Snap for 12373988 from d00ccc1124509d7e1cf59e6e59c0e47a5c03c4ca to 24Q4-release

Change-Id: I2723e2caf6c24e94afe40d8b981c4f5515b96e0b

35 files changed, 1991 insertions, 323 deletions

diff --git a/libs/WindowManager/Jetpack/src/TEST_MAPPING b/libs/WindowManager/Jetpack/src/TEST_MAPPING
index f8f64001dd24..600c79bb88a4 100644
--- a/libs/WindowManager/Jetpack/src/TEST_MAPPING
+++ b/libs/WindowManager/Jetpack/src/TEST_MAPPING
@@ -1,32 +1,10 @@
 {
   "presubmit": [
     {
-      "name": "WMJetpackUnitTests",
-      "options": [
-        {
-          "include-annotation": "android.platform.test.annotations.Presubmit"
-        },
-        {
-          "exclude-annotation": "androidx.test.filters.FlakyTest"
-        },
-        {
-          "exclude-annotation": "org.junit.Ignore"
-        }
-      ]
+      "name": "WMJetpackUnitTests_Presubmit"
     },
     {
-      "name": "CtsWindowManagerJetpackTestCases",
-      "options": [
-        {
-          "include-annotation": "android.platform.test.annotations.Presubmit"
-        },
-        {
-          "exclude-annotation": "androidx.test.filters.FlakyTest"
-        },
-        {
-          "exclude-annotation": "org.junit.Ignore"
-        }
-      ]
+      "name": "CtsWindowManagerJetpackTestCases_Presubmit"
     }
   ],
   "imports": [
diff --git a/libs/WindowManager/Shell/res/values-es-rUS/strings.xml b/libs/WindowManager/Shell/res/values-es-rUS/strings.xml
index 8644780dba03..0dd0a99dd9ae 100644
--- a/libs/WindowManager/Shell/res/values-es-rUS/strings.xml
+++ b/libs/WindowManager/Shell/res/values-es-rUS/strings.xml
@@ -73,8 +73,7 @@
     <string name="bubble_accessibility_announce_collapse" msgid="3178806224494537097">"contraer <xliff:g id="BUBBLE_TITLE">%1$s</xliff:g>"</string>
     <string name="bubbles_app_settings" msgid="3617224938701566416">"Configuración de <xliff:g id="NOTIFICATION_TITLE">%1$s</xliff:g>"</string>
     <string name="bubble_dismiss_text" msgid="8816558050659478158">"Descartar burbuja"</string>
-    <!-- no translation found for bubble_fullscreen_text (1006758103218086231) -->
-    <skip />
+    <string name="bubble_fullscreen_text" msgid="1006758103218086231">"Mover a pantalla completa"</string>
     <string name="bubbles_dont_bubble_conversation" msgid="310000317885712693">"No mostrar la conversación en burbuja"</string>
     <string name="bubbles_user_education_title" msgid="2112319053732691899">"Chat con burbujas"</string>
     <string name="bubbles_user_education_description" msgid="4215862563054175407">"Las conversaciones nuevas aparecen como elementos flotantes o burbujas. Presiona para abrir la burbuja. Arrástrala para moverla."</string>
diff --git a/libs/WindowManager/Shell/res/values-es/strings.xml b/libs/WindowManager/Shell/res/values-es/strings.xml
index 9718bf19fcc3..6df154d9233d 100644
--- a/libs/WindowManager/Shell/res/values-es/strings.xml
+++ b/libs/WindowManager/Shell/res/values-es/strings.xml
@@ -73,8 +73,7 @@
     <string name="bubble_accessibility_announce_collapse" msgid="3178806224494537097">"contraer <xliff:g id="BUBBLE_TITLE">%1$s</xliff:g>"</string>
     <string name="bubbles_app_settings" msgid="3617224938701566416">"Ajustes de <xliff:g id="NOTIFICATION_TITLE">%1$s</xliff:g>"</string>
     <string name="bubble_dismiss_text" msgid="8816558050659478158">"Cerrar burbuja"</string>
-    <!-- no translation found for bubble_fullscreen_text (1006758103218086231) -->
-    <skip />
+    <string name="bubble_fullscreen_text" msgid="1006758103218086231">"Cambiar a pantalla completa"</string>
     <string name="bubbles_dont_bubble_conversation" msgid="310000317885712693">"No mostrar conversación en burbuja"</string>
     <string name="bubbles_user_education_title" msgid="2112319053732691899">"Chatea con burbujas"</string>
     <string name="bubbles_user_education_description" msgid="4215862563054175407">"Las conversaciones nuevas aparecen como iconos flotantes llamados \"burbujas\". Toca una burbuja para abrirla. Arrástrala para moverla."</string>
diff --git a/libs/WindowManager/Shell/res/values-fr/strings.xml b/libs/WindowManager/Shell/res/values-fr/strings.xml
index 63b5994cd707..92f579db10b5 100644
--- a/libs/WindowManager/Shell/res/values-fr/strings.xml
+++ b/libs/WindowManager/Shell/res/values-fr/strings.xml
@@ -73,8 +73,7 @@
     <string name="bubble_accessibility_announce_collapse" msgid="3178806224494537097">"Réduire <xliff:g id="BUBBLE_TITLE">%1$s</xliff:g>"</string>
     <string name="bubbles_app_settings" msgid="3617224938701566416">"Paramètres <xliff:g id="NOTIFICATION_TITLE">%1$s</xliff:g>"</string>
     <string name="bubble_dismiss_text" msgid="8816558050659478158">"Fermer la bulle"</string>
-    <!-- no translation found for bubble_fullscreen_text (1006758103218086231) -->
-    <skip />
+    <string name="bubble_fullscreen_text" msgid="1006758103218086231">"Passer en plein écran"</string>
     <string name="bubbles_dont_bubble_conversation" msgid="310000317885712693">"Ne pas afficher la conversation dans une bulle"</string>
     <string name="bubbles_user_education_title" msgid="2112319053732691899">"Chatter en utilisant des bulles"</string>
     <string name="bubbles_user_education_description" msgid="4215862563054175407">"Les nouvelles conversations s\'affichent sous forme d\'icônes flottantes ou de bulles. Appuyez sur la bulle pour l\'ouvrir. Faites-la glisser pour la déplacer."</string>
diff --git a/libs/WindowManager/Shell/res/values-it/strings.xml b/libs/WindowManager/Shell/res/values-it/strings.xml
index 3ba6873617f6..5f9c492bf055 100644
--- a/libs/WindowManager/Shell/res/values-it/strings.xml
+++ b/libs/WindowManager/Shell/res/values-it/strings.xml
@@ -73,8 +73,7 @@
     <string name="bubble_accessibility_announce_collapse" msgid="3178806224494537097">"comprimi <xliff:g id="BUBBLE_TITLE">%1$s</xliff:g>"</string>
     <string name="bubbles_app_settings" msgid="3617224938701566416">"Impostazioni <xliff:g id="NOTIFICATION_TITLE">%1$s</xliff:g>"</string>
     <string name="bubble_dismiss_text" msgid="8816558050659478158">"Ignora bolla"</string>
-    <!-- no translation found for bubble_fullscreen_text (1006758103218086231) -->
-    <skip />
+    <string name="bubble_fullscreen_text" msgid="1006758103218086231">"Passa a schermo intero"</string>
     <string name="bubbles_dont_bubble_conversation" msgid="310000317885712693">"Non mettere la conversazione nella bolla"</string>
     <string name="bubbles_user_education_title" msgid="2112319053732691899">"Chatta utilizzando le bolle"</string>
     <string name="bubbles_user_education_description" msgid="4215862563054175407">"Le nuove conversazioni vengono mostrate come icone mobili o bolle. Tocca per aprire la bolla. Trascinala per spostarla."</string>
diff --git a/libs/WindowManager/Shell/shared/src/com/android/wm/shell/shared/desktopmode/DesktopModeStatus.java b/libs/WindowManager/Shell/shared/src/com/android/wm/shell/shared/desktopmode/DesktopModeStatus.java
index 341ca0eb6bed..3f9711718a27 100644
--- a/libs/WindowManager/Shell/shared/src/com/android/wm/shell/shared/desktopmode/DesktopModeStatus.java
+++ b/libs/WindowManager/Shell/shared/src/com/android/wm/shell/shared/desktopmode/DesktopModeStatus.java
@@ -90,6 +90,9 @@ public class DesktopModeStatus {
     /** The maximum override density allowed for tasks inside the desktop. */
     private static final int DESKTOP_DENSITY_MAX = 1000;
 
+    /** The number of [WindowDecorViewHost] instances to warm up on system start. */
+    private static final int WINDOW_DECOR_PRE_WARM_SIZE = 2;
+
     /**
      * Sysprop declaring the maximum number of Tasks to show in Desktop Mode at any one time.
      *
@@ -102,6 +105,14 @@ public class DesktopModeStatus {
     private static final String MAX_TASK_LIMIT_SYS_PROP = "persist.wm.debug.desktop_max_task_limit";
 
     /**
+     * Sysprop declaring the number of [WindowDecorViewHost] instances to warm up on system start.
+     *
+     * <p>If it is not defined, then [WINDOW_DECOR_PRE_WARM_SIZE] is used.
+     */
+    private static final String WINDOW_DECOR_PRE_WARM_SIZE_SYS_PROP =
+            "persist.wm.debug.desktop_window_decor_pre_warm_size";
+
+    /**
      * Return {@code true} if veiled resizing is active. If false, fluid resizing is used.
      */
     public static boolean isVeiledResizeEnabled() {
@@ -141,6 +152,12 @@ public class DesktopModeStatus {
                 context.getResources().getInteger(R.integer.config_maxDesktopWindowingActiveTasks));
     }
 
+    /** The number of [WindowDecorViewHost] instances to warm up on system start. */
+    public static int getWindowDecorPreWarmSize() {
+        return SystemProperties.getInt(WINDOW_DECOR_PRE_WARM_SIZE_SYS_PROP,
+                WINDOW_DECOR_PRE_WARM_SIZE);
+    }
+
     /**
      * Return {@code true} if the current device supports desktop mode.
      */
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/back/TEST_MAPPING b/libs/WindowManager/Shell/src/com/android/wm/shell/back/TEST_MAPPING
index f02559f36169..df3a369febbc 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/back/TEST_MAPPING
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/back/TEST_MAPPING
@@ -1,32 +1,10 @@
 {
   "presubmit": [
     {
-      "name": "WMShellUnitTests",
-      "options": [
-        {
-          "exclude-annotation": "androidx.test.filters.FlakyTest"
-        },
-        {
-          "include-filter": "com.android.wm.shell.back"
-        }
-      ]
+      "name": "WMShellUnitTests_shell_back"
     },
     {
-      "name": "CtsWindowManagerDeviceBackNavigation",
-      "options": [
-        {
-          "exclude-annotation": "androidx.test.filters.FlakyTest"
-        },
-        {
-          "include-filter": "android.server.wm.backnavigation.BackGestureInvokedTest"
-        },
-        {
-          "include-filter": "android.server.wm.backnavigation.BackNavigationTests"
-        },
-        {
-          "include-filter": "android.server.wm.backnavigation.OnBackInvokedCallbackGestureTest"
-        }
-      ]
+      "name": "CtsWindowManagerDeviceBackNavigation_com_android_wm_shell_back"
     }
   ]
 }
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/common/DisplayImeController.java b/libs/WindowManager/Shell/src/com/android/wm/shell/common/DisplayImeController.java
index f03daada4ca0..c4082d9f649c 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/common/DisplayImeController.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/common/DisplayImeController.java
@@ -303,21 +303,29 @@ public class DisplayImeController implements DisplayController.OnDisplaysChanged
                             lastSurfacePosition);
                 } else {
                     if (!haveSameLeash(mImeSourceControl, imeSourceControl)) {
-                        applyVisibilityToLeash(imeSourceControl);
-
                         if (android.view.inputmethod.Flags.refactorInsetsController()) {
                             pendingImeStartAnimation = true;
+                            // The starting point for the IME should be it's previous state
+                            // (whether it is initiallyVisible or not)
+                            updateImeVisibility(imeSourceControl.isInitiallyVisible());
                         }
+                        applyVisibilityToLeash(imeSourceControl);
                     }
                     if (!mImeShowing) {
                         removeImeSurface(mDisplayId);
                     }
                 }
-            } else if (!android.view.inputmethod.Flags.refactorInsetsController()
-                    && mAnimation != null) {
-                // we don"t want to cancel the hide animation, when the control is lost, but
-                // continue the bar to slide to the end (even without visible IME)
-                mAnimation.cancel();
+            } else {
+                if (!android.view.inputmethod.Flags.refactorInsetsController()
+                        && mAnimation != null) {
+                    // we don't want to cancel the hide animation, when the control is lost, but
+                    // continue the bar to slide to the end (even without visible IME)
+                    mAnimation.cancel();
+                } else if (android.view.inputmethod.Flags.refactorInsetsController() && mImeShowing
+                        && mAnimation == null) {
+                    // There is no leash, so the IME cannot be in a showing state
+                    updateImeVisibility(false);
+                }
             }
 
             // Make mImeSourceControl point to the new control before starting the animation.
@@ -341,7 +349,7 @@ public class DisplayImeController implements DisplayController.OnDisplaysChanged
 
             if (android.view.inputmethod.Flags.refactorInsetsController()) {
                 if (pendingImeStartAnimation) {
-                    startAnimation(true, true /* forceRestart */);
+                    startAnimation(mImeRequestedVisible, true /* forceRestart */);
                 }
             }
         }
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellModule.java b/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellModule.java
index 8c7dcf295319..b151c8b7e718 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellModule.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/dagger/WMShellModule.java
@@ -116,6 +116,8 @@ import com.android.wm.shell.windowdecor.CaptionWindowDecorViewModel;
 import com.android.wm.shell.windowdecor.DesktopModeWindowDecorViewModel;
 import com.android.wm.shell.windowdecor.WindowDecorViewModel;
 import com.android.wm.shell.windowdecor.viewhost.DefaultWindowDecorViewHostSupplier;
+import com.android.wm.shell.windowdecor.viewhost.PooledWindowDecorViewHostSupplier;
+import com.android.wm.shell.windowdecor.viewhost.ReusableWindowDecorViewHost;
 import com.android.wm.shell.windowdecor.viewhost.WindowDecorViewHostSupplier;
 
 import dagger.Binds;
@@ -380,8 +382,19 @@ public abstract class WMShellModule {
     @WMSingleton
     @Provides
     static WindowDecorViewHostSupplier provideWindowDecorViewHostSupplier(
-            @ShellMainThread @NonNull CoroutineScope mainScope) {
-        return new DefaultWindowDecorViewHostSupplier(mainScope);
+            @NonNull Context context,
+            @ShellMainThread @NonNull CoroutineScope mainScope,
+            @NonNull ShellInit shellInit) {
+        if (DesktopModeStatus.canEnterDesktopMode(context)
+                && Flags.enableDesktopWindowingScvhCache()) {
+            final int maxPoolSize = DesktopModeStatus.getMaxTaskLimit(context);
+            final int preWarmSize = DesktopModeStatus.getWindowDecorPreWarmSize();
+            return new PooledWindowDecorViewHostSupplier(
+                    context, mainScope, shellInit,
+                    ReusableWindowDecorViewHost.DefaultFactory.INSTANCE, maxPoolSize, preWarmSize);
+        } else {
+            return new DefaultWindowDecorViewHostSupplier(mainScope);
+        }
     }
 
     //
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/DefaultTransitionHandler.java b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/DefaultTransitionHandler.java
index f40e0bac1b4e..1573291aef63 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/DefaultTransitionHandler.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/DefaultTransitionHandler.java
@@ -358,9 +358,12 @@ public class DefaultTransitionHandler implements Transitions.TransitionHandler {
 
             if (mode == TRANSIT_CHANGE && change.hasFlags(FLAG_IS_DISPLAY)) {
                 if (info.getType() == TRANSIT_CHANGE) {
-                    final int anim = getRotationAnimationHint(change, info, mDisplayController);
+                    int anim = getRotationAnimationHint(change, info, mDisplayController);
                     isSeamlessDisplayChange = anim == ROTATION_ANIMATION_SEAMLESS;
                     if (!(isSeamlessDisplayChange || anim == ROTATION_ANIMATION_JUMPCUT)) {
+                        if (wallpaperTransit != WALLPAPER_TRANSITION_NONE) {
+                            anim |= ScreenRotationAnimation.ANIMATION_HINT_HAS_WALLPAPER;
+                        }
                         startRotationAnimation(startTransaction, change, info, anim, animations,
                                 onAnimFinish);
                         isDisplayRotationAnimationStarted = true;
@@ -826,24 +829,26 @@ public class DefaultTransitionHandler implements Transitions.TransitionHandler {
             @NonNull Runnable finishCallback, @NonNull TransactionPool pool,
             @NonNull ShellExecutor mainExecutor, @Nullable Point position, float cornerRadius,
             @Nullable Rect clipRect, boolean isActivity) {
+        final DefaultAnimationAdapter adapter = new DefaultAnimationAdapter(anim, leash,
+                position, clipRect, cornerRadius, isActivity);
+        buildSurfaceAnimation(animations, anim, finishCallback, pool, mainExecutor, adapter);
+    }
+
+    /** Builds an animator for the surface and adds it to the `animations` list. */
+    static void buildSurfaceAnimation(@NonNull ArrayList<Animator> animations,
+            @NonNull Animation anim, @NonNull Runnable finishCallback,
+            @NonNull TransactionPool pool, @NonNull ShellExecutor mainExecutor,
+            @NonNull AnimationAdapter updateListener) {
         final SurfaceControl.Transaction transaction = pool.acquire();
+        updateListener.setTransaction(transaction);
         final ValueAnimator va = ValueAnimator.ofFloat(0f, 1f);
-        final Transformation transformation = new Transformation();
-        final float[] matrix = new float[9];
         // Animation length is already expected to be scaled.
         va.overrideDurationScale(1.0f);
         va.setDuration(anim.computeDurationHint());
-        final ValueAnimator.AnimatorUpdateListener updateListener = animation -> {
-            final long currentPlayTime = Math.min(va.getDuration(), va.getCurrentPlayTime());
-
-            applyTransformation(currentPlayTime, transaction, leash, anim, transformation, matrix,
-                    position, cornerRadius, clipRect, isActivity);
-        };
         va.addUpdateListener(updateListener);
 
         final Runnable finisher = () -> {
-            applyTransformation(va.getDuration(), transaction, leash, anim, transformation, matrix,
-                    position, cornerRadius, clipRect, isActivity);
+            updateListener.onAnimationUpdate(va);
 
             pool.release(transaction);
             mainExecutor.execute(() -> {
@@ -1007,37 +1012,88 @@ public class DefaultTransitionHandler implements Transitions.TransitionHandler {
                 || animType == ANIM_FROM_STYLE;
     }
 
