src/com/android/car/carlauncher/displayarea/CarDisplayAreaController.java - platform/packages/apps/Car/Launcher - 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.car.carlauncher.displayarea;

 import static com.android.car.carlauncher.displayarea.CarDisplayAreaOrganizer.BACKGROUND_TASK_CONTAINER;
 import static com.android.car.carlauncher.displayarea.CarDisplayAreaOrganizer.CONTROL_BAR_DISPLAY_AREA;
 import static com.android.car.carlauncher.displayarea.CarDisplayAreaOrganizer.FOREGROUND_DISPLAY_AREA_ROOT;

 import android.content.Context;
 import android.content.res.Resources;
 import android.graphics.Rect;
 import android.util.DisplayMetrics;
 import android.window.DisplayAreaAppearedInfo;
 import android.window.WindowContainerToken;
 import android.window.WindowContainerTransaction;

 import com.android.car.carlauncher.AppGridActivity;
 import com.android.car.carlauncher.R;
 import com.android.wm.shell.common.HandlerExecutor;
 import com.android.wm.shell.common.SyncTransactionQueue;

 import java.util.List;

 /**
  * Controls the bounds of the home background and application displays. This is a singleton class as
  * there should be one controller used to register and control the DA's
  */
 public class CarDisplayAreaController {
     private static final String TAG = "CarDisplayAreaController";
     // Layer index of how display areas should be placed. Keeping a gap of 100 if we want to
     // add some other display area layers in between in future.
     static final int BACKGROUND_LAYER_INDEX = 0;
     static final int FOREGROUND_LAYER_INDEX = 100;
     static final int CONTROL_BAR_LAYER_INDEX = 200;
     static final CarDisplayAreaController INSTANCE = new CarDisplayAreaController();

     private final Rect mControlBarDisplayBounds = new Rect();
     private final Rect mForegroundApplicationDisplayBounds = new Rect();
     private final Rect mBackgroundApplicationDisplayBounds = new Rect();
     private final Rect mNavBarBounds = new Rect();

     private SyncTransactionQueue mSyncQueue;
     private CarDisplayAreaOrganizer mOrganizer;
     private DisplayAreaAppearedInfo mForegroundApplicationsDisplay;
     private DisplayAreaAppearedInfo mBackgroundApplicationDisplay;
     private DisplayAreaAppearedInfo mControlBarDisplay;
     private int mDpiDensity;
     private int mTotalScreenWidth = -1;
     // height of DA hosting the control bar.
     private int mControlBarDisplayHeight;
     // height of DA hosting default apps and covering the maps fully.
     private int mFullDisplayHeight;
     // height of DA hosting default apps and covering the maps to default height.
     private int mDefaultDisplayHeight;
     private int mScreenHeightWithoutNavBar;
     private boolean mIsHostingDefaultApplicationDisplayAreaVisible;
     private CarDisplayAreaTouchHandler mCarDisplayAreaTouchHandler;
     public static boolean sIsRegistered;

     /**
      * Gets the instance of {@link CarDisplayAreaController}
      */
     public static CarDisplayAreaController getInstance() {
         return INSTANCE;
     }

     /**
      * Initializes the controller
      */
     public void init(Context context, SyncTransactionQueue syncQueue,
             CarDisplayAreaOrganizer organizer) {
         mSyncQueue = syncQueue;
         mOrganizer = organizer;
         int totalScreenHeight = context.getResources().getDimensionPixelSize(
                 R.dimen.total_screen_height);
         mTotalScreenWidth = context.getResources().getDimensionPixelSize(
                 R.dimen.total_screen_width);
         mControlBarDisplayHeight = context.getResources().getDimensionPixelSize(
                 R.dimen.control_bar_height);
         mFullDisplayHeight = context.getResources().getDimensionPixelSize(
                 R.dimen.full_app_display_area_height);
         mDefaultDisplayHeight = context.getResources().getDimensionPixelSize(
                 R.dimen.default_app_display_area_height);
         mCarDisplayAreaTouchHandler = new CarDisplayAreaTouchHandler(
                 new HandlerExecutor(context.getMainThreadHandler()));

