Merge "Fix Letterboxing for Transparent Activities" into tm-qpr-dev

8 files changed, 474 insertions, 25 deletions

diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index 18c29d196ada..bbbb79c79527 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -5300,6 +5300,10 @@
     <!-- Whether using split screen aspect ratio as a default aspect ratio for unresizable apps. -->
     <bool name="config_letterboxIsSplitScreenAspectRatioForUnresizableAppsEnabled">false</bool>
 
+    <!-- Whether the specific behaviour for translucent activities letterboxing is enabled.
+         TODO(b/255532890) Enable when ignoreOrientationRequest is set -->
+    <bool name="config_letterboxIsEnabledForTranslucentActivities">false</bool>
+
     <!-- Whether a camera compat controller is enabled to allow the user to apply or revert
          treatment for stretched issues in camera viewfinder. -->
     <bool name="config_isCameraCompatControlForStretchedIssuesEnabled">false</bool>
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index b9259218c2d3..b0f6ae6085e3 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -4401,6 +4401,9 @@
   <!-- Set to true to make assistant show in front of the dream/screensaver. -->
   <java-symbol type="bool" name="config_assistantOnTopOfDream"/>
 
+  <!-- Set to true to enable letterboxing on translucent activities. -->
+  <java-symbol type="bool" name="config_letterboxIsEnabledForTranslucentActivities" />
+
   <java-symbol type="string" name="config_overrideComponentUiPackage" />
 
   <java-symbol type="string" name="notification_channel_network_status" />
diff --git a/services/core/java/com/android/server/wm/ActivityRecord.java b/services/core/java/com/android/server/wm/ActivityRecord.java
index 2c274827ba8e..e639866a6bab 100644
--- a/services/core/java/com/android/server/wm/ActivityRecord.java
+++ b/services/core/java/com/android/server/wm/ActivityRecord.java
@@ -1239,8 +1239,8 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
                 pw.println(prefix + "supportsEnterPipOnTaskSwitch: "
                         + supportsEnterPipOnTaskSwitch);
             }
-            if (info.getMaxAspectRatio() != 0) {
-                pw.println(prefix + "maxAspectRatio=" + info.getMaxAspectRatio());
+            if (getMaxAspectRatio() != 0) {
+                pw.println(prefix + "maxAspectRatio=" + getMaxAspectRatio());
             }
             final float minAspectRatio = getMinAspectRatio();
             if (minAspectRatio != 0) {
@@ -1590,6 +1590,7 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
                 newParent.setResumedActivity(this, "onParentChanged");
                 mImeInsetsFrozenUntilStartInput = false;
             }
+            mLetterboxUiController.onActivityParentChanged(newParent);
         }
 
         if (rootTask != null && rootTask.topRunningActivity() == this) {
@@ -7682,6 +7683,15 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
     @Configuration.Orientation
     @Override
     int getRequestedConfigurationOrientation(boolean forDisplay) {
+        if (mLetterboxUiController.hasInheritedOrientation()) {
+            final RootDisplayArea root = getRootDisplayArea();
+            if (forDisplay && root != null && root.isOrientationDifferentFromDisplay()) {
+                return ActivityInfo.reverseOrientation(
+                        mLetterboxUiController.getInheritedOrientation());
+            } else {
+                return mLetterboxUiController.getInheritedOrientation();
+            }
+        }
         if (mOrientation == SCREEN_ORIENTATION_BEHIND && task != null) {
             // We use Task here because we want to be consistent with what happens in
             // multi-window mode where other tasks orientations are ignored.
@@ -7809,6 +7819,9 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
 
     @Nullable
     CompatDisplayInsets getCompatDisplayInsets() {
+        if (mLetterboxUiController.hasInheritedLetterboxBehavior()) {
+            return mLetterboxUiController.getInheritedCompatDisplayInsets();
+        }
         return mCompatDisplayInsets;
     }
 
@@ -7891,6 +7904,10 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
 
     // TODO(b/36505427): Consider moving this method and similar ones to ConfigurationContainer.
     private void updateCompatDisplayInsets() {
+        if (mLetterboxUiController.hasInheritedLetterboxBehavior()) {
+            mCompatDisplayInsets =  mLetterboxUiController.getInheritedCompatDisplayInsets();
+            return;
+        }
         if (mCompatDisplayInsets != null || !shouldCreateCompatDisplayInsets()) {
             // The override configuration is set only once in size compatibility mode.
             return;
@@ -7952,6 +7969,9 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
 
     @Override
     float getCompatScale() {
+        if (mLetterboxUiController.hasInheritedLetterboxBehavior()) {
+            return mLetterboxUiController.getInheritedSizeCompatScale();
+        }
         return hasSizeCompatBounds() ? mSizeCompatScale : super.getCompatScale();
     }
 
