From 27d61388bd3c48f24788a3ef2fad28eb30866df3 Mon Sep 17 00:00:00 2001
From: Joshua Gross <joshuagross@fb.com>
Date: Thu, 23 Jan 2020 19:25:35 -0800
Subject: [PATCH] TextInput: update selection on native when JS calls view
 command

Summary:
We should have been calling this already. Trivial fix. The intent of the view command was always to update selection, I just forgot to add it. See test videos.

Changelog: [Internal]

Reviewed By: mdvacca

Differential Revision: D19548178

fbshipit-source-id: 14a1bdc11d84c05f2435c48c3bb96b64e8c68cb4
---
 .../react/views/textinput/ReactEditText.java  | 26 ++++++++++++++++++-
 .../textinput/ReactTextInputManager.java      |  5 ++--
 2 files changed, 28 insertions(+), 3 deletions(-)

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 67b4c1aa702..639e01ba1eb 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
@@ -80,6 +80,8 @@ public class ReactEditText extends AppCompatEditText {
   /** 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;
   private @Nullable TextWatcherDelegator mTextWatcherDelegator;
   private int mStagedInputType;
@@ -296,6 +298,24 @@ public class ReactEditText extends AppCompatEditText {
     mScrollWatcher = scrollWatcher;
   }
 
+  /**
+   * Attempt to set a selection or fail silently. Intentionally meant to handle bad inputs.
+   * EventCounter is the same one used as with text.
+   *
+   * @param eventCounter
+   * @param start
+   * @param end
+   */
+  public void maybeSetSelection(int eventCounter, int start, int end) {
+    if (!canUpdateWithEventCount(eventCounter)) {
+      return;
+    }
+
+    if (start != UNSET && end != UNSET) {
+      setSelection(start, end);
+    }
+  }
+
   @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     // Skip setting the selection if the text wasn't set because of an out of date value.
@@ -465,6 +485,10 @@ public class ReactEditText extends AppCompatEditText {
     mIsSettingTextFromState = false;
   }
 
+  public boolean canUpdateWithEventCount(int eventCounter) {
+    return eventCounter >= mNativeEventCount;
+  }
+
   // VisibleForTesting from {@link TextInputEventsTestCase}.
   public void maybeSetText(ReactTextUpdate reactTextUpdate) {
     if (isSecureText() && TextUtils.equals(getText(), reactTextUpdate.getText())) {
@@ -473,7 +497,7 @@ public class ReactEditText extends AppCompatEditText {
 
     // Only set the text if it is up to date.
     mMostRecentEventCount = reactTextUpdate.getJsEventCounter();
-    if (mMostRecentEventCount < mNativeEventCount) {
+    if (!canUpdateWithEventCount(mMostRecentEventCount)) {
       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 423fd80a300..2e3bcf41507 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
@@ -239,6 +239,7 @@ public class ReactTextInputManager extends BaseViewManager<ReactEditText, Layout
           // instead of calling setText, etc directly - doing that will definitely cause bugs.
           reactEditText.maybeSetTextFromJS(
               getReactTextUpdate(text, mostRecentEventCount, start, end));
+          reactEditText.maybeSetSelection(mostRecentEventCount, start, end);
         }
         break;
     }
@@ -281,8 +282,8 @@ public class ReactTextInputManager extends BaseViewManager<ReactEditText, Layout
         TextInlineImageSpan.possiblyUpdateInlineImageSpans(spannable, view);
       }
       view.maybeSetTextFromState(update);
-      if (update.getSelectionStart() != UNSET && update.getSelectionEnd() != UNSET)
-        view.setSelection(update.getSelectionStart(), update.getSelectionEnd());
+      view.maybeSetSelection(
+          update.getJsEventCounter(), update.getSelectionStart(), update.getSelectionEnd());
     }
   }