feat(vertical): partical support vertical scrolling (#1017)

Author: ArrayZoneYour

package.json

@@ -5,7 +5,7 @@
     "react-native",
     "ios"
   ],
-  "version": "1.6.0-nightly.2",
+  "version": "1.6.0-nightly.4",
   "description": "Swiper component for React Native.",
   "main": "index.js",
   "scripts": {

src/index.js

@@ -435,20 +435,38 @@ export default class extends Component {
    * @param  {string} dir    'x' || 'y'
    */
   updateIndex = (offset, dir, cb) => {
+    const state = this.state
     // Android ScrollView will not scrollTo certain offset when props change
-    const callback = () => {
+    const callback = async () => {
       cb()
       if (Platform.OS === 'android') {
-        this.state.index === 0 &&
-          this.scrollView.scrollTo({ x: state.width, y: 0, animated: false })
-        this.state.index === this.state.total - 1 &&
-          this.scrollView.scrollTo({
-            x: state.width * this.state.total,
-            animated: false
-          })
+        if (this.state.index === 0) {
+          this.props.horizontal
+            ? this.scrollView.scrollTo({
+                x: state.width,
+                y: 0,
+                animated: false
+              })
+            : this.scrollView.scrollTo({
+                x: 0,
+                y: state.height,
+                animated: false
+              })
+        } else if (this.state.index === this.state.total - 1) {
+          this.props.horizontal
+            ? this.scrollView.scrollTo({
+                x: state.width * this.state.total,
+                y: 0,
+                animated: false
+              })
+            : this.scrollView.scrollTo({
+                x: 0,
+                y: state.height * this.state.total,
+                animated: false
+              })
+        }
       }
     }
-    const state = this.state
     let index = state.index
     if (!this.internals.offset)
       // Android not setting this onLayout first? https://github.com/leecade/react-native-swiper/issues/582