-    private static void applyTransformation(long time, SurfaceControl.Transaction t,
-            SurfaceControl leash, Animation anim, Transformation tmpTransformation, float[] matrix,
-            Point position, float cornerRadius, @Nullable Rect immutableClipRect,
-            boolean isActivity) {
-        tmpTransformation.clear();
-        anim.getTransformation(time, tmpTransformation);
-        if (com.android.graphics.libgui.flags.Flags.edgeExtensionShader()
-                && anim.getExtensionEdges() != 0x0 && isActivity) {
-            t.setEdgeExtensionEffect(leash, anim.getExtensionEdges());
+    /** The animation adapter for buildSurfaceAnimation. */
+    abstract static class AnimationAdapter implements ValueAnimator.AnimatorUpdateListener {
+        @NonNull final SurfaceControl mLeash;
+        @NonNull SurfaceControl.Transaction mTransaction;
+        private Choreographer mChoreographer;
+
+        AnimationAdapter(@NonNull SurfaceControl leash) {
+            mLeash = leash;
         }
-        if (position != null) {
-            tmpTransformation.getMatrix().postTranslate(position.x, position.y);
+
+        void setTransaction(@NonNull SurfaceControl.Transaction transaction) {
+            mTransaction = transaction;
         }
-        t.setMatrix(leash, tmpTransformation.getMatrix(), matrix);
-        t.setAlpha(leash, tmpTransformation.getAlpha());
-
-        final Rect clipRect = immutableClipRect == null ? null : new Rect(immutableClipRect);
-        Insets extensionInsets = Insets.min(tmpTransformation.getInsets(), Insets.NONE);
-        if (!extensionInsets.equals(Insets.NONE) && clipRect != null && !clipRect.isEmpty()) {
-            // Clip out any overflowing edge extension
-            clipRect.inset(extensionInsets);
-            t.setCrop(leash, clipRect);
+
+        @Override
+        public void onAnimationUpdate(@NonNull ValueAnimator animator) {
+            applyTransformation(animator);
+            if (mChoreographer == null) {
+                mChoreographer = Choreographer.getInstance();
+            }
+            mTransaction.setFrameTimelineVsync(mChoreographer.getVsyncId());
+            mTransaction.apply();
         }
 
-        if (anim.hasRoundedCorners() && cornerRadius > 0 && clipRect != null) {
-            // We can only apply rounded corner if a crop is set
-            t.setCrop(leash, clipRect);
-            t.setCornerRadius(leash, cornerRadius);
+        abstract void applyTransformation(@NonNull ValueAnimator animator);
+    }
+
+    private static class DefaultAnimationAdapter extends AnimationAdapter {
+        final Transformation mTransformation = new Transformation();
+        final float[] mMatrix = new float[9];
+        @NonNull final Animation mAnim;
+        @Nullable final Point mPosition;
+        @Nullable final Rect mClipRect;
+        final float mCornerRadius;
+        final boolean mIsActivity;
+
+        DefaultAnimationAdapter(@NonNull Animation anim, @NonNull SurfaceControl leash,
+                @Nullable Point position, @Nullable Rect clipRect, float cornerRadius,
+                boolean isActivity) {
+            super(leash);
+            mAnim = anim;
+            mPosition = (position != null && (position.x != 0 || position.y != 0))
+                    ? position : null;
+            mClipRect = (clipRect != null && !clipRect.isEmpty()) ? clipRect : null;
+            mCornerRadius = cornerRadius;
+            mIsActivity = isActivity;
         }
 
-        t.setFrameTimelineVsync(Choreographer.getInstance().getVsyncId());
-        t.apply();
+        @Override
+        void applyTransformation(@NonNull ValueAnimator animator) {
+            final long currentPlayTime = Math.min(animator.getDuration(),
+                    animator.getCurrentPlayTime());
+            final Transformation transformation = mTransformation;
+            final SurfaceControl.Transaction t = mTransaction;
+            final SurfaceControl leash = mLeash;
+            transformation.clear();
+            mAnim.getTransformation(currentPlayTime, transformation);
+            if (com.android.graphics.libgui.flags.Flags.edgeExtensionShader()
+                    && mIsActivity && mAnim.getExtensionEdges() != 0) {
+                t.setEdgeExtensionEffect(leash, mAnim.getExtensionEdges());
+            }
+            if (mPosition != null) {
+                transformation.getMatrix().postTranslate(mPosition.x, mPosition.y);
+            }
+            t.setMatrix(leash, transformation.getMatrix(), mMatrix);
+            t.setAlpha(leash, transformation.getAlpha());
+
+            if (mClipRect != null) {
+                Rect clipRect = mClipRect;
+                final Insets extensionInsets = Insets.min(transformation.getInsets(), Insets.NONE);
+                if (!extensionInsets.equals(Insets.NONE)) {
+                    // Clip out any overflowing edge extension.
+                    clipRect = new Rect(mClipRect);
+                    clipRect.inset(extensionInsets);
+                    t.setCrop(leash, clipRect);
+                }
+                if (mCornerRadius > 0 && mAnim.hasRoundedCorners()) {
+                    // Rounded corner can only be applied if a crop is set.
+                    t.setCrop(leash, clipRect);
+                    t.setCornerRadius(leash, mCornerRadius);
+                }
+            }
+        }
     }
 }
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/ScreenRotationAnimation.java b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/ScreenRotationAnimation.java
index 5802e2ca8133..b9d11a3d0c06 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/transition/ScreenRotationAnimation.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/transition/ScreenRotationAnimation.java
@@ -25,12 +25,9 @@ import static com.android.wm.shell.transition.DefaultTransitionHandler.buildSurf
 import static com.android.wm.shell.transition.Transitions.TAG;
 
 import android.animation.Animator;
-import android.animation.AnimatorListenerAdapter;
-import android.animation.ArgbEvaluator;
 import android.animation.ValueAnimator;
 import android.annotation.NonNull;
 import android.content.Context;
-import android.graphics.Color;
 import android.graphics.Matrix;
 import android.graphics.Rect;
 import android.hardware.HardwareBuffer;
@@ -38,6 +35,7 @@ import android.util.Slog;
 import android.view.Surface;
 import android.view.SurfaceControl;
 import android.view.SurfaceControl.Transaction;
+import android.view.animation.AccelerateInterpolator;
 import android.view.animation.Animation;
 import android.view.animation.AnimationUtils;
 import android.window.ScreenCapture;
@@ -74,6 +72,9 @@ import java.util.ArrayList;
  */
 class ScreenRotationAnimation {
     static final int MAX_ANIMATION_DURATION = 10 * 1000;
+    static final int ANIMATION_HINT_HAS_WALLPAPER = 1 << 8;
+    /** It must cover all WindowManager#ROTATION_ANIMATION_*. */
+    private static final int ANIMATION_TYPE_MASK = 0xff;
 
     private final Context mContext;
     private final TransactionPool mTransactionPool;
@@ -81,7 +82,7 @@ class ScreenRotationAnimation {
     /** The leash of the changing window container. */
     private final SurfaceControl mSurfaceControl;
 
-    private final int mAnimHint;
+    private final int mAnimType;
     private final int mStartWidth;
     private final int mStartHeight;
     private final int mEndWidth;
@@ -98,6 +99,12 @@ class ScreenRotationAnimation {
     private SurfaceControl mBackColorSurface;
     /** The leash using to animate screenshot layer. */
     private final SurfaceControl mAnimLeash;
+    /**
+     * The container with background color for {@link #mSurfaceControl}. It is only created if
+     * {@link #mSurfaceControl} may be translucent. E.g. visible wallpaper with alpha < 1 (dimmed).
+     * That prevents flickering of alpha blending.
+     */
+    private SurfaceControl mBackEffectSurface;
 
     // The current active animation to move from the old to the new rotated
     // state.  Which animation is run here will depend on the old and new
@@ -115,7 +122,7 @@ class ScreenRotationAnimation {
             Transaction t, TransitionInfo.Change change, SurfaceControl rootLeash, int animHint) {
         mContext = context;
         mTransactionPool = pool;
-        mAnimHint = animHint;
+        mAnimType = animHint & ANIMATION_TYPE_MASK;
 
         mSurfaceControl = change.getLeash();
         mStartWidth = change.getStartAbsBounds().width();
@@ -170,11 +177,20 @@ class ScreenRotationAnimation {
                 }
                 hardwareBuffer.close();
             }
+            if ((animHint & ANIMATION_HINT_HAS_WALLPAPER) != 0) {
+                mBackEffectSurface = new SurfaceControl.Builder()
+                        .setCallsite("ShellRotationAnimation").setParent(rootLeash)
+                        .setEffectLayer().setOpaque(true).setName("BackEffect").build();
+                t.reparent(mSurfaceControl, mBackEffectSurface)
+                        .setColor(mBackEffectSurface,
+                                new float[] {mStartLuma, mStartLuma, mStartLuma})
+                        .show(mBackEffectSurface);
+            }
 
             t.setLayer(mAnimLeash, SCREEN_FREEZE_LAYER_BASE);
             t.show(mAnimLeash);
             // Crop the real content in case it contains a larger child layer, e.g. wallpaper.
-            t.setCrop(mSurfaceControl, new Rect(0, 0, mEndWidth, mEndHeight));
+            t.setCrop(getEnterSurface(), new Rect(0, 0, mEndWidth, mEndHeight));
 
             if (!isCustomRotate()) {
                 mBackColorSurface = new SurfaceControl.Builder()
@@ -199,7 +215,12 @@ class ScreenRotationAnimation {
     }
 
     private boolean isCustomRotate() {
-        return mAnimHint == ROTATION_ANIMATION_CROSSFADE || mAnimHint == ROTATION_ANIMATION_JUMPCUT;
+        return mAnimType == ROTATION_ANIMATION_CROSSFADE || mAnimType == ROTATION_ANIMATION_JUMPCUT;
+    }
+
+    /** Returns the surface which contains the real content to animate enter. */
+    private SurfaceControl getEnterSurface() {
+        return mBackEffectSurface != null ? mBackEffectSurface : mSurfaceControl;
     }
 
     private void setScreenshotTransform(SurfaceControl.Transaction t) {
@@ -260,7 +281,7 @@ class ScreenRotationAnimation {
         final boolean customRotate = isCustomRotate();
         if (customRotate) {
             mRotateExitAnimation = AnimationUtils.loadAnimation(mContext,
-                    mAnimHint == ROTATION_ANIMATION_JUMPCUT ? R.anim.rotation_animation_jump_exit
+                    mAnimType == ROTATION_ANIMATION_JUMPCUT ? R.anim.rotation_animation_jump_exit
                             : R.anim.rotation_animation_xfade_exit);
             mRotateEnterAnimation = AnimationUtils.loadAnimation(mContext,
                     R.anim.rotation_animation_enter);
@@ -314,7 +335,11 @@ class ScreenRotationAnimation {
         } else {
             startDisplayRotation(animations, finishCallback, mainExecutor);
             startScreenshotRotationAnimation(animations, finishCallback, mainExecutor);
-            //startColorAnimation(mTransaction, animationScale);
+            if (mBackEffectSurface != null && mStartLuma > 0.1f) {
+                // Animate from the color of background to black for smooth alpha blending.
+                buildLumaAnimation(animations, mStartLuma, 0f /* endLuma */, mBackEffectSurface,
+                        animationScale, finishCallback, mainExecutor);
+            }
         }
 
         return true;
@@ -322,7 +347,7 @@ class ScreenRotationAnimation {
 
     private void startDisplayRotation(@NonNull ArrayList<Animator> animations,
             @NonNull Runnable finishCallback, @NonNull ShellExecutor mainExecutor) {
-        buildSurfaceAnimation(animations, mRotateEnterAnimation, mSurfaceControl, finishCallback,
+        buildSurfaceAnimation(animations, mRotateEnterAnimation, getEnterSurface(), finishCallback,
                 mTransactionPool, mainExecutor, null /* position */, 0 /* cornerRadius */,
                 null /* clipRect */, false /* isActivity */);
     }
@@ -341,40 +366,17 @@ class ScreenRotationAnimation {
                 null /* clipRect */, false /* isActivity */);
     }
 
-    private void startColorAnimation(float animationScale, @NonNull ShellExecutor animExecutor) {
-        int colorTransitionMs = mContext.getResources().getInteger(
-                R.integer.config_screen_rotation_color_transition);
-        final float[] rgbTmpFloat = new float[3];
-        final int startColor = Color.rgb(mStartLuma, mStartLuma, mStartLuma);
-        final int endColor = Color.rgb(mEndLuma, mEndLuma, mEndLuma);
-        final long duration = colorTransitionMs * (long) animationScale;
-        final Transaction t = mTransactionPool.acquire();
-
-        final ValueAnimator va = ValueAnimator.ofFloat(0f, 1f);
-        // Animation length is already expected to be scaled.
-        va.overrideDurationScale(1.0f);
-        va.setDuration(duration);
-        va.addUpdateListener(animation -> {
-            final long currentPlayTime = Math.min(va.getDuration(), va.getCurrentPlayTime());
-            final float fraction = currentPlayTime / va.getDuration();
-            applyColor(startColor, endColor, rgbTmpFloat, fraction, mBackColorSurface, t);
-        });
-        va.addListener(new AnimatorListenerAdapter() {
-            @Override
-            public void onAnimationCancel(Animator animation) {
-                applyColor(startColor, endColor, rgbTmpFloat, 1f /* fraction */, mBackColorSurface,
-                        t);
-                mTransactionPool.release(t);
-            }
-
-            @Override
-            public void onAnimationEnd(Animator animation) {
-                applyColor(startColor, endColor, rgbTmpFloat, 1f /* fraction */, mBackColorSurface,
-                        t);
-                mTransactionPool.release(t);
-            }
-        });
-        animExecutor.execute(va::start);
+    private void buildLumaAnimation(@NonNull ArrayList<Animator> animations,
+            float startLuma, float endLuma, SurfaceControl surface, float animationScale,
+            @NonNull Runnable finishCallback, @NonNull ShellExecutor mainExecutor) {
+        final long durationMillis = (long) (mContext.getResources().getInteger(
+                R.integer.config_screen_rotation_color_transition) * animationScale);
+        final LumaAnimation animation = new LumaAnimation(durationMillis);
+        // Align the end with the enter animation.
+        animation.setStartOffset(mRotateEnterAnimation.getDuration() - durationMillis);
+        final LumaAnimationAdapter adapter = new LumaAnimationAdapter(surface, startLuma, endLuma);
+        buildSurfaceAnimation(animations, animation, finishCallback, mTransactionPool,
+                mainExecutor, adapter);
     }
 
     public void kill() {
@@ -389,21 +391,47 @@ class ScreenRotationAnimation {
         if (mBackColorSurface != null && mBackColorSurface.isValid()) {
             t.remove(mBackColorSurface);
         }
+        if (mBackEffectSurface != null && mBackEffectSurface.isValid()) {
+            t.remove(mBackEffectSurface);
+        }
         t.apply();
         mTransactionPool.release(t);
     }
 
-    private static void applyColor(int startColor, int endColor, float[] rgbFloat,
-            float fraction, SurfaceControl surface, SurfaceControl.Transaction t) {
-        final int color = (Integer) ArgbEvaluator.getInstance().evaluate(fraction, startColor,
-                endColor);
-        Color middleColor = Color.valueOf(color);
-        rgbFloat[0] = middleColor.red();
-        rgbFloat[1] = middleColor.green();
-        rgbFloat[2] = middleColor.blue();
-        if (surface.isValid()) {
-            t.setColor(surface, rgbFloat);
+    /** A no-op wrapper to provide animation duration. */
+    private static class LumaAnimation extends Animation {
+        LumaAnimation(long durationMillis) {
+            setDuration(durationMillis);
+        }
+    }
+
+    private static class LumaAnimationAdapter extends DefaultTransitionHandler.AnimationAdapter {
+        final float[] mColorArray = new float[3];
+        final float mStartLuma;
+        final float mEndLuma;
+        final AccelerateInterpolator mInterpolation;
+
+        LumaAnimationAdapter(@NonNull SurfaceControl leash, float startLuma, float endLuma) {
+            super(leash);
+            mStartLuma = startLuma;
+            mEndLuma = endLuma;
+            // Make the initial progress color lighter if the background is light. That avoids
+            // darker content when fading into the entering surface.
+            final float factor = Math.min(3f, (Math.max(0.5f, mStartLuma) - 0.5f) * 10);
+            Slog.d(TAG, "Luma=" + mStartLuma + " factor=" + factor);
+            mInterpolation = factor > 0.5f ? new AccelerateInterpolator(factor) : null;
+        }
+
+        @Override
+        void applyTransformation(ValueAnimator animator) {
+            final float fraction = mInterpolation != null
+                    ? mInterpolation.getInterpolation(animator.getAnimatedFraction())
+                    : animator.getAnimatedFraction();
+            final float luma = mStartLuma + fraction * (mEndLuma - mStartLuma);
+            mColorArray[0] = luma;
+            mColorArray[1] = luma;
+            mColorArray[2] = luma;
+            mTransaction.setColor(mLeash, mColorArray);
         }
-        t.apply();
     }
 }
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/CaptionWindowDecoration.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/CaptionWindowDecoration.java
index 46fe68f44bed..0caa8e93d4eb 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/CaptionWindowDecoration.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/CaptionWindowDecoration.java
@@ -55,6 +55,7 @@ import com.android.wm.shell.common.DisplayLayout;
 import com.android.wm.shell.common.ShellExecutor;
 import com.android.wm.shell.common.SyncTransactionQueue;
 import com.android.wm.shell.shared.annotations.ShellBackgroundThread;
+import com.android.wm.shell.shared.desktopmode.DesktopModeFlags;
 import com.android.wm.shell.windowdecor.extension.TaskInfoKt;
 import com.android.wm.shell.windowdecor.viewhost.WindowDecorViewHostSupplier;
 
