Notify IMMS synchronously on IME insets hidden.

Currently, IMMS will be notified asynchronously when an IME hide
animation finishes, via message dispatching through IMS
(IMM#notifyImeHidden -> IMS#notifyImeHidden -> IMMS#hideMySoftInput).
This creates a race condition when IMM#showSoftInput or WIC#show is
called around the end of hide animation.

This CL fixes the race condition by synchronously and directly
calling IMMS#hideSoftInput from IMM#notifyImeHidden.

Note that there is still another race condition for IMM#showSoftInput
(not WIC#show) if it's called during an IME hide animation;
IMM#showSoftInput ended up calling WIC#show asynchronously, but at that
time the running IME hide animation may have already been finished
successfully and WIC#show may fail to cancel the hide animation
(then the cleanup IMM#notifyImeHidden hides the IME again disruptively).
I will fix the latter issue in a separate CL.

Bug: 221483132
Bug: 225674038
Test: atest InputMethodStressTest
Test: atest CtsInputMethodTestCases
Test: atest WindowInsetsAnimationControllerTests
Change-Id: I7c71dc5a1d6b61aa79d1666f0e257e6401e4adb2

core/java/android/inputmethodservice/IInputMethodSessionWrapper.java

@@ -53,7 +53,6 @@ class IInputMethodSessionWrapper extends IInputMethodSession.Stub
     private static final int DO_APP_PRIVATE_COMMAND = 100;
     private static final int DO_FINISH_SESSION = 110;
     private static final int DO_VIEW_CLICKED = 115;
-    private static final int DO_NOTIFY_IME_HIDDEN = 120;
     private static final int DO_REMOVE_IME_SURFACE = 130;
     private static final int DO_FINISH_INPUT = 140;
     private static final int DO_INVALIDATE_INPUT = 150;
@@ -133,10 +132,6 @@ class IInputMethodSessionWrapper extends IInputMethodSession.Stub
                 mInputMethodSession.viewClicked(msg.arg1 == 1);
                 return;
             }
-            case DO_NOTIFY_IME_HIDDEN: {
-                mInputMethodSession.notifyImeHidden();
-                return;
-            }
             case DO_REMOVE_IME_SURFACE: {
                 mInputMethodSession.removeImeSurface();
                 return;
@@ -197,11 +192,6 @@ class IInputMethodSessionWrapper extends IInputMethodSession.Stub
                 mCaller.obtainMessageI(DO_VIEW_CLICKED, focusChanged ? 1 : 0));
     }
 
-    @Override
-    public void notifyImeHidden() {
-        mCaller.executeOrSendMessage(mCaller.obtainMessage(DO_NOTIFY_IME_HIDDEN));
-    }
-
     @Override
     public void removeImeSurface() {
         mCaller.executeOrSendMessage(mCaller.obtainMessage(DO_REMOVE_IME_SURFACE));

core/java/android/inputmethodservice/InputMethodService.java

@@ -1059,10 +1059,6 @@ public class InputMethodService extends AbstractInputMethodService {
         return viewRoot == null ? null : viewRoot.getInputToken();
     }
 
-    private void notifyImeHidden() {
-        requestHideSelf(0 /* flags */, SoftInputShowHideReason.HIDE_SOFT_INPUT_BY_INSETS_API);
-    }
-
     private void scheduleImeSurfaceRemoval() {
         if (mShowInputRequested || mWindowVisible || mWindow == null
                 || mImeSurfaceScheduledForRemoval) {
@@ -1225,14 +1221,6 @@ public class InputMethodService extends AbstractInputMethodService {
             InputMethodService.this.onUpdateCursorAnchorInfo(info);
         }
 