         // Get bottom nav bar height.
         Resources resources = context.getResources();
         int navBarHeight = resources.getDimensionPixelSize(
                 com.android.internal.R.dimen.navigation_bar_height);
         if (navBarHeight > 0) {
             mNavBarBounds.set(0, totalScreenHeight - navBarHeight, mTotalScreenWidth,
                     totalScreenHeight);
         }

         // Get left nav bar width.
         int leftNavBarWidthResId = resources
                 .getIdentifier("car_left_system_bar_width", "dimen", "android");
         int leftNavBarWidth = 0;
         if (leftNavBarWidthResId > 0) {
             leftNavBarWidth = resources.getDimensionPixelSize(leftNavBarWidthResId);
             mNavBarBounds.set(0, 0, leftNavBarWidth, totalScreenHeight);
         }

         // Get right nav bar width.
         int rightNavBarWidthResId = resources
                 .getIdentifier("car_right_system_bar_width", "dimen", "android");
         int rightNavBarWidth = 0;
         if (rightNavBarWidthResId > 0) {
             rightNavBarWidth = resources.getDimensionPixelSize(rightNavBarWidthResId);
             mNavBarBounds.set(mTotalScreenWidth - rightNavBarWidth, 0, mTotalScreenWidth,
                     totalScreenHeight);
         }

         mScreenHeightWithoutNavBar = totalScreenHeight - mNavBarBounds.height();
     }

     private CarDisplayAreaController() {
     }

     /**
      * Returns if display area hosting default application is visible to user or not.
      */
     public boolean isHostingDefaultApplicationDisplayAreaVisible() {
         return mIsHostingDefaultApplicationDisplayAreaVisible;
     }

     /** Registers the DA organizer. */
     public void register() {
         mDpiDensity = mOrganizer.getDpiDensity();
         sIsRegistered = true;

         // Register DA organizer.
         registerOrganizer();

         // Pre-calculate the foreground and background display bounds for different configs.
         populateBounds();

         // Set the initial bounds for first and second displays.
         WindowContainerTransaction wct = new WindowContainerTransaction();
         updateBounds(wct);
         mOrganizer.applyTransaction(wct);

         mCarDisplayAreaTouchHandler.registerTouchEventListener((x, y) -> {
             // Check if the click is outside the bounds of default display. If so, close the
             // display area.
             if (mIsHostingDefaultApplicationDisplayAreaVisible
                     && y < (mScreenHeightWithoutNavBar - mDefaultDisplayHeight)) {
                 // TODO: closing logic goes here, something like: startAnimation(CONTROL_BAR);
             }
         });
         mCarDisplayAreaTouchHandler.enable(true);
     }

     /** Registers DA organizer. */
     private void registerOrganizer() {
         List<DisplayAreaAppearedInfo> foregroundDisplayAreaInfos =
                 mOrganizer.registerOrganizer(FOREGROUND_DISPLAY_AREA_ROOT);
         List<DisplayAreaAppearedInfo> backgroundDisplayAreaInfos =
                 mOrganizer.registerOrganizer(BACKGROUND_TASK_CONTAINER);
         List<DisplayAreaAppearedInfo> controlBarDisplayAreaInfos =
                 mOrganizer.registerOrganizer(CONTROL_BAR_DISPLAY_AREA);
         if (foregroundDisplayAreaInfos.size() != 1) {
             throw new IllegalStateException("Can't find display to launch default applications");
         }
         if (backgroundDisplayAreaInfos.size() != 1) {
             throw new IllegalStateException("Can't find display to launch activity in background");
         }
         if (controlBarDisplayAreaInfos.size() != 1) {
             throw new IllegalStateException("Can't find display to launch audio control");
         }