@@ -240,7 +241,8 @@ public class CaptionWindowDecoration extends WindowDecoration<WindowDecorLinearL
             boolean applyStartTransactionOnDraw, boolean setTaskCropAndPosition) {
         final boolean isFreeform =
                 taskInfo.getWindowingMode() == WindowConfiguration.WINDOWING_MODE_FREEFORM;
-        final boolean isDragResizeable = isFreeform && taskInfo.isResizeable;
+        final boolean isDragResizeable = DesktopModeFlags.SCALED_RESIZING.isEnabled(mContext)
+                ? isFreeform : isFreeform && taskInfo.isResizeable;
 
         final WindowDecorLinearLayout oldRootView = mResult.mRootView;
         final SurfaceControl oldDecorationSurface = mDecorationContainerSurface;
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
index 2519ce4e6571..b14283f878a3 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModel.java
@@ -413,7 +413,7 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
         final RunningTaskInfo oldTaskInfo = decoration.mTaskInfo;
 
         if (taskInfo.displayId != oldTaskInfo.displayId
-                && !Flags.enableAdditionalWindowsAboveStatusBar()) {
+                && !Flags.enableHandleInputFix()) {
             removeTaskFromEventReceiver(oldTaskInfo.displayId);
             incrementEventReceiverTasks(taskInfo.displayId);
         }
@@ -480,7 +480,7 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
         decoration.close();
         final int displayId = taskInfo.displayId;
         if (mEventReceiversByDisplay.contains(displayId)
-                && !Flags.enableAdditionalWindowsAboveStatusBar()) {
+                && !Flags.enableHandleInputFix()) {
             removeTaskFromEventReceiver(displayId);
         }
         // Remove the decoration from the cache last because WindowDecoration#close could still
@@ -1096,7 +1096,7 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
         relevantDecor.updateHoverAndPressStatus(ev);
         final int action = ev.getActionMasked();
         if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) {
-            if (!mTransitionDragActive && !Flags.enableAdditionalWindowsAboveStatusBar()) {
+            if (!mTransitionDragActive && !Flags.enableHandleInputFix()) {
                 relevantDecor.closeHandleMenuIfNeeded(ev);
             }
         }
@@ -1139,7 +1139,7 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
                 }
                 final boolean shouldStartTransitionDrag =
                         relevantDecor.checkTouchEventInFocusedCaptionHandle(ev)
-                                || Flags.enableAdditionalWindowsAboveStatusBar();
+                                || Flags.enableHandleInputFix();
                 if (dragFromStatusBarAllowed && shouldStartTransitionDrag) {
                     mTransitionDragActive = true;
                 }
@@ -1424,7 +1424,7 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
         windowDecoration.setDragDetector(touchEventListener.mDragDetector);
         windowDecoration.relayout(taskInfo, startT, finishT,
                 false /* applyStartTransactionOnDraw */, false /* shouldSetTaskPositionAndCrop */);
-        if (!Flags.enableAdditionalWindowsAboveStatusBar()) {
+        if (!Flags.enableHandleInputFix()) {
             incrementEventReceiverTasks(taskInfo.displayId);
         }
     }
@@ -1580,7 +1580,7 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
                         && Flags.enableDesktopWindowingImmersiveHandleHiding()) {
                     decor.onInsetsStateChanged(insetsState);
                 }
-                if (!Flags.enableAdditionalWindowsAboveStatusBar()) {
+                if (!Flags.enableHandleInputFix()) {
                     // If status bar inset is visible, top task is not in immersive mode.
                     // This value is only needed when the App Handle input is being handled
                     // through the global input monitor (hence the flag check) to ignore gestures
@@ -1603,14 +1603,27 @@ public class DesktopModeWindowDecorViewModel implements WindowDecorViewModel {
                 Transitions transitions,
                 InteractionJankMonitor interactionJankMonitor,
                 Supplier<SurfaceControl.Transaction> transactionFactory) {
-            if (!DesktopModeStatus.isVeiledResizeEnabled()) {
-                return new FluidResizeTaskPositioner(
-                        taskOrganizer, transitions, windowDecoration, displayController,
-                        dragStartListener, transactionFactory);
+            final TaskPositioner taskPositioner = DesktopModeStatus.isVeiledResizeEnabled()
+                    ? new VeiledResizeTaskPositioner(
+                            taskOrganizer,
+                            windowDecoration,
+                            displayController,
+                            dragStartListener,
+                            transitions,
+                            interactionJankMonitor)
+                    : new FluidResizeTaskPositioner(
+                            taskOrganizer,
+                            transitions,
+                            windowDecoration,
+                            displayController,
+                            dragStartListener,
+                            transactionFactory);
+
+            if (DesktopModeFlags.SCALED_RESIZING.isEnabled(windowDecoration.mContext)) {
+                return new FixedAspectRatioTaskPositionerDecorator(windowDecoration,
+                        taskPositioner);
             }
-            return new VeiledResizeTaskPositioner(
-                    taskOrganizer, windowDecoration, displayController,
-                    dragStartListener, transitions, interactionJankMonitor);
+            return taskPositioner;
         }
     }
 }
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java
index 5d16d972a0f2..55da78e74ba2 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java
@@ -455,7 +455,7 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
     }
 
     private void updateDragResizeListener(SurfaceControl oldDecorationSurface) {
-        if (!isDragResizable(mTaskInfo)) {
+        if (!isDragResizable(mTaskInfo, mContext)) {
             if (!mTaskInfo.positionInParent.equals(mPositionInParent)) {
                 // We still want to track caption bar's exclusion region on a non-resizeable task.
                 updateExclusionRegion();
@@ -497,12 +497,16 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
         }
     }
 
-    private static boolean isDragResizable(ActivityManager.RunningTaskInfo taskInfo) {
+    private static boolean isDragResizable(ActivityManager.RunningTaskInfo taskInfo,
+            Context context) {
+        if (DesktopModeFlags.SCALED_RESIZING.isEnabled(context)) {
+            return taskInfo.isFreeform();
+        }
         return taskInfo.isFreeform() && taskInfo.isResizeable;
     }
 
     private void updateMaximizeMenu(SurfaceControl.Transaction startT) {
-        if (!isDragResizable(mTaskInfo) || !isMaximizeMenuActive()) {
+        if (!isDragResizable(mTaskInfo, mContext) || !isMaximizeMenuActive()) {
             return;
         }
         if (!mTaskInfo.isVisible()) {
@@ -532,7 +536,7 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
      */
     void disposeStatusBarInputLayer() {
         if (!isAppHandle(mWindowDecorViewHolder)
-                || !Flags.enableAdditionalWindowsAboveStatusBar()) {
+                || !Flags.enableHandleInputFix()) {
             return;
         }
         ((AppHandleViewHolder) mWindowDecorViewHolder).disposeStatusBarInputLayer();
@@ -628,7 +632,7 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
             }
             controlsElement.mAlignment = RelayoutParams.OccludingCaptionElement.Alignment.END;
             relayoutParams.mOccludingCaptionElements.add(controlsElement);
-        } else if (isAppHandle && !Flags.enableAdditionalWindowsAboveStatusBar()) {
+        } else if (isAppHandle && !Flags.enableHandleInputFix()) {
             // The focused decor (fullscreen/split) does not need to handle input because input in
             // the App Handle is handled by the InputMonitor in DesktopModeWindowDecorViewModel.
             // Note: This does not apply with the above flag enabled as the status bar input layer
@@ -1153,13 +1157,13 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
      */
     boolean checkTouchEventInFocusedCaptionHandle(MotionEvent ev) {
         if (isHandleMenuActive() || !isAppHandle(mWindowDecorViewHolder)
-                || Flags.enableAdditionalWindowsAboveStatusBar()) {
+                || Flags.enableHandleInputFix()) {
             return false;
         }
         // The status bar input layer can only receive input in handle coordinates to begin with,
         // so checking coordinates is unnecessary as input is always within handle bounds.
         if (isAppHandle(mWindowDecorViewHolder)
-                && Flags.enableAdditionalWindowsAboveStatusBar()
+                && Flags.enableHandleInputFix()
                 && isCaptionVisible()) {
             return true;
         }
@@ -1196,7 +1200,7 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
      * @param ev the MotionEvent to compare
      */
     void checkTouchEvent(MotionEvent ev) {
-        if (mResult.mRootView == null || Flags.enableAdditionalWindowsAboveStatusBar()) return;
+        if (mResult.mRootView == null || Flags.enableHandleInputFix()) return;
         final View caption = mResult.mRootView.findViewById(R.id.desktop_mode_caption);
         final View handle = caption.findViewById(R.id.caption_handle);
         final boolean inHandle = !isHandleMenuActive()
@@ -1209,7 +1213,7 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
             // If the whole handle menu can be touched directly, rely on FLAG_WATCH_OUTSIDE_TOUCH.
             // This is for the case that some of the handle menu is underneath the status bar.
             if (isAppHandle(mWindowDecorViewHolder)
-                    && !Flags.enableAdditionalWindowsAboveStatusBar()) {
+                    && !Flags.enableHandleInputFix()) {
                 mHandleMenu.checkMotionEvent(ev);
                 closeHandleMenuIfNeeded(ev);
             }
@@ -1223,7 +1227,7 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
      * @param ev the MotionEvent to compare against.
      */
     void updateHoverAndPressStatus(MotionEvent ev) {
-        if (mResult.mRootView == null || Flags.enableAdditionalWindowsAboveStatusBar()) return;
+        if (mResult.mRootView == null || Flags.enableHandleInputFix()) return;
         final View handle = mResult.mRootView.findViewById(R.id.caption_handle);
         final boolean inHandle = !isHandleMenuActive()
                 && checkTouchEventInFocusedCaptionHandle(ev);
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DragPositioningCallbackUtility.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DragPositioningCallbackUtility.java
index cb9781e86c87..cad34621c82a 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DragPositioningCallbackUtility.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DragPositioningCallbackUtility.java
@@ -84,22 +84,47 @@ public class DragPositioningCallbackUtility {
 
         repositionTaskBounds.set(taskBoundsAtDragStart);
 
+        boolean isAspectRatioMaintained = true;
         // Make sure the new resizing destination in any direction falls within the stable bounds.
         if ((ctrlType & CTRL_TYPE_LEFT) != 0) {
             repositionTaskBounds.left = Math.max(repositionTaskBounds.left + (int) delta.x,
                     stableBounds.left);
+            if (repositionTaskBounds.left == stableBounds.left
+                    && repositionTaskBounds.left + (int) delta.x != stableBounds.left) {
+                // If the task edge have been set to the stable bounds and not due to the users
+                // drag, the aspect ratio of the task will not be maintained.
+                isAspectRatioMaintained = false;
+            }
         }
         if ((ctrlType & CTRL_TYPE_RIGHT) != 0) {
             repositionTaskBounds.right = Math.min(repositionTaskBounds.right + (int) delta.x,
                     stableBounds.right);
+            if (repositionTaskBounds.right == stableBounds.right
+                    && repositionTaskBounds.right + (int) delta.x != stableBounds.right) {
+                // If the task edge have been set to the stable bounds and not due to the users
+                // drag, the aspect ratio of the task will not be maintained.
+                isAspectRatioMaintained = false;
+            }
         }
         if ((ctrlType & CTRL_TYPE_TOP) != 0) {
             repositionTaskBounds.top = Math.max(repositionTaskBounds.top + (int) delta.y,
                     stableBounds.top);
+            if (repositionTaskBounds.top == stableBounds.top
+                    && repositionTaskBounds.top + (int) delta.y != stableBounds.top) {
+                // If the task edge have been set to the stable bounds and not due to the users
+                // drag, the aspect ratio of the task will not be maintained.
+                isAspectRatioMaintained = false;
+            }
         }
         if ((ctrlType & CTRL_TYPE_BOTTOM) != 0) {
             repositionTaskBounds.bottom = Math.min(repositionTaskBounds.bottom + (int) delta.y,
                     stableBounds.bottom);
+            if (repositionTaskBounds.bottom == stableBounds.bottom
+                    && repositionTaskBounds.bottom + (int) delta.y != stableBounds.bottom) {
+                // If the task edge have been set to the stable bounds and not due to the users
+                // drag, the aspect ratio of the task will not be maintained.
+                isAspectRatioMaintained = false;
+            }
         }
 
         // If width or height are negative or exceeding the width or height constraints, revert the
@@ -108,11 +133,24 @@ public class DragPositioningCallbackUtility {
                 windowDecoration)) {
             repositionTaskBounds.right = oldRight;
             repositionTaskBounds.left = oldLeft;
+            isAspectRatioMaintained = false;
         }
         if (isExceedingHeightConstraint(repositionTaskBounds, stableBounds, displayController,
                 windowDecoration)) {
             repositionTaskBounds.top = oldTop;
             repositionTaskBounds.bottom = oldBottom;
+            isAspectRatioMaintained = false;
+        }
+
+        // If the application is unresizeable and any bounds have been set back to their old
+        // location or to a stable bound edge, reset all the bounds to maintain the applications
+        // aspect ratio.
+        if (DesktopModeFlags.SCALED_RESIZING.isEnabled(windowDecoration.mDecorWindowContext)
+                && !isAspectRatioMaintained && !windowDecoration.mTaskInfo.isResizeable) {
+            repositionTaskBounds.top = oldTop;
+            repositionTaskBounds.bottom = oldBottom;
+            repositionTaskBounds.right = oldRight;
+            repositionTaskBounds.left = oldLeft;
         }
 
         // If there are no changes to the bounds after checking new bounds against minimum and
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/FixedAspectRatioTaskPositionerDecorator.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/FixedAspectRatioTaskPositionerDecorator.kt
index e8131a00ba40..3885761d0742 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/FixedAspectRatioTaskPositionerDecorator.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/FixedAspectRatioTaskPositionerDecorator.kt
@@ -16,8 +16,10 @@
 
 package com.android.wm.shell.windowdecor
 
+import android.app.ActivityManager.RunningTaskInfo
 import android.graphics.PointF
 import android.graphics.Rect
+import com.android.internal.annotations.VisibleForTesting
 import com.android.wm.shell.windowdecor.DragPositioningCallback.CTRL_TYPE_BOTTOM
 import com.android.wm.shell.windowdecor.DragPositioningCallback.CTRL_TYPE_LEFT
 import com.android.wm.shell.windowdecor.DragPositioningCallback.CTRL_TYPE_RIGHT
@@ -51,8 +53,7 @@ class FixedAspectRatioTaskPositionerDecorator (
             return super.onDragPositioningStart(originalCtrlType, x, y)
         }
 
-        lastRepositionedBounds.set(
-            windowDecoration.mTaskInfo.configuration.windowConfiguration.bounds)
+        lastRepositionedBounds.set(getBounds(windowDecoration.mTaskInfo))
         startingPoint.set(x, y)
         lastValidPoint.set(x, y)
         val startingBoundWidth = lastRepositionedBounds.width()
@@ -255,4 +256,9 @@ class FixedAspectRatioTaskPositionerDecorator (
     private fun requiresFixedAspectRatio(): Boolean {
         return originalCtrlType.isResizing() && !windowDecoration.mTaskInfo.isResizeable
     }
+
+    @VisibleForTesting
+    fun getBounds(taskInfo: RunningTaskInfo): Rect {
+        return taskInfo.configuration.windowConfiguration.bounds
+    }
 }
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/HandleMenu.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/HandleMenu.kt
index 3d00a445d9e0..faffe4a07d63 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/HandleMenu.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/HandleMenu.kt
@@ -81,7 +81,7 @@ class HandleMenu(
     private val taskInfo: RunningTaskInfo = parentDecor.mTaskInfo
 
     private val isViewAboveStatusBar: Boolean
-        get() = (Flags.enableAdditionalWindowsAboveStatusBar() && !taskInfo.isFreeform)
+        get() = (Flags.enableHandleInputFix() && !taskInfo.isFreeform)
 
     private val pillElevation: Int = loadDimensionPixelSize(
         R.dimen.desktop_mode_handle_menu_pill_elevation)
@@ -183,7 +183,7 @@ class HandleMenu(
         val x = handleMenuPosition.x.toInt()
         val y = handleMenuPosition.y.toInt()
         handleMenuViewContainer =
-            if (!taskInfo.isFreeform && Flags.enableAdditionalWindowsAboveStatusBar()) {
+            if (!taskInfo.isFreeform && Flags.enableHandleInputFix()) {
                 AdditionalSystemViewContainer(
                     windowManagerWrapper = windowManagerWrapper,
                     taskId = taskInfo.taskId,
@@ -218,7 +218,7 @@ class HandleMenu(
             menuX = marginMenuStart
             menuY = marginMenuTop
         } else {
-            if (Flags.enableAdditionalWindowsAboveStatusBar()) {
+            if (Flags.enableHandleInputFix()) {
                 // In a focused decor, we use global coordinates for handle menu. Therefore we
                 // need to account for other factors like split stage and menu/handle width to
                 // center the menu.
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/HandleMenuImageButton.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/HandleMenuImageButton.kt
index 18757ef6ff40..cf82bb4f9919 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/HandleMenuImageButton.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/HandleMenuImageButton.kt
@@ -39,7 +39,7 @@ class HandleMenuImageButton(
     lateinit var taskInfo: RunningTaskInfo
 
     override fun onHoverEvent(motionEvent: MotionEvent): Boolean {
-        if (Flags.enableAdditionalWindowsAboveStatusBar() || taskInfo.isFreeform) {
+        if (Flags.enableHandleInputFix() || taskInfo.isFreeform) {
             return super.onHoverEvent(motionEvent)
         } else {
             return false
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewholder/AppHandleViewHolder.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewholder/AppHandleViewHolder.kt
index 9ef4b8cde8ef..1c11a8dfbbb4 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewholder/AppHandleViewHolder.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewholder/AppHandleViewHolder.kt
@@ -100,7 +100,7 @@ internal class AppHandleViewHolder(
     private fun createStatusBarInputLayer(handlePosition: Point,
                                           handleWidth: Int,
                                           handleHeight: Int) {
-        if (!Flags.enableAdditionalWindowsAboveStatusBar()) return
+        if (!Flags.enableHandleInputFix()) return
         statusBarInputLayer = AdditionalSystemViewContainer(context, windowManagerWrapper,
             taskInfo.taskId, handlePosition.x, handlePosition.y, handleWidth, handleHeight,
             WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE)
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/DefaultWindowDecorViewHost.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/DefaultWindowDecorViewHost.kt
index 139e6790b744..5156e47cfd13 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/DefaultWindowDecorViewHost.kt
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/DefaultWindowDecorViewHost.kt
@@ -19,51 +19,33 @@ import android.content.Context
 import android.content.res.Configuration
 import android.view.Display
 import android.view.SurfaceControl
-import android.view.SurfaceControlViewHost
 import android.view.View
 import android.view.WindowManager
-import android.view.WindowlessWindowManager
 import androidx.tracing.Trace
 import com.android.internal.annotations.VisibleForTesting
 import com.android.wm.shell.shared.annotations.ShellMainThread
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.launch
-typealias SurfaceControlViewHostFactory =
-            (Context, Display, WindowlessWindowManager, String) -> SurfaceControlViewHost
 
