diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index a29fcb17b083f..9603f4d43d8bf 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -13580,6 +13580,28 @@ public final class Settings {
         public static final String POWER_BUTTON_VERY_LONG_PRESS =
                 "power_button_very_long_press";
 
+
+        /**
+         * Keyguard should be on the left hand side of the screen, for wide screen layouts.
+         *
+         * @hide
+         */
+        public static final int ONE_HANDED_KEYGUARD_SIDE_LEFT = 0;
+
+        /**
+         * Keyguard should be on the right hand side of the screen, for wide screen layouts.
+         *
+         * @hide
+         */
+        public static final int ONE_HANDED_KEYGUARD_SIDE_RIGHT = 1;
+        /**
+         * In one handed mode, which side the keyguard should be on. Allowable values are one of
+         * the ONE_HANDED_KEYGUARD_SIDE_* constants.
+         *
+         * @hide
+         */
+        public static final String ONE_HANDED_KEYGUARD_SIDE = "one_handed_keyguard_side";
+
         /**
          * Keys we no longer back up under the current schema, but want to continue to
          * process when restoring historical backup datasets.
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index 367c9b93c4389..416bc84478693 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -4708,4 +4708,7 @@
 
     <!-- Whether to select voice/data/sms preference without user confirmation -->
     <bool name="config_voice_data_sms_auto_fallback">false</bool>
+
+    <!-- Whether to enable the one-handed keyguard on the lock screen for wide-screen devices. -->
+    <bool name="config_enableOneHandedKeyguard">false</bool>
 </resources>
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index 4d3f5eb36e54f..672aec62f6a6c 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -4174,4 +4174,6 @@
   <java-symbol type="bool" name="config_telephony5gNonStandalone" />
 
   <java-symbol type="bool" name="config_voice_data_sms_auto_fallback" />
+
+  <java-symbol type="bool" name="config_enableOneHandedKeyguard" />
 </resources>
diff --git a/packages/SettingsProvider/src/android/provider/settings/validators/GlobalSettingsValidators.java b/packages/SettingsProvider/src/android/provider/settings/validators/GlobalSettingsValidators.java
index 66165b6d1ff2e..ad6a5312f1562 100644
--- a/packages/SettingsProvider/src/android/provider/settings/validators/GlobalSettingsValidators.java
+++ b/packages/SettingsProvider/src/android/provider/settings/validators/GlobalSettingsValidators.java
@@ -147,5 +147,10 @@ public class GlobalSettingsValidators {
         VALIDATORS.put(Global.DEVELOPMENT_SETTINGS_ENABLED, BOOLEAN_VALIDATOR);
         VALIDATORS.put(Global.NOTIFICATION_FEEDBACK_ENABLED, BOOLEAN_VALIDATOR);
         VALIDATORS.put(Global.RESTRICTED_NETWORKING_MODE, BOOLEAN_VALIDATOR);
+        VALIDATORS.put(
+                Global.ONE_HANDED_KEYGUARD_SIDE,
+                new InclusiveIntegerRangeValidator(
+                        /* first= */Global.ONE_HANDED_KEYGUARD_SIDE_LEFT,
+                        /* last= */Global.ONE_HANDED_KEYGUARD_SIDE_RIGHT));
     }
 }
diff --git a/packages/SettingsProvider/test/src/android/provider/SettingsBackupTest.java b/packages/SettingsProvider/test/src/android/provider/SettingsBackupTest.java
index 438cec8ef68f6..c11877a8a9631 100644
--- a/packages/SettingsProvider/test/src/android/provider/SettingsBackupTest.java
+++ b/packages/SettingsProvider/test/src/android/provider/SettingsBackupTest.java
@@ -283,6 +283,7 @@ public class SettingsBackupTest {
                     Settings.Global.EUICC_REMOVING_INVISIBLE_PROFILES_TIMEOUT_MILLIS,
                     Settings.Global.EUICC_SWITCH_SLOT_TIMEOUT_MILLIS,
                     Settings.Global.FANCY_IME_ANIMATIONS,
+                    Settings.Global.ONE_HANDED_KEYGUARD_SIDE,
                     Settings.Global.FORCE_ALLOW_ON_EXTERNAL,
                     Settings.Global.FORCED_APP_STANDBY_ENABLED,
                     Settings.Global.FORCED_APP_STANDBY_FOR_SMALL_BATTERY_ENABLED,
diff --git a/packages/SystemUI/res-keyguard/layout/keyguard_bouncer.xml b/packages/SystemUI/res-keyguard/layout/keyguard_bouncer.xml
index 79868093fb127..b5f55af50bff5 100644
--- a/packages/SystemUI/res-keyguard/layout/keyguard_bouncer.xml
+++ b/packages/SystemUI/res-keyguard/layout/keyguard_bouncer.xml
@@ -24,7 +24,7 @@
     <include
         style="@style/BouncerSecurityContainer"
         layout="@layout/keyguard_host_view"
-        android:layout_width="wrap_content"
-        android:layout_height="wrap_content" />
+        android:layout_width="match_parent"
+        android:layout_height="match_parent" />
 </FrameLayout>
 