@@ -8061,6 +8081,16 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
     }
 
     /**
+     * @return The orientation to use to understand if reachability is enabled.
+     */
+    @ActivityInfo.ScreenOrientation
+    int getOrientationForReachability() {
+        return mLetterboxUiController.hasInheritedLetterboxBehavior()
+                ? mLetterboxUiController.getInheritedOrientation()
+                : getRequestedConfigurationOrientation();
+    }
+
+    /**
      * Returns whether activity bounds are letterboxed.
      *
      * <p>Note that letterbox UI may not be shown even when this returns {@code true}. See {@link
@@ -8100,6 +8130,10 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
         if (!ignoreVisibility && !mVisibleRequested) {
             return APP_COMPAT_STATE_CHANGED__STATE__NOT_VISIBLE;
         }
+        // TODO(b/256564921): Investigate if we need new metrics for translucent activities
+        if (mLetterboxUiController.hasInheritedLetterboxBehavior()) {
+            return mLetterboxUiController.getInheritedAppCompatState();
+        }
         if (mInSizeCompatModeForBounds) {
             return APP_COMPAT_STATE_CHANGED__STATE__LETTERBOXED_FOR_SIZE_COMPAT_MODE;
         }
@@ -8570,6 +8604,11 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
     }
 
     private boolean isInSizeCompatModeForBounds(final Rect appBounds, final Rect containerBounds) {
+        if (mLetterboxUiController.hasInheritedLetterboxBehavior()) {
+            // To avoid wrong app behaviour, we decided to disable SCM when a translucent activity
+            // is letterboxed.
+            return false;
+        }
         final int appWidth = appBounds.width();
         final int appHeight = appBounds.height();
         final int containerAppWidth = containerBounds.width();
@@ -8590,10 +8629,11 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
 
         // The rest of the condition is that only one side is smaller than the container, but it
         // still needs to exclude the cases where the size is limited by the fixed aspect ratio.
-        if (info.getMaxAspectRatio() > 0) {
+        final float maxAspectRatio = getMaxAspectRatio();
+        if (maxAspectRatio > 0) {
             final float aspectRatio = (0.5f + Math.max(appWidth, appHeight))
                     / Math.min(appWidth, appHeight);
-            if (aspectRatio >= info.getMaxAspectRatio()) {
+            if (aspectRatio >= maxAspectRatio) {
                 // The current size has reached the max aspect ratio.
                 return false;
             }
@@ -8815,7 +8855,7 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
     // TODO(b/36505427): Consider moving this method and similar ones to ConfigurationContainer.
     private boolean applyAspectRatio(Rect outBounds, Rect containingAppBounds,
             Rect containingBounds, float desiredAspectRatio) {
-        final float maxAspectRatio = info.getMaxAspectRatio();
+        final float maxAspectRatio = getMaxAspectRatio();
         final Task rootTask = getRootTask();
         final float minAspectRatio = getMinAspectRatio();
         final TaskFragment organizedTf = getOrganizedTaskFragment();
@@ -8922,6 +8962,9 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
      * Returns the min aspect ratio of this activity.
      */
     float getMinAspectRatio() {
+        if (mLetterboxUiController.hasInheritedLetterboxBehavior()) {
+            return mLetterboxUiController.getInheritedMinAspectRatio();
+        }
         if (info.applicationInfo == null) {
             return info.getMinAspectRatio();
         }
@@ -8966,11 +9009,18 @@ final class ActivityRecord extends WindowToken implements WindowManagerService.A
                 && parent.getWindowConfiguration().getWindowingMode() == WINDOWING_MODE_FULLSCREEN;
     }
 
+    float getMaxAspectRatio() {
+        if (mLetterboxUiController.hasInheritedLetterboxBehavior()) {
+            return mLetterboxUiController.getInheritedMaxAspectRatio();
+        }
+        return info.getMaxAspectRatio();
+    }
+
     /**
      * Returns true if the activity has maximum or minimum aspect ratio.
      */
     private boolean hasFixedAspectRatio() {
-        return info.getMaxAspectRatio() != 0 || getMinAspectRatio() != 0;
+        return getMaxAspectRatio() != 0 || getMinAspectRatio() != 0;
     }
 
     /**
diff --git a/services/core/java/com/android/server/wm/LetterboxConfiguration.java b/services/core/java/com/android/server/wm/LetterboxConfiguration.java
index c19353cb2676..127a7bf1c9a5 100644
--- a/services/core/java/com/android/server/wm/LetterboxConfiguration.java
+++ b/services/core/java/com/android/server/wm/LetterboxConfiguration.java
@@ -21,6 +21,7 @@ import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.content.Context;
 import android.graphics.Color;
+import android.provider.DeviceConfig;
 
 import com.android.internal.R;
 import com.android.internal.annotations.VisibleForTesting;
@@ -103,6 +104,10 @@ final class LetterboxConfiguration {
 
     final Context mContext;
 
+    // Responsible for the persistence of letterbox[Horizontal|Vertical]PositionMultiplier
+    @NonNull
+    private final LetterboxConfigurationPersister mLetterboxConfigurationPersister;
+
     // Aspect ratio of letterbox for fixed orientation, values <=
     // MIN_FIXED_ORIENTATION_LETTERBOX_ASPECT_RATIO will be ignored.
     private float mFixedOrientationLetterboxAspectRatio;
@@ -165,9 +170,12 @@ final class LetterboxConfiguration {
     // Whether using split screen aspect ratio as a default aspect ratio for unresizable apps.
     private boolean mIsSplitScreenAspectRatioForUnresizableAppsEnabled;
 
-    // Responsible for the persistence of letterbox[Horizontal|Vertical]PositionMultiplier
-    @NonNull
-    private final LetterboxConfigurationPersister mLetterboxConfigurationPersister;
+    // Whether letterboxing strategy is enabled for translucent activities. If {@value false}
+    // all the feature is disabled
+    private boolean mTranslucentLetterboxingEnabled;
+
+    // Allows to enable letterboxing strategy for translucent activities ignoring flags.
+    private boolean mTranslucentLetterboxingOverrideEnabled;
 