 /**
- * A default implementation of [WindowDecorViewHost] backed by a [SurfaceControlViewHost].
+ * A default implementation of [WindowDecorViewHost] backed by a [SurfaceControlViewHostAdapter].
  *
- * It does not support swapping the root view added to the VRI of the [SurfaceControlViewHost], and
- * any attempts to do will throw, which means that once a [View] is added using [updateView] or
- * [updateViewAsync], only its properties and binding may be changed, its children views may be
- * added, removed or changed and its [WindowManager.LayoutParams] may be changed.
- * It also supports asynchronously updating the view hierarchy using [updateViewAsync], in which
+ * It supports asynchronously updating the view hierarchy using [updateViewAsync], in which
  * case the update work will be posted on the [ShellMainThread] with no delay.
  */
 class DefaultWindowDecorViewHost(
-    private val context: Context,
+    context: Context,
     @ShellMainThread private val mainScope: CoroutineScope,
-    private val display: Display,
-    private val surfaceControlViewHostFactory: SurfaceControlViewHostFactory = { c, d, wwm, s ->
-        SurfaceControlViewHost(c, d, wwm, s)
-    }
+    display: Display,
+    @VisibleForTesting val viewHostAdapter: SurfaceControlViewHostAdapter =
+        SurfaceControlViewHostAdapter(context, display)
 ) : WindowDecorViewHost {
 
-    private val rootSurface: SurfaceControl = SurfaceControl.Builder()
-            .setName("DefaultWindowDecorViewHost surface")
-            .setContainerLayer()
-            .setCallsite("DefaultWindowDecorViewHost#init")
-            .build()
-
-    private var wwm: WindowlessWindowManager? = null
-    @VisibleForTesting
-    var viewHost: SurfaceControlViewHost? = null
     private var currentUpdateJob: Job? = null
 
     override val surfaceControl: SurfaceControl
-        get() = rootSurface
+        get() = viewHostAdapter.rootSurface
 
     override fun updateView(
         view: View,
@@ -92,8 +74,7 @@ class DefaultWindowDecorViewHost(
 
     override fun release(t: SurfaceControl.Transaction) {
         clearCurrentUpdateJob()
-        viewHost?.release()
-        t.remove(rootSurface)
+        viewHostAdapter.release(t)
     }
 
     private fun updateViewHost(
@@ -102,45 +83,15 @@ class DefaultWindowDecorViewHost(
         configuration: Configuration,
         onDrawTransaction: SurfaceControl.Transaction?
     ) {
-        Trace.beginSection("DefaultWindowDecorViewHost#updateViewHost")
-        if (wwm == null) {
-            wwm = WindowlessWindowManager(configuration, rootSurface, null)
-        }
-        requireWindowlessWindowManager().setConfiguration(configuration)
-        if (viewHost == null) {
-            viewHost = surfaceControlViewHostFactory.invoke(
-                context,
-                display,
-                requireWindowlessWindowManager(),
-                "DefaultWindowDecorViewHost#updateViewHost"
-            )
-        }
+        viewHostAdapter.prepareViewHost(configuration)
         onDrawTransaction?.let {
-            requireViewHost().rootSurfaceControl.applyTransactionOnDraw(it)
-        }
-        if (requireViewHost().view == null) {
-            Trace.beginSection("DefaultWindowDecorViewHost#updateViewHost-setView")
-            requireViewHost().setView(view, attrs)
-            Trace.endSection()
-        } else {
-            check(requireViewHost().view == view) { "Changing view is not allowed" }
-            Trace.beginSection("DefaultWindowDecorViewHost#updateViewHost-relayout")
-            requireViewHost().relayout(attrs)
-            Trace.endSection()
+            viewHostAdapter.applyTransactionOnDraw(it)
         }
-        Trace.endSection()
+        viewHostAdapter.updateView(view, attrs)
     }
 
     private fun clearCurrentUpdateJob() {
         currentUpdateJob?.cancel()
         currentUpdateJob = null
     }
-
-    private fun requireWindowlessWindowManager(): WindowlessWindowManager {
-        return wwm ?: error("Expected non-null windowless window manager")
-    }
-
-    private fun requireViewHost(): SurfaceControlViewHost {
-        return viewHost ?: error("Expected non-null view host")
-    }
 }
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/PooledWindowDecorViewHostSupplier.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/PooledWindowDecorViewHostSupplier.kt
new file mode 100644
index 000000000000..b04188fa82a8
--- /dev/null
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/PooledWindowDecorViewHostSupplier.kt
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2024 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.wm.shell.windowdecor.viewhost
+
+import android.content.Context
+import android.os.Trace
+import android.util.Pools
+import android.view.Display
+import android.view.SurfaceControl
+import com.android.wm.shell.shared.annotations.ShellMainThread
+import com.android.wm.shell.sysui.ShellInit
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.launch
+
+/**
+ * A [WindowDecorViewHostSupplier] backed by a pool to allow recycling view hosts which may be
+ * expensive to recreate for each new/updated window decoration.
+ *
+ * Callers can obtain [ReusableWindowDecorViewHost] using [acquire], which will return a pooled
+ * object if available, or create a new instance and return it if needed. When done using a
+ * [ReusableWindowDecorViewHost], it must be released using [release] to allow it to be sent back
+ * into the pool and reused later on.
+ *
+ * This class also supports pre-warming [ReusableWindowDecorViewHost] instances, which will be put
+ * into the pool immediately after creation.
+ */
+class PooledWindowDecorViewHostSupplier(
+    private val context: Context,
+    @ShellMainThread private val mainScope: CoroutineScope,
+    shellInit: ShellInit,
+    private val viewHostFactory: ReusableWindowDecorViewHost.Factory =
+        ReusableWindowDecorViewHost.DefaultFactory,
+    maxPoolSize: Int,
+    private val preWarmSize: Int,
+) : WindowDecorViewHostSupplier<ReusableWindowDecorViewHost> {
+
+    private val pool: Pools.Pool<ReusableWindowDecorViewHost> = Pools.SynchronizedPool(maxPoolSize)
+    private var nextDecorViewHostId = 0
+
+    init {
+        require(preWarmSize <= maxPoolSize) { "Pre-warm size should not exceed pool size" }
+        shellInit.addInitCallback(this::onShellInit, this)
+    }
+
+    private fun onShellInit() {
+        if (preWarmSize <= 0) {
+            return
+        }
+        preWarmViewHosts(preWarmSize)
+    }
+
+    private fun preWarmViewHosts(preWarmSize: Int) {
+        mainScope.launch {
+            // Applying isn't needed, as the surface was never actually shown.
+            val t = SurfaceControl.Transaction()
+            repeat(preWarmSize) {
+                val warmedViewHost = create(context, context.display).apply {
+                    warmUp()
+                }
+                // Put the warmed view host in the pool by releasing it.
+                release(warmedViewHost, t)
+            }
+        }
+    }
+
+    override fun acquire(context: Context, display: Display): ReusableWindowDecorViewHost {
+        val reusedDecorViewHost = pool.acquire()
+        if (reusedDecorViewHost != null) {
+            return reusedDecorViewHost
+        }
+        Trace.beginSection("WindowDecorViewHostPool#acquire-new")
+        val newDecorViewHost = create(context, display)
+        Trace.endSection()
+        return newDecorViewHost
+    }
+
+    override fun release(viewHost: ReusableWindowDecorViewHost, t: SurfaceControl.Transaction) {
+        val cached = pool.release(viewHost)
+        if (!cached) {
+            viewHost.release(t)
+        }
+    }
+
+    private fun create(context: Context, display: Display): ReusableWindowDecorViewHost {
+        return viewHostFactory.create(
+            context,
+            mainScope,
+            display,
+            nextDecorViewHostId++
+        )
+    }
+}
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/ReusableWindowDecorViewHost.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/ReusableWindowDecorViewHost.kt
new file mode 100644
index 000000000000..64536d1a7897
--- /dev/null
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/ReusableWindowDecorViewHost.kt
@@ -0,0 +1,161 @@
+/*
+ * Copyright (C) 2024 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.wm.shell.windowdecor.viewhost
+
+import android.content.Context
+import android.content.res.Configuration
+import android.graphics.PixelFormat
+import android.os.Trace
+import android.view.Display
+import android.view.SurfaceControl
+import android.view.SurfaceControlViewHost
+import android.view.View
+import android.view.WindowManager
+import android.view.WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE
+import android.view.WindowManager.LayoutParams.FLAG_SPLIT_TOUCH
+import android.view.WindowManager.LayoutParams.TYPE_APPLICATION
+import android.widget.FrameLayout
+import com.android.internal.annotations.VisibleForTesting
+import com.android.wm.shell.shared.annotations.ShellMainThread
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.launch
+
+/**
+ * An implementation of [WindowDecorViewHost] that supports:
+ *  1) Replacing the root [View], meaning [WindowDecorViewHost.updateView] maybe be
+ *    called with different [View] instances. This is useful when reusing [WindowDecorViewHost]s
+ *    instances for vastly different view hierarchies, such as Desktop Windowing's App Handles and
+ *    App Headers.
+ *  2) Pre-warming of the underlying [SurfaceControlViewHost]s. Useful because their creation and
+ *    first root view assignment are expensive, which is undesirable in latency-sensitive code
+ *    paths like during a shell transition.
+ */
+class ReusableWindowDecorViewHost(
+    private val context: Context,
+    @ShellMainThread private val mainScope: CoroutineScope,
+    display: Display,
+    val id: Int,
+    @VisibleForTesting val viewHostAdapter: SurfaceControlViewHostAdapter =
+        SurfaceControlViewHostAdapter(context, display)
+) : WindowDecorViewHost, Warmable {
+
+    @VisibleForTesting
+    val rootView = FrameLayout(context)
+
+    private var currentUpdateJob: Job? = null
+
+    override val surfaceControl: SurfaceControl
+        get() = viewHostAdapter.rootSurface
+
+    override fun warmUp() {
+        if (viewHostAdapter.isInitialized()) {
+            // Already warmed up.
+            return
+        }
+        Trace.beginSection("$TAG#warmUp")
+        viewHostAdapter.prepareViewHost(context.resources.configuration)
+        viewHostAdapter.updateView(
+            rootView,
+            WindowManager.LayoutParams(
+                0 /* width*/,
+                0 /* height */,
+                TYPE_APPLICATION,
+                FLAG_NOT_FOCUSABLE or FLAG_SPLIT_TOUCH,
+                PixelFormat.TRANSPARENT
+            ).apply {
+                setTitle("View root of $TAG#$id")
+                setTrustedOverlay()
+            }
+        )
+        Trace.endSection()
+    }
+
+    override fun updateView(
+        view: View,
+        attrs: WindowManager.LayoutParams,
+        configuration: Configuration,
+        onDrawTransaction: SurfaceControl.Transaction?
+    ) {
+        clearCurrentUpdateJob()
+        updateViewHost(view, attrs, configuration, onDrawTransaction)
+    }
+
+    override fun updateViewAsync(
+        view: View,
+        attrs: WindowManager.LayoutParams,
+        configuration: Configuration
+    ) {
+        clearCurrentUpdateJob()
+        currentUpdateJob = mainScope.launch {
+            updateViewHost(view, attrs, configuration, onDrawTransaction = null)
+        }
+    }
+
+    override fun release(t: SurfaceControl.Transaction) {
+        clearCurrentUpdateJob()
+        viewHostAdapter.release(t)
+    }
+
+    private fun updateViewHost(
+        view: View,
+        attrs: WindowManager.LayoutParams,
+        configuration: Configuration,
+        onDrawTransaction: SurfaceControl.Transaction?
+    ) {
+        viewHostAdapter.prepareViewHost(configuration)
+        onDrawTransaction?.let {
+            viewHostAdapter.applyTransactionOnDraw(it)
+        }
+        rootView.removeAllViews()
+        rootView.addView(view)
+        viewHostAdapter.updateView(rootView, attrs)
+    }
+
+    private fun clearCurrentUpdateJob() {
+        currentUpdateJob?.cancel()
+        currentUpdateJob = null
+    }
+
+    interface Factory {
+        fun create(
+            context: Context,
+            @ShellMainThread mainScope: CoroutineScope,
+            display: Display,
+            id: Int
+        ): ReusableWindowDecorViewHost
+    }
+
+    object DefaultFactory : Factory {
+        override fun create(
+            context: Context,
+            @ShellMainThread mainScope: CoroutineScope,
+            display: Display,
+            id: Int
+        ): ReusableWindowDecorViewHost {
+            return ReusableWindowDecorViewHost(
+                context,
+                mainScope,
+                display,
+                id
+            )
+        }
+    }
+
+    companion object {
+        private const val TAG = "ReusableWindowDecorViewHost"
+    }
+}
\ No newline at end of file
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/SurfaceControlViewHostAdapter.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/SurfaceControlViewHostAdapter.kt
new file mode 100644
index 000000000000..a54c9ba67cf8
--- /dev/null
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/SurfaceControlViewHostAdapter.kt
@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2024 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.wm.shell.windowdecor.viewhost
+
+import android.content.Context
+import android.content.res.Configuration
+import android.view.AttachedSurfaceControl
+import android.view.Display
+import android.view.SurfaceControl
+import android.view.SurfaceControlViewHost
+import android.view.View
+import android.view.WindowManager
+import android.view.WindowlessWindowManager
+import androidx.tracing.Trace
+import com.android.internal.annotations.VisibleForTesting
+typealias SurfaceControlViewHostFactory =
+            (Context, Display, WindowlessWindowManager, String) -> SurfaceControlViewHost
+
+/**
+ * Adapter for a [SurfaceControlViewHost] and its backing [SurfaceControl].
+ *
+ * It does not support swapping the root view added to the VRI of the [SurfaceControlViewHost], and
+ * any attempts to do will throw, which means that once a [View] is added using [updateView], only
+ * its properties and binding may be changed, its children views may be added, removed or changed
+ * and its [WindowManager.LayoutParams] may be changed.
+ */
+class SurfaceControlViewHostAdapter(
+    private val context: Context,
+    private val display: Display,
+    private val surfaceControlViewHostFactory: SurfaceControlViewHostFactory = { c, d, wwm, s ->
+        SurfaceControlViewHost(c, d, wwm, s)
+    }
+) {
+    val rootSurface: SurfaceControl = SurfaceControl.Builder()
+        .setName("SurfaceControlViewHostAdapter surface")
+        .setContainerLayer()
+        .setCallsite("SurfaceControlViewHostAdapter#init")
+        .build()
+
+    private var wwm: WindowlessWindowManager? = null
+    @VisibleForTesting
+    var viewHost: SurfaceControlViewHost? = null
+
+    /** Initialize the [SurfaceControlViewHost] if needed. */
+    fun prepareViewHost(configuration: Configuration) {
+        if (wwm == null) {
+            wwm = WindowlessWindowManager(configuration, rootSurface, null)
+        }
+        requireWindowlessWindowManager().setConfiguration(configuration)
+        if (viewHost == null) {
+            viewHost = surfaceControlViewHostFactory.invoke(
+                context,
+                display,
+                requireWindowlessWindowManager(),
+                "SurfaceControlViewHostAdapter#prepareViewHost"
+            )
+        }
+    }
+
+    /**
+     * Request to apply the transaction atomically with the next draw of the view hierarchy.
+     * See [AttachedSurfaceControl.applyTransactionOnDraw].
+     */
+    fun applyTransactionOnDraw(t: SurfaceControl.Transaction) {
+        requireViewHost().rootSurfaceControl.applyTransactionOnDraw(t)
+    }
+
+    /** Update the view hierarchy of the view host. */
+    fun updateView(view: View, attrs: WindowManager.LayoutParams) {
+        if (requireViewHost().view == null) {
+            Trace.beginSection("SurfaceControlViewHostAdapter#updateView-setView")
+            requireViewHost().setView(view, attrs)
+            Trace.endSection()
+        } else {
+            check(requireViewHost().view == view) { "Changing view is not allowed" }
+            Trace.beginSection("SurfaceControlViewHostAdapter#updateView-relayout")
+            requireViewHost().relayout(attrs)
+            Trace.endSection()
+        }
+    }
+
+    /** Release the view host and remove the backing surface. */
+    fun release(t: SurfaceControl.Transaction) {
+        viewHost?.release()
+        t.remove(rootSurface)
+    }
+
+    /** Whether the view host has had a view hierarchy set. */
+    fun isInitialized(): Boolean = viewHost?.view != null
+
+    private fun requireWindowlessWindowManager(): WindowlessWindowManager {
+        return wwm ?: error("Expected non-null windowless window manager")
+    }
+
+    private fun requireViewHost(): SurfaceControlViewHost {
+        return viewHost ?: error("Expected non-null view host")
+    }
+}
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/Warmable.kt b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/Warmable.kt
new file mode 100644
index 000000000000..0df9bfa2ee78
--- /dev/null
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/viewhost/Warmable.kt
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2024 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.wm.shell.windowdecor.viewhost
+
+/**
+ * An interface for an object that can be warmed up before it's needed.
+ */
+interface Warmable {
+    fun warmUp()
+}
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModelTests.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModelTests.kt
index a17d08d8fbfb..a18fbf0891ef 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModelTests.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorViewModelTests.kt
@@ -316,7 +316,7 @@ class DesktopModeWindowDecorViewModelTests : ShellTestCase() {
     }
 