         // As we have only 1 display defined for each display area feature get the 0th index.
         mForegroundApplicationsDisplay = foregroundDisplayAreaInfos.get(0);
         mBackgroundApplicationDisplay = backgroundDisplayAreaInfos.get(0);
         mControlBarDisplay = controlBarDisplayAreaInfos.get(0);
     }

     /** Un-Registers DA organizer. */
     public void unregister() {
         mOrganizer.resetWindowsOffset();
         mOrganizer.unregisterOrganizer();
         mForegroundApplicationsDisplay = null;
         mBackgroundApplicationDisplay = null;
         mControlBarDisplay = null;
         mCarDisplayAreaTouchHandler.enable(false);
         sIsRegistered = false;
     }

     /**
      * This method should be called after the registration of DA's are done. The method expects a
      * target state as an argument, according to which the animations will take place. For example,
      * if the target state is {@link AppGridActivity.CAR_LAUNCHER_STATE#DEFAULT} then the foreground
      * DA hosting default applications will animate to the default set height.
      */
     public void startAnimation(AppGridActivity.CAR_LAUNCHER_STATE toState) {
         // TODO: currently the animations are only bottom/up. Make it more generic animations here.
         int fromPos = 0;
         int toPos = 0;
         switch (toState) {
             case CONTROL_BAR:
                 // Foreground DA closes.
                 fromPos = mScreenHeightWithoutNavBar - mDefaultDisplayHeight
                         - mControlBarDisplayHeight;
                 toPos = mScreenHeightWithoutNavBar;
                 mBackgroundApplicationDisplayBounds.bottom =
                         mScreenHeightWithoutNavBar - mControlBarDisplayHeight;
                 mOrganizer.scheduleOffset(fromPos, toPos, mBackgroundApplicationDisplayBounds,
                         mBackgroundApplicationDisplay, mForegroundApplicationsDisplay,
                         mControlBarDisplay, toState);
                 mIsHostingDefaultApplicationDisplayAreaVisible = false;
                 break;
             case FULL:
                 // TODO: Implement this.
                 break;
             default:
                 // Foreground DA opens to default height.
                 // update the bounds to expand the foreground display area before starting
                 // animations.
                 fromPos = mScreenHeightWithoutNavBar;
                 toPos = mScreenHeightWithoutNavBar - mDefaultDisplayHeight
                         - mControlBarDisplayHeight;
                 mBackgroundApplicationDisplayBounds.bottom = toPos;
                 mOrganizer.scheduleOffset(fromPos, toPos, mBackgroundApplicationDisplayBounds,
                         mBackgroundApplicationDisplay, mForegroundApplicationsDisplay,
                         mControlBarDisplay, toState);
                 mIsHostingDefaultApplicationDisplayAreaVisible = true;
         }
     }

     /** Pre-calculates the default and background display bounds for different configs. */
     private void populateBounds() {
         int controlBarTop = mScreenHeightWithoutNavBar - mControlBarDisplayHeight;

         // Bottom nav bar. Bottom nav bar height will be 0 if the nav bar is present on the sides.
         Rect backgroundBounds = new Rect(0, 0, mTotalScreenWidth, controlBarTop);
         Rect controlBarBounds = new Rect(0, controlBarTop, mTotalScreenWidth,
                 mScreenHeightWithoutNavBar);
         Rect foregroundBounds = new Rect(0,
                 mScreenHeightWithoutNavBar - mDefaultDisplayHeight - mControlBarDisplayHeight,
                 mTotalScreenWidth, mScreenHeightWithoutNavBar - mControlBarDisplayHeight);

         // Adjust the bounds based on the nav bar.
         // TODO: account for the case where nav bar is at the top.

