packages/SystemUI/src/com/android/systemui/statusbar/phone/NavBarTintController.java - platform/frameworks/base - Gitiles

 /*
  * Copyright (C) 2018 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.systemui.statusbar.phone;

 import android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.Bitmap.Config;
 import android.graphics.Color;
 import android.graphics.Rect;
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.os.Looper;
 import android.provider.Settings;
 import android.util.DisplayMetrics;
 import android.view.SurfaceControl;

 public class NavBarTintController {
     public static final String NAV_COLOR_TRANSITION_TIME_SETTING = "navbar_color_adapt_transition";
     public static final int MIN_COLOR_ADAPT_TRANSITION_TIME = 400;
     public static final int DEFAULT_COLOR_ADAPT_TRANSITION_TIME = 1500;

     private final HandlerThread mColorAdaptHandlerThread = new HandlerThread("ColorExtractThread");
     private Handler mColorAdaptionHandler;

     // Poll time for each iteration to color sample
     private static final int COLOR_ADAPTION_TIMEOUT = 300;

     // Passing the threshold of this luminance value will make the button black otherwise white
     private static final float LUMINANCE_THRESHOLD = 0.3f;

     // The home button's icon is actually smaller than the button's size, the percentage will
     // cut into the button's size to determine the icon size
     private static final float PERCENTAGE_BUTTON_PADDING = 0.3f;

     // The distance from the home button to color sample around
     private static final int COLOR_SAMPLE_MARGIN = 20;

     private boolean mRunning;

     private final NavigationBarView mNavigationBarView;
     private final LightBarTransitionsController mLightBarController;
     private final Handler mMainHandler = new Handler(Looper.getMainLooper());

     public NavBarTintController(NavigationBarView navigationBarView,
             LightBarTransitionsController lightBarController) {
         mNavigationBarView = navigationBarView;
         mLightBarController = lightBarController;
     }

     public void start() {
         if (!isEnabled(mNavigationBarView.getContext())) {
             return;
         }
         if (mColorAdaptionHandler == null) {
             mColorAdaptHandlerThread.start();
             mColorAdaptionHandler = new Handler(mColorAdaptHandlerThread.getLooper());
         }
         mColorAdaptionHandler.removeCallbacksAndMessages(null);
         mColorAdaptionHandler.post(this::updateTint);
         mRunning = true;
     }

     public void end() {
         if (mColorAdaptionHandler != null) {
             mColorAdaptionHandler.removeCallbacksAndMessages(null);
         }
         mRunning = false;
     }

     public void stop() {
         end();
         if (mColorAdaptionHandler != null) {
             mColorAdaptHandlerThread.quitSafely();
         }
     }

     private void updateTint() {
         int[] navPos = new int[2];
         int[] butPos = new int[2];
         if (mNavigationBarView.getHomeButton().getCurrentView() == null) {
             return;
         }

         // Determine the area of the home icon in the larger home button
         mNavigationBarView.getHomeButton().getCurrentView().getLocationInSurface(butPos);
         final int navWidth = mNavigationBarView.getHomeButton().getCurrentView().getWidth();
         final int navHeight = mNavigationBarView.getHomeButton().getCurrentView().getHeight();
         final int xPadding = (int) (PERCENTAGE_BUTTON_PADDING * navWidth);
         final int yPadding = (int) (PERCENTAGE_BUTTON_PADDING * navHeight);
         final Rect homeButtonRect = new Rect(butPos[0] + xPadding, butPos[1] + yPadding,
                 navWidth + butPos[0]  - xPadding, navHeight + butPos[1] - yPadding);
         if (mNavigationBarView.getCurrentView() == null || homeButtonRect.isEmpty()) {
             scheduleColorAdaption();
             return;
         }
         mNavigationBarView.getCurrentView().getLocationOnScreen(navPos);
         homeButtonRect.offset(navPos[0], navPos[1]);

