update scroll/resize info for scroll/resize start/end

yahoo · Aug 30, 2015 · 20cfc81 · 20cfc81
1 parent ccd64de
commit 20cfc81
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Showing 2 changed files with 46 additions and 32 deletions.
diff --git a/src/AugmentedEvent.js b/src/AugmentedEvent.js
@@ -4,6 +4,15 @@
  */
 'use strict';
 
+var scroll = {
+    delta: 0,
+    top: 0
+};
+var resize = {
+    width: 0,
+    height: 0
+};
+
 /**
  * ArgmentedEvent will hold some global information, such like window scroll postion,
  * so that those information is only calculated once.
@@ -12,14 +21,8 @@
 function ArgmentedEvent(option) {
     option = option || {};
     this.type = option.type || '';
-    this.scroll = {
-        delta: 0,
-        top: 0
-    };
-    this.resize = {
-        width: 0,
-        height: 0
-    };
+    this.scroll = scroll;
+    this.resize = resize;
 }
 
 module.exports = ArgmentedEvent;
diff --git a/src/eventHandlers/index.js b/src/eventHandlers/index.js
@@ -7,15 +7,20 @@
 'use strict';
 
 var AugmentedEvent = require('../AugmentedEvent');
-var doc;
-var docBody;
-var docEl;
 var ee = require('../eventEmitter').eventEmitter;
 var leIE8 = require('../lib/leIE8');
-var win;
 
+// constants
 var EVENT_END_DELAY = 200;
 
+// global variables
+var doc;
+var docBody;
+var docEl;
+var enableResizeInfo = false;
+var enableScrollInfo = false;
+var win;
+
 if (typeof window !== 'undefined' && typeof document !== 'undefined') {
     win = window;
     doc = document;
@@ -41,6 +46,23 @@ function copyEventObj(o) {
     return r;
 }
 
+/**
+ * Update global scroll/resize info
+ * @param {Object} ae - The additional event object
+ * @param {String} eventType - The event type
+ */
+function updateAdditionalInfo(ae, eventType) {
+    var top;
+    if (eventType === 'scroll' && enableScrollInfo) {
+        top = docEl.scrollTop + docBody.scrollTop;
+        ae.scroll.delta = top - ae.scroll.top;
+        ae.scroll.top = top;
+    } else if (eventType === 'resize' && enableResizeInfo) {
+        ae.resize.width = win.innerWidth || docEl.clientWidth;
+        ae.resize.height = win.innerHeight || docEl.clientHeight;
+    }
+}
+
 /**
  * Cross-browser addEventListener.
  * @method listen
@@ -83,20 +105,22 @@ function generateEdgeEventHandler(target, eventType, eventStart) {
 
         var throttleRate = options.throttleRate;
         var throttle = options.throttleFunc;
-        var augmentedEvent = new AugmentedEvent({type: eventType + (eventStart ? 'Start' : 'End')});
+        var ae = new AugmentedEvent({type: eventType + (eventStart ? 'Start' : 'End')});
         var timer;
 
         function eventEndCallback(e) {
             if (!eventStart) {
-                ee.emit(eeType, e, augmentedEvent);
+                updateAdditionalInfo(ae, eventType);
+                ee.emit(eeType, e, ae);
             }
             timer = null;
         }
 
         function eventHandler(e) {
             if (!timer) {
                 if (eventStart) {
-                    ee.emit(eeType, e, augmentedEvent);
+                    updateAdditionalInfo(ae, eventType);
+                    ee.emit(eeType, e, ae);
                 }
             }
 
@@ -128,32 +152,19 @@ function generateEdgeEventHandler(target, eventType, eventStart) {
  * @return {Function} The function to generate throttle event.
  */
 function generateContinuousEventHandler(target, eventType, noThrottle) {
-    var enableScrollInfo = false;
-    var enableResizeInfo = false;
-
     return function(eeType, options) {
         if (ee.listeners(eeType, true)) {
             return;
         }
 
         var throttleRate = options.throttleRate;
         var throttle = options.throttleFunc;
-        var augmentedEvent = new AugmentedEvent({type: eventType});
+        var ae = new AugmentedEvent({type: eventType});
         enableScrollInfo = enableScrollInfo || options.enableScrollInfo;
         enableResizeInfo = enableResizeInfo || options.enableResizeInfo;
 
         function eventHandler(e) {
-            var ae = augmentedEvent;
-            var top;
-            if (enableScrollInfo && ae.type === 'scroll') {
-                top = docEl.scrollTop + docBody.scrollTop;
-                ae.scroll.delta = top - ae.scroll.top;
-                ae.scroll.top = top;
-            }
-            if (enableResizeInfo && ae.type === 'resize') {
-                ae.resize.width = win.innerWidth || docEl.clientWidth;
-                ae.resize.height = win.innerHeight || docEl.clientHeight;
-            }
+            updateAdditionalInfo(ae, eventType);
             ee.emit(eeType, e, ae);
         }
 
@@ -169,9 +180,9 @@ function viewportchange(eeType, options) {
 
     var throttleRate = options.throttleRate;
     var throttle = options.throttleFunc;
-    var augmentedEvent = new AugmentedEvent({type: 'viewportchange'});
+    var ae = new AugmentedEvent({type: 'viewportchange'});
     function eventHandler(e) {
-        ee.emit(eeType, e, augmentedEvent);
+        ee.emit(eeType, e, ae);
     }
 
     var handler = throttleRate > 0 ? throttle(eventHandler, throttleRate) : eventHandler;