         // Populate the bounds depending on where the nav bar is.
         if (mNavBarBounds.left == 0 && mNavBarBounds.top == 0) {
             // Left nav bar.
             backgroundBounds.left = mNavBarBounds.right;
             controlBarBounds.left = mNavBarBounds.right;
             foregroundBounds.left = mNavBarBounds.right;
         } else if (mNavBarBounds.top == 0) {
             // Right nav bar.
             backgroundBounds.right = mNavBarBounds.left;
             controlBarBounds.right = mNavBarBounds.left;
             foregroundBounds.right = mNavBarBounds.left;
         }

         mBackgroundApplicationDisplayBounds.set(backgroundBounds);
         mControlBarDisplayBounds.set(controlBarBounds);
         mForegroundApplicationDisplayBounds.set(foregroundBounds);
     }

     /** Updates the default and background display bounds for the given config. */
     private void updateBounds(WindowContainerTransaction wct) {
         Rect foregroundApplicationDisplayBound = mForegroundApplicationDisplayBounds;
         Rect backgroundApplicationDisplayBound = mBackgroundApplicationDisplayBounds;
         Rect controlBarDisplayBound = mControlBarDisplayBounds;
         WindowContainerToken foregroundDisplayToken =
                 mForegroundApplicationsDisplay.getDisplayAreaInfo().token;
         WindowContainerToken backgroundDisplayToken =
                 mBackgroundApplicationDisplay.getDisplayAreaInfo().token;
         WindowContainerToken controlBarDisplayToken =
                 mControlBarDisplay.getDisplayAreaInfo().token;

         int foregroundDisplayWidthDp =
                 foregroundApplicationDisplayBound.width() * DisplayMetrics.DENSITY_DEFAULT
                         / mDpiDensity;
         int foregroundDisplayHeightDp =
                 foregroundApplicationDisplayBound.height() * DisplayMetrics.DENSITY_DEFAULT
                         / mDpiDensity;
         wct.setBounds(foregroundDisplayToken, foregroundApplicationDisplayBound);
         wct.setScreenSizeDp(foregroundDisplayToken, foregroundDisplayWidthDp,
                 foregroundDisplayHeightDp);
         wct.setSmallestScreenWidthDp(foregroundDisplayToken, foregroundDisplayWidthDp);

         int backgroundDisplayWidthDp =
                 backgroundApplicationDisplayBound.width() * DisplayMetrics.DENSITY_DEFAULT
                         / mDpiDensity;
         int backgroundDisplayHeightDp =
                 backgroundApplicationDisplayBound.height() * DisplayMetrics.DENSITY_DEFAULT
                         / mDpiDensity;
         wct.setBounds(backgroundDisplayToken, backgroundApplicationDisplayBound);
         wct.setScreenSizeDp(backgroundDisplayToken, backgroundDisplayWidthDp,
                 backgroundDisplayHeightDp);
         wct.setSmallestScreenWidthDp(backgroundDisplayToken, backgroundDisplayWidthDp);

         int controlBarDisplayWidthDp =
                 controlBarDisplayBound.width() * DisplayMetrics.DENSITY_DEFAULT
                         / mDpiDensity;
         int controlBarDisplayHeightDp =
                 controlBarDisplayBound.height() * DisplayMetrics.DENSITY_DEFAULT
                         / mDpiDensity;
         wct.setBounds(controlBarDisplayToken, controlBarDisplayBound);
         wct.setScreenSizeDp(controlBarDisplayToken, controlBarDisplayWidthDp,
                 controlBarDisplayHeightDp);
         wct.setSmallestScreenWidthDp(controlBarDisplayToken, controlBarDisplayWidthDp);

         mSyncQueue.runInSync(t -> {
             t.setPosition(mForegroundApplicationsDisplay.getLeash(),
                     foregroundApplicationDisplayBound.left,
                     foregroundApplicationDisplayBound.top);
             t.setPosition(mBackgroundApplicationDisplay.getLeash(),
                     backgroundApplicationDisplayBound.left,
                     backgroundApplicationDisplayBound.top);
             t.setPosition(mControlBarDisplay.getLeash(),
                     controlBarDisplayBound.left,
                     controlBarDisplayBound.top);
         });
     }
 }
	/*
	* 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.car.carlauncher.displayarea;