     LetterboxConfiguration(Context systemUiContext) {
         this(systemUiContext, new LetterboxConfigurationPersister(systemUiContext,
@@ -206,6 +214,8 @@ final class LetterboxConfiguration {
                 R.dimen.config_letterboxDefaultMinAspectRatioForUnresizableApps));
         mIsSplitScreenAspectRatioForUnresizableAppsEnabled = mContext.getResources().getBoolean(
                 R.bool.config_letterboxIsSplitScreenAspectRatioForUnresizableAppsEnabled);
+        mTranslucentLetterboxingEnabled = mContext.getResources().getBoolean(
+                R.bool.config_letterboxIsEnabledForTranslucentActivities);
         mLetterboxConfigurationPersister = letterboxConfigurationPersister;
         mLetterboxConfigurationPersister.start();
     }
@@ -817,6 +827,32 @@ final class LetterboxConfiguration {
                 R.bool.config_letterboxIsSplitScreenAspectRatioForUnresizableAppsEnabled);
     }
 
+    boolean isTranslucentLetterboxingEnabled() {
+        return mTranslucentLetterboxingOverrideEnabled || (mTranslucentLetterboxingEnabled
+                && isTranslucentLetterboxingAllowed());
+    }
+
+    void setTranslucentLetterboxingEnabled(boolean translucentLetterboxingEnabled) {
+        mTranslucentLetterboxingEnabled = translucentLetterboxingEnabled;
+    }
+
+    void setTranslucentLetterboxingOverrideEnabled(
+            boolean translucentLetterboxingOverrideEnabled) {
+        mTranslucentLetterboxingOverrideEnabled = translucentLetterboxingOverrideEnabled;
+        setTranslucentLetterboxingEnabled(translucentLetterboxingOverrideEnabled);
+    }
+
+    /**
+     * Resets whether we use the constraints override strategy for letterboxing when dealing
+     * with translucent activities {@link R.bool.config_letterboxIsEnabledForTranslucentActivities}.
+     */
+    void resetTranslucentLetterboxingEnabled() {
+        final boolean newValue = mContext.getResources().getBoolean(
+                R.bool.config_letterboxIsEnabledForTranslucentActivities);
+        setTranslucentLetterboxingEnabled(newValue);
+        setTranslucentLetterboxingOverrideEnabled(false);
+    }
+
     /** Calculates a new letterboxPositionForHorizontalReachability value and updates the store */
     private void updatePositionForHorizontalReachability(
             Function<Integer, Integer> newHorizonalPositionFun) {
@@ -839,4 +875,9 @@ final class LetterboxConfiguration {
                 nextVerticalPosition);
     }
 
+    // TODO(b/262378106): Cache runtime flag and implement DeviceConfig.OnPropertiesChangedListener
+    static boolean isTranslucentLetterboxingAllowed() {
+        return DeviceConfig.getBoolean(DeviceConfig.NAMESPACE_WINDOW_MANAGER,
+                "enable_translucent_activity_letterbox", false);
+    }
 }
diff --git a/services/core/java/com/android/server/wm/LetterboxUiController.java b/services/core/java/com/android/server/wm/LetterboxUiController.java
index bcea6f4db1dc..a53a5fc00b0c 100644
--- a/services/core/java/com/android/server/wm/LetterboxUiController.java
+++ b/services/core/java/com/android/server/wm/LetterboxUiController.java
@@ -17,6 +17,7 @@
 package com.android.server.wm;
 
 import static android.app.WindowConfiguration.WINDOWING_MODE_FULLSCREEN;
+import static android.content.pm.ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
 import static android.content.res.Configuration.ORIENTATION_LANDSCAPE;
 import static android.content.res.Configuration.ORIENTATION_PORTRAIT;
 import static android.view.WindowManager.LayoutParams.FLAG_SHOW_WALLPAPER;
@@ -27,6 +28,7 @@ import static com.android.internal.util.FrameworkStatsLog.APP_COMPAT_STATE_CHANG
 import static com.android.internal.util.FrameworkStatsLog.APP_COMPAT_STATE_CHANGED__LETTERBOX_POSITION__RIGHT;
 import static com.android.internal.util.FrameworkStatsLog.APP_COMPAT_STATE_CHANGED__LETTERBOX_POSITION__TOP;
 import static com.android.internal.util.FrameworkStatsLog.APP_COMPAT_STATE_CHANGED__LETTERBOX_POSITION__UNKNOWN_POSITION;
+import static com.android.internal.util.FrameworkStatsLog.APP_COMPAT_STATE_CHANGED__STATE__UNKNOWN;
 import static com.android.internal.util.FrameworkStatsLog.LETTERBOX_POSITION_CHANGED__POSITION_CHANGE__BOTTOM_TO_CENTER;
 import static com.android.internal.util.FrameworkStatsLog.LETTERBOX_POSITION_CHANGED__POSITION_CHANGE__CENTER_TO_BOTTOM;
 import static com.android.internal.util.FrameworkStatsLog.LETTERBOX_POSITION_CHANGED__POSITION_CHANGE__CENTER_TO_LEFT;
@@ -82,13 +84,44 @@ final class LetterboxUiController {
 
     private static final String TAG = TAG_WITH_CLASS_NAME ? "LetterboxUiController" : TAG_ATM;
 
+    private static final float UNDEFINED_ASPECT_RATIO = 0f;
+
     private final Point mTmpPoint = new Point();
 
     private final LetterboxConfiguration mLetterboxConfiguration;
+
     private final ActivityRecord mActivityRecord;
 
