Use explicit properties to avoid for-in loops

Author: dfreedm

src/PointerGestureEvent.js

@@ -19,20 +19,17 @@ function PointerGestureEvent(inType, inDict) {
   var dict = inDict || {};
   var e = document.createEvent('Event');
   var props = {
-    bubbles: true,
-    cancelable: true,
+    bubbles: Boolean(dict.bubbles) === dict.bubbles || true,
+    cancelable: Boolean(dict.cancelable) === dict.cancelable || true
   };
-  Object.keys(props).forEach(function(k) {
-    if (k in dict) {
-      props[k] = dict[k];
-    }
-  });
 
   e.initEvent(inType, props.bubbles, props.cancelable);
 
-  Object.keys(dict).forEach(function(k) {
-    e[k] = inDict[k];
-  });
+  var keys = Object.keys(dict), k;
+  for (var i = 0; i < keys.length; i++) {
+    k = keys[i];
+    e[k] = dict[k];
+  }
 
   e.preventTap = this.preventTap;
 

src/dispatcher.js

@@ -5,9 +5,85 @@
  */
 
 (function(scope) {
+  var CLONE_PROPS = [
+    // MouseEvent
+    'bubbles',
+    'cancelable',
+    'view',
+    'detail',
+    'screenX',
+    'screenY',
+    'clientX',
+    'clientY',
+    'ctrlKey',
+    'altKey',
+    'shiftKey',
+    'metaKey',
+    'button',
+    'relatedTarget',
+    // DOM Level 3
+    'buttons',
+    // PointerEvent
+    'pointerId',
+    'width',
+    'height',
+    'pressure',
+    'tiltX',
+    'tiltY',
+    'pointerType',
+    'hwTimestamp',
+    'isPrimary',
+    // event instance
+    'type',
+    'target',
+    'currentTarget',
+    'screenX',
+    'screenY',
+    'pageX',
+    'pageY',
+  ];
+
+  var CLONE_DEFAULTS = [
+    // MouseEvent
+    false,
+    false,
+    null,
+    null,
+    0,
+    0,
+    0,
+    0,
+    false,
+    false,
+    false,
+    false,
+    0,
+    null,
+    // DOM Level 3
+    0,
+    // PointerEvent
+    0,
+    0,
+    0,
+    0,
+    0,
+    0,
+    '',
+    0,
+    false,
+    // event instance
+    '',
+    null,
+    null,
+    0,
+    0,
+    0,
+    0
+  ];
+
   var dispatcher = {
-    handledEvents: new WeakMap,
-    targets: new WeakMap,
+    handledEvents: new WeakMap(),
+    targets: new WeakMap(),
     handlers: {},
     recognizers: {},
     events: {},
@@ -98,9 +174,10 @@
      *    properties.
      */
     cloneEvent: function(inEvent) {
-      var eventCopy = {};
-      for (var n in inEvent) {
-        eventCopy[n] = inEvent[n];
+      var eventCopy = {}, p;
+      for (var i = 0; i < CLONE_PROPS.length; i++) {
+        p = CLONE_PROPS[i];
+        eventCopy[p] = inEvent[p] || CLONE_DEFAULTS[i];
       }
       return eventCopy;
     },