diff --git a/core/api/current.txt b/core/api/current.txt
index 5c3f077..c0b7675 100644
--- a/core/api/current.txt
+++ b/core/api/current.txt
@@ -189,6 +189,7 @@
     field public static final String START_VIEW_APP_FEATURES = "android.permission.START_VIEW_APP_FEATURES";
     field public static final String START_VIEW_PERMISSION_USAGE = "android.permission.START_VIEW_PERMISSION_USAGE";
     field public static final String STATUS_BAR = "android.permission.STATUS_BAR";
+    field public static final String SUBSCRIBE_TO_KEYGUARD_LOCKED_STATE = "android.permission.SUBSCRIBE_TO_KEYGUARD_LOCKED_STATE";
     field public static final String SYSTEM_ALERT_WINDOW = "android.permission.SYSTEM_ALERT_WINDOW";
     field public static final String TRANSMIT_IR = "android.permission.TRANSMIT_IR";
     field public static final String UNINSTALL_SHORTCUT = "com.android.launcher.permission.UNINSTALL_SHORTCUT";
@@ -5674,6 +5675,7 @@
   }
 
   public class KeyguardManager {
+    method @RequiresPermission(android.Manifest.permission.SUBSCRIBE_TO_KEYGUARD_LOCKED_STATE) public void addKeyguardLockedStateListener(@NonNull java.util.concurrent.Executor, @NonNull android.app.KeyguardManager.KeyguardLockedStateListener);
     method @Deprecated public android.content.Intent createConfirmDeviceCredentialIntent(CharSequence, CharSequence);
     method @Deprecated @RequiresPermission(android.Manifest.permission.DISABLE_KEYGUARD) public void exitKeyguardSecurely(android.app.KeyguardManager.OnKeyguardExitResult);
     method @Deprecated public boolean inKeyguardRestrictedInputMode();
@@ -5682,6 +5684,7 @@
     method public boolean isKeyguardLocked();
     method public boolean isKeyguardSecure();
     method @Deprecated public android.app.KeyguardManager.KeyguardLock newKeyguardLock(String);
+    method @RequiresPermission(android.Manifest.permission.SUBSCRIBE_TO_KEYGUARD_LOCKED_STATE) public void removeKeyguardLockedStateListener(@NonNull android.app.KeyguardManager.KeyguardLockedStateListener);
     method public void requestDismissKeyguard(@NonNull android.app.Activity, @Nullable android.app.KeyguardManager.KeyguardDismissCallback);
   }
 
@@ -5697,6 +5700,10 @@
     method @Deprecated @RequiresPermission(android.Manifest.permission.DISABLE_KEYGUARD) public void reenableKeyguard();
   }
 
+  @java.lang.FunctionalInterface public static interface KeyguardManager.KeyguardLockedStateListener {
+    method public void onKeyguardLockedStateChanged(boolean);
+  }
+
   @Deprecated public static interface KeyguardManager.OnKeyguardExitResult {
     method @Deprecated public void onKeyguardExitResult(boolean);
   }
diff --git a/core/java/android/app/KeyguardManager.java b/core/java/android/app/KeyguardManager.java
index 9910000..87ba197 100644
--- a/core/java/android/app/KeyguardManager.java
+++ b/core/java/android/app/KeyguardManager.java
@@ -52,6 +52,7 @@
 import android.view.WindowManagerGlobal;
 
 import com.android.internal.policy.IKeyguardDismissCallback;
+import com.android.internal.policy.IKeyguardLockedStateListener;
 import com.android.internal.util.Preconditions;
 import com.android.internal.widget.IWeakEscrowTokenActivatedListener;
 import com.android.internal.widget.IWeakEscrowTokenRemovedListener;
@@ -183,6 +184,10 @@
     })
     @interface LockTypes {}
 