     @Test
-    @DisableFlags(Flags.FLAG_ENABLE_ADDITIONAL_WINDOWS_ABOVE_STATUS_BAR)
+    @DisableFlags(Flags.FLAG_ENABLE_HANDLE_INPUT_FIX)
     fun testCreateAndDisposeEventReceiver() {
         val decor = createOpenTaskDecoration(windowingMode = WINDOWING_MODE_FREEFORM)
         desktopModeWindowDecorViewModel.destroyWindowDecoration(decor.mTaskInfo)
@@ -326,7 +326,7 @@ class DesktopModeWindowDecorViewModelTests : ShellTestCase() {
     }
 
     @Test
-    @DisableFlags(Flags.FLAG_ENABLE_ADDITIONAL_WINDOWS_ABOVE_STATUS_BAR)
+    @DisableFlags(Flags.FLAG_ENABLE_HANDLE_INPUT_FIX)
     fun testEventReceiversOnMultipleDisplays() {
         val secondaryDisplay = createVirtualDisplay() ?: return
         val secondaryDisplayId = secondaryDisplay.display.displayId
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorationTests.java b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorationTests.java
index 1741fe447fad..92199a11e837 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorationTests.java
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecorationTests.java
@@ -107,6 +107,7 @@ import kotlin.jvm.functions.Function1;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.BeforeClass;
+import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -406,7 +407,7 @@ public class DesktopModeWindowDecorationTests extends ShellTestCase {
     }
 
     @Test
-    @DisableFlags(Flags.FLAG_ENABLE_ADDITIONAL_WINDOWS_ABOVE_STATUS_BAR)
+    @DisableFlags(Flags.FLAG_ENABLE_HANDLE_INPUT_FIX)
     public void updateRelayoutParams_fullscreen_inputChannelNotNeeded() {
         final ActivityManager.RunningTaskInfo taskInfo = createTaskInfo(/* visible= */ true);
         taskInfo.configuration.windowConfiguration.setWindowingMode(WINDOWING_MODE_FULLSCREEN);
@@ -423,7 +424,7 @@ public class DesktopModeWindowDecorationTests extends ShellTestCase {
     }
 
     @Test
-    @DisableFlags(Flags.FLAG_ENABLE_ADDITIONAL_WINDOWS_ABOVE_STATUS_BAR)
+    @DisableFlags(Flags.FLAG_ENABLE_HANDLE_INPUT_FIX)
     public void updateRelayoutParams_multiwindow_inputChannelNotNeeded() {
         final ActivityManager.RunningTaskInfo taskInfo = createTaskInfo(/* visible= */ true);
         taskInfo.configuration.windowConfiguration.setWindowingMode(WINDOWING_MODE_MULTI_WINDOW);
@@ -563,6 +564,7 @@ public class DesktopModeWindowDecorationTests extends ShellTestCase {
     }
 
     @Test
+    @Ignore("TODO(b/367235906): Due to MONITOR_INPUT permission error")
     public void relayout_freeformTask_appliesTransactionOnDraw() {
         final ActivityManager.RunningTaskInfo taskInfo = createTaskInfo(/* visible= */ true);
         final DesktopModeWindowDecoration spyWindowDecor = spy(createWindowDecoration(taskInfo));
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DragPositioningCallbackUtilityTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DragPositioningCallbackUtilityTest.kt
index 1f33ae69b724..24f6becc3536 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DragPositioningCallbackUtilityTest.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/DragPositioningCallbackUtilityTest.kt
@@ -39,6 +39,7 @@ import com.android.wm.shell.windowdecor.DragPositioningCallback.CTRL_TYPE_BOTTOM
 import com.android.wm.shell.windowdecor.DragPositioningCallback.CTRL_TYPE_RIGHT
 import com.android.wm.shell.windowdecor.DragPositioningCallback.CTRL_TYPE_TOP
 import com.google.common.truth.Truth.assertThat
+import junit.framework.Assert.assertFalse
 import junit.framework.Assert.assertTrue
 import org.junit.After
 import org.junit.Before
@@ -105,6 +106,7 @@ class DragPositioningCallbackUtilityTest {
         initializeTaskInfo()
         mockWindowDecoration.mDisplay = mockDisplay
         mockWindowDecoration.mDecorWindowContext = mockContext
+        mockWindowDecoration.mTaskInfo.isResizeable = true
         whenever(mockContext.getResources()).thenReturn(mockResources)
         whenever(mockWindowDecoration.mDecorWindowContext.resources).thenReturn(mockResources)
         whenever(mockResources.getDimensionPixelSize(R.dimen.desktop_mode_minimum_window_width))
@@ -164,6 +166,60 @@ class DragPositioningCallbackUtilityTest {
     }
 
     @Test
+    @EnableFlags(Flags.FLAG_ENABLE_WINDOWING_SCALED_RESIZING)
+    fun testChangeBounds_unresizeableApp_heightLessThanMin_resetToStartingBounds() {
+        mockWindowDecoration.mTaskInfo.isResizeable = false
+        val startingPoint = PointF(STARTING_BOUNDS.right.toFloat(), STARTING_BOUNDS.top.toFloat())
+        val repositionTaskBounds = Rect(STARTING_BOUNDS)
+
+        // Resize to width of 95px and height of 5px with min width of 10px
+        val newX = STARTING_BOUNDS.right.toFloat() - 5
+        val newY = STARTING_BOUNDS.top.toFloat() + 95
+        val delta = DragPositioningCallbackUtility.calculateDelta(newX, newY, startingPoint)
+
+        assertFalse(
+            DragPositioningCallbackUtility.changeBounds(
+                CTRL_TYPE_RIGHT or CTRL_TYPE_TOP,
+                repositionTaskBounds, STARTING_BOUNDS, STABLE_BOUNDS, delta, mockDisplayController,
+                mockWindowDecoration
+            )
+        )
+
+        assertThat(repositionTaskBounds.left).isEqualTo(STARTING_BOUNDS.left)
+        assertThat(repositionTaskBounds.top).isEqualTo(STARTING_BOUNDS.top)
+        assertThat(repositionTaskBounds.right).isEqualTo(STARTING_BOUNDS.right)
+        assertThat(repositionTaskBounds.bottom).isEqualTo(STARTING_BOUNDS.bottom)
+    }
+
+    @Test
+    @EnableFlags(Flags.FLAG_ENABLE_WINDOWING_SCALED_RESIZING)
+    fun testChangeBounds_unresizeableApp_widthLessThanMin_resetToStartingBounds() {
+        mockWindowDecoration.mTaskInfo.isResizeable = false
+        val startingPoint = PointF(STARTING_BOUNDS.right.toFloat(), STARTING_BOUNDS.top.toFloat())
+        val repositionTaskBounds = Rect(STARTING_BOUNDS)
+
+        // Resize to height of 95px and width of 5px with min width of 10px
+        val newX = STARTING_BOUNDS.right.toFloat() - 95
+        val newY = STARTING_BOUNDS.top.toFloat() + 5
+        val delta = DragPositioningCallbackUtility.calculateDelta(newX, newY, startingPoint)
+
+        assertFalse(
+            DragPositioningCallbackUtility.changeBounds(
+                CTRL_TYPE_RIGHT or CTRL_TYPE_TOP,
+                repositionTaskBounds, STARTING_BOUNDS, STABLE_BOUNDS, delta, mockDisplayController,
+                mockWindowDecoration
+            )
+        )
+
+
+        assertThat(repositionTaskBounds.left).isEqualTo(STARTING_BOUNDS.left)
+        assertThat(repositionTaskBounds.top).isEqualTo(STARTING_BOUNDS.top)
+        assertThat(repositionTaskBounds.right).isEqualTo(STARTING_BOUNDS.right)
+        assertThat(repositionTaskBounds.bottom).isEqualTo(STARTING_BOUNDS.bottom)
+    }
+
+
+    @Test
     fun testChangeBoundsDoesNotChangeHeightWhenNegative() {
         val startingPoint = PointF(STARTING_BOUNDS.right.toFloat(), STARTING_BOUNDS.top.toFloat())
         val repositionTaskBounds = Rect(STARTING_BOUNDS)
@@ -317,6 +373,34 @@ class DragPositioningCallbackUtilityTest {
     }
 