	import static com.android.car.carlauncher.displayarea.CarDisplayAreaOrganizer.BACKGROUND_TASK_CONTAINER;
	import static com.android.car.carlauncher.displayarea.CarDisplayAreaOrganizer.CONTROL_BAR_DISPLAY_AREA;
	import static com.android.car.carlauncher.displayarea.CarDisplayAreaOrganizer.FOREGROUND_DISPLAY_AREA_ROOT;

	import android.content.Context;
	import android.content.res.Resources;
	import android.graphics.Rect;
	import android.util.DisplayMetrics;
	import android.window.DisplayAreaAppearedInfo;
	import android.window.WindowContainerToken;
	import android.window.WindowContainerTransaction;

	import com.android.car.carlauncher.AppGridActivity;
	import com.android.car.carlauncher.R;
	import com.android.wm.shell.common.HandlerExecutor;
	import com.android.wm.shell.common.SyncTransactionQueue;

	import java.util.List;

	/**
	* Controls the bounds of the home background and application displays. This is a singleton class as
	* there should be one controller used to register and control the DA's
	*/
	public class CarDisplayAreaController {
	private static final String TAG = "CarDisplayAreaController";
	// Layer index of how display areas should be placed. Keeping a gap of 100 if we want to
	// add some other display area layers in between in future.
	static final int BACKGROUND_LAYER_INDEX = 0;
	static final int FOREGROUND_LAYER_INDEX = 100;
	static final int CONTROL_BAR_LAYER_INDEX = 200;
	static final CarDisplayAreaController INSTANCE = new CarDisplayAreaController();

	private final Rect mControlBarDisplayBounds = new Rect();
	private final Rect mForegroundApplicationDisplayBounds = new Rect();
	private final Rect mBackgroundApplicationDisplayBounds = new Rect();
	private final Rect mNavBarBounds = new Rect();

	private SyncTransactionQueue mSyncQueue;
	private CarDisplayAreaOrganizer mOrganizer;
	private DisplayAreaAppearedInfo mForegroundApplicationsDisplay;
	private DisplayAreaAppearedInfo mBackgroundApplicationDisplay;
	private DisplayAreaAppearedInfo mControlBarDisplay;
	private int mDpiDensity;
	private int mTotalScreenWidth = -1;
	// height of DA hosting the control bar.
	private int mControlBarDisplayHeight;
	// height of DA hosting default apps and covering the maps fully.
	private int mFullDisplayHeight;
	// height of DA hosting default apps and covering the maps to default height.
	private int mDefaultDisplayHeight;
	private int mScreenHeightWithoutNavBar;
	private boolean mIsHostingDefaultApplicationDisplayAreaVisible;
	private CarDisplayAreaTouchHandler mCarDisplayAreaTouchHandler;
	public static boolean sIsRegistered;

	/**
	* Gets the instance of {@link CarDisplayAreaController}
	*/
	public static CarDisplayAreaController getInstance() {
	return INSTANCE;
	}

	/**
	* Initializes the controller
	*/
	public void init(Context context, SyncTransactionQueue syncQueue,
	CarDisplayAreaOrganizer organizer) {
	mSyncQueue = syncQueue;
	mOrganizer = organizer;
	int totalScreenHeight = context.getResources().getDimensionPixelSize(
	R.dimen.total_screen_height);
	mTotalScreenWidth = context.getResources().getDimensionPixelSize(
	R.dimen.total_screen_width);
	mControlBarDisplayHeight = context.getResources().getDimensionPixelSize(
	R.dimen.control_bar_height);
	mFullDisplayHeight = context.getResources().getDimensionPixelSize(
	R.dimen.full_app_display_area_height);
	mDefaultDisplayHeight = context.getResources().getDimensionPixelSize(
	R.dimen.default_app_display_area_height);
	mCarDisplayAreaTouchHandler = new CarDisplayAreaTouchHandler(
	new HandlerExecutor(context.getMainThreadHandler()));