         // Apply a margin area around the button region to sample the colors, crop from screenshot
         final Rect cropRect = new Rect(homeButtonRect);
         cropRect.inset(-COLOR_SAMPLE_MARGIN, -COLOR_SAMPLE_MARGIN);
         if (cropRect.isEmpty()) {
             scheduleColorAdaption();
             return;
         }

         // Determine the size of the home area
         Rect homeArea = new Rect(COLOR_SAMPLE_MARGIN, COLOR_SAMPLE_MARGIN,
                 homeButtonRect.width() + COLOR_SAMPLE_MARGIN,
                 homeButtonRect.height() + COLOR_SAMPLE_MARGIN);

         // Get the screenshot around the home button icon to determine the color
         DisplayMetrics mDisplayMetrics = new DisplayMetrics();
         mNavigationBarView.getContext().getDisplay().getRealMetrics(mDisplayMetrics);
         final Bitmap hardBitmap = SurfaceControl
                 .screenshot(new Rect(), mDisplayMetrics.widthPixels, mDisplayMetrics.heightPixels,
                         mNavigationBarView.getContext().getDisplay().getRotation());
         if (hardBitmap != null && cropRect.bottom <= hardBitmap.getHeight()) {
             final Bitmap cropBitmap = Bitmap.createBitmap(hardBitmap, cropRect.left, cropRect.top,
                     cropRect.width(), cropRect.height());
             final Bitmap softBitmap = cropBitmap.copy(Config.ARGB_8888, false);

             // Get the luminance value to determine if the home button should be black or white
             final int[] pixels = new int[softBitmap.getByteCount() / 4];
             softBitmap.getPixels(pixels, 0, softBitmap.getWidth(), 0, 0, softBitmap.getWidth(),
                     softBitmap.getHeight());
             float r = 0, g = 0, blue = 0;

             int width = cropRect.width();
             int total = 0;
             for (int i = 0; i < pixels.length; i += 4) {
                 int x = i % width;
                 int y = i / width;
                 if (!homeArea.contains(x, y)) {
                     r += Color.red(pixels[i]);
                     g += Color.green(pixels[i]);
                     blue += Color.blue(pixels[i]);
                     total++;
                 }
             }

             r /= total;
             g /= total;
             blue /= total;

             r = Math.max(Math.min(r / 255f, 1), 0);
             g = Math.max(Math.min(g / 255f, 1), 0);
             blue = Math.max(Math.min(blue / 255f, 1), 0);

             if (r <= 0.03928) {
                 r /= 12.92;
             } else {
                 r = (float) Math.pow((r + 0.055) / 1.055, 2.4);
             }
             if (g <= 0.03928) {
                 g /= 12.92;
             } else {
                 g = (float) Math.pow((g + 0.055) / 1.055, 2.4);
             }
             if (blue <= 0.03928) {
                 blue /= 12.92;
             } else {
                 blue = (float) Math.pow((blue + 0.055) / 1.055, 2.4);
             }

             if (r * 0.2126 + g * 0.7152 + blue * 0.0722 > LUMINANCE_THRESHOLD) {
                 // Black
                 mMainHandler.post(
                         () -> mLightBarController
                                 .setIconsDark(true /* dark */, true /* animate */));
             } else {
                 // White
                 mMainHandler.post(
                         () -> mLightBarController
                                 .setIconsDark(false /* dark */, true /* animate */));
             }
             cropBitmap.recycle();
             hardBitmap.recycle();
         }
         scheduleColorAdaption();
     }

     private void scheduleColorAdaption() {
         mColorAdaptionHandler.removeCallbacksAndMessages(null);
         if (!mRunning || !isEnabled(mNavigationBarView.getContext())) {
             return;
         }
         mColorAdaptionHandler.postDelayed(this::updateTint, COLOR_ADAPTION_TIMEOUT);
     }

     public static boolean isEnabled(Context context) {
         return Settings.Global.getInt(context.getContentResolver(),
                 NavigationPrototypeController.NAV_COLOR_ADAPT_ENABLE_SETTING, 0) == 1;
     }
 }
	/*
	* Copyright (C) 2018 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.systemui.statusbar.phone;

