Add observatory_pub_packages snapshot to third_party

observatory_pub_packages/polymer/src/events.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// Code from declaration/events.js
+part of polymer;
+
+/// An extension of [polymer_expressions.PolymerExpressions] that adds support
+/// for binding events using `on-eventName` using [PolymerEventBindings].
+// TODO(jmesserly): the JS layering is a bit odd, with polymer-dev implementing
+// events and polymer-expressions implementing everything else. I don't think
+// this separation is right in the long term, so we're using the same class name
+// until we can sort it out.
+class PolymerExpressions extends BindingDelegate with PolymerEventBindings {
+
+  /// A wrapper around polymer_expressions used to implement forwarding.
+  /// Ideally we would inherit from it, but mixins can't be applied to a type
+  /// that forwards to a superclass with a constructor that has optional or
+  /// named arguments.
+  final polymer_expressions.PolymerExpressions _delegate;
+
+  Map<String, Object> get globals => _delegate.globals;
+
+  PolymerExpressions({Map<String, Object> globals})
+      : _delegate = new polymer_expressions.PolymerExpressions(
+          globals: globals);
+
+  prepareBinding(String path, name, node) {
+    if (_hasEventPrefix(name)) {
+      return prepareEventBinding(path, name, node);
+    }
+    return _delegate.prepareBinding(path, name, node);
+  }
+
+  prepareInstanceModel(Element template) =>
+      _delegate.prepareInstanceModel(template);
+
+  prepareInstancePositionChanged(Element template) =>
+      _delegate.prepareInstancePositionChanged(template);
+
+  static final getExpression =
+      polymer_expressions.PolymerExpressions.getExpression;
+  static final getBinding = polymer_expressions.PolymerExpressions.getBinding;
+
+}
+
+/// A mixin for a [BindingDelegate] to add Polymer event support.
+/// This is included in [PolymerExpressions].
+abstract class PolymerEventBindings {
+  /// Finds the event controller for this node.
+  Element findController(Node node) {
+    while (node.parentNode != null) {
+      if (node is Polymer && node.eventController != null) {
+        return node.eventController;
+      } else if (node is Element) {
+        // If it is a normal element, js polymer element, or dart wrapper to a
+        // js polymer element, then we try js interop.
+        var eventController =
+            new JsObject.fromBrowserObject(node)['eventController'];
+        if (eventController != null) return eventController;
+      }
+      node = node.parentNode;
+    }
+    return node is ShadowRoot ? node.host : null;
+  }
+
+  EventListener getEventHandler(controller, target, String method) => (e) {
+    if (controller == null || controller is! Polymer) {
+      controller = findController(target);
+    }
+
+    if (controller is Polymer) {
+      var detail = null;
+      if (e is CustomEvent) {
+        detail = e.detail;
+        // TODO(sigmund): this shouldn't be necessary. See issue 19315.
+        if (detail == null) {
+          detail = new JsObject.fromBrowserObject(e)['detail'];
+        }
+      }
+      var args = [e, detail, e.currentTarget];
+      controller.dispatchMethod(controller, method, args);
+    } else {
+      throw new StateError('controller $controller is not a '
+          'Dart polymer-element.');
+    }
+  };
+
+  prepareEventBinding(String path, String name, Node node) {
+    if (!_hasEventPrefix(name)) return null;
+
+    var eventType = _removeEventPrefix(name);
+    var translated = _eventTranslations[eventType];
+    eventType = translated != null ? translated : eventType;
+
+    return (model, node, oneTime) {
+      var eventHandler =
+          Zone.current.bindUnaryCallback(getEventHandler(null, node, path));
+      // TODO(jakemac): Remove this indirection if/when JsFunction gets a
+      // simpler constructor that doesn't pass this, http://dartbug.com/20545.
+      var handler = new JsFunction.withThis((_, e) => eventHandler(e));
+      _PolymerGestures.callMethod(
+          'addEventListener', [node, eventType, handler]);
+
+      if (oneTime) return null;
+      return new _EventBindable(path, node, eventType, handler);
+    };
+  }
+}
+
+
+class _EventBindable extends Bindable {
+  final String _path;
+  final Node _node;
+  final String _eventType;
+  final JsFunction _handler;
+
+  _EventBindable(this._path, this._node, this._eventType, this._handler);
+
+  // TODO(rafaelw): This is really pointless work. Aside from the cost
+  // of these allocations, NodeBind is going to setAttribute back to its
+  // current value. Fixing this would mean changing the TemplateBinding
+  // binding delegate API.
+  get value => '{{ $_path }}';
+
+  open(callback) => value;
+
+  void close() {
+    _PolymerGestures.callMethod(
+        'removeEventListener', [_node, _eventType, _handler]);
+  }
+}
+
+
+/// Attribute prefix used for declarative event handlers.
+const _EVENT_PREFIX = 'on-';
+
+/// Whether an attribute declares an event.
+bool _hasEventPrefix(String attr) => attr.startsWith(_EVENT_PREFIX);
+
+String _removeEventPrefix(String name) => name.substring(_EVENT_PREFIX.length);
+
+// Dart note: polymer.js calls this mixedCaseEventTypes. But we have additional
+// things that need translation due to renames.
+final _eventTranslations = const {
+  'domfocusout': 'DOMFocusOut',
+  'domfocusin': 'DOMFocusIn',
+  'dommousescroll': 'DOMMouseScroll',
+
+  // Dart note: handle Dart-specific event names.
+  'animationend': 'webkitAnimationEnd',
+  'animationiteration': 'webkitAnimationIteration',
+  'animationstart': 'webkitAnimationStart',
+  'doubleclick': 'dblclick',
+  'fullscreenchange': 'webkitfullscreenchange',
+  'fullscreenerror': 'webkitfullscreenerror',
+  'keyadded': 'webkitkeyadded',
+  'keyerror': 'webkitkeyerror',
+  'keymessage': 'webkitkeymessage',
+  'needkey': 'webkitneedkey',
+  'speechchange': 'webkitSpeechChange',
+};
+
+final _reverseEventTranslations = () {
+  final map = new Map<String, String>();
+  _eventTranslations.forEach((onName, eventType) {
+    map[eventType] = onName;
+  });
+  return map;
+}();
+
+// Dart note: we need this function because we have additional renames JS does
+// not have. The JS renames are simply case differences, whereas we have ones
+// like doubleclick -> dblclick and stripping the webkit prefix.
+String _eventNameFromType(String eventType) {
+  final result = _reverseEventTranslations[eventType];
+  return result != null ? result : eventType;
+}