection.wrap(VerticalDirection.up),
+    'down': $VerticalDirection.wrap(VerticalDirection.down),
+  };
+
+  $VerticalDirection.wrap(this.$value);
+
+  @override
+  final VerticalDirection $value;
+
+  @override
+  get $reified => $value;
+
+  @override
+  $Value? $getProperty(Runtime runtime, String identifier) {
+    throw UnimplementedError();
+  }
+
+  @override
+  int get $runtimeType => throw UnimplementedError();
+
+  @override
+  void $setProperty(Runtime runtime, String identifier, $Value value) {
+    throw UnimplementedError();
+  }
+}
diff --git a/lib/src/rendering.dart b/lib/src/rendering.dart
index ce79d1c..78fd141 100644
--- a/lib/src/rendering.dart
+++ b/lib/src/rendering.dart
@@ -1,3 +1,5 @@
 const renderingSource = '''
+export 'package:flutter/src/rendering/box.dart';
 export 'package:flutter/src/rendering/flex.dart';
+export 'package:flutter/src/rendering/object.dart';
 ''';
diff --git a/lib/src/rendering/box.dart b/lib/src/rendering/box.dart
new file mode 100644
index 0000000..cfa0f84
--- /dev/null
+++ b/lib/src/rendering/box.dart
@@ -0,0 +1,113 @@
+import 'package:dart_eval/dart_eval.dart';
+import 'package:dart_eval/dart_eval_bridge.dart';
+import 'package:dart_eval/stdlib/core.dart';
+import 'package:flutter/rendering.dart';
+import 'package:flutter_eval/src/rendering/object.dart';
+
+class $BoxConstraints implements $Instance {
+  static const $type = BridgeTypeRef.spec(BridgeTypeSpec('package:flutter/src/rendering/box.dart', 'BoxConstraints'));
+
+  static const $declaration = BridgeClassDef(BridgeClassType($type, isAbstract: true),
+      constructors: {
+        '': BridgeConstructorDef(BridgeFunctionDef(returns: BridgeTypeAnnotation($type), namedParams: [
+          BridgeParameter('minWidth', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)), true),
+          BridgeParameter('maxWidth', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)), true),
+          BridgeParameter('minHeight', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)), true),
+          BridgeParameter('maxHeight', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)), true),
+        ])),
+        'tightFor': BridgeConstructorDef(BridgeFunctionDef(returns: BridgeTypeAnnotation($type), namedParams: [
+          BridgeParameter(
+              'width', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType), nullable: true), true),
+          BridgeParameter(
+              'height', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType), nullable: true), true),
+        ])),
+        'tightForFinite': BridgeConstructorDef(BridgeFunctionDef(returns: BridgeTypeAnnotation($type), namedParams: [
+          BridgeParameter('width', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)), true),
+          BridgeParameter('height', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)), true),
+        ])),
+        'expand': BridgeConstructorDef(BridgeFunctionDef(returns: BridgeTypeAnnotation($type), namedParams: [
+          BridgeParameter(
+              'width', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType), nullable: true), true),
+          BridgeParameter(
+              'height', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType), nullable: true), true),
+        ])),
+      },
+      methods: {},
+      getters: {
+        'minWidth': BridgeMethodDef(
+            BridgeFunctionDef(returns: BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)))),
+        'maxWidth': BridgeMethodDef(
+            BridgeFunctionDef(returns: BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)))),
+        'minHeight': BridgeMethodDef(
+            BridgeFunctionDef(returns: BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)))),
+        'maxHeight': BridgeMethodDef(
+            BridgeFunctionDef(returns: BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)))),
+      },
+      setters: {},
+      fields: {},
+      wrap: true);
+
+  late final $Instance _superclass = $Constraints.wrap($value);
+
+  $BoxConstraints.wrap(this.$value);
+
+  @override
+  final BoxConstraints $value;
+
+  static $Value? $new(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $BoxConstraints.wrap(BoxConstraints(
+      minWidth: args[0]?.$value ?? 0.0,
+      maxWidth: args[1]?.$value ?? double.infinity,
+      minHeight: args[2]?.$value ?? 0.0,
+      maxHeight: args[3]?.$value ?? double.infinity,
+    ));
+  }
+
+  static $Value? $tightFor(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $BoxConstraints.wrap(BoxConstraints.tightFor(
+      width: args[0]?.$value,
+      height: args[1]?.$value,
+    ));
+  }
+
+  static $Value? $tightForFinite(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $BoxConstraints.wrap(BoxConstraints.tightForFinite(
+      width: args[0]?.$value ?? 0.0,
+      height: args[1]?.$value ?? 0.0,
+    ));
+  }
+
+  static $Value? $expand(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $BoxConstraints.wrap(BoxConstraints.expand(
+      width: args[0]?.$value,
+      height: args[1]?.$value,
+    ));
+  }
+
+  @override
+  $Value? $getProperty(Runtime runtime, String identifier) {