     @Test
+    @EnableFlags(Flags.FLAG_ENABLE_WINDOWING_SCALED_RESIZING)
+    fun testChangeBounds_unresizeableApp_beyondStableBounds_resetToStartingBounds() {
+        mockWindowDecoration.mTaskInfo.isResizeable = false
+        val startingPoint = PointF(
+            STARTING_BOUNDS.right.toFloat(),
+            STARTING_BOUNDS.bottom.toFloat()
+        )
+        val repositionTaskBounds = Rect(STARTING_BOUNDS)
+
+        // Resize to beyond stable bounds.
+        val newX = STARTING_BOUNDS.right.toFloat() + STABLE_BOUNDS.width()
+        val newY = STARTING_BOUNDS.bottom.toFloat() + STABLE_BOUNDS.height()
+
+        val delta = DragPositioningCallbackUtility.calculateDelta(newX, newY, startingPoint)
+        assertFalse(
+            DragPositioningCallbackUtility.changeBounds(
+                CTRL_TYPE_RIGHT or CTRL_TYPE_BOTTOM,
+                repositionTaskBounds, STARTING_BOUNDS, STABLE_BOUNDS, delta, mockDisplayController,
+                mockWindowDecoration
+            )
+        )
+        assertThat(repositionTaskBounds.left).isEqualTo(STARTING_BOUNDS.left)
+        assertThat(repositionTaskBounds.top).isEqualTo(STARTING_BOUNDS.top)
+        assertThat(repositionTaskBounds.right).isEqualTo(STARTING_BOUNDS.right)
+        assertThat(repositionTaskBounds.bottom).isEqualTo(STARTING_BOUNDS.bottom)
+    }
+
+    @Test
     @EnableFlags(Flags.FLAG_ENABLE_DESKTOP_WINDOWING_SIZE_CONSTRAINTS)
     fun taskMinWidthHeightUndefined_changeBoundsInDesktopModeLessThanMin_shouldNotChangeBounds() {
         doReturn(true).`when` { DesktopModeStatus.canEnterDesktopMode(mockContext) }
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/FixedAspectRatioTaskPositionerDecoratorTests.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/FixedAspectRatioTaskPositionerDecoratorTests.kt
new file mode 100644
index 000000000000..ce17c1df50bc
--- /dev/null
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/FixedAspectRatioTaskPositionerDecoratorTests.kt
@@ -0,0 +1,636 @@
+/*
+ * Copyright (C) 2024 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.wm.shell.windowdecor
+
+import android.app.ActivityManager
+import android.graphics.PointF
+import android.graphics.Rect
+import android.util.MathUtils.abs
+import android.util.MathUtils.max
+import androidx.test.filters.SmallTest
+import com.android.wm.shell.ShellTestCase
+import com.android.wm.shell.windowdecor.DragPositioningCallback.CTRL_TYPE_BOTTOM
+import com.android.wm.shell.windowdecor.DragPositioningCallback.CTRL_TYPE_LEFT
+import com.android.wm.shell.windowdecor.DragPositioningCallback.CTRL_TYPE_RIGHT
+import com.android.wm.shell.windowdecor.DragPositioningCallback.CTRL_TYPE_TOP
+import com.android.wm.shell.windowdecor.DragPositioningCallback.CTRL_TYPE_UNDEFINED
+import com.android.wm.shell.windowdecor.DragPositioningCallback.CtrlType
+import com.google.common.truth.Truth.assertThat
+import com.google.testing.junit.testparameterinjector.TestParameter
+import com.google.testing.junit.testparameterinjector.TestParameterInjector
+import kotlin.math.min
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mock
+import org.mockito.Mockito.spy
+import org.mockito.Mockito.verify
+import org.mockito.kotlin.any
+import org.mockito.kotlin.argumentCaptor
+import org.mockito.kotlin.doReturn
+import org.mockito.kotlin.never
+
+/**
+ * Tests for the [FixedAspectRatioTaskPositionerDecorator], written in parameterized form to check
+ * decorators behaviour for different variations of drag actions.
+ *
+ * Build/Install/Run:
+ * atest WMShellUnitTests:FixedAspectRatioTaskPositionerDecoratorTests
+ */
+@SmallTest
+@RunWith(TestParameterInjector::class)
+class FixedAspectRatioTaskPositionerDecoratorTests : ShellTestCase(){
+    @Mock
+    private lateinit var mockDesktopWindowDecoration: DesktopModeWindowDecoration
+    @Mock
+    private lateinit var mockTaskPositioner: VeiledResizeTaskPositioner
+
+    private lateinit var decoratedTaskPositioner: FixedAspectRatioTaskPositionerDecorator
+
+    @Before
+    fun setUp() {
+        mockDesktopWindowDecoration.mTaskInfo = ActivityManager.RunningTaskInfo().apply {
+            isResizeable = false
+            configuration.windowConfiguration.setBounds(PORTRAIT_BOUNDS)
+        }
+        doReturn(PORTRAIT_BOUNDS).`when`(mockTaskPositioner).onDragPositioningStart(
+            any(), any(), any())
+        doReturn(Rect()).`when`(mockTaskPositioner).onDragPositioningMove(any(), any())
+        doReturn(Rect()).`when`(mockTaskPositioner).onDragPositioningEnd(any(), any())
+        decoratedTaskPositioner = spy(
+            FixedAspectRatioTaskPositionerDecorator(
+            mockDesktopWindowDecoration, mockTaskPositioner)
+        )
+    }
+
+    @Test
+    fun testOnDragPositioningStart_noAdjustment(
+        @TestParameter testCase: ResizeableOrNotResizingTestCases
+    ) {
+        val originalX = 0f
+        val originalY = 0f
+        mockDesktopWindowDecoration.mTaskInfo = ActivityManager.RunningTaskInfo().apply {
+            isResizeable = testCase.isResizeable
+        }
+
+        decoratedTaskPositioner.onDragPositioningStart(testCase.ctrlType, originalX, originalY)
+
+        val capturedValues = getLatestOnStartArguments()
+        assertThat(capturedValues.ctrlType).isEqualTo(testCase.ctrlType)
+        assertThat(capturedValues.x).isEqualTo(originalX)
+        assertThat(capturedValues.y).isEqualTo(originalY)
+    }
+
+    @Test
+    fun testOnDragPositioningStart_cornerResize_noAdjustment(
+        @TestParameter testCase: CornerResizeStartTestCases
+    ) {
+        val originalX = 0f
+        val originalY = 0f
+
+        decoratedTaskPositioner.onDragPositioningStart(testCase.ctrlType, originalX, originalY)
+
+        val capturedValues = getLatestOnStartArguments()
+        assertThat(capturedValues.ctrlType).isEqualTo(testCase.ctrlType)
+        assertThat(capturedValues.x).isEqualTo(originalX)
+        assertThat(capturedValues.y).isEqualTo(originalY)
+    }
+
+    @Test
+    fun testOnDragPositioningStart_edgeResize_ctrlTypeAdjusted(
+        @TestParameter testCase: EdgeResizeStartTestCases, @TestParameter orientation: Orientation
+    ) {
+        val startingBounds = getAndMockBounds(orientation)
+        val startingPoint = getEdgeStartingPoint(
+            testCase.ctrlType, testCase.additionalEdgeCtrlType, startingBounds)
+
+        decoratedTaskPositioner.onDragPositioningStart(
+            testCase.ctrlType, startingPoint.x, startingPoint.y)
+
+        val adjustedCtrlType = testCase.ctrlType + testCase.additionalEdgeCtrlType
+        val capturedValues = getLatestOnStartArguments()
+        assertThat(capturedValues.ctrlType).isEqualTo(adjustedCtrlType)
+        assertThat(capturedValues.x).isEqualTo(startingPoint.x)
+        assertThat(capturedValues.y).isEqualTo(startingPoint.y)
+    }
+
+    @Test
+    fun testOnDragPositioningMove_noAdjustment(
+        @TestParameter testCase: ResizeableOrNotResizingTestCases
+    ) {
+        val originalX = 0f
+        val originalY = 0f
+        decoratedTaskPositioner.onDragPositioningStart(testCase.ctrlType, originalX, originalX)
+        mockDesktopWindowDecoration.mTaskInfo = ActivityManager.RunningTaskInfo().apply {
+            isResizeable = testCase.isResizeable
+        }
+
+        decoratedTaskPositioner.onDragPositioningMove(
+            originalX + SMALL_DELTA, originalY + SMALL_DELTA)
+
+        val capturedValues = getLatestOnMoveArguments()
+        assertThat(capturedValues.x).isEqualTo(originalX + SMALL_DELTA)
+        assertThat(capturedValues.y).isEqualTo(originalY + SMALL_DELTA)
+    }
+
+    @Test
+    fun testOnDragPositioningMove_cornerResize_invalidRegion_noResize(
+        @TestParameter testCase: InvalidCornerResizeTestCases,
+        @TestParameter orientation: Orientation
+    ) {
+        val startingBounds = getAndMockBounds(orientation)
+        val startingPoint = getCornerStartingPoint(testCase.ctrlType, startingBounds)
+
+        decoratedTaskPositioner.onDragPositioningStart(
+            testCase.ctrlType, startingPoint.x, startingPoint.y)
+
+        val updatedBounds = decoratedTaskPositioner.onDragPositioningMove(
+            startingPoint.x + testCase.dragDelta.x,
+            startingPoint.y + testCase.dragDelta.y)
+
+        verify(mockTaskPositioner, never()).onDragPositioningMove(any(), any())
+        assertThat(updatedBounds).isEqualTo(startingBounds)
+    }
+
+
+    @Test
+    fun testOnDragPositioningMove_cornerResize_validRegion_resizeToAdjustedCoordinates(
+        @TestParameter testCase: ValidCornerResizeTestCases,
+        @TestParameter orientation: Orientation
+    ) {
+        val startingBounds = getAndMockBounds(orientation)
+        val startingPoint = getCornerStartingPoint(testCase.ctrlType, startingBounds)
+
+        decoratedTaskPositioner.onDragPositioningStart(
+            testCase.ctrlType, startingPoint.x, startingPoint.y)
+
+        decoratedTaskPositioner.onDragPositioningMove(
+            startingPoint.x + testCase.dragDelta.x, startingPoint.y + testCase.dragDelta.y)
+
+        val adjustedDragDelta = calculateAdjustedDelta(
+            testCase.ctrlType, testCase.dragDelta, orientation)
+        val capturedValues = getLatestOnMoveArguments()
+        val absChangeX = abs(capturedValues.x - startingPoint.x)
+        val absChangeY = abs(capturedValues.y - startingPoint.y)
+        val resultAspectRatio = max(absChangeX, absChangeY) / min(absChangeX, absChangeY)
+        assertThat(capturedValues.x).isEqualTo(startingPoint.x + adjustedDragDelta.x)
+        assertThat(capturedValues.y).isEqualTo(startingPoint.y + adjustedDragDelta.y)
+        assertThat(resultAspectRatio).isEqualTo(STARTING_ASPECT_RATIO)
+    }
+
+    @Test
+    fun testOnDragPositioningMove_edgeResize_resizeToAdjustedCoordinates(
+        @TestParameter testCase: EdgeResizeTestCases,
+        @TestParameter orientation: Orientation
+    ) {
+        val startingBounds = getAndMockBounds(orientation)
+        val startingPoint = getEdgeStartingPoint(
+            testCase.ctrlType, testCase.additionalEdgeCtrlType, startingBounds)
+
+        decoratedTaskPositioner.onDragPositioningStart(
+            testCase.ctrlType, startingPoint.x, startingPoint.y)
+
+        decoratedTaskPositioner.onDragPositioningMove(
+            startingPoint.x + testCase.dragDelta.x,
+            startingPoint.y + testCase.dragDelta.y)
+
+        val adjustedDragDelta = calculateAdjustedDelta(
+            testCase.ctrlType + testCase.additionalEdgeCtrlType,
+            testCase.dragDelta,
+            orientation)
+        val capturedValues = getLatestOnMoveArguments()
+        val absChangeX = abs(capturedValues.x - startingPoint.x)
+        val absChangeY = abs(capturedValues.y - startingPoint.y)
+        val resultAspectRatio = max(absChangeX, absChangeY) / min(absChangeX, absChangeY)
+        assertThat(capturedValues.x).isEqualTo(startingPoint.x + adjustedDragDelta.x)
+        assertThat(capturedValues.y).isEqualTo(startingPoint.y + adjustedDragDelta.y)
+        assertThat(resultAspectRatio).isEqualTo(STARTING_ASPECT_RATIO)
+    }
+
+    @Test
+    fun testOnDragPositioningEnd_noAdjustment(
+        @TestParameter testCase: ResizeableOrNotResizingTestCases
+    ) {
+        val originalX = 0f
+        val originalY = 0f
+        decoratedTaskPositioner.onDragPositioningStart(testCase.ctrlType, originalX, originalX)
+        mockDesktopWindowDecoration.mTaskInfo = ActivityManager.RunningTaskInfo().apply {
+            isResizeable = testCase.isResizeable
+        }
+
+        decoratedTaskPositioner.onDragPositioningEnd(
+            originalX + SMALL_DELTA, originalY + SMALL_DELTA)
+
+        val capturedValues = getLatestOnEndArguments()
+        assertThat(capturedValues.x).isEqualTo(originalX + SMALL_DELTA)
+        assertThat(capturedValues.y).isEqualTo(originalY + SMALL_DELTA)
+    }
+
+    @Test
+    fun testOnDragPositioningEnd_cornerResize_invalidRegion_endsAtPreviousValidPoint(
+        @TestParameter testCase: InvalidCornerResizeTestCases,
+        @TestParameter orientation: Orientation
+    ) {
+        val startingBounds = getAndMockBounds(orientation)
+        val startingPoint = getCornerStartingPoint(testCase.ctrlType, startingBounds)
+
+        decoratedTaskPositioner.onDragPositioningStart(
+            testCase.ctrlType, startingPoint.x, startingPoint.y)
+
+        decoratedTaskPositioner.onDragPositioningEnd(
+            startingPoint.x + testCase.dragDelta.x,
+            startingPoint.y + testCase.dragDelta.y)
+
+        val capturedValues = getLatestOnEndArguments()
+        assertThat(capturedValues.x).isEqualTo(startingPoint.x)
+        assertThat(capturedValues.y).isEqualTo(startingPoint.y)
+    }
+
+    @Test
+    fun testOnDragPositioningEnd_cornerResize_validRegion_endAtAdjustedCoordinates(
+        @TestParameter testCase: ValidCornerResizeTestCases,
+        @TestParameter orientation: Orientation
+    ) {
+        val startingBounds = getAndMockBounds(orientation)
+        val startingPoint = getCornerStartingPoint(testCase.ctrlType, startingBounds)
+
+        decoratedTaskPositioner.onDragPositioningStart(
+            testCase.ctrlType, startingPoint.x, startingPoint.y)
+
+        decoratedTaskPositioner.onDragPositioningEnd(
+            startingPoint.x + testCase.dragDelta.x, startingPoint.y + testCase.dragDelta.y)
+
+        val adjustedDragDelta = calculateAdjustedDelta(
+            testCase.ctrlType, testCase.dragDelta, orientation)
+        val capturedValues = getLatestOnEndArguments()
+        val absChangeX = abs(capturedValues.x - startingPoint.x)
+        val absChangeY = abs(capturedValues.y - startingPoint.y)
+        val resultAspectRatio = max(absChangeX, absChangeY) / min(absChangeX, absChangeY)
+        assertThat(capturedValues.x).isEqualTo(startingPoint.x + adjustedDragDelta.x)
+        assertThat(capturedValues.y).isEqualTo(startingPoint.y + adjustedDragDelta.y)
+        assertThat(resultAspectRatio).isEqualTo(STARTING_ASPECT_RATIO)
+    }
+
+    @Test
+    fun testOnDragPositioningEnd_edgeResize_endAtAdjustedCoordinates(
+        @TestParameter testCase: EdgeResizeTestCases,
+        @TestParameter orientation: Orientation
+    ) {
+        val startingBounds = getAndMockBounds(orientation)
+        val startingPoint = getEdgeStartingPoint(
+            testCase.ctrlType, testCase.additionalEdgeCtrlType, startingBounds)
+
+        decoratedTaskPositioner.onDragPositioningStart(
+            testCase.ctrlType, startingPoint.x, startingPoint.y)
+
+        decoratedTaskPositioner.onDragPositioningEnd(
+            startingPoint.x + testCase.dragDelta.x,
+            startingPoint.y + testCase.dragDelta.y)
+
+        val adjustedDragDelta = calculateAdjustedDelta(
+            testCase.ctrlType + testCase.additionalEdgeCtrlType,
+            testCase.dragDelta,
+            orientation)
+        val capturedValues = getLatestOnEndArguments()
+        val absChangeX = abs(capturedValues.x - startingPoint.x)
+        val absChangeY = abs(capturedValues.y - startingPoint.y)
+        val resultAspectRatio = max(absChangeX, absChangeY) / min(absChangeX, absChangeY)
+        assertThat(capturedValues.x).isEqualTo(startingPoint.x + adjustedDragDelta.x)
+        assertThat(capturedValues.y).isEqualTo(startingPoint.y + adjustedDragDelta.y)
+        assertThat(resultAspectRatio).isEqualTo(STARTING_ASPECT_RATIO)
+    }
+
+    /**
+     * Returns the most recent arguments passed to the `.onPositioningStart()` of the
+     * [mockTaskPositioner].
+     */
+    private fun getLatestOnStartArguments(): CtrlCoordinateCapture {
+        val captorCtrlType = argumentCaptor<Int>()
+        val captorCoordinates = argumentCaptor<Float>()
+        verify(mockTaskPositioner).onDragPositioningStart(
+            captorCtrlType.capture(), captorCoordinates.capture(), captorCoordinates.capture())
+
+        return CtrlCoordinateCapture(captorCtrlType.firstValue, captorCoordinates.firstValue,
+            captorCoordinates.secondValue)
+    }
+
+    /**
+     * Returns the most recent arguments passed to the `.onPositioningMove()` of the
+     * [mockTaskPositioner].
+     */
+    private fun getLatestOnMoveArguments(): PointF {
+        val captorCoordinates = argumentCaptor<Float>()
+        verify(mockTaskPositioner).onDragPositioningMove(
+            captorCoordinates.capture(), captorCoordinates.capture())
+
+        return PointF(captorCoordinates.firstValue, captorCoordinates.secondValue)
+    }
+
+    /**
+     * Returns the most recent arguments passed to the `.onPositioningEnd()` of the
+     * [mockTaskPositioner].
+     */
+    private fun getLatestOnEndArguments(): PointF {
+        val captorCoordinates = argumentCaptor<Float>()
+        verify(mockTaskPositioner).onDragPositioningEnd(
+            captorCoordinates.capture(), captorCoordinates.capture())
+
+        return PointF(captorCoordinates.firstValue, captorCoordinates.secondValue)
+    }
+
+    /**
+     * Mocks the app bounds to correspond with a given orientation and returns the mocked bounds.
+     */
+    private fun getAndMockBounds(orientation: Orientation): Rect {
+        val mockBounds = if (orientation.isPortrait) PORTRAIT_BOUNDS else LANDSCAPE_BOUNDS
+        doReturn(mockBounds).`when`(mockTaskPositioner).onDragPositioningStart(
+            any(), any(), any())
+        doReturn(mockBounds).`when`(decoratedTaskPositioner).getBounds(any())
+        return mockBounds
+    }
+
+    /**
+     * Calculates the corner point a given drag action should start from, based on the [ctrlType],
+     * given the [startingBounds].
+     */
+    private fun getCornerStartingPoint(@CtrlType ctrlType: Int, startingBounds: Rect): PointF {
+        return when (ctrlType) {
+            CTRL_TYPE_BOTTOM + CTRL_TYPE_RIGHT ->
+                PointF(startingBounds.right.toFloat(), startingBounds.bottom.toFloat())
+
+            CTRL_TYPE_BOTTOM + CTRL_TYPE_LEFT ->
+                PointF(startingBounds.left.toFloat(), startingBounds.bottom.toFloat())
+
+            CTRL_TYPE_TOP + CTRL_TYPE_RIGHT ->
+                PointF(startingBounds.right.toFloat(), startingBounds.top.toFloat())
+            // CTRL_TYPE_TOP + CTRL_TYPE_LEFT
+            else ->
+                PointF(startingBounds.left.toFloat(), startingBounds.top.toFloat())
+        }
+    }
+
+    /**
+     * Calculates the point along an edge the edge resize should start from, based on the starting
+     * edge ([edgeCtrlType]) and the additional edge we expect to resize ([additionalEdgeCtrlType]),
+     * given the [startingBounds].
+     */
+    private fun getEdgeStartingPoint(
+        @CtrlType edgeCtrlType: Int, @CtrlType additionalEdgeCtrlType: Int, startingBounds: Rect
+    ): PointF {
+        val simulatedCorner = getCornerStartingPoint(
+            edgeCtrlType + additionalEdgeCtrlType, startingBounds)
+        when (additionalEdgeCtrlType) {
+            CTRL_TYPE_TOP -> {
+                simulatedCorner.offset(0f, -SMALL_DELTA)
+                return simulatedCorner
+            }
+            CTRL_TYPE_BOTTOM -> {
+                simulatedCorner.offset(0f, SMALL_DELTA)
+                return simulatedCorner
+            }
+            CTRL_TYPE_LEFT -> {
+                simulatedCorner.offset(SMALL_DELTA, 0f)
+                return simulatedCorner
+            }
+            // CTRL_TYPE_RIGHT
+            else -> {
+                simulatedCorner.offset(-SMALL_DELTA, 0f)
+                return simulatedCorner
+            }
+        }
+    }
+
+    /**
+     * Calculates the adjustments to the drag delta we expect for a given action and orientation.
+     */
+    private fun calculateAdjustedDelta(
+        @CtrlType ctrlType: Int, delta: PointF, orientation: Orientation
+    ): PointF {
+        if ((abs(delta.x) < abs(delta.y) && delta.x != 0f) || delta.y == 0f) {
+            // Only respect x delta if it's less than y delta but non-zero (i.e there is a change
+            // in x to be applied), or if the y delta is zero (i.e there is no change in y to be
+            // applied).
+            val adjustedY = if (orientation.isPortrait)
+                delta.x * STARTING_ASPECT_RATIO else
+                delta.x / STARTING_ASPECT_RATIO
+            if (ctrlType.isBottomRightOrTopLeftCorner()) {
+                return PointF(delta.x, adjustedY)
+            }
+            return PointF(delta.x, -adjustedY)
+        }
+        // Respect y delta.
+        val adjustedX = if (orientation.isPortrait)
+            delta.y / STARTING_ASPECT_RATIO else
+            delta.y * STARTING_ASPECT_RATIO
+        if (ctrlType.isBottomRightOrTopLeftCorner()) {
+            return PointF(adjustedX, delta.y)
+        }
+        return PointF(-adjustedX, delta.y)
+    }
+
+    private fun @receiver:CtrlType Int.isBottomRightOrTopLeftCorner(): Boolean {
+        return this == CTRL_TYPE_BOTTOM + CTRL_TYPE_RIGHT || this == CTRL_TYPE_TOP + CTRL_TYPE_LEFT
+    }
+
+    private inner class CtrlCoordinateCapture(ctrl: Int, xValue: Float, yValue: Float) {
+        var ctrlType = ctrl
+        var x = xValue
+        var y = yValue
+    }
+
+    companion object {
+        private val PORTRAIT_BOUNDS = Rect(100, 100, 200, 400)
+        private val LANDSCAPE_BOUNDS = Rect(100, 100, 400, 200)
+        private val STARTING_ASPECT_RATIO = PORTRAIT_BOUNDS.height() / PORTRAIT_BOUNDS.width()
+        private const val LARGE_DELTA = 50f
+        private const val SMALL_DELTA = 30f
+
+        enum class Orientation(
+            val isPortrait: Boolean
+        ) {
+            PORTRAIT (true),
+            LANDSCAPE (false)
+        }
+
+        enum class ResizeableOrNotResizingTestCases(
+            val ctrlType: Int,
+            val isResizeable: Boolean
+        ) {
+            NotResizing (CTRL_TYPE_UNDEFINED, false),
+            Resizeable (CTRL_TYPE_RIGHT, true)
+        }
+
+        /**
+         * Tests cases for the start of a corner resize.
+         * @param ctrlType the control type of the corner the resize is initiated on.
+         */
+        enum class CornerResizeStartTestCases(
+            val ctrlType: Int
+        ) {
+            BottomRightCorner (CTRL_TYPE_BOTTOM + CTRL_TYPE_RIGHT),
+            BottomLeftCorner (CTRL_TYPE_BOTTOM + CTRL_TYPE_LEFT),
+            TopRightCorner (CTRL_TYPE_TOP + CTRL_TYPE_RIGHT),
+            TopLeftCorner (CTRL_TYPE_TOP + CTRL_TYPE_LEFT)
+        }
+
+        /**
+         * Tests cases for the moving and ending of a invalid corner resize. Where the compass point
+         * (e.g `SouthEast`) represents the direction of the drag.
+         * @param ctrlType the control type of the corner the resize is initiated on.
+         * @param dragDelta the delta of the attempted drag action, from the [ctrlType]'s
+         * corresponding corner point. Represented as a combination a different signed small and
+         * large deltas which correspond to the direction/angle of drag.
+         */
+        enum class InvalidCornerResizeTestCases(
+            val ctrlType: Int,
+            val dragDelta: PointF
+        ) {
+            BottomRightCornerNorthEastDrag (
+                CTRL_TYPE_BOTTOM + CTRL_TYPE_RIGHT,
+                PointF(LARGE_DELTA, -LARGE_DELTA)),
+            BottomRightCornerSouthWestDrag (
+                CTRL_TYPE_BOTTOM + CTRL_TYPE_RIGHT,
+                PointF(-LARGE_DELTA, LARGE_DELTA)),
+            TopLeftCornerNorthEastDrag (
+                CTRL_TYPE_TOP + CTRL_TYPE_LEFT,
+                PointF(LARGE_DELTA, -LARGE_DELTA)),
+            TopLeftCornerSouthWestDrag (
+                CTRL_TYPE_TOP + CTRL_TYPE_LEFT,
+                PointF(-LARGE_DELTA, LARGE_DELTA)),
+            BottomLeftCornerSouthEastDrag (
+                CTRL_TYPE_BOTTOM + CTRL_TYPE_LEFT,
+                PointF(LARGE_DELTA, LARGE_DELTA)),
+            BottomLeftCornerNorthWestDrag (
+                CTRL_TYPE_BOTTOM + CTRL_TYPE_LEFT,
+                PointF(-LARGE_DELTA, -LARGE_DELTA)),
+            TopRightCornerSouthEastDrag (
+                CTRL_TYPE_TOP + CTRL_TYPE_RIGHT,
+                PointF(LARGE_DELTA, LARGE_DELTA)),
+            TopRightCornerNorthWestDrag (
+                CTRL_TYPE_TOP + CTRL_TYPE_RIGHT,
+                PointF(-LARGE_DELTA, -LARGE_DELTA)),
+        }
+
+        /**
+         * Tests cases for the moving and ending of a valid corner resize. Where the compass point
+         * (e.g `SouthEast`) represents the direction of the drag, followed by the expected
+         * behaviour in that direction (i.e `RespectY` means the y delta will be respected whereas
+         * `RespectX` means the x delta will be respected).
+         * @param ctrlType the control type of the corner the resize is initiated on.
+         * @param dragDelta the delta of the attempted drag action, from the [ctrlType]'s
+         * corresponding corner point. Represented as a combination a different signed small and
+         * large deltas which correspond to the direction/angle of drag.
+         */
+        enum class ValidCornerResizeTestCases(
+            val ctrlType: Int,
+            val dragDelta: PointF,
+        ) {
+            BottomRightCornerSouthEastDragRespectY (
+                CTRL_TYPE_BOTTOM + CTRL_TYPE_RIGHT,
+                PointF(+LARGE_DELTA, SMALL_DELTA)),
+            BottomRightCornerSouthEastDragRespectX (
+                CTRL_TYPE_BOTTOM + CTRL_TYPE_RIGHT,
+                PointF(SMALL_DELTA, LARGE_DELTA)),
+            BottomRightCornerNorthWestDragRespectY (
+                CTRL_TYPE_BOTTOM + CTRL_TYPE_RIGHT,
+                PointF(-LARGE_DELTA, -SMALL_DELTA)),
+            BottomRightCornerNorthWestDragRespectX (
+                CTRL_TYPE_BOTTOM + CTRL_TYPE_RIGHT,
+                PointF(-SMALL_DELTA, -LARGE_DELTA)),
+            TopLeftCornerSouthEastDragRespectY (
+                CTRL_TYPE_TOP + CTRL_TYPE_LEFT,
+                PointF(LARGE_DELTA, SMALL_DELTA)),
+            TopLeftCornerSouthEastDragRespectX (
+                CTRL_TYPE_TOP + CTRL_TYPE_LEFT,
+                PointF(SMALL_DELTA, LARGE_DELTA)),
+            TopLeftCornerNorthWestDragRespectY (
+                CTRL_TYPE_TOP + CTRL_TYPE_LEFT,
+                PointF(-LARGE_DELTA, -SMALL_DELTA)),
+            TopLeftCornerNorthWestDragRespectX (
+                CTRL_TYPE_TOP + CTRL_TYPE_LEFT,
+                PointF(-SMALL_DELTA, -LARGE_DELTA)),
+            BottomLeftCornerSouthWestDragRespectY (
+                CTRL_TYPE_BOTTOM + CTRL_TYPE_LEFT,
+                PointF(-LARGE_DELTA, SMALL_DELTA)),
+            BottomLeftCornerSouthWestDragRespectX (
+                CTRL_TYPE_BOTTOM + CTRL_TYPE_LEFT,
+                PointF(-SMALL_DELTA, LARGE_DELTA)),
+            BottomLeftCornerNorthEastDragRespectY (
+                CTRL_TYPE_BOTTOM + CTRL_TYPE_LEFT,
+                PointF(LARGE_DELTA, -SMALL_DELTA)),
+            BottomLeftCornerNorthEastDragRespectX (
+                CTRL_TYPE_BOTTOM + CTRL_TYPE_LEFT,
+                PointF(SMALL_DELTA, -LARGE_DELTA)),
+            TopRightCornerSouthWestDragRespectY (
+                CTRL_TYPE_TOP + CTRL_TYPE_RIGHT,
+                PointF(-LARGE_DELTA, SMALL_DELTA)),
+            TopRightCornerSouthWestDragRespectX (
+                CTRL_TYPE_TOP + CTRL_TYPE_RIGHT,
+                PointF(-SMALL_DELTA, LARGE_DELTA)),
+            TopRightCornerNorthEastDragRespectY (
+                CTRL_TYPE_TOP + CTRL_TYPE_RIGHT,
+                PointF(LARGE_DELTA, -SMALL_DELTA)),
+            TopRightCornerNorthEastDragRespectX (
+                CTRL_TYPE_TOP + CTRL_TYPE_RIGHT,
+                PointF(+SMALL_DELTA, -LARGE_DELTA))
+        }
+
+        /**
+         * Tests cases for the start of an edge resize.
+         * @param ctrlType the control type of the edge the resize is initiated on.
+         * @param additionalEdgeCtrlType the expected additional edge to be included in the ctrl
+         * type.
+         */
+        enum class EdgeResizeStartTestCases(
+            val ctrlType: Int,
+            val additionalEdgeCtrlType: Int
+        ) {
+            BottomOfLeftEdgeResize (CTRL_TYPE_LEFT, CTRL_TYPE_BOTTOM),
+            TopOfLeftEdgeResize (CTRL_TYPE_LEFT, CTRL_TYPE_TOP),
+            BottomOfRightEdgeResize (CTRL_TYPE_RIGHT, CTRL_TYPE_BOTTOM),
+            TopOfRightEdgeResize (CTRL_TYPE_RIGHT, CTRL_TYPE_TOP),
+            RightOfTopEdgeResize (CTRL_TYPE_TOP, CTRL_TYPE_RIGHT),
+            LeftOfTopEdgeResize (CTRL_TYPE_TOP, CTRL_TYPE_LEFT),
+            RightOfBottomEdgeResize (CTRL_TYPE_BOTTOM, CTRL_TYPE_RIGHT),
+            LeftOfBottomEdgeResize (CTRL_TYPE_BOTTOM, CTRL_TYPE_LEFT)
+        }
+
+        /**
+         * Tests cases for the moving and ending of an edge resize.
+         * @param ctrlType the control type of the edge the resize is initiated on.
+         * @param additionalEdgeCtrlType the expected additional edge to be included in the ctrl
+         * type.
+         * @param dragDelta the delta of the attempted drag action, from the [ctrlType]'s
+         * corresponding edge point. Represented as a combination a different signed small and
+         * large deltas which correspond to the direction/angle of drag.
+         */
+        enum class EdgeResizeTestCases(
+            val ctrlType: Int,
+            val additionalEdgeCtrlType: Int,
+            val dragDelta: PointF
+        ) {
+            BottomOfLeftEdgeResize (CTRL_TYPE_LEFT, CTRL_TYPE_BOTTOM, PointF(-SMALL_DELTA, 0f)),
+            TopOfLeftEdgeResize (CTRL_TYPE_LEFT, CTRL_TYPE_TOP, PointF(-SMALL_DELTA, 0f)),
+            BottomOfRightEdgeResize (CTRL_TYPE_RIGHT, CTRL_TYPE_BOTTOM, PointF(SMALL_DELTA, 0f)),
+            TopOfRightEdgeResize (CTRL_TYPE_RIGHT, CTRL_TYPE_TOP, PointF(SMALL_DELTA, 0f)),
+            RightOfTopEdgeResize (CTRL_TYPE_TOP, CTRL_TYPE_RIGHT, PointF(0f, -SMALL_DELTA)),
+            LeftOfTopEdgeResize (CTRL_TYPE_TOP, CTRL_TYPE_LEFT, PointF(0f, -SMALL_DELTA)),
+            RightOfBottomEdgeResize (CTRL_TYPE_BOTTOM, CTRL_TYPE_RIGHT, PointF(0f, SMALL_DELTA)),
+            LeftOfBottomEdgeResize (CTRL_TYPE_BOTTOM, CTRL_TYPE_LEFT, PointF(0f, SMALL_DELTA))
+        }
+    }
+}
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/FluidResizeTaskPositionerTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/FluidResizeTaskPositionerTest.kt
index 3a3e965b625e..7543fed4b085 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/FluidResizeTaskPositionerTest.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/FluidResizeTaskPositionerTest.kt
@@ -121,6 +121,7 @@ class FluidResizeTaskPositionerTest : ShellTestCase() {
             displayId = DISPLAY_ID
             configuration.windowConfiguration.setBounds(STARTING_BOUNDS)
             configuration.windowConfiguration.displayRotation = ROTATION_90
+            isResizeable = true
         }
         `when`(mockWindowDecoration.calculateValidDragArea()).thenReturn(VALID_DRAG_AREA)
         mockWindowDecoration.mDisplay = mockDisplay
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/HandleMenuTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/HandleMenuTest.kt
index a84523112d9b..cabd472ec263 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/HandleMenuTest.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/HandleMenuTest.kt
@@ -134,7 +134,7 @@ class HandleMenuTest : ShellTestCase() {
     }
 
