From c8b1c73bd45182cb37f3e97fd0aa2f368910ef2b Mon Sep 17 00:00:00 2001
From: Spencer Ahrens <sahrens@fb.com>
Date: Mon, 6 Mar 2017 21:34:32 -0800
Subject: [PATCH] Simplify scroll interaction stuff

Reviewed By: angelahess

Differential Revision: D4662787

fbshipit-source-id: 6e28f8cacd08601254e70f30ab98ee27bd08cc5a
---
 .../Lists/ViewabilityHelper.js                | 24 -------------------
 .../CustomComponents/Lists/VirtualizedList.js |  5 ++++
 .../Lists/__tests__/ViewabilityHelper-test.js | 17 ++++---------
 3 files changed, 9 insertions(+), 37 deletions(-)

diff --git a/Libraries/CustomComponents/Lists/ViewabilityHelper.js b/Libraries/CustomComponents/Lists/ViewabilityHelper.js
index 8da31962478..31ce384ba97 100644
--- a/Libraries/CustomComponents/Lists/ViewabilityHelper.js
+++ b/Libraries/CustomComponents/Lists/ViewabilityHelper.js
@@ -42,15 +42,6 @@ export type ViewabilityConfig = {|
    * render.
    */
   waitForInteraction?: boolean,
-
-  /**
-   * Criteria to filter out certain scroll events so they don't count as interactions. By default,
-   * any non-zero scroll offset will be considered an interaction.
-   */
-  scrollInteractionFilter?: {|
-    minimumOffset?: number, // scrolls with an offset less than this are ignored.
-    minimumElapsed?: number, // scrolls that happen before this are ignored.
-  |},
 |};
 
 /**
@@ -74,10 +65,6 @@ class ViewabilityHelper {
   _viewableItems: Map<string, ViewToken> = new Map();
 
   constructor(config: ViewabilityConfig = {viewAreaCoveragePercentThreshold: 0}) {
-    invariant(
-      config.scrollInteractionFilter == null || config.waitForInteraction,
-      'scrollInteractionFilter only works in conjunction with waitForInteraction',
-    );
     this._config = config;
   }
 
@@ -163,17 +150,6 @@ class ViewabilityHelper {
       this._lastUpdateTime = updateTime;
     }
     const updateElapsed = this._lastUpdateTime ? updateTime - this._lastUpdateTime : 0;
-    if (this._config.waitForInteraction && !this._hasInteracted && scrollOffset !== 0) {
-      const filter = this._config.scrollInteractionFilter;
-      if (filter) {
-        if ((filter.minimumOffset == null || scrollOffset >= filter.minimumOffset) &&
-            (filter.minimumElapsed == null || updateElapsed >= filter.minimumElapsed)) {
-          this._hasInteracted = true;
-        }
-      } else {
-        this._hasInteracted = true;
-      }
-    }
     if (this._config.waitForInteraction && !this._hasInteracted) {
       return;
     }
diff --git a/Libraries/CustomComponents/Lists/VirtualizedList.js b/Libraries/CustomComponents/Lists/VirtualizedList.js
index 23a842c7c43..c532e1aadfe 100644
--- a/Libraries/CustomComponents/Lists/VirtualizedList.js
+++ b/Libraries/CustomComponents/Lists/VirtualizedList.js
@@ -415,6 +415,7 @@ class VirtualizedList extends React.PureComponent<OptionalProps, Props, State> {
         onContentSizeChange: this._onContentSizeChange,
         onLayout: this._onLayout,
         onScroll: this._onScroll,
+        onScrollBeginDrag: this._onScrollBeginDrag,
         ref: this._captureScrollRef,
         scrollEventThrottle: 50, // TODO: Android support
       },
@@ -609,6 +610,10 @@ class VirtualizedList extends React.PureComponent<OptionalProps, Props, State> {
     this._updateCellsToRenderBatcher.schedule();
   };
 
+  _onScrollBeginDrag = (e): void => {
+    this._viewabilityHelper.recordInteraction();
+    this.props.onScrollBeginDrag && this.props.onScrollBeginDrag(e);
+  };
   _updateCellsToRender = () => {
     const {data, disableVirtualization, getItemCount, onEndReachedThreshold} = this.props;
     this._updateViewableItems(data);
diff --git a/Libraries/CustomComponents/Lists/__tests__/ViewabilityHelper-test.js b/Libraries/CustomComponents/Lists/__tests__/ViewabilityHelper-test.js
index 2ad5afe9684..1d97105a7ad 100644
--- a/Libraries/CustomComponents/Lists/__tests__/ViewabilityHelper-test.js
+++ b/Libraries/CustomComponents/Lists/__tests__/ViewabilityHelper-test.js
@@ -316,14 +316,11 @@ describe('onUpdate', function() {
   );
 
   it(
-    'waitForInteraction blocks callback until scroll',
+    'waitForInteraction blocks callback until interaction',
     function() {
       const helper = new ViewabilityHelper({
         waitForInteraction: true,
         viewAreaCoveragePercentThreshold: 0,
-        scrollInteractionFilter: {
-          minimumOffset: 20,
-        },
       });
       rowFrames = {
         a: {y: 0, height: 200},
@@ -340,15 +337,9 @@ describe('onUpdate', function() {
         onViewableItemsChanged,
       );
       expect(onViewableItemsChanged).not.toBeCalled();
-      helper.onUpdate(
-        data.length,
-        10, // not far enough to meet minimumOffset
-        100,
-        getFrameMetrics,
-        createViewToken,
-        onViewableItemsChanged,
-      );
-      expect(onViewableItemsChanged).not.toBeCalled();
+
+      helper.recordInteraction();
+
       helper.onUpdate(
         data.length,
         20,