+    switch (identifier) {
+      case 'minWidth':
+        return $double($value.minWidth);
+      case 'maxWidth':
+        return $double($value.maxWidth);
+      case 'minHeight':
+        return $double($value.minHeight);
+      case 'maxHeight':
+        return $double($value.maxHeight);
+      default:
+        return _superclass.$getProperty(runtime, identifier);
+    }
+  }
+
+  @override
+  get $reified => $value;
+
+  @override
+  int get $runtimeType => throw UnimplementedError();
+
+  @override
+  void $setProperty(Runtime runtime, String identifier, $Value value) {
+    throw UnimplementedError('Property not found or cannot set $identifier on Constraints');
+  }
+}
diff --git a/lib/src/rendering/object.dart b/lib/src/rendering/object.dart
new file mode 100644
index 0000000..a800fb6
--- /dev/null
+++ b/lib/src/rendering/object.dart
@@ -0,0 +1,49 @@
+import 'package:dart_eval/dart_eval.dart';
+import 'package:dart_eval/dart_eval_bridge.dart';
+import 'package:dart_eval/stdlib/core.dart';
+import 'package:flutter/rendering.dart';
+
+class $Constraints implements $Instance {
+  static const $type = BridgeTypeRef.spec(BridgeTypeSpec('package:flutter/src/rendering/object.dart', 'Constraints'));
+
+  static const $declaration = BridgeClassDef(BridgeClassType($type, isAbstract: true),
+      constructors: {},
+      methods: {},
+      getters: {
+        'isTight': BridgeMethodDef(
+            BridgeFunctionDef(returns: BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.boolType)))),
+        'isNormalized': BridgeMethodDef(
+            BridgeFunctionDef(returns: BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.boolType)))),
+      },
+      setters: {},
+      fields: {},
+      wrap: true);
+
+  $Constraints.wrap(this.$value);
+
+  @override
+  final Constraints $value;
+
+  @override
+  $Value? $getProperty(Runtime runtime, String identifier) {
+    switch (identifier) {
+      case 'isTight':
+        return $bool($value.isTight);
+      case 'isNormalized':
+        return $bool($value.isNormalized);
+      default:
+        throw UnimplementedError('Property not found $identifier on Constraints');
+    }
+  }
+
+  @override
+  get $reified => $value;
+
+  @override
+  int get $runtimeType => throw UnimplementedError();
+
+  @override
+  void $setProperty(Runtime runtime, String identifier, $Value value) {
+    throw UnimplementedError('Property not found or cannot set $identifier on Constraints');
+  }
+}
diff --git a/lib/src/sky_engine/ui/text.dart b/lib/src/sky_engine/ui/text.dart
index c34a4d2..26ee4a7 100644
--- a/lib/src/sky_engine/ui/text.dart
+++ b/lib/src/sky_engine/ui/text.dart
@@ -75,3 +75,66 @@ class $FontWeight implements $Instance {
     throw UnimplementedError();
   }
 }
+
+class $TextDirection implements $Instance {
+  static const $type = BridgeTypeRef.spec(BridgeTypeSpec('dart:ui', 'TextDirection'));
+
+  static const $declaration =
+      BridgeEnumDef($type, methods: {}, getters: {}, setters: {}, values: ['rtl', 'ltr'], fields: {});
+
+  static final $values = {'rtl': $TextDirection.wrap(TextDirection.rtl), 'ltr': $TextDirection.wrap(TextDirection.ltr)};
+
+  $TextDirection.wrap(this.$value);
+
+  @override
+  final TextDirection $value;
+
+  @override
+  get $reified => $value;
+
+  @override
+  $Value? $getProperty(Runtime runtime, String identifier) {
+    throw UnimplementedError();
+  }
+
+  @override
+  int get $runtimeType => throw UnimplementedError();
+
+  @override
+  void $setProperty(Runtime runtime, String identifier, $Value value) {
+    throw UnimplementedError();
+  }
+}
+
+class $TextBaseline implements $Instance {
+  static const $type = BridgeTypeRef.spec(BridgeTypeSpec('dart:ui', 'TextBaseline'));
+
+  static const $declaration =
+      BridgeEnumDef($type, methods: {}, getters: {}, setters: {}, values: ['alphabetic', 'ideographic'], fields: {});
+
+  static final $values = {
+    'alphabetic': $TextBaseline.wrap(TextBaseline.alphabetic),
+    'ideographic': $TextBaseline.wrap(TextBaseline.ideographic)
+  };
+
+  $TextBaseline.wrap(this.$value);
+
+  @override
+  final TextBaseline $value;
+
+  @override
+  get $reified => $value;
+
+  @override
+  $Value? $getProperty(Runtime runtime, String identifier) {
+    throw UnimplementedError();
+  }
+
+  @override
+  int get $runtimeType => throw UnimplementedError();
+
+  @override
+  void $setProperty(Runtime runtime, String identifier, $Value value) {
+    throw UnimplementedError();
+  }
+}
diff --git a/lib/src/widgets/basic.dart b/lib/src/widgets/basic.dart
index 1e9cfc7..93b748f 100644
--- a/lib/src/widgets/basic.dart
+++ b/lib/src/widgets/basic.dart
@@ -2,8 +2,10 @@ import 'package:dart_eval/dart_eval.dart';
 import 'package:dart_eval/dart_eval_bridge.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_eval/src/foundation/key.dart';
+import 'package:flutter_eval/src/painting/basic_types.dart';
 import 'package:flutter_eval/src/painting/edge_insets.dart';
 import 'package:flutter_eval/src/rendering/flex.dart';
+import 'package:flutter_eval/src/sky_engine/ui/text.dart';
 import 'package:flutter_eval/src/widgets/framework.dart';
 