     @Test
-    @EnableFlags(Flags.FLAG_ENABLE_ADDITIONAL_WINDOWS_ABOVE_STATUS_BAR)
+    @EnableFlags(Flags.FLAG_ENABLE_HANDLE_INPUT_FIX)
     fun testFullscreenMenuUsesSystemViewContainer() {
         createTaskInfo(WINDOWING_MODE_FULLSCREEN, SPLIT_POSITION_UNDEFINED)
         val handleMenu = createAndShowHandleMenu(SPLIT_POSITION_UNDEFINED)
@@ -146,7 +146,7 @@ class HandleMenuTest : ShellTestCase() {
     }
 
     @Test
-    @EnableFlags(Flags.FLAG_ENABLE_ADDITIONAL_WINDOWS_ABOVE_STATUS_BAR)
+    @EnableFlags(Flags.FLAG_ENABLE_HANDLE_INPUT_FIX)
     fun testFreeformMenu_usesViewHostViewContainer() {
         createTaskInfo(WINDOWING_MODE_FREEFORM, SPLIT_POSITION_UNDEFINED)
         handleMenu = createAndShowHandleMenu(SPLIT_POSITION_UNDEFINED)
@@ -157,7 +157,7 @@ class HandleMenuTest : ShellTestCase() {
     }
 
     @Test
-    @EnableFlags(Flags.FLAG_ENABLE_ADDITIONAL_WINDOWS_ABOVE_STATUS_BAR)
+    @EnableFlags(Flags.FLAG_ENABLE_HANDLE_INPUT_FIX)
     fun testSplitLeftMenu_usesSystemViewContainer() {
         createTaskInfo(WINDOWING_MODE_MULTI_WINDOW, SPLIT_POSITION_TOP_OR_LEFT)
         handleMenu = createAndShowHandleMenu(SPLIT_POSITION_TOP_OR_LEFT)
@@ -172,7 +172,7 @@ class HandleMenuTest : ShellTestCase() {
     }
 
     @Test
-    @EnableFlags(Flags.FLAG_ENABLE_ADDITIONAL_WINDOWS_ABOVE_STATUS_BAR)
+    @EnableFlags(Flags.FLAG_ENABLE_HANDLE_INPUT_FIX)
     fun testSplitRightMenu_usesSystemViewContainer() {
         createTaskInfo(WINDOWING_MODE_MULTI_WINDOW, SPLIT_POSITION_BOTTOM_OR_RIGHT)
         handleMenu = createAndShowHandleMenu(SPLIT_POSITION_BOTTOM_OR_RIGHT)
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/VeiledResizeTaskPositionerTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/VeiledResizeTaskPositionerTest.kt
index 6ae16edaf3df..7784af6b1111 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/VeiledResizeTaskPositionerTest.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/VeiledResizeTaskPositionerTest.kt
@@ -141,6 +141,7 @@ class VeiledResizeTaskPositionerTest : ShellTestCase() {
             displayId = DISPLAY_ID
             configuration.windowConfiguration.setBounds(STARTING_BOUNDS)
             configuration.windowConfiguration.displayRotation = ROTATION_90
+            isResizeable = true
         }
         `when`(mockDesktopWindowDecoration.calculateValidDragArea()).thenReturn(VALID_DRAG_AREA)
         mockDesktopWindowDecoration.mDisplay = mockDisplay
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/DefaultWindowDecorViewHostTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/DefaultWindowDecorViewHostTest.kt
index 1b2ce9e4df36..1b0b7d95e657 100644
--- a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/DefaultWindowDecorViewHostTest.kt
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/DefaultWindowDecorViewHostTest.kt
@@ -18,7 +18,6 @@ package com.android.wm.shell.windowdecor.viewhost
 import android.testing.AndroidTestingRunner
 import android.testing.TestableLooper
 import android.view.SurfaceControl
-import android.view.SurfaceControlViewHost
 import android.view.View
 import android.view.WindowManager
 import androidx.test.filters.SmallTest
@@ -28,7 +27,6 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.test.advanceUntilIdle
 import kotlinx.coroutines.test.runTest
-import org.junit.Assert.assertThrows
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.mockito.Mockito.mock
@@ -59,54 +57,8 @@ class DefaultWindowDecorViewHostTest : ShellTestCase() {
             onDrawTransaction = null
         )
 
-        assertThat(windowDecorViewHost.viewHost).isNotNull()
-        assertThat(windowDecorViewHost.viewHost!!.view).isEqualTo(view)
-    }
-
-    @Test
-    fun updateView_alreadyLaidOut_relayouts() = runTest {
-        val windowDecorViewHost = createDefaultViewHost()
-        val view = View(context)
-        windowDecorViewHost.updateView(
-            view = view,
-            attrs = WindowManager.LayoutParams(100, 100),
-            configuration = context.resources.configuration,
-            onDrawTransaction = null
-        )
-
-        val otherParams = WindowManager.LayoutParams(200, 200)
-        windowDecorViewHost.updateView(
-            view = view,
-            attrs = otherParams,
-            configuration = context.resources.configuration,
-            onDrawTransaction = null
-        )
-
-        assertThat(windowDecorViewHost.viewHost!!.view).isEqualTo(view)
-        assertThat(windowDecorViewHost.viewHost!!.view!!.layoutParams.width)
-            .isEqualTo(otherParams.width)
-    }
-
-    @Test
-    fun updateView_replacingView_throws() = runTest {
-        val windowDecorViewHost = createDefaultViewHost()
-        val view = View(context)
-        windowDecorViewHost.updateView(
-            view = view,
-            attrs = WindowManager.LayoutParams(100, 100),
-            configuration = context.resources.configuration,
-            onDrawTransaction = null
-        )
-
-        val otherView = View(context)
-        assertThrows(Exception::class.java) {
-            windowDecorViewHost.updateView(
-                view = otherView,
-                attrs = WindowManager.LayoutParams(100, 100),
-                configuration = context.resources.configuration,
-                onDrawTransaction = null
-            )
-        }
+        assertThat(windowDecorViewHost.viewHostAdapter.isInitialized()).isTrue()
+        assertThat(windowDecorViewHost.view()).isEqualTo(view)
     }
 
     @OptIn(ExperimentalCoroutinesApi::class)
@@ -125,7 +77,7 @@ class DefaultWindowDecorViewHostTest : ShellTestCase() {
         )
 
         // No view host yet, since the coroutine hasn't run.
-        assertThat(windowDecorViewHost.viewHost).isNull()
+        assertThat(windowDecorViewHost.viewHostAdapter.isInitialized()).isFalse()
 
         windowDecorViewHost.updateView(
             view = syncView,
@@ -137,14 +89,13 @@ class DefaultWindowDecorViewHostTest : ShellTestCase() {
         // Would run coroutine if it hadn't been cancelled.
         advanceUntilIdle()
 
-        assertThat(windowDecorViewHost.viewHost).isNotNull()
-        assertThat(windowDecorViewHost.viewHost!!.view).isNotNull()
+        assertThat(windowDecorViewHost.viewHostAdapter.isInitialized()).isTrue()
+        assertThat(windowDecorViewHost.view()).isNotNull()
         // View host view/attrs should match the ones from the sync call, plus, since the
         // sync/async were made with different views, if the job hadn't been cancelled there
         // would've been an exception thrown as replacing views isn't allowed.
-        assertThat(windowDecorViewHost.viewHost!!.view).isEqualTo(syncView)
-        assertThat(windowDecorViewHost.viewHost!!.view!!.layoutParams.width)
-            .isEqualTo(syncAttrs.width)
+        assertThat(windowDecorViewHost.view()).isEqualTo(syncView)
+        assertThat(windowDecorViewHost.view()!!.layoutParams.width).isEqualTo(syncAttrs.width)
     }
 
     @OptIn(ExperimentalCoroutinesApi::class)
@@ -160,11 +111,11 @@ class DefaultWindowDecorViewHostTest : ShellTestCase() {
             configuration = context.resources.configuration,
         )
 
-        assertThat(windowDecorViewHost.viewHost).isNull()
+        assertThat(windowDecorViewHost.viewHostAdapter.isInitialized()).isFalse()
 
         advanceUntilIdle()
 
-        assertThat(windowDecorViewHost.viewHost).isNotNull()
+        assertThat(windowDecorViewHost.viewHostAdapter.isInitialized()).isTrue()
     }
 
     @OptIn(ExperimentalCoroutinesApi::class)
@@ -187,9 +138,8 @@ class DefaultWindowDecorViewHostTest : ShellTestCase() {
 
         advanceUntilIdle()
 
-        assertThat(windowDecorViewHost.viewHost).isNotNull()
-        assertThat(windowDecorViewHost.viewHost!!.view).isNotNull()
-        assertThat(windowDecorViewHost.viewHost!!.view).isEqualTo(otherView)
+        assertThat(windowDecorViewHost.viewHostAdapter.isInitialized()).isTrue()
+        assertThat(windowDecorViewHost.view()).isEqualTo(otherView)
     }
 
