services/core/java/com/android/server/wm/LetterboxConfiguration.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2021 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.server.wm;

 import android.annotation.IntDef;
 import android.annotation.Nullable;
 import android.content.Context;
 import android.graphics.Color;

 import com.android.internal.R;
 import com.android.internal.annotations.VisibleForTesting;

 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;

 /** Reads letterbox configs from resources and controls their overrides at runtime. */
 final class LetterboxConfiguration {

     /**
      * Override of aspect ratio for fixed orientation letterboxing that is set via ADB with
      * set-fixed-orientation-letterbox-aspect-ratio or via {@link
      * com.android.internal.R.dimen.config_fixedOrientationLetterboxAspectRatio} will be ignored
      * if it is <= this value.
      */
     static final float MIN_FIXED_ORIENTATION_LETTERBOX_ASPECT_RATIO = 1.0f;

     /** Enum for Letterbox background type. */
     @Retention(RetentionPolicy.SOURCE)
     @IntDef({LETTERBOX_BACKGROUND_SOLID_COLOR, LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND,
             LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND_FLOATING, LETTERBOX_BACKGROUND_WALLPAPER})
     @interface LetterboxBackgroundType {};
     /** Solid background using color specified in R.color.config_letterboxBackgroundColor. */
     static final int LETTERBOX_BACKGROUND_SOLID_COLOR = 0;

     /** Color specified in R.attr.colorBackground for the letterboxed application. */
     static final int LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND = 1;

     /** Color specified in R.attr.colorBackgroundFloating for the letterboxed application. */
     static final int LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND_FLOATING = 2;

     /** Using wallpaper as a background which can be blurred or dimmed with dark scrim. */
     static final int LETTERBOX_BACKGROUND_WALLPAPER = 3;

     /**
      * Enum for Letterbox reachability position types.
      *
      * <p>Order from left to right is important since it's used in {@link
      * #movePositionForReachabilityToNextRightStop} and {@link
      * #movePositionForReachabilityToNextLeftStop}.
      */
     @Retention(RetentionPolicy.SOURCE)
     @IntDef({LETTERBOX_REACHABILITY_POSITION_LEFT, LETTERBOX_REACHABILITY_POSITION_CENTER,
             LETTERBOX_REACHABILITY_POSITION_RIGHT})
     @interface LetterboxReachabilityPosition {};

     /** Letterboxed app window is aligned to the left side. */
     static final int LETTERBOX_REACHABILITY_POSITION_LEFT = 0;

     /** Letterboxed app window is positioned in the horizontal center. */
     static final int LETTERBOX_REACHABILITY_POSITION_CENTER = 1;

     /** Letterboxed app window is aligned to the right side. */
     static final int LETTERBOX_REACHABILITY_POSITION_RIGHT = 2;

     final Context mContext;

     // Aspect ratio of letterbox for fixed orientation, values <=
     // MIN_FIXED_ORIENTATION_LETTERBOX_ASPECT_RATIO will be ignored.
     private float mFixedOrientationLetterboxAspectRatio;

     // Corners radius for activities presented in the letterbox mode, values < 0 will be ignored.
     private int mLetterboxActivityCornersRadius;

     // Color for {@link #LETTERBOX_BACKGROUND_SOLID_COLOR} letterbox background type.
     @Nullable private Color mLetterboxBackgroundColorOverride;

     // Color resource id for {@link #LETTERBOX_BACKGROUND_SOLID_COLOR} letterbox background type.
     @Nullable private Integer mLetterboxBackgroundColorResourceIdOverride;

     @LetterboxBackgroundType
     private int mLetterboxBackgroundType;

     // Blur radius for LETTERBOX_BACKGROUND_WALLPAPER option in mLetterboxBackgroundType.
     // Values <= 0 are ignored and 0 is used instead.
     private int mLetterboxBackgroundWallpaperBlurRadius;

     // Alpha of a black scrim shown over wallpaper letterbox background when
     // LETTERBOX_BACKGROUND_WALLPAPER option is selected for mLetterboxBackgroundType.
     // Values < 0 or >= 1 are ignored and 0.0 (transparent) is used instead.
     private float mLetterboxBackgroundWallpaperDarkScrimAlpha;

     // Horizontal position of a center of the letterboxed app window. 0 corresponds to the left
     // side of the screen and 1.0 to the right side.
     private float mLetterboxHorizontalPositionMultiplier;