 const widgetsBasicSource = '''
@@ -74,9 +76,11 @@ class $Column implements $Instance {
       constructors: {
         '': BridgeConstructorDef(BridgeFunctionDef(returns: BridgeTypeAnnotation($type), namedParams: [
           BridgeParameter('key', BridgeTypeAnnotation($Key.$type, nullable: true), true),
-          BridgeParameter('mainAxisSize', BridgeTypeAnnotation($MainAxisSize.$type), true),
           BridgeParameter('mainAxisAlignment', BridgeTypeAnnotation($MainAxisAlignment.$type), true),
+          BridgeParameter('mainAxisSize', BridgeTypeAnnotation($MainAxisSize.$type), true),
           BridgeParameter('crossAxisAlignment', BridgeTypeAnnotation($CrossAxisAlignment.$type), true),
+          BridgeParameter('verticalDirection', BridgeTypeAnnotation($VerticalDirection.$type), true),
+          BridgeParameter('textBaseline', BridgeTypeAnnotation($TextBaseline.$type), true),
           BridgeParameter(
               'children', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.listType, [$Widget.$type])), true),
         ]))
@@ -92,10 +96,12 @@ class $Column implements $Instance {
   static $Value? $new(Runtime runtime, $Value? target, List<$Value?> args) {
     return $Column.wrap(Column(
       key: args[0]?.$value,
-      mainAxisSize: args[1]?.$value ?? MainAxisSize.max,
-      mainAxisAlignment: args[2]?.$value ?? MainAxisAlignment.start,
+      mainAxisAlignment: args[1]?.$value ?? MainAxisAlignment.start,
+      mainAxisSize: args[2]?.$value ?? MainAxisSize.max,
       crossAxisAlignment: args[3]?.$value ?? CrossAxisAlignment.center,
-      children: (args[4]?.$reified as List).cast(),
+      verticalDirection: args[4]?.$value ?? VerticalDirection.down,
+      textBaseline: args[5]?.$value,
+      children: (args[6]?.$reified as List).cast(),
     ));
   }
 