	// Get bottom nav bar height.
	Resources resources = context.getResources();
	int navBarHeight = resources.getDimensionPixelSize(
	com.android.internal.R.dimen.navigation_bar_height);
	if (navBarHeight > 0) {
	mNavBarBounds.set(0, totalScreenHeight - navBarHeight, mTotalScreenWidth,
	totalScreenHeight);
	}

	// Get left nav bar width.
	int leftNavBarWidthResId = resources
	.getIdentifier("car_left_system_bar_width", "dimen", "android");
	int leftNavBarWidth = 0;
	if (leftNavBarWidthResId > 0) {
	leftNavBarWidth = resources.getDimensionPixelSize(leftNavBarWidthResId);
	mNavBarBounds.set(0, 0, leftNavBarWidth, totalScreenHeight);
	}

	// Get right nav bar width.
	int rightNavBarWidthResId = resources
	.getIdentifier("car_right_system_bar_width", "dimen", "android");
	int rightNavBarWidth = 0;
	if (rightNavBarWidthResId > 0) {
	rightNavBarWidth = resources.getDimensionPixelSize(rightNavBarWidthResId);
	mNavBarBounds.set(mTotalScreenWidth - rightNavBarWidth, 0, mTotalScreenWidth,
	totalScreenHeight);
	}

	mScreenHeightWithoutNavBar = totalScreenHeight - mNavBarBounds.height();
	}

	private CarDisplayAreaController() {
	}

	/**
	* Returns if display area hosting default application is visible to user or not.
	*/
	public boolean isHostingDefaultApplicationDisplayAreaVisible() {
	return mIsHostingDefaultApplicationDisplayAreaVisible;
	}

	/** Registers the DA organizer. */
	public void register() {
	mDpiDensity = mOrganizer.getDpiDensity();
	sIsRegistered = true;

	// Register DA organizer.
	registerOrganizer();

	// Pre-calculate the foreground and background display bounds for different configs.
	populateBounds();

	// Set the initial bounds for first and second displays.
	WindowContainerTransaction wct = new WindowContainerTransaction();
	updateBounds(wct);
	mOrganizer.applyTransaction(wct);

	mCarDisplayAreaTouchHandler.registerTouchEventListener((x, y) -> {
	// Check if the click is outside the bounds of default display. If so, close the
	// display area.
	if (mIsHostingDefaultApplicationDisplayAreaVisible
	&& y < (mScreenHeightWithoutNavBar - mDefaultDisplayHeight)) {
	// TODO: closing logic goes here, something like: startAnimation(CONTROL_BAR);
	}
	});
	mCarDisplayAreaTouchHandler.enable(true);
	}

	/** Registers DA organizer. */
	private void registerOrganizer() {
	List<DisplayAreaAppearedInfo> foregroundDisplayAreaInfos =
	mOrganizer.registerOrganizer(FOREGROUND_DISPLAY_AREA_ROOT);
	List<DisplayAreaAppearedInfo> backgroundDisplayAreaInfos =
	mOrganizer.registerOrganizer(BACKGROUND_TASK_CONTAINER);
	List<DisplayAreaAppearedInfo> controlBarDisplayAreaInfos =
	mOrganizer.registerOrganizer(CONTROL_BAR_DISPLAY_AREA);
	if (foregroundDisplayAreaInfos.size() != 1) {
	throw new IllegalStateException("Can't find display to launch default applications");
	}
	if (backgroundDisplayAreaInfos.size() != 1) {
	throw new IllegalStateException("Can't find display to launch activity in background");
	}
	if (controlBarDisplayAreaInfos.size() != 1) {
	throw new IllegalStateException("Can't find display to launch audio control");
	}