+    /*
+     * WindowContainerListener responsible to make translucent activities inherit
+     * constraints from the first opaque activity beneath them. It's null for not
+     * translucent activities.
+     */
+    @Nullable
+    private WindowContainerListener mLetterboxConfigListener;
+
     private boolean mShowWallpaperForLetterboxBackground;
 
+    // In case of transparent activities we might need to access the aspectRatio of the
+    // first opaque activity beneath.
+    private float mInheritedMinAspectRatio = UNDEFINED_ASPECT_RATIO;
+    private float mInheritedMaxAspectRatio = UNDEFINED_ASPECT_RATIO;
+
+    @Configuration.Orientation
+    private int mInheritedOrientation = Configuration.ORIENTATION_UNDEFINED;
+
+    // The app compat state for the opaque activity if any
+    private int mInheritedAppCompatState = APP_COMPAT_STATE_CHANGED__STATE__UNKNOWN;
+
+    // If true it means that the opaque activity beneath a translucent one is in SizeCompatMode.
+    private boolean mIsInheritedInSizeCompatMode;
+
+    // This is the SizeCompatScale of the opaque activity beneath a translucent one
+    private float mInheritedSizeCompatScale;
+
+    // The CompatDisplayInsets of the opaque activity beneath the translucent one.
+    private ActivityRecord.CompatDisplayInsets mInheritedCompatDisplayInsets;
+
     @Nullable
     private Letterbox mLetterbox;
 
@@ -220,7 +253,9 @@ final class LetterboxUiController {
                     : mActivityRecord.inMultiWindowMode()
                             ? mActivityRecord.getTask().getBounds()
                             : mActivityRecord.getRootTask().getParent().getBounds();
-            mLetterbox.layout(spaceToFill, w.getFrame(), mTmpPoint);
+            final Rect innerFrame = hasInheritedLetterboxBehavior()
+                    ? mActivityRecord.getWindowConfiguration().getBounds() : w.getFrame();
+            mLetterbox.layout(spaceToFill, innerFrame, mTmpPoint);
         } else if (mLetterbox != null) {
             mLetterbox.hide();
         }
@@ -305,7 +340,9 @@ final class LetterboxUiController {
     }
 
     private void handleHorizontalDoubleTap(int x) {
-        if (!isHorizontalReachabilityEnabled() || mActivityRecord.isInTransition()) {
+        // TODO(b/260857308): Investigate if enabling reachability for translucent activity
+        if (hasInheritedLetterboxBehavior() || !isHorizontalReachabilityEnabled()
+                || mActivityRecord.isInTransition()) {
             return;
         }
 
@@ -341,7 +378,9 @@ final class LetterboxUiController {
     }
 
     private void handleVerticalDoubleTap(int y) {
-        if (!isVerticalReachabilityEnabled() || mActivityRecord.isInTransition()) {
+        // TODO(b/260857308): Investigate if enabling reachability for translucent activity
+        if (hasInheritedLetterboxBehavior() || !isVerticalReachabilityEnabled()
+                || mActivityRecord.isInTransition()) {
             return;
         }
 
@@ -390,7 +429,7 @@ final class LetterboxUiController {
                 && parentConfiguration.windowConfiguration.getWindowingMode()
                         == WINDOWING_MODE_FULLSCREEN
                 && (parentConfiguration.orientation == ORIENTATION_LANDSCAPE
-                && mActivityRecord.getRequestedConfigurationOrientation() == ORIENTATION_PORTRAIT);
+                && mActivityRecord.getOrientationForReachability() == ORIENTATION_PORTRAIT);
     }
 
     private boolean isHorizontalReachabilityEnabled() {
@@ -412,7 +451,7 @@ final class LetterboxUiController {
                 && parentConfiguration.windowConfiguration.getWindowingMode()
                         == WINDOWING_MODE_FULLSCREEN
                 && (parentConfiguration.orientation == ORIENTATION_PORTRAIT
-                && mActivityRecord.getRequestedConfigurationOrientation() == ORIENTATION_LANDSCAPE);
+                && mActivityRecord.getOrientationForReachability() == ORIENTATION_LANDSCAPE);
     }
 
     private boolean isVerticalReachabilityEnabled() {
@@ -576,9 +615,7 @@ final class LetterboxUiController {
         // Rounded corners should be displayed above the taskbar.
         bounds.bottom =
                 Math.min(bounds.bottom, getTaskbarInsetsSource(mainWindow).getFrame().top);
-        if (mActivityRecord.inSizeCompatMode() && mActivityRecord.getCompatScale() < 1.0f) {
-            bounds.scale(1.0f / mActivityRecord.getCompatScale());
-        }
+        scaleIfNeeded(bounds);
     }
 