diff --git a/packages/SystemUI/res-keyguard/layout/keyguard_host_view.xml b/packages/SystemUI/res-keyguard/layout/keyguard_host_view.xml
index 04e645bd0a321..c75ee51517d1d 100644
--- a/packages/SystemUI/res-keyguard/layout/keyguard_host_view.xml
+++ b/packages/SystemUI/res-keyguard/layout/keyguard_host_view.xml
@@ -41,13 +41,14 @@
         android:layout_gravity="center">
         <com.android.keyguard.KeyguardSecurityViewFlipper
             android:id="@+id/view_flipper"
-            android:layout_width="match_parent"
-            android:layout_height="match_parent"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
             android:clipChildren="false"
             android:clipToPadding="false"
             android:paddingTop="@dimen/keyguard_security_view_top_margin"
             android:paddingStart="@dimen/keyguard_security_view_lateral_margin"
             android:paddingEnd="@dimen/keyguard_security_view_lateral_margin"
+            android:layout_gravity="center"
             android:gravity="center">
         </com.android.keyguard.KeyguardSecurityViewFlipper>
     </com.android.keyguard.KeyguardSecurityContainer>
diff --git a/packages/SystemUI/res-keyguard/values-sw600dp-land/bools.xml b/packages/SystemUI/res-keyguard/values-sw600dp-land/bools.xml
new file mode 100644
index 0000000000000..e09bf7e37ed0c
--- /dev/null
+++ b/packages/SystemUI/res-keyguard/values-sw600dp-land/bools.xml
@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (C) 2021 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.
+  -->
+
+<resources>
+    <bool name="can_use_one_handed_bouncer">true</bool>
+</resources>
diff --git a/packages/SystemUI/res-keyguard/values/config.xml b/packages/SystemUI/res-keyguard/values/config.xml
index 8d9d6ee68c67d..6176f7c1dd0ac 100644
--- a/packages/SystemUI/res-keyguard/values/config.xml
+++ b/packages/SystemUI/res-keyguard/values/config.xml
@@ -22,4 +22,5 @@
 
     <!-- Allow the menu hard key to be disabled in LockScreen on some devices [DO NOT TRANSLATE] -->
     <bool name="config_disableMenuKeyInLockScreen">false</bool>
+    <bool name="can_use_one_handed_bouncer">false</bool>
 </resources>
diff --git a/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityContainer.java b/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityContainer.java
index 30db341a061c8..a7ed67287fc73 100644
--- a/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityContainer.java
+++ b/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityContainer.java
@@ -29,12 +29,17 @@ import android.app.AlertDialog;
 import android.content.Context;
 import android.graphics.Insets;
 import android.graphics.Rect;
+import android.provider.Settings;
 import android.util.AttributeSet;
 import android.util.MathUtils;
 import android.util.TypedValue;
+import android.view.Gravity;
 import android.view.MotionEvent;
+import android.view.OrientationEventListener;
 import android.view.VelocityTracker;
+import android.view.View;
 import android.view.ViewConfiguration;
+import android.view.ViewPropertyAnimator;
 import android.view.WindowInsets;
 import android.view.WindowInsetsAnimation;
 import android.view.WindowInsetsAnimationControlListener;
@@ -55,6 +60,7 @@ import com.android.internal.widget.LockPatternUtils;
 import com.android.keyguard.KeyguardSecurityModel.SecurityMode;
 import com.android.systemui.Interpolators;
 import com.android.systemui.R;
+import com.android.systemui.statusbar.notification.stack.StackStateAnimator;
 
 import java.util.List;
 