     // Default horizontal position the letterboxed app window when reachability is enabled and
     // an app is fullscreen in landscape device orientatio.
     // It is used as a starting point for mLetterboxPositionForReachability.
     @LetterboxReachabilityPosition
     private int mDefaultPositionForReachability;

     // Whether reachability repositioning is allowed for letterboxed fullscreen apps in landscape
     // device orientation.
     private boolean mIsReachabilityEnabled;

     // Horizontal position of a center of the letterboxed app window which is global to prevent
     // "jumps" when switching between letterboxed apps. It's updated to reposition the app window
     // in response to a double tap gesture (see LetterboxUiController#handleDoubleTap). Used in
     // LetterboxUiController#getHorizontalPositionMultiplier which is called from
     // ActivityRecord#updateResolvedBoundsHorizontalPosition.
     // TODO(b/199426138): Global reachability setting causes a jump when resuming an app from
     // Overview after changing position in another app.
     @LetterboxReachabilityPosition
     private volatile int mLetterboxPositionForReachability;

     // Whether education is allowed for letterboxed fullscreen apps.
     private boolean mIsEducationEnabled;

     LetterboxConfiguration(Context systemUiContext) {
         mContext = systemUiContext;
         mFixedOrientationLetterboxAspectRatio = mContext.getResources().getFloat(
                 R.dimen.config_fixedOrientationLetterboxAspectRatio);
         mLetterboxActivityCornersRadius = mContext.getResources().getInteger(
                 R.integer.config_letterboxActivityCornersRadius);
         mLetterboxBackgroundType = readLetterboxBackgroundTypeFromConfig(mContext);
         mLetterboxBackgroundWallpaperBlurRadius = mContext.getResources().getDimensionPixelSize(
                 R.dimen.config_letterboxBackgroundWallpaperBlurRadius);
         mLetterboxBackgroundWallpaperDarkScrimAlpha = mContext.getResources().getFloat(
                 R.dimen.config_letterboxBackgroundWallaperDarkScrimAlpha);
         mLetterboxHorizontalPositionMultiplier = mContext.getResources().getFloat(
                 R.dimen.config_letterboxHorizontalPositionMultiplier);
         mIsReachabilityEnabled = mContext.getResources().getBoolean(
                 R.bool.config_letterboxIsReachabilityEnabled);
         mDefaultPositionForReachability = readLetterboxReachabilityPositionFromConfig(mContext);
         mLetterboxPositionForReachability = mDefaultPositionForReachability;
         mIsEducationEnabled = mContext.getResources().getBoolean(
                 R.bool.config_letterboxIsEducationEnabled);
     }

     /**
      * Overrides the aspect ratio of letterbox for fixed orientation. If given value is <= {@link
      * #MIN_FIXED_ORIENTATION_LETTERBOX_ASPECT_RATIO}, both it and a value of {@link
      * com.android.internal.R.dimen.config_fixedOrientationLetterboxAspectRatio} will be ignored and
      * the framework implementation will be used to determine the aspect ratio.
      */
     @VisibleForTesting
     void setFixedOrientationLetterboxAspectRatio(float aspectRatio) {
         mFixedOrientationLetterboxAspectRatio = aspectRatio;
     }

     /**
      * Resets the aspect ratio of letterbox for fixed orientation to {@link
      * com.android.internal.R.dimen.config_fixedOrientationLetterboxAspectRatio}.
      */
     @VisibleForTesting
     void resetFixedOrientationLetterboxAspectRatio() {
         mFixedOrientationLetterboxAspectRatio = mContext.getResources().getFloat(
                 com.android.internal.R.dimen.config_fixedOrientationLetterboxAspectRatio);
     }

     /**
      * Gets the aspect ratio of letterbox for fixed orientation.
      */
     float getFixedOrientationLetterboxAspectRatio() {
         return mFixedOrientationLetterboxAspectRatio;
     }

     /**
      * Whether corners of letterboxed activities are rounded.
      */
     boolean isLetterboxActivityCornersRounded() {
         return getLetterboxActivityCornersRadius() != 0;
     }

     /**
      * Gets corners raidus for activities presented in the letterbox mode.
      */
     int getLetterboxActivityCornersRadius() {
         return mLetterboxActivityCornersRadius;
     }