+    // TODO(b/220379118): register only one binder listener and keep a map of listener to executor.
+    private final ArrayMap<KeyguardLockedStateListener, IKeyguardLockedStateListener>
+            mKeyguardLockedStateListeners = new ArrayMap<>();
+
     /**
      * Get an intent to prompt the user to confirm credentials (pin, pattern, password or biometrics
      * if enrolled) for the current user of the device. The caller is expected to launch this
@@ -534,7 +539,7 @@
     /**
      * Return whether the keyguard is currently locked.
      *
-     * @return true if keyguard is locked.
+     * @return {@code true} if the keyguard is locked.
      */
     public boolean isKeyguardLocked() {
         try {
@@ -550,7 +555,7 @@
      *
      * <p>See also {@link #isDeviceSecure()} which ignores SIM locked states.
      *
-     * @return true if a PIN, pattern or password is set or a SIM card is locked.
+     * @return {@code true} if a PIN, pattern or password is set or a SIM card is locked.
      */
     public boolean isKeyguardSecure() {
         try {
@@ -565,7 +570,7 @@
      * keyguard password emergency screen). When in such mode, certain keys,
      * such as the Home key and the right soft keys, don't work.
      *
-     * @return true if in keyguard restricted input mode.
+     * @return {@code true} if in keyguard restricted input mode.
      * @deprecated Use {@link #isKeyguardLocked()} instead.
      */
     public boolean inKeyguardRestrictedInputMode() {
@@ -576,7 +581,7 @@
      * Returns whether the device is currently locked and requires a PIN, pattern or
      * password to unlock.
      *
-     * @return true if unlocking the device currently requires a PIN, pattern or
+     * @return {@code true} if unlocking the device currently requires a PIN, pattern or
      * password.
      */
     public boolean isDeviceLocked() {
@@ -603,7 +608,7 @@
      *
      * <p>See also {@link #isKeyguardSecure} which treats SIM locked states as secure.
      *
-     * @return true if a PIN, pattern or password was set.
+     * @return {@code true} if a PIN, pattern or password was set.
      */
     public boolean isDeviceSecure() {
         return isDeviceSecure(mContext.getUserId());
@@ -762,7 +767,7 @@
     *        as the output of String#getBytes
     * @param complexity - complexity level imposed by the requester
     *        as defined in {@code DevicePolicyManager.PasswordComplexity}
-    * @return true if the password is valid, false otherwise
+    * @return {@code true} if the password is valid, false otherwise
     * @hide
     */
     @RequiresPermission(Manifest.permission.SET_INITIAL_LOCK)
@@ -821,7 +826,7 @@
     *        as the output of String#getBytes
     * @param complexity - complexity level imposed by the requester
     *        as defined in {@code DevicePolicyManager.PasswordComplexity}
-    * @return true if the lock is successfully set, false otherwise
+    * @return {@code true} if the lock is successfully set, false otherwise
     * @hide
     */
     @RequiresPermission(Manifest.permission.SET_INITIAL_LOCK)
@@ -903,8 +908,8 @@
     /**
      * Remove a weak escrow token.
      *
-     * @return true if the given handle refers to a valid weak token previously returned from
-     * {@link #addWeakEscrowToken}, whether it's active or not. return false otherwise.
+     * @return {@code true} if the given handle refers to a valid weak token previously returned
+     * from {@link #addWeakEscrowToken}, whether it's active or not. return false otherwise.
      * @hide
      */
     @RequiresFeature(PackageManager.FEATURE_AUTOMOTIVE)
@@ -944,7 +949,7 @@
     /**
      * Register the given WeakEscrowTokenRemovedListener.
      *
-     * @return true if the listener is registered successfully, return false otherwise.
+     * @return {@code true} if the listener is registered successfully, return false otherwise.
      * @hide
      */
     @RequiresFeature(PackageManager.FEATURE_AUTOMOTIVE)
@@ -982,7 +987,7 @@
     /**
      * Unregister the given WeakEscrowTokenRemovedListener.
      *
-     * @return true if the listener is unregistered successfully, return false otherwise.
+     * @return {@code true} if the listener is unregistered successfully, return false otherwise.
      * @hide
      */
     @RequiresFeature(PackageManager.FEATURE_AUTOMOTIVE)
@@ -1076,4 +1081,61 @@
                 throw new IllegalArgumentException("Unknown lock type " + lockType);
         }
     }
+
+    /**
+     * Listener for keyguard locked state changes.
+     */
+    @FunctionalInterface
+    public interface KeyguardLockedStateListener {
+        /**
+         * Callback function that executes when the keyguard locked state changes.
+         */
+        void onKeyguardLockedStateChanged(boolean isKeyguardLocked);
+    }
+
+    /**
+     * Registers a listener to execute when the keyguard visibility changes.
+     *
+     * @param listener The listener to add to receive keyguard visibility changes.
+     */
+    @RequiresPermission(Manifest.permission.SUBSCRIBE_TO_KEYGUARD_LOCKED_STATE)
+    public void addKeyguardLockedStateListener(@NonNull @CallbackExecutor Executor executor,
+            @NonNull KeyguardLockedStateListener listener) {
+        synchronized (mKeyguardLockedStateListeners) {
+            try {
+                final IKeyguardLockedStateListener innerListener =
+                        new IKeyguardLockedStateListener.Stub() {
+                    @Override
+                    public void onKeyguardLockedStateChanged(boolean isKeyguardLocked) {
+                        executor.execute(
+                                () -> listener.onKeyguardLockedStateChanged(isKeyguardLocked));
+                    }
+                };
+                mWM.addKeyguardLockedStateListener(innerListener);
+                mKeyguardLockedStateListeners.put(listener, innerListener);
+            } catch (RemoteException e) {
+                throw e.rethrowFromSystemServer();
+            }
+        }
+    }
+
+    /**
+     * Unregisters a listener that executes when the keyguard visibility changes.
+     */
+    @RequiresPermission(Manifest.permission.SUBSCRIBE_TO_KEYGUARD_LOCKED_STATE)
+    public void removeKeyguardLockedStateListener(@NonNull KeyguardLockedStateListener listener) {
+        synchronized (mKeyguardLockedStateListeners) {
+            IKeyguardLockedStateListener innerListener = mKeyguardLockedStateListeners.get(
+                    listener);
+            if (innerListener == null) {
+                return;
+            }
+            try {
+                mWM.removeKeyguardLockedStateListener(innerListener);
+            } catch (RemoteException e) {
+                throw e.rethrowFromSystemServer();
+            }
+            mKeyguardLockedStateListeners.remove(listener);
+        }
+    }
 }
diff --git a/core/java/android/view/IWindowManager.aidl b/core/java/android/view/IWindowManager.aidl
index ce21086..53b842a 100644
--- a/core/java/android/view/IWindowManager.aidl
+++ b/core/java/android/view/IWindowManager.aidl
@@ -18,6 +18,7 @@
 
