From 9685d06f4529acb99afb1cd1f13ea8bcaddc257c Mon Sep 17 00:00:00 2001
From: Benjy Cui <benjytrys@gmail.com>
Date: Thu, 29 Sep 2016 18:00:23 +0800
Subject: [PATCH] fix: should test if window exist, close: #3216

---
 components/_util/getScroll.tsx | 17 +++++++++++++++++
 components/affix/index.tsx     | 15 +--------------
 components/back-top/index.tsx  | 19 +------------------
 3 files changed, 19 insertions(+), 32 deletions(-)
 create mode 100644 components/_util/getScroll.tsx

diff --git a/components/_util/getScroll.tsx b/components/_util/getScroll.tsx
new file mode 100644
index 0000000000..1b085e3e3d
--- /dev/null
+++ b/components/_util/getScroll.tsx
@@ -0,0 +1,17 @@
+export default function getScroll(target, top) {
+  if (typeof window === 'undefined') {
+    return 0;
+  }
+
+  const prop = top ? 'pageYOffset' : 'pageXOffset';
+  const method = top ? 'scrollTop' : 'scrollLeft';
+  const isWindow = target === window;
+
+  let ret = isWindow ? target[prop] : target[method];
+  // ie6,7,8 standard mode
+  if (isWindow && typeof ret !== 'number') {
+    ret = window.document.documentElement[method];
+  }
+
+  return ret;
+}
diff --git a/components/affix/index.tsx b/components/affix/index.tsx
index c8b7a08744..d5f2eae115 100644
--- a/components/affix/index.tsx
+++ b/components/affix/index.tsx
@@ -4,20 +4,7 @@ import addEventListener from 'rc-util/lib/Dom/addEventListener';
 import classNames from 'classnames';
 import shallowequal from 'shallowequal';
 import omit from 'omit.js';
-
-function getScroll(target, top) {
-  const prop = top ? 'pageYOffset' : 'pageXOffset';
-  const method = top ? 'scrollTop' : 'scrollLeft';
-  const isWindow = target === window;
-
-  let ret = isWindow ? target[prop] : target[method];
-  // ie6,7,8 standard mode
-  if (isWindow && typeof ret !== 'number') {
-    ret = window.document.documentElement[method];
-  }
-
-  return ret;
-}
+import getScroll from '../_util/getScroll';
 
 function getTargetRect(target): any {
   return target !== window ?
diff --git a/components/back-top/index.tsx b/components/back-top/index.tsx
index f81dea4f0b..a10e5187fc 100644
--- a/components/back-top/index.tsx
+++ b/components/back-top/index.tsx
@@ -4,6 +4,7 @@ import Icon from '../icon';
 import addEventListener from 'rc-util/lib/Dom/addEventListener';
 import classNames from 'classnames';
 import omit from 'omit.js';
+import getScroll from '../_util/getScroll';
 
 const reqAnimFrame = (() => {
   if (window.requestAnimationFrame) {
@@ -29,24 +30,6 @@ const easeInOutCubic = (t, b, c, d) => {
   }
 };
 
-function getScroll(target, top) {
-  if (typeof window === 'undefined') {
-    return 0;
-  }
-
-  const prop = top ? 'pageYOffset' : 'pageXOffset';
-  const method = top ? 'scrollTop' : 'scrollLeft';
-  const isWindow = target === window;
-
-  let ret = isWindow ? target[prop] : target[method];
-  // ie6,7,8 standard mode
-  if (isWindow && typeof ret !== 'number') {
-    ret = window.document.documentElement[method];
-  }
-
-  return ret;
-}
-
 export interface BackTopProps {
   visibilityHeight?: number;
   onClick?: (event) => void;