	import android.content.Context;
	import android.graphics.Bitmap;
	import android.graphics.Bitmap.Config;
	import android.graphics.Color;
	import android.graphics.Rect;
	import android.os.Handler;
	import android.os.HandlerThread;
	import android.os.Looper;
	import android.provider.Settings;
	import android.util.DisplayMetrics;
	import android.view.SurfaceControl;

	public class NavBarTintController {
	public static final String NAV_COLOR_TRANSITION_TIME_SETTING = "navbar_color_adapt_transition";
	public static final int MIN_COLOR_ADAPT_TRANSITION_TIME = 400;
	public static final int DEFAULT_COLOR_ADAPT_TRANSITION_TIME = 1500;

	private final HandlerThread mColorAdaptHandlerThread = new HandlerThread("ColorExtractThread");
	private Handler mColorAdaptionHandler;

	// Poll time for each iteration to color sample
	private static final int COLOR_ADAPTION_TIMEOUT = 300;

	// Passing the threshold of this luminance value will make the button black otherwise white
	private static final float LUMINANCE_THRESHOLD = 0.3f;

	// The home button's icon is actually smaller than the button's size, the percentage will
	// cut into the button's size to determine the icon size
	private static final float PERCENTAGE_BUTTON_PADDING = 0.3f;

	// The distance from the home button to color sample around
	private static final int COLOR_SAMPLE_MARGIN = 20;

	private boolean mRunning;

	private final NavigationBarView mNavigationBarView;
	private final LightBarTransitionsController mLightBarController;
	private final Handler mMainHandler = new Handler(Looper.getMainLooper());

	public NavBarTintController(NavigationBarView navigationBarView,
	LightBarTransitionsController lightBarController) {
	mNavigationBarView = navigationBarView;
	mLightBarController = lightBarController;
	}

	public void start() {
	if (!isEnabled(mNavigationBarView.getContext())) {
	return;
	}
	if (mColorAdaptionHandler == null) {
	mColorAdaptHandlerThread.start();
	mColorAdaptionHandler = new Handler(mColorAdaptHandlerThread.getLooper());
	}
	mColorAdaptionHandler.removeCallbacksAndMessages(null);
	mColorAdaptionHandler.post(this::updateTint);
	mRunning = true;
	}

	public void end() {
	if (mColorAdaptionHandler != null) {
	mColorAdaptionHandler.removeCallbacksAndMessages(null);
	}
	mRunning = false;
	}

	public void stop() {
	end();
	if (mColorAdaptionHandler != null) {
	mColorAdaptHandlerThread.quitSafely();
	}
	}

	private void updateTint() {
	int[] navPos = new int[2];
	int[] butPos = new int[2];
	if (mNavigationBarView.getHomeButton().getCurrentView() == null) {
	return;
	}

	// Determine the area of the home icon in the larger home button
	mNavigationBarView.getHomeButton().getCurrentView().getLocationInSurface(butPos);
	final int navWidth = mNavigationBarView.getHomeButton().getCurrentView().getWidth();
	final int navHeight = mNavigationBarView.getHomeButton().getCurrentView().getHeight();
	final int xPadding = (int) (PERCENTAGE_BUTTON_PADDING * navWidth);
	final int yPadding = (int) (PERCENTAGE_BUTTON_PADDING * navHeight);
	final Rect homeButtonRect = new Rect(butPos[0] + xPadding, butPos[1] + yPadding,
	navWidth + butPos[0] - xPadding, navHeight + butPos[1] - yPadding);
	if (mNavigationBarView.getCurrentView() == null \|\| homeButtonRect.isEmpty()) {
	scheduleColorAdaption();
	return;
	}
	mNavigationBarView.getCurrentView().getLocationOnScreen(navPos);
	homeButtonRect.offset(navPos[0], navPos[1]);