 import com.android.internal.os.IResultReceiver;
 import com.android.internal.policy.IKeyguardDismissCallback;
+import com.android.internal.policy.IKeyguardLockedStateListener;
 import com.android.internal.policy.IShortcutService;
 
 import android.app.IAssistDataReceiver;
@@ -199,6 +200,9 @@
     boolean isKeyguardSecure(int userId);
     void dismissKeyguard(IKeyguardDismissCallback callback, CharSequence message);
 
+    void addKeyguardLockedStateListener(in IKeyguardLockedStateListener listener);
+    void removeKeyguardLockedStateListener(in IKeyguardLockedStateListener listener);
+
     // Requires INTERACT_ACROSS_USERS_FULL permission
     void setSwitchingUser(boolean switching);
 
diff --git a/core/java/com/android/internal/policy/IKeyguardLockedStateListener.aidl b/core/java/com/android/internal/policy/IKeyguardLockedStateListener.aidl
new file mode 100644
index 0000000..ee50219
--- /dev/null
+++ b/core/java/com/android/internal/policy/IKeyguardLockedStateListener.aidl
@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.internal.policy;
+
+oneway interface IKeyguardLockedStateListener {
+    void onKeyguardLockedStateChanged(boolean isKeyguardLocked);
+}
\ No newline at end of file
diff --git a/core/res/AndroidManifest.xml b/core/res/AndroidManifest.xml
index 68c8143..28653d9 100644
--- a/core/res/AndroidManifest.xml
+++ b/core/res/AndroidManifest.xml
@@ -4119,6 +4119,13 @@
     <permission android:name="android.permission.MANAGE_HOTWORD_DETECTION"
                 android:protectionLevel="internal|preinstalled" />
 
+    <!-- Allows an application to subscribe to keyguard locked (i.e., showing) state.
+         <p>Protection level: internal|role
+         <p>Intended for use by ROLE_ASSISTANT only.
+    -->
+    <permission android:name="android.permission.SUBSCRIBE_TO_KEYGUARD_LOCKED_STATE"
+                android:protectionLevel="internal|role"/>
+
     <!-- Must be required by a {@link android.service.autofill.AutofillService},
          to ensure that only the system can bind to it.
          <p>Protection level: signature
diff --git a/packages/Shell/AndroidManifest.xml b/packages/Shell/AndroidManifest.xml
index 741fe4f..39a8c82 100644
--- a/packages/Shell/AndroidManifest.xml
+++ b/packages/Shell/AndroidManifest.xml
@@ -585,6 +585,9 @@
     <uses-permission android:name="android.permission.MANAGE_HOTWORD_DETECTION" />
     <uses-permission android:name="android.permission.BIND_HOTWORD_DETECTION_SERVICE" />
 