     /**
      * Gets color of letterbox background which is used when {@link
      * #getLetterboxBackgroundType()} is {@link #LETTERBOX_BACKGROUND_SOLID_COLOR} or as
      * fallback for other backfround types.
      */
     Color getLetterboxBackgroundColor() {
         if (mLetterboxBackgroundColorOverride != null) {
             return mLetterboxBackgroundColorOverride;
         }
         int colorId = mLetterboxBackgroundColorResourceIdOverride != null
                 ? mLetterboxBackgroundColorResourceIdOverride
                 : R.color.config_letterboxBackgroundColor;
         // Query color dynamically because material colors extracted from wallpaper are updated
         // when wallpaper is changed.
         return Color.valueOf(mContext.getResources().getColor(colorId));
     }

     /**
      * Gets {@link LetterboxBackgroundType} specified in {@link
      * com.android.internal.R.integer.config_letterboxBackgroundType} or over via ADB command.
      */
     @LetterboxBackgroundType
     int getLetterboxBackgroundType() {
         return mLetterboxBackgroundType;
     }

     /** Returns a string representing the given {@link LetterboxBackgroundType}. */
     static String letterboxBackgroundTypeToString(
             @LetterboxBackgroundType int backgroundType) {
         switch (backgroundType) {
             case LETTERBOX_BACKGROUND_SOLID_COLOR:
                 return "LETTERBOX_BACKGROUND_SOLID_COLOR";
             case LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND:
                 return "LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND";
             case LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND_FLOATING:
                 return "LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND_FLOATING";
             case LETTERBOX_BACKGROUND_WALLPAPER:
                 return "LETTERBOX_BACKGROUND_WALLPAPER";
             default:
                 return "unknown=" + backgroundType;
         }
     }

     @LetterboxBackgroundType
     private static int readLetterboxBackgroundTypeFromConfig(Context context) {
         int backgroundType = context.getResources().getInteger(
                 com.android.internal.R.integer.config_letterboxBackgroundType);
         return backgroundType == LETTERBOX_BACKGROUND_SOLID_COLOR
                     || backgroundType == LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND
                     || backgroundType == LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND_FLOATING
                     || backgroundType == LETTERBOX_BACKGROUND_WALLPAPER
                     ? backgroundType : LETTERBOX_BACKGROUND_SOLID_COLOR;
     }

     /**
      * Gets alpha of a black scrim shown over wallpaper letterbox background.
      */
     float getLetterboxBackgroundWallpaperDarkScrimAlpha() {
         return mLetterboxBackgroundWallpaperDarkScrimAlpha;
     }

     /**
      * Gets blur raidus for {@link #LETTERBOX_BACKGROUND_WALLPAPER} option in {@link
      * mLetterboxBackgroundType}.
      */
     int getLetterboxBackgroundWallpaperBlurRadius() {
         return mLetterboxBackgroundWallpaperBlurRadius;
     }

     /*
      * Gets horizontal position of a center of the letterboxed app window specified
      * in {@link com.android.internal.R.dimen.config_letterboxHorizontalPositionMultiplier}
      * or via an ADB command. 0 corresponds to the left side of the screen and 1 to the
      * right side.
      */
     float getLetterboxHorizontalPositionMultiplier() {
         return (mLetterboxHorizontalPositionMultiplier < 0.0f
                 || mLetterboxHorizontalPositionMultiplier > 1.0f)
                         // Default to central position if invalid value is provided.
                         ? 0.5f : mLetterboxHorizontalPositionMultiplier;
     }

     /**
      * Overrides horizontal position of a center of the letterboxed app window. If given value < 0
      * or > 1, then it and a value of {@link
      * com.android.internal.R.dimen.config_letterboxHorizontalPositionMultiplier} are ignored and
      * central position (0.5) is used.
      */
     @VisibleForTesting
     void setLetterboxHorizontalPositionMultiplier(float multiplier) {
         mLetterboxHorizontalPositionMultiplier = multiplier;
     }

     /**
      * Resets horizontal position of a center of the letterboxed app window to {@link
      * com.android.internal.R.dimen.config_letterboxHorizontalPositionMultiplier}.
      */
     @VisibleForTesting
     void resetLetterboxHorizontalPositionMultiplier() {
         mLetterboxHorizontalPositionMultiplier = mContext.getResources().getFloat(
                 com.android.internal.R.dimen.config_letterboxHorizontalPositionMultiplier);
     }

