From ede3a97e6f0c5613ceaa7e55f2a3e50292a17cd9 Mon Sep 17 00:00:00 2001
From: Taran Singh <tarandeep@google.com>
Date: Tue, 22 Feb 2022 13:23:17 +0000
Subject: [PATCH] Introduce Stylus handwriting developer option

Introduce stylus handwriting settings and check if its enabled before
calling IMM#startStylusHandwriting()

Bug: 219777744
Test: atest StylusHandwritingTest

Change-Id: Id58b2eb66a0a1178743d08921918f3d9d717546c
---
 core/api/test-current.txt                           |  1 +
 core/java/android/provider/Settings.java            | 13 +++++++++++++
 .../view/inputmethod/InputMethodManager.java        |  9 ++++++++-
 .../src/android/provider/SettingsBackupTest.java    |  1 +
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/core/api/test-current.txt b/core/api/test-current.txt
index 9757b2ff318f9..804052c7e876a 100644
--- a/core/api/test-current.txt
+++ b/core/api/test-current.txt
@@ -2157,6 +2157,7 @@ package android.provider {
     field @Deprecated public static final String NOTIFICATION_BUBBLES = "notification_bubbles";
     field public static final String OVERLAY_DISPLAY_DEVICES = "overlay_display_devices";
     field public static final String SHOW_FIRST_CRASH_DIALOG = "show_first_crash_dialog";
+    field public static final String STYLUS_HANDWRITING_ENABLED = "stylus_handwriting_enabled";
     field public static final String USER_DISABLED_HDR_FORMATS = "user_disabled_hdr_formats";
     field public static final String USER_PREFERRED_REFRESH_RATE = "user_preferred_refresh_rate";
     field public static final String USER_PREFERRED_RESOLUTION_HEIGHT = "user_preferred_resolution_height";
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 23e02e9d9968b..29b988c2ebb8c 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -86,8 +86,10 @@ import android.util.ArraySet;
 import android.util.Log;
 import android.util.MemoryIntArray;
 import android.view.Display;
+import android.view.MotionEvent;
 import android.view.Window;
 import android.view.WindowManager.LayoutParams;
+import android.widget.Editor;
 
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.util.Preconditions;
@@ -15482,6 +15484,17 @@ public final class Settings {
         @Readable
         public static final String AUTOFILL_MAX_VISIBLE_DATASETS = "autofill_max_visible_datasets";
 
+        /**
+         * Toggle for enabling stylus handwriting. When enabled, current Input method receives
+         * stylus {@link MotionEvent}s if an {@link Editor} is focused.
+         *
+         * @hide
+         */
+        @TestApi
+        @Readable
+        @SuppressLint("NoSettingsProvider")
+        public static final String STYLUS_HANDWRITING_ENABLED = "stylus_handwriting_enabled";
+
         /**
          * Exemptions to the hidden API blacklist.
          *
diff --git a/core/java/android/view/inputmethod/InputMethodManager.java b/core/java/android/view/inputmethod/InputMethodManager.java
index 27174630bfa33..38bb1d9c8ec82 100644
--- a/core/java/android/view/inputmethod/InputMethodManager.java
+++ b/core/java/android/view/inputmethod/InputMethodManager.java
@@ -1895,10 +1895,17 @@ public final class InputMethodManager {
         if (fallbackImm != null) {
             fallbackImm.startStylusHandwriting(view);
         }
+        Objects.requireNonNull(view);
+
+        if (Settings.Global.getInt(view.getContext().getContentResolver(),
+                Settings.Global.STYLUS_HANDWRITING_ENABLED, 0) == 0) {
+            Log.d(TAG, "Ignoring startStylusHandwriting(view) as stylus handwriting is disabled");
+            return;
+        }
 
         checkFocus();
         synchronized (mH) {
-            if (view == null || !hasServedByInputMethodLocked(view)) {
+            if (!hasServedByInputMethodLocked(view)) {
                 Log.w(TAG,
                         "Ignoring startStylusHandwriting() as view=" + view + " is not served.");
                 return;
diff --git a/packages/SettingsProvider/test/src/android/provider/SettingsBackupTest.java b/packages/SettingsProvider/test/src/android/provider/SettingsBackupTest.java
index 3f4372bd78ffc..057a9b05de589 100644
--- a/packages/SettingsProvider/test/src/android/provider/SettingsBackupTest.java
+++ b/packages/SettingsProvider/test/src/android/provider/SettingsBackupTest.java
@@ -271,6 +271,7 @@ public class SettingsBackupTest {
                     Settings.Global.DYNAMIC_POWER_SAVINGS_DISABLE_THRESHOLD,
                     Settings.Global.SMART_REPLIES_IN_NOTIFICATIONS_FLAGS,
                     Settings.Global.SMART_SUGGESTIONS_IN_NOTIFICATIONS_FLAGS,
+                    Settings.Global.STYLUS_HANDWRITING_ENABLED,
                     Settings.Global.ENABLE_ADB_INCREMENTAL_INSTALL_DEFAULT,
                     Settings.Global.ENABLE_MULTI_SLOT_TIMEOUT_MILLIS,
                     Settings.Global.ENHANCED_4G_MODE_ENABLED,