+    <!-- Permission required for CTS test - KeyguardLockedStateApiTest -->
+    <uses-permission android:name="android.permission.SUBSCRIBE_TO_KEYGUARD_LOCKED_STATE" />
+
     <uses-permission android:name="android.permission.MANAGE_APP_HIBERNATION"/>
 
     <!-- Permission required for CTS test - ResourceObserverNativeTest -->
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 48fab47..7f16d61 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -200,6 +200,7 @@
 import android.os.PowerManagerInternal;
 import android.os.PowerSaveState;
 import android.os.RemoteCallback;
+import android.os.RemoteCallbackList;
 import android.os.RemoteException;
 import android.os.ResultReceiver;
 import android.os.ServiceManager;
@@ -288,6 +289,7 @@
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.os.IResultReceiver;
 import com.android.internal.policy.IKeyguardDismissCallback;
+import com.android.internal.policy.IKeyguardLockedStateListener;
 import com.android.internal.policy.IShortcutService;
 import com.android.internal.policy.KeyInterceptionInfo;
 import com.android.internal.protolog.ProtoLogImpl;
@@ -458,6 +460,10 @@
 
     final private KeyguardDisableHandler mKeyguardDisableHandler;
 
+    private final RemoteCallbackList<IKeyguardLockedStateListener> mKeyguardLockedStateListeners =
+            new RemoteCallbackList<>();
+    private boolean mDispatchedKeyguardLockedState = false;
+
     // VR Vr2d Display Id.
     int mVr2dDisplayId = INVALID_DISPLAY;
     boolean mVrModeEnabled = false;
@@ -3027,6 +3033,7 @@
     @Override
     public void onKeyguardShowingAndNotOccludedChanged() {
         mH.sendEmptyMessage(H.RECOMPUTE_FOCUS);
+        dispatchKeyguardLockedStateState();
     }
 
     @Override
@@ -3216,6 +3223,50 @@
         }
     }
 
+    @RequiresPermission(Manifest.permission.SUBSCRIBE_TO_KEYGUARD_LOCKED_STATE)
+    @Override
+    public void addKeyguardLockedStateListener(IKeyguardLockedStateListener listener) {
+        enforceSubscribeToKeyguardLockedStatePermission();
+        boolean registered = mKeyguardLockedStateListeners.register(listener);
+        if (!registered) {
+            Slog.w(TAG, "Failed to register listener: " + listener);
+        }
+    }
+
+    @RequiresPermission(Manifest.permission.SUBSCRIBE_TO_KEYGUARD_LOCKED_STATE)
+    @Override
+    public void removeKeyguardLockedStateListener(IKeyguardLockedStateListener listener) {
+        enforceSubscribeToKeyguardLockedStatePermission();
+        mKeyguardLockedStateListeners.unregister(listener);
+    }
+
+    private void enforceSubscribeToKeyguardLockedStatePermission() {
+        mContext.enforceCallingOrSelfPermission(
+                Manifest.permission.SUBSCRIBE_TO_KEYGUARD_LOCKED_STATE,
+                Manifest.permission.SUBSCRIBE_TO_KEYGUARD_LOCKED_STATE
+                        + " permission required to read keyguard visibility");
+    }
+
+    private void dispatchKeyguardLockedStateState() {
+        mH.post(() -> {
+            final boolean isKeyguardLocked = mPolicy.isKeyguardShowing();
+            if (mDispatchedKeyguardLockedState == isKeyguardLocked) {
+                return;
+            }
+            final int n = mKeyguardLockedStateListeners.beginBroadcast();
+            for (int i = 0; i < n; i++) {
+                try {
+                    mKeyguardLockedStateListeners.getBroadcastItem(i).onKeyguardLockedStateChanged(
+                            isKeyguardLocked);
+                } catch (RemoteException e) {
+                    // Handled by the RemoteCallbackList.
+                }
+            }
+            mKeyguardLockedStateListeners.finishBroadcast();
+            mDispatchedKeyguardLockedState = isKeyguardLocked;
+        });
+    }
+
     @Override
     public void setSwitchingUser(boolean switching) {
         if (!checkCallingPermission(Manifest.permission.INTERACT_ACROSS_USERS_FULL,