     /*
      * Whether reachability repositioning is allowed for letterboxed fullscreen apps in landscape
      * device orientation.
      */
     boolean getIsReachabilityEnabled() {
         return mIsReachabilityEnabled;
     }

     /**
      * Overrides whether reachability repositioning is allowed for letterboxed fullscreen apps in
      * landscape device orientation.
      */
     @VisibleForTesting
     void setIsReachabilityEnabled(boolean enabled) {
         mIsReachabilityEnabled = enabled;
     }

     /**
      * Resets whether reachability repositioning is allowed for letterboxed fullscreen apps in
      * landscape device orientation to {@link R.bool.config_letterboxIsReachabilityEnabled}.
      */
     @VisibleForTesting
     void resetIsReachabilityEnabled() {
         mIsReachabilityEnabled = mContext.getResources().getBoolean(
                 R.bool.config_letterboxIsReachabilityEnabled);
     }

     /*
      * Gets default horizontal position of the letterboxed app window when reachability is enabled.
      * Specified in {@link R.integer.config_letterboxDefaultPositionForReachability} or via an ADB
      * command.
      */
     @LetterboxReachabilityPosition
     int getDefaultPositionForReachability() {
         return mDefaultPositionForReachability;
     }

     @LetterboxReachabilityPosition
     private static int readLetterboxReachabilityPositionFromConfig(Context context) {
         int position = context.getResources().getInteger(
                 R.integer.config_letterboxDefaultPositionForReachability);
         return position == LETTERBOX_REACHABILITY_POSITION_LEFT
                     || position == LETTERBOX_REACHABILITY_POSITION_CENTER
                     || position == LETTERBOX_REACHABILITY_POSITION_RIGHT
                     ? position : LETTERBOX_REACHABILITY_POSITION_CENTER;
     }

     /*
      * Gets horizontal position of a center of the letterboxed app window when reachability
      * is enabled specified. 0 corresponds to the left side of the screen and 1 to the right side.
      *
      * <p>The position multiplier is changed after each double tap in the letterbox area.
      */
     float getHorizontalMultiplierForReachability() {
         switch (mLetterboxPositionForReachability) {
             case LETTERBOX_REACHABILITY_POSITION_LEFT:
                 return 0.0f;
             case LETTERBOX_REACHABILITY_POSITION_CENTER:
                 return 0.5f;
             case LETTERBOX_REACHABILITY_POSITION_RIGHT:
                 return 1.0f;
             default:
                 throw new AssertionError(
                     "Unexpected letterbox position type: " + mLetterboxPositionForReachability);
         }
     }

     /** Returns a string representing the given {@link LetterboxReachabilityPosition}. */
     static String letterboxReachabilityPositionToString(
             @LetterboxReachabilityPosition int position) {
         switch (position) {
             case LETTERBOX_REACHABILITY_POSITION_LEFT:
                 return "LETTERBOX_REACHABILITY_POSITION_LEFT";
             case LETTERBOX_REACHABILITY_POSITION_CENTER:
                 return "LETTERBOX_REACHABILITY_POSITION_CENTER";
             case LETTERBOX_REACHABILITY_POSITION_RIGHT:
                 return "LETTERBOX_REACHABILITY_POSITION_RIGHT";
             default:
                 throw new AssertionError(
                     "Unexpected letterbox position type: " + position);
         }
     }

     /**
      * Changes letterbox position for reachability to the next available one on the right side.
      */
     void movePositionForReachabilityToNextRightStop() {
         mLetterboxPositionForReachability = Math.min(
                 mLetterboxPositionForReachability + 1, LETTERBOX_REACHABILITY_POSITION_RIGHT);
     }

     /**
      * Changes letterbox position for reachability to the next available one on the left side.
      */
     void movePositionForReachabilityToNextLeftStop() {
         mLetterboxPositionForReachability = Math.max(mLetterboxPositionForReachability - 1, 0);
     }

     /**
      * Whether education is allowed for letterboxed fullscreen apps.
      */
     boolean getIsEducationEnabled() {
         return mIsEducationEnabled;
     }