-        /**
-         * Notify IME that window is hidden.
-         * @hide
-         */
-        public final void notifyImeHidden() {
-            InputMethodService.this.notifyImeHidden();
-        }
-
         /**
          * Notify IME that surface can be now removed.
          * @hide

core/java/android/view/ImeInsetsSourceConsumer.java

@@ -23,7 +23,6 @@ import static android.view.InsetsController.AnimationType;
 import static android.view.InsetsState.ITYPE_IME;
 
 import android.annotation.Nullable;
-import android.inputmethodservice.InputMethodService;
 import android.os.IBinder;
 import android.os.Trace;
 import android.util.proto.ProtoOutputStream;
@@ -104,7 +103,8 @@ public final class ImeInsetsSourceConsumer extends InsetsSourceConsumer {
     }
 
     /**
-     * Notify {@link InputMethodService} that IME window is hidden.
+     * Notify {@link com.android.server.inputmethod.InputMethodManagerService} that
+     * IME insets are hidden.
      */
     @Override
     void notifyHidden() {

core/java/android/view/inputmethod/InputMethodManager.java

@@ -2521,7 +2521,7 @@ public final class InputMethodManager {
     }
 
     /**
-     * Notify IME directly that it is no longer visible.
+     * Notify IMMS that IME insets are no longer visible.
      *
      * @param windowToken the window from which this request originates. If this doesn't match the
      *                    currently served view, the request is ignored.
@@ -2533,7 +2533,13 @@ public final class InputMethodManager {
         synchronized (mH) {
             if (mCurrentInputMethodSession != null && mCurRootView != null
                     && mCurRootView.getWindowToken() == windowToken) {
-                mCurrentInputMethodSession.notifyImeHidden();
+                try {
+                    mService.hideSoftInput(mClient, windowToken, 0 /* flags */,
+                            null /* resultReceiver */,
+                            SoftInputShowHideReason.HIDE_SOFT_INPUT_BY_INSETS_API);
+                } catch (RemoteException e) {
+                    throw e.rethrowFromSystemServer();
+                }
             }
         }
     }

core/java/android/view/inputmethod/InputMethodSession.java

@@ -194,13 +194,6 @@ public interface InputMethodSession {
      */
     public void updateCursorAnchorInfo(CursorAnchorInfo cursorAnchorInfo);
 
-    /**
-     * Notifies {@link android.inputmethodservice.InputMethodService} that IME has been
-     * hidden from user.
-     * @hide
-     */
-    public void notifyImeHidden();
-
     /**
      * Notify IME directly to remove surface as it is no longer visible.
      * @hide

core/java/android/view/inputmethod/InputMethodSessionWrapper.java

@@ -105,15 +105,6 @@ final class InputMethodSessionWrapper {
         }
     }
 
-    @AnyThread
-    void notifyImeHidden() {
-        try {
-            mSession.notifyImeHidden();
-        } catch (RemoteException e) {
-            Log.w(TAG, "IME died", e);
-        }
-    }
-
     @AnyThread
     void viewClicked(boolean focusChanged) {
         try {

core/java/com/android/internal/view/IInputMethodSession.aidl

@@ -50,8 +50,6 @@ oneway interface IInputMethodSession {
 
     void updateCursorAnchorInfo(in CursorAnchorInfo cursorAnchorInfo);
 
-    void notifyImeHidden();
-
     void removeImeSurface();
 
     void finishInput();

tests/InputMethodStressTest/src/com/android/inputmethod/stresstest/ImeOpenCloseStressTest.java

@@ -27,7 +27,6 @@ import android.app.Activity;
 import android.app.Instrumentation;
 import android.content.Intent;
 import android.os.Bundle;
-import android.os.SystemClock;
 import android.platform.test.annotations.RootPermissionTest;
 import android.platform.test.rule.UnlockScreenRule;
 import android.view.WindowInsets;
@@ -78,9 +77,6 @@ public final class ImeOpenCloseStressTest {
             instrumentation.runOnMainSync(activity::hideIme);
             waitOnMainUntil(msgPrefix + "IME should be hidden",
                     () -> !activity.isAnimating() && !isImeShown(editText));
-            // b/b/221483132, wait until IMS and IMMS handles IMM#notifyImeHidden.
-            // There is no good signal, so we just wait a second.
-            SystemClock.sleep(1000);
         }
     }