Adding Angular and dependent packages for testing

third_party/pkg/angular/lib/directive/ng_switch.dart

+part of angular.directive;
+
+/**
+ * The ngSwitch directive is used to conditionally swap DOM structure on your
+ * template based on a scope expression. Elements within ngSwitch but without
+ * ngSwitchWhen or ngSwitchDefault directives will be preserved at the location
+ * as specified in the template.
+ *
+ * The directive itself works similar to ngInclude, however, instead of
+ * downloading template code (or loading it from the template cache), ngSwitch
+ * simply choses one of the nested elements and makes it visible based on which
+ * element matches the value obtained from the evaluated expression. In other
+ * words, you define a container element (where you place the directive), place
+ * an expression on the **ng-switch="..." attribute**, define any inner elements
+ * inside of the directive and place a when attribute per element. The when
+ * attribute is used to inform ngSwitch which element to display when the on
+ * expression is evaluated. If a matching expression is not found via a when
+ * attribute then an element with the default attribute is displayed.
+ *
+ * ## Example:
+ *
+ *     <ANY ng-switch="expression">
+ *       <ANY ng-switch-when="matchValue1">...</ANY>
+ *       <ANY ng-switch-when="matchValue2">...</ANY>
+ *       <ANY ng-switch-default>...</ANY>
+ *     </ANY>
+ *
+ * On child elements add:
+ *
+ * * `ngSwitchWhen`: the case statement to match against. If match then this
+ *   case will be displayed. If the same match appears multiple times, all the
+ *   elements will be displayed.
+ * * `ngSwitchDefault`: the default case when no other case match. If there
+ *   are multiple default cases, all of them will be displayed when no other
+ *   case match.
+ *
+ * ## Example:
+ *
+ *     <div>
+ *       <button ng-click="selection='settings'">Show Settings</button>
+ *       <button ng-click="selection='home'">Show Home Span</button>
+ *       <button ng-click="selection=''">Show default</button>
+ *       <tt>selection={{selection}}</tt>
+ *       <hr/>
+ *       <div ng-switch="selection">
+ *           <div ng-switch-when="settings">Settings Div</div>
+ *           <div ng-switch-when="home">Home Span</div>
+ *           <div ng-switch-default>default</div>
+ *       </div>
+ *     </div>
+ */
+@NgDirective(
+    selector: '[ng-switch]',
+    map: const {
+      'ng-switch': '=>value',
+      'change': '&onChange'
+    },
+    visibility: NgDirective.DIRECT_CHILDREN_VISIBILITY
+)
+class NgSwitchDirective {
+  Map<String, List<_Case>> cases = new Map<String, List<_Case>>();
+  List<_BlockScopePair> currentBlocks = <_BlockScopePair>[];
+  Function onChange;
+  Scope scope;
+
+  NgSwitchDirective(this.scope) {
+    cases['?'] = <_Case>[];
+  }
+
+  addCase(String value, BlockHole anchor, BoundBlockFactory blockFactory) {
+    cases.putIfAbsent(value, () => <_Case>[]);
+    cases[value].add(new _Case(anchor, blockFactory));
+  }
+
+  set value(val) {
+    currentBlocks
+      ..forEach((_BlockScopePair pair) {
+        pair.block.remove();
+        pair.scope.$destroy();
+      })
+      ..clear();
+
+    val = '!$val';
+    (cases.containsKey(val) ? cases[val] : cases['?'])
+        .forEach((_Case caze) {
+          Scope childScope = scope.$new();
+          var block = caze.blockFactory(childScope)
+            ..insertAfter(caze.anchor);
+          currentBlocks.add(new _BlockScopePair(block, childScope));
+        });
+    if (onChange != null) {
+      onChange();
+    }
+  }
+}
+
+class _BlockScopePair {
+  final Block block;
+  final Scope scope;
+
+  _BlockScopePair(this.block, this.scope);
+}
+
+class _Case {
+  final BlockHole anchor;
+  final BoundBlockFactory blockFactory;
+
+  _Case(this.anchor, this.blockFactory);
+}
+
+@NgDirective(
+    selector: '[ng-switch-when]',
+    children: NgAnnotation.TRANSCLUDE_CHILDREN,
+    map: const {
+      '.': '@value'
+    }
+)
+class NgSwitchWhenDirective {
+  final NgSwitchDirective ngSwitch;
+  final BlockHole hole;
+  final BoundBlockFactory blockFactory;
+  final Scope scope;
+
+  NgSwitchWhenDirective(this.ngSwitch, this.hole, this.blockFactory, this.scope);
+
+  set value(String value) =>
+      ngSwitch.addCase('!$value', hole, blockFactory);
+}
+
+
+@NgDirective(
+    children: NgAnnotation.TRANSCLUDE_CHILDREN,
+    selector: '[ng-switch-default]'
+)
+class NgSwitchDefaultDirective {
+
+  NgSwitchDefaultDirective(NgSwitchDirective ngSwitch, BlockHole hole,
+                        BoundBlockFactory blockFactory, Scope scope) {
+    ngSwitch.addCase('?', hole, blockFactory);
+  }
+}