     private int getInsetsStateCornerRadius(
@@ -788,4 +825,144 @@ final class LetterboxUiController {
                 w.mAttrs.insetsFlags.appearance
         );
     }
+
+    /**
+     * Handles translucent activities letterboxing inheriting constraints from the
+     * first opaque activity beneath.
+     * @param parent The parent container.
+     */
+    void onActivityParentChanged(WindowContainer<?> parent) {
+        if (!mLetterboxConfiguration.isTranslucentLetterboxingEnabled()) {
+            return;
+        }
+        if (mLetterboxConfigListener != null) {
+            mLetterboxConfigListener.onRemoved();
+            clearInheritedConfig();
+        }
+        // In case mActivityRecord.getCompatDisplayInsets() is not null we don't apply the
+        // opaque activity constraints because we're expecting the activity is already letterboxed.
+        if (mActivityRecord.getTask() == null || mActivityRecord.getCompatDisplayInsets() != null
+                || mActivityRecord.fillsParent()) {
+            return;
+        }
+        final ActivityRecord firstOpaqueActivityBeneath = mActivityRecord.getTask().getActivity(
+                ActivityRecord::fillsParent, mActivityRecord, false /* includeBoundary */,
+                true /* traverseTopToBottom */);
+        if (firstOpaqueActivityBeneath == null
+                || mActivityRecord.launchedFromUid != firstOpaqueActivityBeneath.getUid()) {
+            // We skip letterboxing if the translucent activity doesn't have any opaque
+            // activities beneath of if it's launched from a different user (e.g. notification)
+            return;
+        }
+        inheritConfiguration(firstOpaqueActivityBeneath);
+        mLetterboxConfigListener = WindowContainer.overrideConfigurationPropagation(
+                mActivityRecord, firstOpaqueActivityBeneath,
+                (opaqueConfig, transparentConfig) -> {
+                    final Configuration mutatedConfiguration = new Configuration();
+                    final Rect parentBounds = parent.getWindowConfiguration().getBounds();
+                    final Rect bounds = mutatedConfiguration.windowConfiguration.getBounds();
+                    final Rect letterboxBounds = opaqueConfig.windowConfiguration.getBounds();
+                    // We cannot use letterboxBounds directly here because the position relies on
+                    // letterboxing. Using letterboxBounds directly, would produce a double offset.
+                    bounds.set(parentBounds.left, parentBounds.top,
+                            parentBounds.left + letterboxBounds.width(),
+                            parentBounds.top + letterboxBounds.height());
+                    // We need to initialize appBounds to avoid NPE. The actual value will
+                    // be set ahead when resolving the Configuration for the activity.
+                    mutatedConfiguration.windowConfiguration.setAppBounds(new Rect());
+                    return mutatedConfiguration;
+                });
+    }
+
+    /**
+     * @return {@code true} if the current activity is translucent with an opaque activity
+     * beneath. In this case it will inherit bounds, orientation and aspect ratios from
+     * the first opaque activity beneath.
+     */
+    boolean hasInheritedLetterboxBehavior() {
+        return mLetterboxConfigListener != null && !mActivityRecord.matchParentBounds();
+    }
+
+    /**
+     * @return {@code true} if the current activity is translucent with an opaque activity
+     * beneath and needs to inherit its orientation.
+     */
+    boolean hasInheritedOrientation() {
+        // To force a different orientation, the transparent one needs to have an explicit one
+        // otherwise the existing one is fine and the actual orientation will depend on the
+        // bounds.
+        // To avoid wrong behaviour, we're not forcing orientation for activities with not
+        // fixed orientation (e.g. permission dialogs).
+        return hasInheritedLetterboxBehavior()
+                && mActivityRecord.mOrientation != SCREEN_ORIENTATION_UNSPECIFIED;
+    }
+
+    float getInheritedMinAspectRatio() {
+        return mInheritedMinAspectRatio;
+    }
+
+    float getInheritedMaxAspectRatio() {
+        return mInheritedMaxAspectRatio;
+    }
+
+    int getInheritedAppCompatState() {
+        return mInheritedAppCompatState;
+    }
+
+    float getInheritedSizeCompatScale() {
+        return mInheritedSizeCompatScale;
+    }
+
+    @Configuration.Orientation
+    int getInheritedOrientation() {
+        return mInheritedOrientation;
+    }
+
+    public ActivityRecord.CompatDisplayInsets getInheritedCompatDisplayInsets() {
+        return mInheritedCompatDisplayInsets;
+    }
+
+    private void inheritConfiguration(ActivityRecord firstOpaque) {
+        // To avoid wrong behaviour, we're not forcing a specific aspet ratio to activities
+        // which are not already providing one (e.g. permission dialogs) and presumably also
+        // not resizable.
+        if (mActivityRecord.getMinAspectRatio() != UNDEFINED_ASPECT_RATIO) {
+            mInheritedMinAspectRatio = firstOpaque.getMinAspectRatio();
+        }
+        if (mActivityRecord.getMaxAspectRatio() != UNDEFINED_ASPECT_RATIO) {
+            mInheritedMaxAspectRatio = firstOpaque.getMaxAspectRatio();
+        }
+        mInheritedOrientation = firstOpaque.getRequestedConfigurationOrientation();
+        mInheritedAppCompatState = firstOpaque.getAppCompatState();
+        mIsInheritedInSizeCompatMode = firstOpaque.inSizeCompatMode();
+        mInheritedSizeCompatScale = firstOpaque.getCompatScale();
+        mInheritedCompatDisplayInsets = firstOpaque.getCompatDisplayInsets();
+    }
+
+    private void clearInheritedConfig() {
+        mLetterboxConfigListener = null;
+        mInheritedMinAspectRatio = UNDEFINED_ASPECT_RATIO;
+        mInheritedMaxAspectRatio = UNDEFINED_ASPECT_RATIO;
+        mInheritedOrientation = Configuration.ORIENTATION_UNDEFINED;
+        mInheritedAppCompatState = APP_COMPAT_STATE_CHANGED__STATE__UNKNOWN;
+        mIsInheritedInSizeCompatMode = false;
+        mInheritedSizeCompatScale = 1f;
+        mInheritedCompatDisplayInsets = null;
+    }
+
+    private void scaleIfNeeded(Rect bounds) {
+        if (boundsNeedToScale()) {
+            bounds.scale(1.0f / mActivityRecord.getCompatScale());
+        }
+    }
+
+    private boolean boundsNeedToScale() {
+        if (hasInheritedLetterboxBehavior()) {
+            return mIsInheritedInSizeCompatMode
+                    && mInheritedSizeCompatScale < 1.0f;
+        } else {
+            return mActivityRecord.inSizeCompatMode()
+                    && mActivityRecord.getCompatScale() < 1.0f;
+        }
+    }
 }
diff --git a/services/core/java/com/android/server/wm/WindowContainer.java b/services/core/java/com/android/server/wm/WindowContainer.java
index 80e7ddb432d3..5c893de6b920 100644
--- a/services/core/java/com/android/server/wm/WindowContainer.java
+++ b/services/core/java/com/android/server/wm/WindowContainer.java
@@ -3938,27 +3938,54 @@ class WindowContainer<E extends WindowContainer> extends ConfigurationContainer<
         unregisterConfigurationChangeListener(listener);
     }
 