     /**
      * Overrides whether education is allowed for letterboxed fullscreen apps.
      */
     @VisibleForTesting
     void setIsEducationEnabled(boolean enabled) {
         mIsEducationEnabled = enabled;
     }
 }
	/*
	* Copyright (C) 2021 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.server.wm;

	import android.annotation.IntDef;
	import android.annotation.Nullable;
	import android.content.Context;
	import android.graphics.Color;

	import com.android.internal.R;
	import com.android.internal.annotations.VisibleForTesting;

	import java.lang.annotation.Retention;
	import java.lang.annotation.RetentionPolicy;

	/** Reads letterbox configs from resources and controls their overrides at runtime. */
	final class LetterboxConfiguration {

	/**
	* Override of aspect ratio for fixed orientation letterboxing that is set via ADB with
	* set-fixed-orientation-letterbox-aspect-ratio or via {@link
	* com.android.internal.R.dimen.config_fixedOrientationLetterboxAspectRatio} will be ignored
	* if it is <= this value.
	*/
	static final float MIN_FIXED_ORIENTATION_LETTERBOX_ASPECT_RATIO = 1.0f;

	/** Enum for Letterbox background type. */
	@Retention(RetentionPolicy.SOURCE)
	@IntDef({LETTERBOX_BACKGROUND_SOLID_COLOR, LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND,
	LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND_FLOATING, LETTERBOX_BACKGROUND_WALLPAPER})
	@interface LetterboxBackgroundType {};
	/** Solid background using color specified in R.color.config_letterboxBackgroundColor. */
	static final int LETTERBOX_BACKGROUND_SOLID_COLOR = 0;

	/** Color specified in R.attr.colorBackground for the letterboxed application. */
	static final int LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND = 1;

	/** Color specified in R.attr.colorBackgroundFloating for the letterboxed application. */
	static final int LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND_FLOATING = 2;

	/** Using wallpaper as a background which can be blurred or dimmed with dark scrim. */
	static final int LETTERBOX_BACKGROUND_WALLPAPER = 3;

	/**
	* Enum for Letterbox reachability position types.
	*
	* <p>Order from left to right is important since it's used in {@link
	* #movePositionForReachabilityToNextRightStop} and {@link
	* #movePositionForReachabilityToNextLeftStop}.
	*/
	@Retention(RetentionPolicy.SOURCE)
	@IntDef({LETTERBOX_REACHABILITY_POSITION_LEFT, LETTERBOX_REACHABILITY_POSITION_CENTER,
	LETTERBOX_REACHABILITY_POSITION_RIGHT})
	@interface LetterboxReachabilityPosition {};

	/** Letterboxed app window is aligned to the left side. */
	static final int LETTERBOX_REACHABILITY_POSITION_LEFT = 0;

	/** Letterboxed app window is positioned in the horizontal center. */
	static final int LETTERBOX_REACHABILITY_POSITION_CENTER = 1;

	/** Letterboxed app window is aligned to the right side. */
	static final int LETTERBOX_REACHABILITY_POSITION_RIGHT = 2;

	final Context mContext;

	// Aspect ratio of letterbox for fixed orientation, values <=
	// MIN_FIXED_ORIENTATION_LETTERBOX_ASPECT_RATIO will be ignored.
	private float mFixedOrientationLetterboxAspectRatio;

	// Corners radius for activities presented in the letterbox mode, values < 0 will be ignored.
	private int mLetterboxActivityCornersRadius;

	// Color for {@link #LETTERBOX_BACKGROUND_SOLID_COLOR} letterbox background type.
	@Nullable private Color mLetterboxBackgroundColorOverride;

	// Color resource id for {@link #LETTERBOX_BACKGROUND_SOLID_COLOR} letterbox background type.
	@Nullable private Integer mLetterboxBackgroundColorResourceIdOverride;

	@LetterboxBackgroundType
	private int mLetterboxBackgroundType;

	// Blur radius for LETTERBOX_BACKGROUND_WALLPAPER option in mLetterboxBackgroundType.
	// Values <= 0 are ignored and 0 is used instead.
	private int mLetterboxBackgroundWallpaperBlurRadius;

	// Alpha of a black scrim shown over wallpaper letterbox background when
	// LETTERBOX_BACKGROUND_WALLPAPER option is selected for mLetterboxBackgroundType.
	// Values < 0 or >= 1 are ignored and 0.0 (transparent) is used instead.
	private float mLetterboxBackgroundWallpaperDarkScrimAlpha;

	// Horizontal position of a center of the letterboxed app window. 0 corresponds to the left
	// side of the screen and 1.0 to the right side.
	private float mLetterboxHorizontalPositionMultiplier;