@@ -99,6 +105,12 @@ public class KeyguardSecurityContainer extends FrameLayout {
     private boolean mDisappearAnimRunning;
     private SwipeListener mSwipeListener;
 
+    private boolean mIsSecurityViewLeftAligned = true;
+    private boolean mOneHandedMode = false;
+    private SecurityMode mSecurityMode = SecurityMode.Invalid;
+    private ViewPropertyAnimator mRunningOneHandedAnimator;
+    private final OrientationEventListener mOrientationEventListener;
+
     private final WindowInsetsAnimation.Callback mWindowInsetsAnimationCallback =
             new WindowInsetsAnimation.Callback(DISPATCH_MODE_STOP) {
 
@@ -157,16 +169,20 @@ public class KeyguardSecurityContainer extends FrameLayout {
     // Used to notify the container when something interesting happens.
     public interface SecurityCallback {
         boolean dismiss(boolean authenticated, int targetUserId, boolean bypassSecondaryLockScreen);
+
         void userActivity();
+
         void onSecurityModeChanged(SecurityMode securityMode, boolean needsInput);
 
         /**
-         * @param strongAuth wheher the user has authenticated with strong authentication like
-         *                   pattern, password or PIN but not by trust agents or fingerprint
+         * @param strongAuth   wheher the user has authenticated with strong authentication like
+         *                     pattern, password or PIN but not by trust agents or fingerprint
          * @param targetUserId a user that needs to be the foreground user at the finish completion.
          */
         void finish(boolean strongAuth, int targetUserId);
+
         void reset();
+
         void onCancelClicked();
     }
 
@@ -224,11 +240,119 @@ public class KeyguardSecurityContainer extends FrameLayout {
         super(context, attrs, defStyle);
         mSpringAnimation = new SpringAnimation(this, DynamicAnimation.Y);
         mViewConfiguration = ViewConfiguration.get(context);
+
+        mOrientationEventListener = new OrientationEventListener(context) {
+            @Override
+            public void onOrientationChanged(int orientation) {
+                updateLayoutForSecurityMode(mSecurityMode);
+            }
+        };
     }
 