+    static void overrideConfigurationPropagation(WindowContainer<?> receiver,
+            WindowContainer<?> supplier) {
+        overrideConfigurationPropagation(receiver, supplier, null /* configurationMerger */);
+    }
+
     /**
      * Forces the receiver container to always use the configuration of the supplier container as
      * its requested override configuration. It allows to propagate configuration without changing
      * the relationship between child and parent.
+     *
+     * @param receiver            The {@link WindowContainer<?>} which will receive the {@link
+     *                            Configuration} result of the merging operation.
+     * @param supplier            The {@link WindowContainer<?>} which provides the initial {@link
+     *                            Configuration}.
+     * @param configurationMerger A {@link ConfigurationMerger} which combines the {@link
+     *                            Configuration} of the receiver and the supplier.
      */
-    static void overrideConfigurationPropagation(WindowContainer<?> receiver,
-            WindowContainer<?> supplier) {
+    static WindowContainerListener overrideConfigurationPropagation(WindowContainer<?> receiver,
+            WindowContainer<?> supplier, @Nullable ConfigurationMerger configurationMerger) {
         final ConfigurationContainerListener listener = new ConfigurationContainerListener() {
             @Override
             public void onMergedOverrideConfigurationChanged(Configuration mergedOverrideConfig) {
-                receiver.onRequestedOverrideConfigurationChanged(supplier.getConfiguration());
+                final Configuration mergedConfiguration =
+                        configurationMerger != null
+                                ? configurationMerger.merge(mergedOverrideConfig,
+                                receiver.getConfiguration())
+                                : supplier.getConfiguration();
+                receiver.onRequestedOverrideConfigurationChanged(mergedConfiguration);
             }
         };
         supplier.registerConfigurationChangeListener(listener);
-        receiver.registerWindowContainerListener(new WindowContainerListener() {
+        final WindowContainerListener wcListener = new WindowContainerListener() {
             @Override
             public void onRemoved() {
                 receiver.unregisterWindowContainerListener(this);
                 supplier.unregisterConfigurationChangeListener(listener);
             }
-        });
+        };
+        receiver.registerWindowContainerListener(wcListener);
+        return wcListener;
+    }
+
+    /**
+     * Abstraction for functions merging two {@link Configuration} objects into one.
+     */
+    @FunctionalInterface
+    interface ConfigurationMerger {
+        Configuration merge(Configuration first, Configuration second);
     }
 
     /**
diff --git a/services/core/java/com/android/server/wm/WindowManagerShellCommand.java b/services/core/java/com/android/server/wm/WindowManagerShellCommand.java
index b8cf0ad2e774..4e692e2d212a 100644
--- a/services/core/java/com/android/server/wm/WindowManagerShellCommand.java
+++ b/services/core/java/com/android/server/wm/WindowManagerShellCommand.java
@@ -963,6 +963,29 @@ public class WindowManagerShellCommand extends ShellCommand {
         return 0;
     }
 
+    private int runSetTranslucentLetterboxingEnabled(PrintWriter pw) {
+        String arg = getNextArg();
+        final boolean enabled;
+        switch (arg) {
+            case "true":
+            case "1":
+                enabled = true;
+                break;
+            case "false":
+            case "0":
+                enabled = false;
+                break;
+            default:
+                getErrPrintWriter().println("Error: expected true, 1, false, 0, but got " + arg);
+                return -1;
+        }
+
+        synchronized (mInternal.mGlobalLock) {
+            mLetterboxConfiguration.setTranslucentLetterboxingOverrideEnabled(enabled);
+        }
+        return 0;
+    }
+
     private int runSetLetterboxStyle(PrintWriter pw) throws RemoteException {
         if (peekNextArg() == null) {
             getErrPrintWriter().println("Error: No arguments provided.");
@@ -1018,6 +1041,9 @@ public class WindowManagerShellCommand extends ShellCommand {
                 case "--isSplitScreenAspectRatioForUnresizableAppsEnabled":
                     runSetLetterboxIsSplitScreenAspectRatioForUnresizableAppsEnabled(pw);
                     break;
+                case "--isTranslucentLetterboxingEnabled":
+                    runSetTranslucentLetterboxingEnabled(pw);
+                    break;
                 default:
                     getErrPrintWriter().println(
                             "Error: Unrecognized letterbox style option: " + arg);
@@ -1081,6 +1107,9 @@ public class WindowManagerShellCommand extends ShellCommand {
                         mLetterboxConfiguration
                                 .getIsSplitScreenAspectRatioForUnresizableAppsEnabled();
                         break;
+                    case "isTranslucentLetterboxingEnabled":
+                        mLetterboxConfiguration.resetTranslucentLetterboxingEnabled();
+                        break;
                     default:
                         getErrPrintWriter().println(
                                 "Error: Unrecognized letterbox style option: " + arg);
@@ -1181,6 +1210,7 @@ public class WindowManagerShellCommand extends ShellCommand {
             mLetterboxConfiguration.resetDefaultPositionForVerticalReachability();
             mLetterboxConfiguration.resetIsEducationEnabled();
             mLetterboxConfiguration.resetIsSplitScreenAspectRatioForUnresizableAppsEnabled();
+            mLetterboxConfiguration.resetTranslucentLetterboxingEnabled();
         }
     }
 