     @Test
@@ -207,16 +157,15 @@ class DefaultWindowDecorViewHostTest : ShellTestCase() {
         val t = mock(SurfaceControl.Transaction::class.java)
         windowDecorViewHost.release(t)
 
-        verify(windowDecorViewHost.viewHost!!).release()
-        verify(t).remove(windowDecorViewHost.surfaceControl)
+        verify(windowDecorViewHost.viewHostAdapter).release(t)
     }
 
     private fun CoroutineScope.createDefaultViewHost() = DefaultWindowDecorViewHost(
         context = context,
         mainScope = this,
         display = context.display,
-        surfaceControlViewHostFactory = { c, d, wwm, s ->
-            spy(SurfaceControlViewHost(c, d, wwm, s))
-        }
+        viewHostAdapter = spy(SurfaceControlViewHostAdapter(context, context.display)),
     )
+
+    private fun DefaultWindowDecorViewHost.view(): View? = viewHostAdapter.viewHost?.view
 }
\ No newline at end of file
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/PooledWindowDecorViewHostSupplierTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/PooledWindowDecorViewHostSupplierTest.kt
new file mode 100644
index 000000000000..a7e4213ad01d
--- /dev/null
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/PooledWindowDecorViewHostSupplierTest.kt
@@ -0,0 +1,181 @@
+/*
+ * Copyright (C) 2024 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.wm.shell.windowdecor.viewhost
+
+import android.testing.AndroidTestingRunner
+import android.view.SurfaceControl
+import androidx.test.filters.SmallTest
+import com.android.wm.shell.ShellTestCase
+import com.android.wm.shell.TestShellExecutor
+import com.android.wm.shell.sysui.ShellInit
+import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.advanceUntilIdle
+import kotlinx.coroutines.test.runTest
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mock
+import org.mockito.MockitoAnnotations
+import org.mockito.kotlin.any
+import org.mockito.kotlin.mock
+import org.mockito.kotlin.never
+import org.mockito.kotlin.verify
+import org.mockito.kotlin.whenever
+
+/**
+ * Tests for [PooledWindowDecorViewHostSupplier].
+ *
+ * Build/Install/Run:
+ *  atest WMShellUnitTests:PooledWindowDecorViewHostSupplierTest
+ */
+@OptIn(ExperimentalCoroutinesApi::class)
+@SmallTest
+@RunWith(AndroidTestingRunner::class)
+class PooledWindowDecorViewHostSupplierTest : ShellTestCase() {
+
+    private val testExecutor = TestShellExecutor()
+    private val testShellInit = ShellInit(testExecutor)
+    @Mock
+    private lateinit var mockViewHostFactory: ReusableWindowDecorViewHost.Factory
+
+    private lateinit var supplier: PooledWindowDecorViewHostSupplier
+
+    @Test
+    fun setUp() {
+        MockitoAnnotations.initMocks(this)
+    }
+
+    @Test
+    fun onInit_warmsAndPoolsViewHosts() = runTest {
+        supplier = createSupplier(maxPoolSize = 5, preWarmSize = 2)
+        val mockViewHost1 = mock<ReusableWindowDecorViewHost>()
+        val mockViewHost2 = mock<ReusableWindowDecorViewHost>()
+        whenever(mockViewHostFactory
+            .create(context, this, context.display, id = 0))
+            .thenReturn(mockViewHost1)
+        whenever(mockViewHostFactory
+            .create(context, this, context.display, id = 1))
+            .thenReturn(mockViewHost2)
+
+        testExecutor.flushAll()
+        advanceUntilIdle()
+
+        // Both were warmed up.
+        verify(mockViewHost1).warmUp()
+        verify(mockViewHost2).warmUp()
+        // Both were released, so re-acquiring them provides the same instance.
+        assertThat(mockViewHost2)
+            .isEqualTo(supplier.acquire(context, context.display))
+        assertThat(mockViewHost1)
+            .isEqualTo(supplier.acquire(context, context.display))
+    }
+
+    @Test(expected = Throwable::class)
+    fun onInit_warmUpSizeExceedsPoolSize_throws() = runTest {
+        createSupplier(maxPoolSize = 3, preWarmSize = 4)
+    }
+
+    @Test
+    fun acquire_poolHasInstances_reuses() = runTest {
+        supplier = createSupplier(maxPoolSize = 5, preWarmSize = 0)
+
+        // Prepare the pool with one instance.
+        val mockViewHost = mock<ReusableWindowDecorViewHost>()
+        supplier.release(mockViewHost, SurfaceControl.Transaction())
+
+        assertThat(mockViewHost)
+            .isEqualTo(supplier.acquire(context, context.display))
+        verify(mockViewHostFactory, never()).create(any(), any(), any(), any())
+    }
+
+    @Test
+    fun acquire_pooledHasZeroInstances_creates() = runTest {
+        supplier = createSupplier(maxPoolSize = 5, preWarmSize = 0)
+
+        supplier.acquire(context, context.display)
+
+        verify(mockViewHostFactory).create(context, this, context.display, id = 0)
+    }
+
+    @Test
+    fun release_poolBelowLimit_caches() = runTest {
+        supplier = createSupplier(maxPoolSize = 5, preWarmSize = 0)
+
+        val mockViewHost = mock<ReusableWindowDecorViewHost>()
+        val mockT = mock<SurfaceControl.Transaction>()
+        supplier.release(mockViewHost, mockT)
+
+        assertThat(mockViewHost)
+            .isEqualTo(supplier.acquire(context, context.display))
+    }
+
+    @Test
+    fun release_poolBelowLimit_doesNotReleaseViewHost() = runTest {
+        supplier = createSupplier(maxPoolSize = 5, preWarmSize = 0)
+
+        val mockViewHost = mock<ReusableWindowDecorViewHost>()
+        val mockT = mock<SurfaceControl.Transaction>()
+        supplier.release(mockViewHost, mockT)
+
+        verify(mockViewHost, never()).release(mockT)
+    }
+
+    @Test
+    fun release_poolAtLimit_doesNotCache() = runTest {
+        supplier = createSupplier(maxPoolSize = 1, preWarmSize = 0)
+        val mockT = mock<SurfaceControl.Transaction>()
+        val mockViewHost = mock<ReusableWindowDecorViewHost>()
+        supplier.release(mockViewHost, mockT) // Maxes pool.
+
+        val mockViewHost2 = mock<ReusableWindowDecorViewHost>()
+        supplier.release(mockViewHost2, mockT) // Beyond limit.
+
+        assertThat(mockViewHost)
+            .isEqualTo(supplier.acquire(context, context.display))
+        // Second one wasn't cached, so the acquired one should've been a new instance.
+        assertThat(mockViewHost2)
+            .isNotEqualTo(supplier.acquire(context, context.display))
+    }
+
+    @Test
+    fun release_poolAtLimit_releasesViewHost() = runTest {
+        supplier = createSupplier(maxPoolSize = 1, preWarmSize = 0)
+        val mockT = mock<SurfaceControl.Transaction>()
+        val mockViewHost = mock<ReusableWindowDecorViewHost>()
+        supplier.release(mockViewHost, mockT) // Maxes pool.
+
+        val mockViewHost2 = mock<ReusableWindowDecorViewHost>()
+        supplier.release(mockViewHost2, mockT) // Beyond limit.
+
+        // Second one doesn't fit, so it needs to be released.
+        verify(mockViewHost2).release(mockT)
+    }
+
+    private fun CoroutineScope.createSupplier(
+        maxPoolSize: Int,
+        preWarmSize: Int
+    ) = PooledWindowDecorViewHostSupplier(
+        context,
+        this,
+        testShellInit,
+        mockViewHostFactory,
+        maxPoolSize,
+        preWarmSize
+    ).also {
+        testShellInit.init()
+    }
+}
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/ReusableWindowDecorViewHostTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/ReusableWindowDecorViewHostTest.kt
new file mode 100644
index 000000000000..de2444e34ca9
--- /dev/null
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/ReusableWindowDecorViewHostTest.kt
@@ -0,0 +1,182 @@
+/*
+ * Copyright (C) 2024 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.wm.shell.windowdecor.viewhost
+
+import android.testing.AndroidTestingRunner
+import android.testing.TestableLooper
+import android.view.SurfaceControl
+import android.view.View
+import android.view.WindowManager
+import androidx.test.filters.SmallTest
+import com.android.wm.shell.ShellTestCase
+import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.advanceUntilIdle
+import kotlinx.coroutines.test.runTest
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.mock
+import org.mockito.kotlin.spy
+import org.mockito.kotlin.verify
+
+/**
+ * Tests for [ReusableWindowDecorViewHost].
+ *
+ * Build/Install/Run:
+ *  atest WMShellUnitTests:ReusableWindowDecorViewHostTest
+ */
+@SmallTest
+@TestableLooper.RunWithLooper
+@RunWith(AndroidTestingRunner::class)
+class ReusableWindowDecorViewHostTest : ShellTestCase() {
+
+    @Test
+    fun warmUp_addsRootView() = runTest {
+        val reusableVH = createReusableViewHost().apply {
+            warmUp()
+        }
+
+        assertThat(reusableVH.viewHostAdapter.isInitialized()).isTrue()
+        assertThat(reusableVH.view()).isEqualTo(reusableVH.rootView)
+    }
+
+    @Test
+    fun update_differentView_replacesView() = runTest {
+        val view = View(context)
+        val lp = WindowManager.LayoutParams()
+        val reusableVH = createReusableViewHost()
+        reusableVH.updateView(view, lp, context.resources.configuration, null)
+
+        assertThat(reusableVH.rootView.childCount).isEqualTo(1)
+        assertThat(reusableVH.rootView.getChildAt(0)).isEqualTo(view)
+
+        val newView = View(context)
+        val newLp = WindowManager.LayoutParams()
+        reusableVH.updateView(newView, newLp, context.resources.configuration, null)
+
+        assertThat(reusableVH.rootView.childCount).isEqualTo(1)
+        assertThat(reusableVH.rootView.getChildAt(0)).isEqualTo(newView)
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun updateView_clearsPendingAsyncJob() = runTest {
+        val reusableVH = createReusableViewHost()
+        val asyncView = View(context)
+        val syncView = View(context)
+        val asyncAttrs = WindowManager.LayoutParams(100, 100)
+        val syncAttrs = WindowManager.LayoutParams(200, 200)
+
+        reusableVH.updateViewAsync(
+            view = asyncView,
+            attrs = asyncAttrs,
+            configuration = context.resources.configuration,
+        )
+
+        // No view host yet, since the coroutine hasn't run.
+        assertThat(reusableVH.viewHostAdapter.isInitialized()).isFalse()
+
+        reusableVH.updateView(
+            view = syncView,
+            attrs = syncAttrs,
+            configuration = context.resources.configuration,
+            onDrawTransaction = null
+        )
+
+        // Would run coroutine if it hadn't been cancelled.
+        advanceUntilIdle()
+
+        assertThat(reusableVH.viewHostAdapter.isInitialized()).isTrue()
+        // View host view/attrs should match the ones from the sync call, plus, since the
+        // sync/async were made with different views, if the job hadn't been cancelled there
+        // would've been an exception thrown as replacing views isn't allowed.
+        assertThat(reusableVH.rootView.getChildAt(0)).isEqualTo(syncView)
+        assertThat(reusableVH.view()!!.layoutParams.width).isEqualTo(syncAttrs.width)
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun updateViewAsync() = runTest {
+        val reusableVH = createReusableViewHost()
+        val view = View(context)
+        val attrs = WindowManager.LayoutParams(100, 100)
+
+        reusableVH.updateViewAsync(
+            view = view,
+            attrs = attrs,
+            configuration = context.resources.configuration,
+        )
+
+        assertThat(reusableVH.viewHostAdapter.isInitialized()).isFalse()
+
+        advanceUntilIdle()
+
+        assertThat(reusableVH.viewHostAdapter.isInitialized()).isTrue()
+    }
+
+    @OptIn(ExperimentalCoroutinesApi::class)
+    @Test
+    fun updateViewAsync_clearsPendingAsyncJob() = runTest {
+        val reusableVH = createReusableViewHost()
+
+        val view = View(context)
+        reusableVH.updateViewAsync(
+            view = view,
+            attrs = WindowManager.LayoutParams(100, 100),
+            configuration = context.resources.configuration,
+        )
+        val otherView = View(context)
+        reusableVH.updateViewAsync(
+            view = otherView,
+            attrs = WindowManager.LayoutParams(100, 100),
+            configuration = context.resources.configuration,
+        )
+
+        advanceUntilIdle()
+
+        assertThat(reusableVH.viewHostAdapter.isInitialized()).isTrue()
+        assertThat(reusableVH.rootView.getChildAt(0)).isEqualTo(otherView)
+    }
+
+    @Test
+    fun release() = runTest {
+        val reusableVH = createReusableViewHost()
+
+        val view = View(context)
+        reusableVH.updateView(
+            view = view,
+            attrs = WindowManager.LayoutParams(100, 100),
+            configuration = context.resources.configuration,
+            onDrawTransaction = null
+        )
+
+        val t = mock(SurfaceControl.Transaction::class.java)
+        reusableVH.release(t)
+
+        verify(reusableVH.viewHostAdapter).release(t)
+    }
+
+    private fun CoroutineScope.createReusableViewHost() = ReusableWindowDecorViewHost(
+        context = context,
+        mainScope = this,
+        display = context.display,
+        id = 1,
+        viewHostAdapter = spy(SurfaceControlViewHostAdapter(context, context.display)),
+    )
+
+    private fun ReusableWindowDecorViewHost.view(): View? = viewHostAdapter.viewHost?.view
+}
diff --git a/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/SurfaceControlViewHostAdapterTest.kt b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/SurfaceControlViewHostAdapterTest.kt
new file mode 100644
index 000000000000..d6c80a7fffc1
--- /dev/null
+++ b/libs/WindowManager/Shell/tests/unittest/src/com/android/wm/shell/windowdecor/viewhost/SurfaceControlViewHostAdapterTest.kt
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2024 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.wm.shell.windowdecor.viewhost
+
+import android.testing.AndroidTestingRunner
+import android.testing.TestableLooper
+import android.view.SurfaceControl
+import android.view.SurfaceControlViewHost
+import android.view.View
+import android.view.WindowManager
+import androidx.test.filters.SmallTest
+import com.android.wm.shell.ShellTestCase
+import com.google.common.truth.Truth.assertThat
+import org.junit.Assert.assertThrows
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.mock
+import org.mockito.kotlin.spy
+import org.mockito.kotlin.verify
+
+/**
+ * Tests for [SurfaceControlViewHostAdapter].
+ *
+ * Build/Install/Run:
+ * atest WMShellUnitTests:SurfaceControlViewHostAdapterTest
+ */
+@SmallTest
+@TestableLooper.RunWithLooper
+@RunWith(AndroidTestingRunner::class)
+class SurfaceControlViewHostAdapterTest : ShellTestCase() {
+
+    private lateinit var adapter: SurfaceControlViewHostAdapter
+
+    @Before
+    fun setUp() {
+        adapter = SurfaceControlViewHostAdapter(
+            context,
+            context.display,
+            surfaceControlViewHostFactory = { c, d, wwm, s ->
+                spy(SurfaceControlViewHost(c, d, wwm, s))
+            }
+        )
+    }
+
+    @Test
+    fun prepareViewHost() {
+        adapter.prepareViewHost(context.resources.configuration)
+
+        assertThat(adapter.viewHost).isNotNull()
+    }
+
+    @Test
+    fun prepareViewHost_alreadyCreated_skips() {
+        adapter.prepareViewHost(context.resources.configuration)
+
+        val viewHost = adapter.viewHost!!
+
+        adapter.prepareViewHost(context.resources.configuration)
+
+        assertThat(adapter.viewHost).isEqualTo(viewHost)
+    }
+
+    @Test
+    fun updateView_layoutInViewHost() {
+        val view = View(context)
+        adapter.prepareViewHost(context.resources.configuration)
+
+        adapter.updateView(
+            view = view,
+            attrs = WindowManager.LayoutParams(100, 100)
+        )
+
+        assertThat(adapter.isInitialized()).isTrue()
+        assertThat(adapter.view()).isEqualTo(view)
+    }
+
+    @Test
+    fun updateView_alreadyLaidOut_relayouts() {
+        val view = View(context)
+        adapter.prepareViewHost(context.resources.configuration)
+        adapter.updateView(
+            view = view,
+            attrs = WindowManager.LayoutParams(100, 100)
+        )
+
+        val otherParams = WindowManager.LayoutParams(200, 200)
+        adapter.updateView(
+            view = view,
+            attrs = otherParams
+        )
+
+        assertThat(adapter.view()).isEqualTo(view)
+        assertThat(adapter.view()!!.layoutParams.width).isEqualTo(otherParams.width)
+    }
+
+    @Test
+    fun updateView_replacingView_throws() {
+        val view = View(context)
+        adapter.prepareViewHost(context.resources.configuration)
+        adapter.updateView(
+            view = view,
+            attrs = WindowManager.LayoutParams(100, 100)
+        )
+
+        val otherView = View(context)
+        assertThrows(Exception::class.java) {
+            adapter.updateView(
+                view = otherView,
+                attrs = WindowManager.LayoutParams(100, 100)
+            )
+        }
+    }
+
+    @Test
+    fun release() {
+        adapter.prepareViewHost(context.resources.configuration)
+        adapter.updateView(
+            view = View(context),
+            attrs = WindowManager.LayoutParams(100, 100)
+        )
+
+        val mockT = mock(SurfaceControl.Transaction::class.java)
+        adapter.release(mockT)
+
+        verify(adapter.viewHost!!).release()
+        verify(mockT).remove(adapter.rootSurface)
+    }
+
+    private fun SurfaceControlViewHostAdapter.view(): View? = viewHost?.view
+}