     void onResume(SecurityMode securityMode, boolean faceAuthEnabled) {
+        mSecurityMode = securityMode;
         mSecurityViewFlipper.setWindowInsetsAnimationCallback(mWindowInsetsAnimationCallback);
         updateBiometricRetry(securityMode, faceAuthEnabled);
+
+        updateLayoutForSecurityMode(securityMode);
+        mOrientationEventListener.enable();
+    }
+
+    void updateLayoutForSecurityMode(SecurityMode securityMode) {
+        mSecurityMode = securityMode;
+        mOneHandedMode = canUseOneHandedBouncer();
+
+        if (mOneHandedMode) {
+            mIsSecurityViewLeftAligned = isOneHandedKeyguardLeftAligned(mContext);
+        }
+
+        updateSecurityViewGravity();
+        updateSecurityViewLocation(false);
+    }
+
+    /** Return whether the one-handed keyguard should be enabled. */
+    private boolean canUseOneHandedBouncer() {
+        // Is it enabled?
+        if (!getResources().getBoolean(
+                com.android.internal.R.bool.config_enableOneHandedKeyguard)) {
+            return false;
+        }
+
+        if (!KeyguardSecurityModel.isSecurityViewOneHanded(mSecurityMode)) {
+            return false;
+        }
+
+        return getResources().getBoolean(R.bool.can_use_one_handed_bouncer);
+    }
+
+    /** Read whether the one-handed keyguard should be on the left/right from settings. */
+    private boolean isOneHandedKeyguardLeftAligned(Context context) {
+        try {
+            return Settings.Global.getInt(context.getContentResolver(),
+                    Settings.Global.ONE_HANDED_KEYGUARD_SIDE)
+                    == Settings.Global.ONE_HANDED_KEYGUARD_SIDE_LEFT;
+        } catch (Settings.SettingNotFoundException ex) {
+            return true;
+        }
+    }
+
+    private void updateSecurityViewGravity() {
+        View securityView = getChildAt(0);
+
+        if (securityView == null) {
+            return;
+        }
+
+        FrameLayout.LayoutParams lp = (FrameLayout.LayoutParams) securityView.getLayoutParams();
+
+        if (mOneHandedMode) {
+            lp.gravity = Gravity.LEFT | Gravity.BOTTOM;
+        } else {
+            lp.gravity = Gravity.CENTER;
+        }
+
+        securityView.setLayoutParams(lp);
+    }
+
+    /**
+     * Moves the inner security view to the correct location (in one handed mode) with animation.
+     * This is triggered when the user taps on the side of the screen that is not currently occupied
+     * by the security view .
+     */
+    private void updateSecurityViewLocation(boolean animate) {
+        View securityView = getChildAt(0);
+
+        if (securityView == null) {
+            return;
+        }
+
+        if (!mOneHandedMode) {
+            securityView.setTranslationX(0);
+            return;
+        }
+
+        if (mRunningOneHandedAnimator != null) {
+            mRunningOneHandedAnimator.cancel();
+            mRunningOneHandedAnimator = null;
+        }
+
+        int targetTranslation = mIsSecurityViewLeftAligned ? 0 : (int) (getMeasuredWidth() / 2f);
+
+        if (animate) {
+            mRunningOneHandedAnimator = securityView.animate().translationX(targetTranslation);
+            mRunningOneHandedAnimator.setInterpolator(Interpolators.FAST_OUT_SLOW_IN);
+            mRunningOneHandedAnimator.setListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    mRunningOneHandedAnimator = null;
+                }
+            });
+
+            mRunningOneHandedAnimator.setDuration(StackStateAnimator.ANIMATION_DURATION_STANDARD);
+            mRunningOneHandedAnimator.start();
+        } else {
+            securityView.setTranslationX(targetTranslation);
+        }
     }
 
     public void onPause() {
@@ -237,6 +361,7 @@ public class KeyguardSecurityContainer extends FrameLayout {
             mAlertDialog = null;
         }
         mSecurityViewFlipper.setWindowInsetsAnimationCallback(null);
+        mOrientationEventListener.disable();
     }
 
     @Override
@@ -318,19 +443,44 @@ public class KeyguardSecurityContainer extends FrameLayout {
                 if (mSwipeListener != null) {
                     mSwipeListener.onSwipeUp();
                 }
+            } else {
+                if (!mIsDragging) {
+                    handleTap(event);
+                }
             }
         }
         return true;
     }
 
+    private void handleTap(MotionEvent event) {
+        // If we're using a fullscreen security mode, skip
+        if (!mOneHandedMode) {
+            return;
+        }
+
+        // Did the tap hit the "other" side of the bouncer?
+        if ((mIsSecurityViewLeftAligned && (event.getX() > getWidth() / 2f))
+                || (!mIsSecurityViewLeftAligned && (event.getX() < getWidth() / 2f))) {
+            mIsSecurityViewLeftAligned = !mIsSecurityViewLeftAligned;
+
+            Settings.Global.putInt(
+                    mContext.getContentResolver(),
+                    Settings.Global.ONE_HANDED_KEYGUARD_SIDE,
+                    mIsSecurityViewLeftAligned ? Settings.Global.ONE_HANDED_KEYGUARD_SIDE_LEFT
+                            : Settings.Global.ONE_HANDED_KEYGUARD_SIDE_RIGHT);
+
+            updateSecurityViewLocation(true);
+        }
+    }
+
     void setSwipeListener(SwipeListener swipeListener) {
         mSwipeListener = swipeListener;
     }
 
     private void startSpringAnimation(float startVelocity) {
         mSpringAnimation
-            .setStartVelocity(startVelocity)
-            .animateToFinalPosition(0);
+                .setStartVelocity(startVelocity)
+                .animateToFinalPosition(0);
     }
 
     public void startDisappearAnimation(SecurityMode securitySelection) {
@@ -440,18 +590,17 @@ public class KeyguardSecurityContainer extends FrameLayout {
         return insets.inset(0, 0, 0, inset);
     }
 
