Added support for resetStyleInheritance and applyAuthorStyles on shadow root

http://www.html5rocks.com/en/tutorials/webcomponents/shadowdom-201/#toc-
style-inheriting

Author: pavelgj

lib/block.dart

@@ -407,6 +407,10 @@ class ComponentWrapper {
   ComponentWrapper(this.directiveRef, this.controller, this.elementRoot, this.parser, $compiler, $http) {
     var directive = directiveRef.directive;
     var shadowRoot = elementRoot.createShadowRoot();
+    shadowRoot.applyAuthorStyles =
+        directive.$shadowRootOptions.$applyAuthorStyles;
+    shadowRoot.resetStyleInheritance =
+        directive.$shadowRootOptions.$resetStyleInheritance;
 
     var styleData = '';
     if (directive.$cssUrl != null) {

lib/directive.dart

@@ -16,6 +16,7 @@ class Directive {
   String $cssUrl;
   Map<String, String> $map;
   String $visibility;
+  ShadowRootOptions $shadowRootOptions;
 
   bool isComponent = false;
   bool isStructural = false;
@@ -46,15 +47,10 @@ class Directive {
     $template = reflectStaticField(type, '\$template');
     $templateUrl = reflectStaticField(type, '\$templateUrl');
     $cssUrl = reflectStaticField(type, '\$cssUrl');
-    $priority = reflectStaticField(type, '\$priority');
-    $visibility = reflectStaticField(type, '\$visibility');
-    if ($visibility == null) {
-      $visibility = DirectiveVisibility.LOCAL;
-    }
+    $priority = _defaultIfNull(reflectStaticField(type, '\$priority'), 0);
+    $visibility = _defaultIfNull(
+        reflectStaticField(type, '\$visibility'), DirectiveVisibility.LOCAL);
     $map = reflectStaticField(type, '\$map');
-    if ($priority == null) {
-      $priority = 0;
-    }
     isStructural = $transclude != null;
     var $selector = reflectStaticField(type, r'$selector');
     if ($selector != null) {
@@ -63,9 +59,17 @@ class Directive {
     if (isComponent && $map == null) {
       $map = new Map<String, String>();
     }
+    if (isComponent) {
+      $shadowRootOptions = _defaultIfNull(
+          reflectStaticField(type, '\$shadowRootOptions'),
+          new ShadowRootOptions());
+    }
   }
 }
 
+dynamic _defaultIfNull(dynamic value, dynamic defaultValue) =>
+    value == null ? defaultValue : value;
+
 class DirectiveRef {
   dom.Node element;
   String selector;
@@ -119,6 +123,17 @@ abstract class DirectiveVisibility {
   static const String DIRECT_CHILDREN = 'direct_children';
 }
 
+/**
+ * See:
+ * http://www.html5rocks.com/en/tutorials/webcomponents/shadowdom-201/#toc-style-inheriting
+ */
+class ShadowRootOptions {
+  bool $applyAuthorStyles = false;
+  bool $resetStyleInheritance = false;
+  ShadowRootOptions([this.$applyAuthorStyles = false,
+                     this.$resetStyleInheritance = false]);
+}
+
 class Controller {
 
 }

test/directive_spec.dart

@@ -12,6 +12,13 @@ class ExplicitNullTranscludeDirective {
   static var $transclude = null;
 }
 
+class WithDefaultShadowRootOptionsComponent {
+}
+
+class WithCustomShadowRootOptionsComponent {
+  static var $shadowRootOptions = new ShadowRootOptions(true, true);
+}
+
 main() {
   describe('directive factory', () {
     it('should guess the directive name correctly', () {
@@ -38,5 +45,17 @@ main() {
       Directive factory = new Directive(ExplicitNullTranscludeDirective);
       expect(factory.$transclude).toEqual(null);
     });
+
+    it('should default \$shadowRootOptions to false/false', () {
+      Directive factory = new Directive(WithDefaultShadowRootOptionsComponent);
+      expect(factory.$shadowRootOptions.$applyAuthorStyles, isFalse);
+      expect(factory.$shadowRootOptions.$resetStyleInheritance, isFalse);
+    });
+
+    it('should override \$shadowRootOptions with values provided by component type', () {
+      Directive factory = new Directive(WithCustomShadowRootOptionsComponent);
+      expect(factory.$shadowRootOptions.$applyAuthorStyles, isTrue);
+      expect(factory.$shadowRootOptions.$resetStyleInheritance, isTrue);
+    });
   });
 }