	// As we have only 1 display defined for each display area feature get the 0th index.
	mForegroundApplicationsDisplay = foregroundDisplayAreaInfos.get(0);
	mBackgroundApplicationDisplay = backgroundDisplayAreaInfos.get(0);
	mControlBarDisplay = controlBarDisplayAreaInfos.get(0);
	}

	/** Un-Registers DA organizer. */
	public void unregister() {
	mOrganizer.resetWindowsOffset();
	mOrganizer.unregisterOrganizer();
	mForegroundApplicationsDisplay = null;
	mBackgroundApplicationDisplay = null;
	mControlBarDisplay = null;
	mCarDisplayAreaTouchHandler.enable(false);
	sIsRegistered = false;
	}

	/**
	* This method should be called after the registration of DA's are done. The method expects a
	* target state as an argument, according to which the animations will take place. For example,
	* if the target state is {@link AppGridActivity.CAR_LAUNCHER_STATE#DEFAULT} then the foreground
	* DA hosting default applications will animate to the default set height.
	*/
	public void startAnimation(AppGridActivity.CAR_LAUNCHER_STATE toState) {
	// TODO: currently the animations are only bottom/up. Make it more generic animations here.
	int fromPos = 0;
	int toPos = 0;
	switch (toState) {
	case CONTROL_BAR:
	// Foreground DA closes.
	fromPos = mScreenHeightWithoutNavBar - mDefaultDisplayHeight
	- mControlBarDisplayHeight;
	toPos = mScreenHeightWithoutNavBar;
	mBackgroundApplicationDisplayBounds.bottom =
	mScreenHeightWithoutNavBar - mControlBarDisplayHeight;
	mOrganizer.scheduleOffset(fromPos, toPos, mBackgroundApplicationDisplayBounds,
	mBackgroundApplicationDisplay, mForegroundApplicationsDisplay,
	mControlBarDisplay, toState);
	mIsHostingDefaultApplicationDisplayAreaVisible = false;
	break;
	case FULL:
	// TODO: Implement this.
	break;
	default:
	// Foreground DA opens to default height.
	// update the bounds to expand the foreground display area before starting
	// animations.
	fromPos = mScreenHeightWithoutNavBar;
	toPos = mScreenHeightWithoutNavBar - mDefaultDisplayHeight
	- mControlBarDisplayHeight;
	mBackgroundApplicationDisplayBounds.bottom = toPos;
	mOrganizer.scheduleOffset(fromPos, toPos, mBackgroundApplicationDisplayBounds,
	mBackgroundApplicationDisplay, mForegroundApplicationsDisplay,
	mControlBarDisplay, toState);
	mIsHostingDefaultApplicationDisplayAreaVisible = true;
	}
	}

	/** Pre-calculates the default and background display bounds for different configs. */
	private void populateBounds() {
	int controlBarTop = mScreenHeightWithoutNavBar - mControlBarDisplayHeight;

	// Bottom nav bar. Bottom nav bar height will be 0 if the nav bar is present on the sides.
	Rect backgroundBounds = new Rect(0, 0, mTotalScreenWidth, controlBarTop);
	Rect controlBarBounds = new Rect(0, controlBarTop, mTotalScreenWidth,
	mScreenHeightWithoutNavBar);
	Rect foregroundBounds = new Rect(0,
	mScreenHeightWithoutNavBar - mDefaultDisplayHeight - mControlBarDisplayHeight,
	mTotalScreenWidth, mScreenHeightWithoutNavBar - mControlBarDisplayHeight);

	// Adjust the bounds based on the nav bar.
	// TODO: account for the case where nav bar is at the top.