-
     private void showDialog(String title, String message) {
         if (mAlertDialog != null) {
             mAlertDialog.dismiss();
         }
 
         mAlertDialog = new AlertDialog.Builder(mContext)
-            .setTitle(title)
-            .setMessage(message)
-            .setCancelable(false)
-            .setNeutralButton(R.string.ok, null)
-            .create();
+                .setTitle(title)
+                .setMessage(message)
+                .setCancelable(false)
+                .setNeutralButton(R.string.ok, null)
+                .create();
         if (!(mContext instanceof Activity)) {
             mAlertDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_KEYGUARD_DIALOG);
         }
@@ -489,6 +638,53 @@ public class KeyguardSecurityContainer extends FrameLayout {
         }
     }
 
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        // This is a little hacky, but this element only ever has one wrap_content child, and is
+        // itself set to match_parent, so we can take a couple of shortcuts compared to
+        // FrameLayout#onMeasure
+        int maxHeight = 0;
+        int maxWidth = 0;
+        int childState = 0;
+
+        int count = getChildCount();
+
+        int halfWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
+                MeasureSpec.getSize(widthMeasureSpec) / 2,
+                MeasureSpec.getMode(widthMeasureSpec));
+
+        if (count > 1) {
+            throw new IllegalStateException("KeyguardSecurityContainer should only have one child");
+        }
+
+        if (count > 0) {
+            final View securityView = getChildAt(0);
+            if (securityView.getVisibility() != GONE) {
+                if (mOneHandedMode) {
+                    measureChildWithMargins(securityView, halfWidthMeasureSpec, 0,
+                            heightMeasureSpec, 0);
+                } else {
+                    measureChildWithMargins(securityView, widthMeasureSpec, 0,
+                            heightMeasureSpec, 0);
+                }
+                final LayoutParams lp = (LayoutParams) securityView.getLayoutParams();
+                maxWidth = Math.max(maxWidth,
+                        securityView.getMeasuredWidth() + lp.leftMargin + lp.rightMargin);
+                maxHeight = Math.max(maxHeight,
+                        securityView.getMeasuredHeight() + lp.topMargin + lp.bottomMargin);
+                childState = combineMeasuredStates(childState, securityView.getMeasuredState());
+            }
+        }
+
+        // Check against our minimum height and width
+        maxHeight = Math.max(maxHeight, getSuggestedMinimumHeight());
+        maxWidth = Math.max(maxWidth, getSuggestedMinimumWidth());
+
+        setMeasuredDimension(resolveSizeAndState(maxWidth, widthMeasureSpec, childState),
+                resolveSizeAndState(maxHeight, heightMeasureSpec,
+                        childState << MEASURED_HEIGHT_STATE_SHIFT));
+    }
+
     void showAlmostAtWipeDialog(int attempts, int remaining, int userType) {
         String message = null;
         switch (userType) {
diff --git a/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityContainerController.java b/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityContainerController.java
index 1a8d420fb3945..fdab8db67431f 100644
--- a/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityContainerController.java
+++ b/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityContainerController.java
@@ -404,6 +404,7 @@ public class KeyguardSecurityContainerController extends ViewController<Keyguard
         if (newView != null) {
             newView.onResume(KeyguardSecurityView.VIEW_REVEALED);
             mSecurityViewFlipperController.show(newView);
+            mView.updateLayoutForSecurityMode(securityMode);
         }
 
         mSecurityCallback.onSecurityModeChanged(
diff --git a/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityModel.java b/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityModel.java
index c77c86711abf0..631c248444173 100644
--- a/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityModel.java
+++ b/packages/SystemUI/src/com/android/keyguard/KeyguardSecurityModel.java
@@ -92,4 +92,13 @@ public class KeyguardSecurityModel {
                 throw new IllegalStateException("Unknown security quality:" + security);
         }
     }
+
+    /**
+     * Returns whether the given security view should be used in a "one handed" way. This can be
+     * used to change how the security view is drawn (e.g. take up less of the screen, and align to
+     * one side).
+     */
+    public static boolean isSecurityViewOneHanded(SecurityMode securityMode) {
+        return securityMode == SecurityMode.Pattern || securityMode == SecurityMode.PIN;
+    }
 }