	// Apply a margin area around the button region to sample the colors, crop from screenshot
	final Rect cropRect = new Rect(homeButtonRect);
	cropRect.inset(-COLOR_SAMPLE_MARGIN, -COLOR_SAMPLE_MARGIN);
	if (cropRect.isEmpty()) {
	scheduleColorAdaption();
	return;
	}

	// Determine the size of the home area
	Rect homeArea = new Rect(COLOR_SAMPLE_MARGIN, COLOR_SAMPLE_MARGIN,
	homeButtonRect.width() + COLOR_SAMPLE_MARGIN,
	homeButtonRect.height() + COLOR_SAMPLE_MARGIN);

	// Get the screenshot around the home button icon to determine the color
	DisplayMetrics mDisplayMetrics = new DisplayMetrics();
	mNavigationBarView.getContext().getDisplay().getRealMetrics(mDisplayMetrics);
	final Bitmap hardBitmap = SurfaceControl
	.screenshot(new Rect(), mDisplayMetrics.widthPixels, mDisplayMetrics.heightPixels,
	mNavigationBarView.getContext().getDisplay().getRotation());
	if (hardBitmap != null && cropRect.bottom <= hardBitmap.getHeight()) {
	final Bitmap cropBitmap = Bitmap.createBitmap(hardBitmap, cropRect.left, cropRect.top,
	cropRect.width(), cropRect.height());
	final Bitmap softBitmap = cropBitmap.copy(Config.ARGB_8888, false);

	// Get the luminance value to determine if the home button should be black or white
	final int[] pixels = new int[softBitmap.getByteCount() / 4];
	softBitmap.getPixels(pixels, 0, softBitmap.getWidth(), 0, 0, softBitmap.getWidth(),
	softBitmap.getHeight());
	float r = 0, g = 0, blue = 0;

	int width = cropRect.width();
	int total = 0;
	for (int i = 0; i < pixels.length; i += 4) {
	int x = i % width;
	int y = i / width;
	if (!homeArea.contains(x, y)) {
	r += Color.red(pixels[i]);
	g += Color.green(pixels[i]);
	blue += Color.blue(pixels[i]);
	total++;
	}
	}

	r /= total;
	g /= total;
	blue /= total;

	r = Math.max(Math.min(r / 255f, 1), 0);
	g = Math.max(Math.min(g / 255f, 1), 0);
	blue = Math.max(Math.min(blue / 255f, 1), 0);

	if (r <= 0.03928) {
	r /= 12.92;
	} else {
	r = (float) Math.pow((r + 0.055) / 1.055, 2.4);
	}
	if (g <= 0.03928) {
	g /= 12.92;
	} else {
	g = (float) Math.pow((g + 0.055) / 1.055, 2.4);
	}
	if (blue <= 0.03928) {
	blue /= 12.92;
	} else {
	blue = (float) Math.pow((blue + 0.055) / 1.055, 2.4);
	}

	if (r * 0.2126 + g * 0.7152 + blue * 0.0722 > LUMINANCE_THRESHOLD) {
	// Black
	mMainHandler.post(
	() -> mLightBarController
	.setIconsDark(true /* dark /, true / animate */));
	} else {
	// White
	mMainHandler.post(
	() -> mLightBarController
	.setIconsDark(false /* dark /, true / animate */));
	}
	cropBitmap.recycle();
	hardBitmap.recycle();
	}
	scheduleColorAdaption();
	}

	private void scheduleColorAdaption() {
	mColorAdaptionHandler.removeCallbacksAndMessages(null);
	if (!mRunning \|\| !isEnabled(mNavigationBarView.getContext())) {
	return;
	}
	mColorAdaptionHandler.postDelayed(this::updateTint, COLOR_ADAPTION_TIMEOUT);
	}

	public static boolean isEnabled(Context context) {
	return Settings.Global.getInt(context.getContentResolver(),
	NavigationPrototypeController.NAV_COLOR_ADAPT_ENABLE_SETTING, 0) == 1;
	}
	}