	// Default horizontal position the letterboxed app window when reachability is enabled and
	// an app is fullscreen in landscape device orientatio.
	// It is used as a starting point for mLetterboxPositionForReachability.
	@LetterboxReachabilityPosition
	private int mDefaultPositionForReachability;

	// Whether reachability repositioning is allowed for letterboxed fullscreen apps in landscape
	// device orientation.
	private boolean mIsReachabilityEnabled;

	// Horizontal position of a center of the letterboxed app window which is global to prevent
	// "jumps" when switching between letterboxed apps. It's updated to reposition the app window
	// in response to a double tap gesture (see LetterboxUiController#handleDoubleTap). Used in
	// LetterboxUiController#getHorizontalPositionMultiplier which is called from
	// ActivityRecord#updateResolvedBoundsHorizontalPosition.
	// TODO(b/199426138): Global reachability setting causes a jump when resuming an app from
	// Overview after changing position in another app.
	@LetterboxReachabilityPosition
	private volatile int mLetterboxPositionForReachability;

	// Whether education is allowed for letterboxed fullscreen apps.
	private boolean mIsEducationEnabled;

	LetterboxConfiguration(Context systemUiContext) {
	mContext = systemUiContext;
	mFixedOrientationLetterboxAspectRatio = mContext.getResources().getFloat(
	R.dimen.config_fixedOrientationLetterboxAspectRatio);
	mLetterboxActivityCornersRadius = mContext.getResources().getInteger(
	R.integer.config_letterboxActivityCornersRadius);
	mLetterboxBackgroundType = readLetterboxBackgroundTypeFromConfig(mContext);
	mLetterboxBackgroundWallpaperBlurRadius = mContext.getResources().getDimensionPixelSize(
	R.dimen.config_letterboxBackgroundWallpaperBlurRadius);
	mLetterboxBackgroundWallpaperDarkScrimAlpha = mContext.getResources().getFloat(
	R.dimen.config_letterboxBackgroundWallaperDarkScrimAlpha);
	mLetterboxHorizontalPositionMultiplier = mContext.getResources().getFloat(
	R.dimen.config_letterboxHorizontalPositionMultiplier);
	mIsReachabilityEnabled = mContext.getResources().getBoolean(
	R.bool.config_letterboxIsReachabilityEnabled);
	mDefaultPositionForReachability = readLetterboxReachabilityPositionFromConfig(mContext);
	mLetterboxPositionForReachability = mDefaultPositionForReachability;
	mIsEducationEnabled = mContext.getResources().getBoolean(
	R.bool.config_letterboxIsEducationEnabled);
	}

	/**
	* Overrides the aspect ratio of letterbox for fixed orientation. If given value is <= {@link
	* #MIN_FIXED_ORIENTATION_LETTERBOX_ASPECT_RATIO}, both it and a value of {@link
	* com.android.internal.R.dimen.config_fixedOrientationLetterboxAspectRatio} will be ignored and
	* the framework implementation will be used to determine the aspect ratio.
	*/
	@VisibleForTesting
	void setFixedOrientationLetterboxAspectRatio(float aspectRatio) {
	mFixedOrientationLetterboxAspectRatio = aspectRatio;
	}

	/**
	* Resets the aspect ratio of letterbox for fixed orientation to {@link
	* com.android.internal.R.dimen.config_fixedOrientationLetterboxAspectRatio}.
	*/
	@VisibleForTesting
	void resetFixedOrientationLetterboxAspectRatio() {
	mFixedOrientationLetterboxAspectRatio = mContext.getResources().getFloat(
	com.android.internal.R.dimen.config_fixedOrientationLetterboxAspectRatio);
	}

	/**
	* Gets the aspect ratio of letterbox for fixed orientation.
	*/
	float getFixedOrientationLetterboxAspectRatio() {
	return mFixedOrientationLetterboxAspectRatio;
	}

	/**
	* Whether corners of letterboxed activities are rounded.
	*/
	boolean isLetterboxActivityCornersRounded() {
	return getLetterboxActivityCornersRadius() != 0;
	}

	/**
	* Gets corners raidus for activities presented in the letterbox mode.
	*/
	int getLetterboxActivityCornersRadius() {
	return mLetterboxActivityCornersRadius;
	}

