react native WebView onScroll patch

webview-onscroll.patch

From 12d5a33175038d872d9d6ca8acb00e57f99202c7 Mon Sep 17 00:00:00 2001
From: Birkir Gudjonsson <birkir.gudjonsson@gmail.com>
Date: Wed, 26 Jul 2017 11:53:42 -0400
Subject: [PATCH] Added onScroll

---
 Libraries/Components/WebView/WebView.ios.js | 11 +++++++++++
 React/Views/RCTWebView.m                    | 29 +++++++++++++++++++++++++++++
 React/Views/RCTWebViewManager.m             |  1 +
 3 files changed, 41 insertions(+)

diff --git a/Libraries/Components/WebView/WebView.ios.js b/Libraries/Components/WebView/WebView.ios.js
index 485af39..be61af3 100644
--- a/Libraries/Components/WebView/WebView.ios.js
+++ b/Libraries/Components/WebView/WebView.ios.js
@@ -365,6 +365,11 @@ class WebView extends React.Component {
       'always',
       'compatibility'
     ]),
+
+    /**
+     * On Scroll event
+     */
+    onScroll: PropTypes.func,
   };

   state = {
@@ -442,6 +447,7 @@ class WebView extends React.Component {
         onLoadingError={this._onLoadingError}
         messagingEnabled={messagingEnabled}
         onMessage={this._onMessage}
+        onScroll={this._onScroll}
         onShouldStartLoadWithRequest={onShouldStartLoadWithRequest}
         scalesPageToFit={this.props.scalesPageToFit}
         allowsInlineMediaPlayback={this.props.allowsInlineMediaPlayback}
@@ -584,6 +590,11 @@ class WebView extends React.Component {
     var {onMessage} = this.props;
     onMessage && onMessage(event);
   }
+
+  _onScroll = (event: Event) => {
+    var {onScroll} = this.props;
+    onScroll && onScroll(event);
+  }
 }

 var RCTWebView = requireNativeComponent('RCTWebView', WebView, {
diff --git a/React/Views/RCTWebView.m b/React/Views/RCTWebView.m
index 2096064..91f2ffc 100644
--- a/React/Views/RCTWebView.m
+++ b/React/Views/RCTWebView.m
@@ -29,6 +29,7 @@ NSString *const RCTJSPostMessageHost = @"postMessage";
 @property (nonatomic, copy) RCTDirectEventBlock onLoadingError;
 @property (nonatomic, copy) RCTDirectEventBlock onShouldStartLoadWithRequest;
 @property (nonatomic, copy) RCTDirectEventBlock onMessage;
+@property (nonatomic, copy) RCTDirectEventBlock onScroll;

 @end

@@ -51,11 +52,39 @@ NSString *const RCTJSPostMessageHost = @"postMessage";
     _contentInset = UIEdgeInsetsZero;
     _webView = [[UIWebView alloc] initWithFrame:self.bounds];
     _webView.delegate = self;
+    _webView.scrollView.delegate = self;
     [self addSubview:_webView];
   }
   return self;
 }

+- (void)scrollViewDidScroll:(UIScrollView *)scrollView
+{
+  NSDictionary *event = @{
+    @"contentOffset": @{
+      @"x": @(scrollView.contentOffset.x),
+      @"y": @(scrollView.contentOffset.y)
+    },
+    @"contentInset": @{
+      @"top": @(scrollView.contentInset.top),
+      @"left": @(scrollView.contentInset.left),
+      @"bottom": @(scrollView.contentInset.bottom),
+      @"right": @(scrollView.contentInset.right)
+    },
+    @"contentSize": @{
+      @"width": @(scrollView.contentSize.width),
+      @"height": @(scrollView.contentSize.height)
+    },
+    @"layoutMeasurement": @{
+      @"width": @(scrollView.frame.size.width),
+      @"height": @(scrollView.frame.size.height)
+    },
+    @"zoomScale": @(scrollView.zoomScale ?: 1),
+  };
+
+  _onScroll(event);
+}
+
 RCT_NOT_IMPLEMENTED(- (instancetype)initWithCoder:(NSCoder *)aDecoder)

 - (void)goForward
diff --git a/React/Views/RCTWebViewManager.m b/React/Views/RCTWebViewManager.m
index ddc66e2..271a98d 100644
--- a/React/Views/RCTWebViewManager.m
+++ b/React/Views/RCTWebViewManager.m
@@ -46,6 +46,7 @@ RCT_EXPORT_VIEW_PROPERTY(onLoadingStart, RCTDirectEventBlock)
 RCT_EXPORT_VIEW_PROPERTY(onLoadingFinish, RCTDirectEventBlock)
 RCT_EXPORT_VIEW_PROPERTY(onLoadingError, RCTDirectEventBlock)
 RCT_EXPORT_VIEW_PROPERTY(onMessage, RCTDirectEventBlock)
+RCT_EXPORT_VIEW_PROPERTY(onScroll, RCTDirectEventBlock)
 RCT_EXPORT_VIEW_PROPERTY(onShouldStartLoadWithRequest, RCTDirectEventBlock)
 RCT_REMAP_VIEW_PROPERTY(allowsInlineMediaPlayback, _webView.allowsInlineMediaPlayback, BOOL)
 RCT_REMAP_VIEW_PROPERTY(mediaPlaybackRequiresUserAction, _webView.mediaPlaybackRequiresUserAction, BOOL)
--
2.6.1

It looks like this only works for iOS?