From f3a53fd3382c7665d79ee78f45c1e855330df6cf Mon Sep 17 00:00:00 2001
From: Joshua Gross <joshuagross@fb.com>
Date: Wed, 11 Mar 2020 12:29:16 -0700
Subject: [PATCH] TextInput: keep less stateful data on the View

Summary:
Allow JS to keep track of mostRecentEventCount and pass it into each event or prop update. We really don't want to separately keep track of that data.

In non-Fabric, the ShadowNode will keep track of the mostRecentEventCount associated to prop updates. In Fabric, that happens on the C++ ShadowNode.

Changelog: [Internal] Simplification to TextInput native state

Reviewed By: mdvacca

Differential Revision: D20374573

fbshipit-source-id: 385fba6ec69a071c78832a686b397699a6c55d67
---
 Libraries/Components/TextInput/TextInput.js   | 10 ++---
 .../react/views/textinput/ReactEditText.java  | 16 +-------
 .../textinput/ReactTextInputManager.java      | 39 ++++++++-----------
 3 files changed, 21 insertions(+), 44 deletions(-)

diff --git a/Libraries/Components/TextInput/TextInput.js b/Libraries/Components/TextInput/TextInput.js
index df98a6402e5..7f4eaf2f1bb 100644
--- a/Libraries/Components/TextInput/TextInput.js
+++ b/Libraries/Components/TextInput/TextInput.js
@@ -985,14 +985,12 @@ function InternalTextInput(props: Props): React.Node {
   };
 
   const _onChange = (event: ChangeEvent) => {
-    // Make sure to fire the mostRecentEventCount first so it is already set on
-    // native when the text value is set.
     if (AndroidTextInputCommands && inputRef.current != null) {
-      AndroidTextInputCommands.setMostRecentEventCount(
-        inputRef.current,
-        event.nativeEvent.eventCount,
-      );
+      // Do nothing
     } else if (inputRef.current != null) {
+      // Make sure to fire the mostRecentEventCount first so it is already set on
+      // native when the text value is set.
+      // This is now only relevant on iOS until we migrate to ViewCommands everywhere
       inputRef.current.setNativeProps({
         mostRecentEventCount: event.nativeEvent.eventCount,
       });
diff --git a/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactEditText.java b/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactEditText.java
index 7d04a3abc68..86ae295b262 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactEditText.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactEditText.java
@@ -74,9 +74,6 @@ public class ReactEditText extends AppCompatEditText {
   /** A count of events sent to JS or C++. */
   protected int mNativeEventCount;
 
-  /** The most recent event number acked by JavaScript. Should only be updated from JS, not C++. */
-  protected int mMostRecentEventCount;
-
   private static final int UNSET = -1;
 
   private @Nullable ArrayList<TextWatcher> mListeners;
@@ -122,7 +119,6 @@ public class ReactEditText extends AppCompatEditText {
         getGravity() & (Gravity.HORIZONTAL_GRAVITY_MASK | Gravity.RELATIVE_HORIZONTAL_GRAVITY_MASK);
     mDefaultGravityVertical = getGravity() & Gravity.VERTICAL_GRAVITY_MASK;
     mNativeEventCount = 0;
-    mMostRecentEventCount = 0;
     mIsSettingTextFromJS = false;
     mBlurOnSubmit = null;
     mDisableFullscreen = false;
@@ -285,10 +281,6 @@ public class ReactEditText extends AppCompatEditText {
     mContentSizeWatcher = contentSizeWatcher;
   }
 
-  public void setMostRecentEventCount(int mostRecentEventCount) {
-    mMostRecentEventCount = mostRecentEventCount;
-  }
-
   public void setScrollWatcher(ScrollWatcher scrollWatcher) {
     mScrollWatcher = scrollWatcher;
   }
@@ -313,11 +305,6 @@ public class ReactEditText extends AppCompatEditText {
 
   @Override
   public void setSelection(int start, int end) {
-    // Skip setting the selection if the text wasn't set because of an out of date value.
-    if (mMostRecentEventCount < mNativeEventCount) {
-      return;
-    }
-
     super.setSelection(start, end);
   }
 
@@ -489,8 +476,7 @@ public class ReactEditText extends AppCompatEditText {
     }
 
     // Only set the text if it is up to date.
-    mMostRecentEventCount = reactTextUpdate.getJsEventCounter();
-    if (!canUpdateWithEventCount(mMostRecentEventCount)) {
+    if (!canUpdateWithEventCount(reactTextUpdate.getJsEventCounter())) {
       return;
     }
 
diff --git a/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactTextInputManager.java b/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactTextInputManager.java
index 6bfde5d42ec..97080239964 100644
--- a/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactTextInputManager.java
+++ b/ReactAndroid/src/main/java/com/facebook/react/views/textinput/ReactTextInputManager.java
@@ -208,7 +208,7 @@ public class ReactTextInputManager extends BaseViewManager<ReactEditText, Layout
         this.receiveCommand(reactEditText, "blur", args);
         break;
       case SET_MOST_RECENT_EVENT_COUNT:
-        this.receiveCommand(reactEditText, "setMostRecentEventCount", args);
+        // TODO: delete, this is no longer used from JS
         break;
       case SET_TEXT_AND_SELECTION:
         this.receiveCommand(reactEditText, "setTextAndSelection", args);
@@ -229,27 +229,25 @@ public class ReactTextInputManager extends BaseViewManager<ReactEditText, Layout
         reactEditText.clearFocusFromJS();
         break;
       case "setMostRecentEventCount":
-        reactEditText.setMostRecentEventCount(args.getInt(0));
+        // TODO: delete, this is no longer used from JS
         break;
       case "setTextAndSelection":
         int mostRecentEventCount = args.getInt(0);
-        reactEditText.setMostRecentEventCount(mostRecentEventCount);
-
-        if (mostRecentEventCount != UNSET) {
-          String text = args.getString(1);
-
-          int start = args.getInt(2);
-          int end = args.getInt(3);
-          if (end == UNSET) {
-            end = start;
-          }
-
-          // TODO: construct a ReactTextUpdate and use that with maybeSetText
-          // instead of calling setText, etc directly - doing that will definitely cause bugs.
-          reactEditText.maybeSetTextFromJS(
-              getReactTextUpdate(text, mostRecentEventCount, start, end));
-          reactEditText.maybeSetSelection(mostRecentEventCount, start, end);
+        if (mostRecentEventCount == UNSET) {
+          return;
         }
+
+        String text = args.getString(1);
+
+        int start = args.getInt(2);
+        int end = args.getInt(3);
+        if (end == UNSET) {
+          end = start;
+        }
+
+        reactEditText.maybeSetTextFromJS(
+            getReactTextUpdate(text, mostRecentEventCount, start, end));
+        reactEditText.maybeSetSelection(mostRecentEventCount, start, end);
         break;
     }
   }
@@ -470,11 +468,6 @@ public class ReactTextInputManager extends BaseViewManager<ReactEditText, Layout
     }
   }
 
-  @ReactProp(name = "mostRecentEventCount", defaultInt = 0)
-  public void setMostRecentEventCount(ReactEditText view, int mostRecentEventCount) {
-    view.setMostRecentEventCount(mostRecentEventCount);
-  }
-
   @ReactProp(name = "caretHidden", defaultBoolean = false)
   public void setCaretHidden(ReactEditText view, boolean caretHidden) {
     view.setCursorVisible(!caretHidden);