	/**
	* Gets color of letterbox background which is used when {@link
	* #getLetterboxBackgroundType()} is {@link #LETTERBOX_BACKGROUND_SOLID_COLOR} or as
	* fallback for other backfround types.
	*/
	Color getLetterboxBackgroundColor() {
	if (mLetterboxBackgroundColorOverride != null) {
	return mLetterboxBackgroundColorOverride;
	}
	int colorId = mLetterboxBackgroundColorResourceIdOverride != null
	? mLetterboxBackgroundColorResourceIdOverride
	: R.color.config_letterboxBackgroundColor;
	// Query color dynamically because material colors extracted from wallpaper are updated
	// when wallpaper is changed.
	return Color.valueOf(mContext.getResources().getColor(colorId));
	}

	/**
	* Gets {@link LetterboxBackgroundType} specified in {@link
	* com.android.internal.R.integer.config_letterboxBackgroundType} or over via ADB command.
	*/
	@LetterboxBackgroundType
	int getLetterboxBackgroundType() {
	return mLetterboxBackgroundType;
	}

	/** Returns a string representing the given {@link LetterboxBackgroundType}. */
	static String letterboxBackgroundTypeToString(
	@LetterboxBackgroundType int backgroundType) {
	switch (backgroundType) {
	case LETTERBOX_BACKGROUND_SOLID_COLOR:
	return "LETTERBOX_BACKGROUND_SOLID_COLOR";
	case LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND:
	return "LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND";
	case LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND_FLOATING:
	return "LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND_FLOATING";
	case LETTERBOX_BACKGROUND_WALLPAPER:
	return "LETTERBOX_BACKGROUND_WALLPAPER";
	default:
	return "unknown=" + backgroundType;
	}
	}

	@LetterboxBackgroundType
	private static int readLetterboxBackgroundTypeFromConfig(Context context) {
	int backgroundType = context.getResources().getInteger(
	com.android.internal.R.integer.config_letterboxBackgroundType);
	return backgroundType == LETTERBOX_BACKGROUND_SOLID_COLOR
	\|\| backgroundType == LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND
	\|\| backgroundType == LETTERBOX_BACKGROUND_APP_COLOR_BACKGROUND_FLOATING
	\|\| backgroundType == LETTERBOX_BACKGROUND_WALLPAPER
	? backgroundType : LETTERBOX_BACKGROUND_SOLID_COLOR;
	}

	/**
	* Gets alpha of a black scrim shown over wallpaper letterbox background.
	*/
	float getLetterboxBackgroundWallpaperDarkScrimAlpha() {
	return mLetterboxBackgroundWallpaperDarkScrimAlpha;
	}

	/**
	* Gets blur raidus for {@link #LETTERBOX_BACKGROUND_WALLPAPER} option in {@link
	* mLetterboxBackgroundType}.
	*/
	int getLetterboxBackgroundWallpaperBlurRadius() {
	return mLetterboxBackgroundWallpaperBlurRadius;
	}

	/*
	* Gets horizontal position of a center of the letterboxed app window specified
	* in {@link com.android.internal.R.dimen.config_letterboxHorizontalPositionMultiplier}
	* or via an ADB command. 0 corresponds to the left side of the screen and 1 to the
	* right side.
	*/
	float getLetterboxHorizontalPositionMultiplier() {
	return (mLetterboxHorizontalPositionMultiplier < 0.0f
	\|\| mLetterboxHorizontalPositionMultiplier > 1.0f)
	// Default to central position if invalid value is provided.
	? 0.5f : mLetterboxHorizontalPositionMultiplier;
	}

	/**
	* Overrides horizontal position of a center of the letterboxed app window. If given value < 0
	* or > 1, then it and a value of {@link
	* com.android.internal.R.dimen.config_letterboxHorizontalPositionMultiplier} are ignored and
	* central position (0.5) is used.
	*/
	@VisibleForTesting
	void setLetterboxHorizontalPositionMultiplier(float multiplier) {
	mLetterboxHorizontalPositionMultiplier = multiplier;
	}

	/**
	* Resets horizontal position of a center of the letterboxed app window to {@link
	* com.android.internal.R.dimen.config_letterboxHorizontalPositionMultiplier}.
	*/
	@VisibleForTesting
	void resetLetterboxHorizontalPositionMultiplier() {
	mLetterboxHorizontalPositionMultiplier = mContext.getResources().getFloat(
	com.android.internal.R.dimen.config_letterboxHorizontalPositionMultiplier);
	}