@@ -126,9 +132,11 @@ class $Row implements $Instance {
       constructors: {
         '': BridgeConstructorDef(BridgeFunctionDef(returns: BridgeTypeAnnotation($type), namedParams: [
           BridgeParameter('key', BridgeTypeAnnotation($Key.$type, nullable: true), true),
-          BridgeParameter('mainAxisSize', BridgeTypeAnnotation($MainAxisSize.$type), true),
           BridgeParameter('mainAxisAlignment', BridgeTypeAnnotation($MainAxisAlignment.$type), true),
+          BridgeParameter('mainAxisSize', BridgeTypeAnnotation($MainAxisSize.$type), true),
           BridgeParameter('crossAxisAlignment', BridgeTypeAnnotation($CrossAxisAlignment.$type), true),
+          BridgeParameter('textDirection', BridgeTypeAnnotation($TextDirection.$type), true),
+          BridgeParameter('verticalDirection', BridgeTypeAnnotation($VerticalDirection.$type), true),
           BridgeParameter(
               'children', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.listType, [$Widget.$type])), true),
         ]))
@@ -144,10 +152,12 @@ class $Row implements $Instance {
   static $Value? $new(Runtime runtime, $Value? target, List<$Value?> args) {
     return $Row.wrap(Row(
       key: args[0]?.$value,
-      mainAxisSize: args[1]?.$value ?? MainAxisSize.max,
-      mainAxisAlignment: args[2]?.$value ?? MainAxisAlignment.start,
+      mainAxisAlignment: args[1]?.$value ?? MainAxisAlignment.start,
+      mainAxisSize: args[2]?.$value ?? MainAxisSize.max,
       crossAxisAlignment: args[3]?.$value ?? CrossAxisAlignment.center,
-      children: (args[4]?.$reified as List).cast(),
+      textDirection: args[4]?.$value,
+      verticalDirection: args[5]?.$value ?? VerticalDirection.down,
+      children: (args[6]?.$reified as List).cast(),
     ));
   }
 