@@ -1217,7 +1247,6 @@ public class WindowManagerShellCommand extends ShellCommand {
             pw.println("Is using split screen aspect ratio as aspect ratio for unresizable apps: "
                     + mLetterboxConfiguration
                             .getIsSplitScreenAspectRatioForUnresizableAppsEnabled());
-
             pw.println("Background type: "
                     + LetterboxConfiguration.letterboxBackgroundTypeToString(
                             mLetterboxConfiguration.getLetterboxBackgroundType()));
@@ -1227,6 +1256,12 @@ public class WindowManagerShellCommand extends ShellCommand {
                     + mLetterboxConfiguration.getLetterboxBackgroundWallpaperBlurRadius());
             pw.println("    Wallpaper dark scrim alpha: "
                     + mLetterboxConfiguration.getLetterboxBackgroundWallpaperDarkScrimAlpha());
+
+            if (mLetterboxConfiguration.isTranslucentLetterboxingEnabled()) {
+                pw.println("Letterboxing for translucent activities: enabled");
+            } else {
+                pw.println("Letterboxing for translucent activities: disabled");
+            }
         }
         return 0;
     }
@@ -1419,12 +1454,16 @@ public class WindowManagerShellCommand extends ShellCommand {
         pw.println("      --isSplitScreenAspectRatioForUnresizableAppsEnabled [true|1|false|0]");
         pw.println("        Whether using split screen aspect ratio as a default aspect ratio for");
         pw.println("        unresizable apps.");
+        pw.println("      --isTranslucentLetterboxingEnabled [true|1|false|0]");
+        pw.println("        Whether letterboxing for translucent activities is enabled.");
+
         pw.println("  reset-letterbox-style [aspectRatio|cornerRadius|backgroundType");
         pw.println("      |backgroundColor|wallpaperBlurRadius|wallpaperDarkScrimAlpha");
         pw.println("      |horizontalPositionMultiplier|verticalPositionMultiplier");
         pw.println("      |isHorizontalReachabilityEnabled|isVerticalReachabilityEnabled");
-        pw.println("      isEducationEnabled||defaultPositionMultiplierForHorizontalReachability");
-        pw.println("      ||defaultPositionMultiplierForVerticalReachability]");
+        pw.println("      |isEducationEnabled||defaultPositionMultiplierForHorizontalReachability");
+        pw.println("      |isTranslucentLetterboxingEnabled");
+        pw.println("      |defaultPositionMultiplierForVerticalReachability]");
         pw.println("    Resets overrides to default values for specified properties separated");
         pw.println("    by space, e.g. 'reset-letterbox-style aspectRatio cornerRadius'.");
         pw.println("    If no arguments provided, all values will be reset.");
diff --git a/services/tests/wmtests/src/com/android/server/wm/SizeCompatTests.java b/services/tests/wmtests/src/com/android/server/wm/SizeCompatTests.java
index babad4d4d744..94c33f27f651 100644
--- a/services/tests/wmtests/src/com/android/server/wm/SizeCompatTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/SizeCompatTests.java
@@ -164,6 +164,114 @@ public class SizeCompatTests extends WindowTestsBase {
     }
 