	/*
	* Whether reachability repositioning is allowed for letterboxed fullscreen apps in landscape
	* device orientation.
	*/
	boolean getIsReachabilityEnabled() {
	return mIsReachabilityEnabled;
	}

	/**
	* Overrides whether reachability repositioning is allowed for letterboxed fullscreen apps in
	* landscape device orientation.
	*/
	@VisibleForTesting
	void setIsReachabilityEnabled(boolean enabled) {
	mIsReachabilityEnabled = enabled;
	}

	/**
	* Resets whether reachability repositioning is allowed for letterboxed fullscreen apps in
	* landscape device orientation to {@link R.bool.config_letterboxIsReachabilityEnabled}.
	*/
	@VisibleForTesting
	void resetIsReachabilityEnabled() {
	mIsReachabilityEnabled = mContext.getResources().getBoolean(
	R.bool.config_letterboxIsReachabilityEnabled);
	}

	/*
	* Gets default horizontal position of the letterboxed app window when reachability is enabled.
	* Specified in {@link R.integer.config_letterboxDefaultPositionForReachability} or via an ADB
	* command.
	*/
	@LetterboxReachabilityPosition
	int getDefaultPositionForReachability() {
	return mDefaultPositionForReachability;
	}

	@LetterboxReachabilityPosition
	private static int readLetterboxReachabilityPositionFromConfig(Context context) {
	int position = context.getResources().getInteger(
	R.integer.config_letterboxDefaultPositionForReachability);
	return position == LETTERBOX_REACHABILITY_POSITION_LEFT
	\|\| position == LETTERBOX_REACHABILITY_POSITION_CENTER
	\|\| position == LETTERBOX_REACHABILITY_POSITION_RIGHT
	? position : LETTERBOX_REACHABILITY_POSITION_CENTER;
	}

	/*
	* Gets horizontal position of a center of the letterboxed app window when reachability
	* is enabled specified. 0 corresponds to the left side of the screen and 1 to the right side.
	*
	* <p>The position multiplier is changed after each double tap in the letterbox area.
	*/
	float getHorizontalMultiplierForReachability() {
	switch (mLetterboxPositionForReachability) {
	case LETTERBOX_REACHABILITY_POSITION_LEFT:
	return 0.0f;
	case LETTERBOX_REACHABILITY_POSITION_CENTER:
	return 0.5f;
	case LETTERBOX_REACHABILITY_POSITION_RIGHT:
	return 1.0f;
	default:
	throw new AssertionError(
	"Unexpected letterbox position type: " + mLetterboxPositionForReachability);
	}
	}

	/** Returns a string representing the given {@link LetterboxReachabilityPosition}. */
	static String letterboxReachabilityPositionToString(
	@LetterboxReachabilityPosition int position) {
	switch (position) {
	case LETTERBOX_REACHABILITY_POSITION_LEFT:
	return "LETTERBOX_REACHABILITY_POSITION_LEFT";
	case LETTERBOX_REACHABILITY_POSITION_CENTER:
	return "LETTERBOX_REACHABILITY_POSITION_CENTER";
	case LETTERBOX_REACHABILITY_POSITION_RIGHT:
	return "LETTERBOX_REACHABILITY_POSITION_RIGHT";
	default:
	throw new AssertionError(
	"Unexpected letterbox position type: " + position);
	}
	}

	/**
	* Changes letterbox position for reachability to the next available one on the right side.
	*/
	void movePositionForReachabilityToNextRightStop() {
	mLetterboxPositionForReachability = Math.min(
	mLetterboxPositionForReachability + 1, LETTERBOX_REACHABILITY_POSITION_RIGHT);
	}

	/**
	* Changes letterbox position for reachability to the next available one on the left side.
	*/
	void movePositionForReachabilityToNextLeftStop() {
	mLetterboxPositionForReachability = Math.max(mLetterboxPositionForReachability - 1, 0);
	}

	/**
	* Whether education is allowed for letterboxed fullscreen apps.
	*/
	boolean getIsEducationEnabled() {
	return mIsEducationEnabled;
	}

	/**
	* Overrides whether education is allowed for letterboxed fullscreen apps.
	*/
	@VisibleForTesting
	void setIsEducationEnabled(boolean enabled) {
	mIsEducationEnabled = enabled;
	}
	}