@@ -178,6 +188,8 @@ class $Center implements $Instance {
       constructors: {
         '': BridgeConstructorDef(BridgeFunctionDef(returns: BridgeTypeAnnotation($type), namedParams: [
           BridgeParameter('key', BridgeTypeAnnotation($Key.$type, nullable: true), true),
+          BridgeParameter('widthFactor', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)), true),
+          BridgeParameter('heightFactor', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType)), true),
           BridgeParameter('child', BridgeTypeAnnotation($Widget.$type), true),
         ]))
       },
@@ -192,7 +204,9 @@ class $Center implements $Instance {
   static $Value? $new(Runtime runtime, $Value? target, List<$Value?> args) {
     return $Center.wrap(Center(
       key: args[0]?.$value,
-      child: args[1]?.$value,
+      widthFactor: args[1]?.$value,
+      heightFactor: args[2]?.$value,
+      child: args[3]?.$value,
     ));
   }
 
@@ -215,3 +229,48 @@ class $Center implements $Instance {
     throw UnimplementedError();
   }
 }
+
+class $Builder implements $Instance {
+  static const $type = BridgeTypeRef.spec(BridgeTypeSpec('package:flutter/src/widgets/basic.dart', 'Builder'));
+
+  static const $declaration = BridgeClassDef(BridgeClassType($type, isAbstract: false, $extends: $Widget.$type),
+      constructors: {
+        '': BridgeConstructorDef(BridgeFunctionDef(returns: BridgeTypeAnnotation($type), namedParams: [
+          BridgeParameter('key', BridgeTypeAnnotation($Key.$type, nullable: true), true),
+          BridgeParameter('builder', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.functionType)), true),
+        ]))
+      },
+      methods: {},
+      getters: {},
+      setters: {},
+      fields: {},
+      wrap: true);
+
+  const $Builder.wrap(this.$value);
+
+  static $Value? $new(Runtime runtime, $Value? target, List<$Value?> args) {
+    return $Builder.wrap(Builder(
+      key: args[0]?.$value,
+      builder: args[1]?.$value,
+    ));
+  }
+
+  @override
+  final Builder $value;
+
+  @override
+  Builder get $reified => $value;
+
+  @override
+  $Value? $getProperty(Runtime runtime, String identifier) {
+    throw UnimplementedError();
+  }
+
+  @override
+  int get $runtimeType => throw UnimplementedError();
+
+  @override
+  void $setProperty(Runtime runtime, String identifier, $Value value) {
+    throw UnimplementedError();
+  }
+}
diff --git a/lib/src/widgets/container.dart b/lib/src/widgets/container.dart
index 67e57fb..33b42ad 100644
--- a/lib/src/widgets/container.dart
+++ b/lib/src/widgets/container.dart
@@ -3,7 +3,9 @@ import 'package:dart_eval/dart_eval_bridge.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_eval/src/foundation/key.dart';
+import 'package:flutter_eval/src/painting/alignment.dart';
 import 'package:flutter_eval/src/painting/edge_insets.dart';
+import 'package:flutter_eval/src/rendering/box.dart';
 import 'package:flutter_eval/src/sky_engine/ui/painting.dart';
 
 import 'framework.dart';
@@ -18,13 +20,17 @@ class $Container implements Container, $Instance {
       constructors: {
         '': BridgeConstructorDef(BridgeFunctionDef(returns: BridgeTypeAnnotation($type), namedParams: [
           BridgeParameter('key', BridgeTypeAnnotation($Key.$type, nullable: true), true),
-          BridgeParameter('color', BridgeTypeAnnotation($Color.$type, nullable: true), true),
-          BridgeParameter('child', BridgeTypeAnnotation($Widget.$type, nullable: true), true),
+          BridgeParameter('alignment', BridgeTypeAnnotation($AlignmentGeometry.$type, nullable: true), true),
           BridgeParameter('padding', BridgeTypeAnnotation($EdgeInsetsGeometry.$type, nullable: true), true),
+          BridgeParameter('color', BridgeTypeAnnotation($Color.$type, nullable: true), true),
           BridgeParameter(
               'width', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType), nullable: true), true),
           BridgeParameter(
               'height', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.doubleType), nullable: true), true),
+          BridgeParameter('constraints', BridgeTypeAnnotation($BoxConstraints.$type, nullable: true), true),
+          BridgeParameter('margin', BridgeTypeAnnotation($EdgeInsetsGeometry.$type, nullable: true), true),
+          BridgeParameter('transformAlignment', BridgeTypeAnnotation($AlignmentGeometry.$type, nullable: true), true),
+          BridgeParameter('child', BridgeTypeAnnotation($Widget.$type, nullable: true), true),
         ]))
       },
       methods: {},
@@ -36,11 +42,15 @@ class $Container implements Container, $Instance {
   static $Value? $new(Runtime runtime, $Value? target, List<$Value?> args) {
     return $Container.wrap(Container(
       key: args[0]?.$value,
-      color: args[1]?.$value,
-      child: args[2]?.$value,
-      padding: args[3]?.$value,
+      alignment: args[1]?.$value,
+      padding: args[2]?.$value,
+      color: args[3]?.$value,
       width: args[4]?.$value,
       height: args[5]?.$value,
+      constraints: args[6]?.$value,
+      margin: args[7]?.$value,
+      transformAlignment: args[8]?.$value,
+      child: args[9]?.$value,
     ));
   }
 
diff --git a/lib/src/widgets/framework.dart b/lib/src/widgets/framework.dart
index 12e2778..eaae2fd 100644
--- a/lib/src/widgets/framework.dart
+++ b/lib/src/widgets/framework.dart
@@ -407,6 +407,9 @@ class $State$bridge<T extends StatefulWidget> extends State<T> with $Bridge<Stat
 