     @Test
+    public void testApplyStrategyToTranslucentActivities() {
+        mWm.mLetterboxConfiguration.setTranslucentLetterboxingOverrideEnabled(true);
+        setUpDisplaySizeWithApp(2000, 1000);
+        prepareUnresizable(mActivity, 1.5f /* maxAspect */, SCREEN_ORIENTATION_PORTRAIT);
+        mActivity.info.setMinAspectRatio(1.2f);
+        mActivity.mDisplayContent.setIgnoreOrientationRequest(true /* ignoreOrientationRequest */);
+        // Translucent Activity
+        final ActivityRecord translucentActivity = new ActivityBuilder(mAtm)
+                .setLaunchedFromUid(mActivity.getUid())
+                .setScreenOrientation(SCREEN_ORIENTATION_LANDSCAPE)
+                .setMinAspectRatio(1.1f)
+                .setMaxAspectRatio(3f)
+                .build();
+        doReturn(false).when(translucentActivity).fillsParent();
+        mTask.addChild(translucentActivity);
+        // We check bounds
+        final Rect opaqueBounds = mActivity.getConfiguration().windowConfiguration.getBounds();
+        final Rect translucentRequestedBounds = translucentActivity.getRequestedOverrideBounds();
+        assertEquals(opaqueBounds, translucentRequestedBounds);
+        // We check orientation
+        final int translucentOrientation =
+                translucentActivity.getRequestedConfigurationOrientation();
+        assertEquals(ORIENTATION_PORTRAIT, translucentOrientation);
+        // We check aspect ratios
+        assertEquals(1.2f, translucentActivity.getMinAspectRatio(), 0.00001f);
+        assertEquals(1.5f, translucentActivity.getMaxAspectRatio(), 0.00001f);
+    }
+
+    @Test
+    public void testNotApplyStrategyToTranslucentActivitiesWithDifferentUid() {
+        mWm.mLetterboxConfiguration.setTranslucentLetterboxingOverrideEnabled(true);
+        setUpDisplaySizeWithApp(2000, 1000);
+        prepareUnresizable(mActivity, 1.5f /* maxAspect */, SCREEN_ORIENTATION_PORTRAIT);
+        mActivity.info.setMinAspectRatio(1.2f);
+        mActivity.mDisplayContent.setIgnoreOrientationRequest(true /* ignoreOrientationRequest */);
+        // Translucent Activity
+        final ActivityRecord translucentActivity = new ActivityBuilder(mAtm)
+                .setScreenOrientation(SCREEN_ORIENTATION_LANDSCAPE)
+                .setMinAspectRatio(1.1f)
+                .setMaxAspectRatio(3f)
+                .build();
+        doReturn(false).when(translucentActivity).fillsParent();
+        mTask.addChild(translucentActivity);
+        // We check bounds
+        final Rect opaqueBounds = mActivity.getConfiguration().windowConfiguration.getBounds();
+        final Rect translucentRequestedBounds = translucentActivity.getRequestedOverrideBounds();
+        assertNotEquals(opaqueBounds, translucentRequestedBounds);
+    }
+
+    @Test
+    public void testApplyStrategyToMultipleTranslucentActivities() {
+        mWm.mLetterboxConfiguration.setTranslucentLetterboxingOverrideEnabled(true);
+        setUpDisplaySizeWithApp(2000, 1000);
+        prepareUnresizable(mActivity, 1.5f /* maxAspect */, SCREEN_ORIENTATION_PORTRAIT);
+        mActivity.info.setMinAspectRatio(1.2f);
+        mActivity.mDisplayContent.setIgnoreOrientationRequest(true /* ignoreOrientationRequest */);
+        // Translucent Activity
+        final ActivityRecord translucentActivity = new ActivityBuilder(mAtm)
+                .setLaunchedFromUid(mActivity.getUid())
+                .setScreenOrientation(SCREEN_ORIENTATION_LANDSCAPE)
+                .setMinAspectRatio(1.1f)
+                .setMaxAspectRatio(3f)
+                .build();
+        doReturn(false).when(translucentActivity).fillsParent();
+        mTask.addChild(translucentActivity);
+        // We check bounds
+        final Rect opaqueBounds = mActivity.getConfiguration().windowConfiguration.getBounds();
+        final Rect translucentRequestedBounds = translucentActivity.getRequestedOverrideBounds();
+        assertEquals(opaqueBounds, translucentRequestedBounds);
+        // Launch another translucent activity
+        final ActivityRecord translucentActivity2 = new ActivityBuilder(mAtm)
+                .setLaunchedFromUid(mActivity.getUid())
+                .setScreenOrientation(SCREEN_ORIENTATION_LANDSCAPE)
+                .build();
+        doReturn(false).when(translucentActivity2).fillsParent();
+        mTask.addChild(translucentActivity2);
+        // We check bounds
+        final Rect translucent2RequestedBounds = translucentActivity2.getRequestedOverrideBounds();
+        assertEquals(opaqueBounds, translucent2RequestedBounds);
+    }
+
+    @Test
+    public void testTranslucentActivitiesDontGoInSizeCompactMode() {
+        mWm.mLetterboxConfiguration.setTranslucentLetterboxingOverrideEnabled(true);
+        setUpDisplaySizeWithApp(2800, 1400);
+        mActivity.mDisplayContent.setIgnoreOrientationRequest(true /* ignoreOrientationRequest */);
+        prepareUnresizable(mActivity, -1f /* maxAspect */, SCREEN_ORIENTATION_PORTRAIT);
+        // Rotate to put activity in size compat mode.
+        rotateDisplay(mActivity.mDisplayContent, ROTATION_90);
+        assertTrue(mActivity.inSizeCompatMode());
+        // Rotate back
+        rotateDisplay(mActivity.mDisplayContent, ROTATION_0);
+        assertFalse(mActivity.inSizeCompatMode());
+        // We launch a transparent activity
+        final ActivityRecord translucentActivity = new ActivityBuilder(mAtm)
+                .setLaunchedFromUid(mActivity.getUid())
+                .setScreenOrientation(SCREEN_ORIENTATION_PORTRAIT)
+                .build();
+        doReturn(true).when(translucentActivity).fillsParent();
+        mTask.addChild(translucentActivity);
+        // It should not be in SCM
+        assertFalse(translucentActivity.inSizeCompatMode());
+        // We rotate again
+        rotateDisplay(translucentActivity.mDisplayContent, ROTATION_90);
+        assertFalse(translucentActivity.inSizeCompatMode());
+    }
+
+    @Test
     public void testRestartProcessIfVisible() {
         setUpDisplaySizeWithApp(1000, 2500);
         doNothing().when(mSupervisor).scheduleRestartTimeout(mActivity);