	// Populate the bounds depending on where the nav bar is.
	if (mNavBarBounds.left == 0 && mNavBarBounds.top == 0) {
	// Left nav bar.
	backgroundBounds.left = mNavBarBounds.right;
	controlBarBounds.left = mNavBarBounds.right;
	foregroundBounds.left = mNavBarBounds.right;
	} else if (mNavBarBounds.top == 0) {
	// Right nav bar.
	backgroundBounds.right = mNavBarBounds.left;
	controlBarBounds.right = mNavBarBounds.left;
	foregroundBounds.right = mNavBarBounds.left;
	}

	mBackgroundApplicationDisplayBounds.set(backgroundBounds);
	mControlBarDisplayBounds.set(controlBarBounds);
	mForegroundApplicationDisplayBounds.set(foregroundBounds);
	}

	/** Updates the default and background display bounds for the given config. */
	private void updateBounds(WindowContainerTransaction wct) {
	Rect foregroundApplicationDisplayBound = mForegroundApplicationDisplayBounds;
	Rect backgroundApplicationDisplayBound = mBackgroundApplicationDisplayBounds;
	Rect controlBarDisplayBound = mControlBarDisplayBounds;
	WindowContainerToken foregroundDisplayToken =
	mForegroundApplicationsDisplay.getDisplayAreaInfo().token;
	WindowContainerToken backgroundDisplayToken =
	mBackgroundApplicationDisplay.getDisplayAreaInfo().token;
	WindowContainerToken controlBarDisplayToken =
	mControlBarDisplay.getDisplayAreaInfo().token;

	int foregroundDisplayWidthDp =
	foregroundApplicationDisplayBound.width() * DisplayMetrics.DENSITY_DEFAULT
	/ mDpiDensity;
	int foregroundDisplayHeightDp =
	foregroundApplicationDisplayBound.height() * DisplayMetrics.DENSITY_DEFAULT
	/ mDpiDensity;
	wct.setBounds(foregroundDisplayToken, foregroundApplicationDisplayBound);
	wct.setScreenSizeDp(foregroundDisplayToken, foregroundDisplayWidthDp,
	foregroundDisplayHeightDp);
	wct.setSmallestScreenWidthDp(foregroundDisplayToken, foregroundDisplayWidthDp);

	int backgroundDisplayWidthDp =
	backgroundApplicationDisplayBound.width() * DisplayMetrics.DENSITY_DEFAULT
	/ mDpiDensity;
	int backgroundDisplayHeightDp =
	backgroundApplicationDisplayBound.height() * DisplayMetrics.DENSITY_DEFAULT
	/ mDpiDensity;
	wct.setBounds(backgroundDisplayToken, backgroundApplicationDisplayBound);
	wct.setScreenSizeDp(backgroundDisplayToken, backgroundDisplayWidthDp,
	backgroundDisplayHeightDp);
	wct.setSmallestScreenWidthDp(backgroundDisplayToken, backgroundDisplayWidthDp);

	int controlBarDisplayWidthDp =
	controlBarDisplayBound.width() * DisplayMetrics.DENSITY_DEFAULT
	/ mDpiDensity;
	int controlBarDisplayHeightDp =
	controlBarDisplayBound.height() * DisplayMetrics.DENSITY_DEFAULT
	/ mDpiDensity;
	wct.setBounds(controlBarDisplayToken, controlBarDisplayBound);
	wct.setScreenSizeDp(controlBarDisplayToken, controlBarDisplayWidthDp,
	controlBarDisplayHeightDp);
	wct.setSmallestScreenWidthDp(controlBarDisplayToken, controlBarDisplayWidthDp);

	mSyncQueue.runInSync(t -> {
	t.setPosition(mForegroundApplicationsDisplay.getLeash(),
	foregroundApplicationDisplayBound.left,
	foregroundApplicationDisplayBound.top);
	t.setPosition(mBackgroundApplicationDisplay.getLeash(),
	backgroundApplicationDisplayBound.left,
	backgroundApplicationDisplayBound.top);
	t.setPosition(mControlBarDisplay.getLeash(),
	controlBarDisplayBound.left,
	controlBarDisplayBound.top);
	});
	}
	}