   @override
   Widget build(BuildContext context) => $_invoke('build', [$BuildContext.wrap(context)]);
+
+  @override
+  T get widget => $_get('widget');
 }
 
 class $BuildContext implements BuildContext, $Instance {
diff --git a/lib/src/widgets/text.dart b/lib/src/widgets/text.dart
index 06d0dc1..27c5486 100644
--- a/lib/src/widgets/text.dart
+++ b/lib/src/widgets/text.dart
@@ -2,6 +2,7 @@ import 'package:dart_eval/dart_eval.dart';
 import 'package:dart_eval/dart_eval_bridge.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/widgets.dart';
+import 'package:flutter_eval/src/foundation/key.dart';
 import 'package:flutter_eval/src/painting/text_style.dart';
 import 'package:flutter_eval/src/widgets/framework.dart';
 
@@ -13,6 +14,7 @@ class $Text implements Text, $Instance {
         '': BridgeConstructorDef(BridgeFunctionDef(returns: BridgeTypeAnnotation($type), params: [
           BridgeParameter('data', BridgeTypeAnnotation(BridgeTypeRef.type(RuntimeTypes.stringType)), false),
         ], namedParams: [
+          BridgeParameter('key', BridgeTypeAnnotation($Key.$type, nullable: true), true),
           BridgeParameter('style', BridgeTypeAnnotation($TextStyle.$type, nullable: true), true),
         ]))
       },
@@ -27,7 +29,8 @@ class $Text implements Text, $Instance {
   static $Value? $new(Runtime runtime, $Value? target, List<$Value?> args) {
     return $Text.wrap(Text(
       args[0]!.$value,
-      style: args[1]?.$value,
+      key: args[1]?.$value,
+      style: args[2]?.$value,
     ));
   }
 
diff --git a/pubspec.yaml b/pubspec.yaml
index 110d8a3..7e008de 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: flutter_eval
 description: Flutter bridge library for dart_eval, enabling creation of fully dynamic Flutter apps and widgets that can be loaded from a file or the Internet at runtime.
-version: 0.4.5
+version: 0.4.6
 homepage: https://github.com/ethanblake4/flutter_eval
 
 environment:
@@ -10,7 +10,7 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  dart_eval: ^0.4.3
+  dart_eval: ^0.4.6
   path_provider: ^2.0.11
   http: ^0.13.5
 
diff --git a/test/flutter_eval_test.dart b/test/flutter_eval_test.dart
index 633aad8..8e09a7e 100644
--- a/test/flutter_eval_test.dart
+++ b/test/flutter_eval_test.dart
@@ -1,6 +1,7 @@
 import 'package:dart_eval/dart_eval.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_eval/flutter_eval.dart';
+import 'package:flutter_eval/src/painting/alignment.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
@@ -111,4 +112,28 @@ void main() {
     await tester.pump();
     expect(find.text('Hello123'), findsOneWidget);
   });
+
+  test('Alignment', () {
+    final compiler = Compiler();
+    setupFlutterForCompile(compiler);
+    final program = compiler.compile({
+      'example': {
+        'main.dart': '''
+        import 'package:flutter/material.dart';
+        
+        List<AlignmentGeometry> main() {
+          return [Alignment.topLeft, Alignment.topCenter];
+        }
+        '''
+      }
+    });
+    final runtime = Runtime(program.write().buffer.asByteData());
+    setupFlutterForRuntime(runtime);
+    runtime.setup();
+    final result = runtime.executeLib('package:example/main.dart', 'main');
+    expect(result, isNotNull);
+    expect(result[0], isA<$Alignment>());
+    expect((result[0] as $Alignment).$value.x, -1.0);
+    expect((result[0] as $Alignment).$value.y, -1.0);
+  });
 }