/* * Copyright (C) 2014 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.internal.util; import android.annotation.ColorInt; import android.annotation.FloatRange; import android.annotation.IntRange; import android.annotation.NonNull; import android.app.Notification; import android.content.Context; import android.content.res.ColorStateList; import android.content.res.Resources; import android.graphics.Bitmap; import android.graphics.Color; import android.graphics.drawable.AnimationDrawable; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.Drawable; import android.graphics.drawable.Icon; import android.graphics.drawable.VectorDrawable; import android.text.SpannableStringBuilder; import android.text.Spanned; import android.text.style.TextAppearanceSpan; import android.util.Log; import android.util.Pair; import java.util.Arrays; import java.util.WeakHashMap; /** * Helper class to process legacy (Holo) notifications to make them look like material notifications. * * @hide */ public class NotificationColorUtil { private static final String TAG = "NotificationColorUtil"; private static final boolean DEBUG = false; private static final Object sLock = new Object(); private static NotificationColorUtil sInstance; private final ImageUtils mImageUtils = new ImageUtils(); private final WeakHashMap> mGrayscaleBitmapCache = new WeakHashMap>(); private final int mGrayscaleIconMaxSize; // @dimen/notification_large_icon_width (64dp) public static NotificationColorUtil getInstance(Context context) { synchronized (sLock) { if (sInstance == null) { sInstance = new NotificationColorUtil(context); } return sInstance; } } private NotificationColorUtil(Context context) { mGrayscaleIconMaxSize = context.getResources().getDimensionPixelSize( com.android.internal.R.dimen.notification_large_icon_width); } /** * Checks whether a Bitmap is a small grayscale icon. * Grayscale here means "very close to a perfect gray"; icon means "no larger than 64dp". * * @param bitmap The bitmap to test. * @return True if the bitmap is grayscale; false if it is color or too large to examine. */ public boolean isGrayscaleIcon(Bitmap bitmap) { // quick test: reject large bitmaps if (bitmap.getWidth() > mGrayscaleIconMaxSize || bitmap.getHeight() > mGrayscaleIconMaxSize) { return false; } synchronized (sLock) { Pair cached = mGrayscaleBitmapCache.get(bitmap); if (cached != null) { if (cached.second == bitmap.getGenerationId()) { return cached.first; } } } boolean result; int generationId; synchronized (mImageUtils) { result = mImageUtils.isGrayscale(bitmap); // generationId and the check whether the Bitmap is grayscale can't be read atomically // here. However, since the thread is in the process of posting the notification, we can // assume that it doesn't modify the bitmap while we are checking the pixels. generationId = bitmap.getGenerationId(); } synchronized (sLock) { mGrayscaleBitmapCache.put(bitmap, Pair.create(result, generationId)); } return result; } /** * Checks whether a Drawable is a small grayscale icon. * Grayscale here means "very close to a perfect gray"; icon means "no larger than 64dp". * * @param d The drawable to test. * @return True if the bitmap is grayscale; false if it is color or too large to examine. */ public boolean isGrayscaleIcon(Drawable d) { if (d == null) { return false; } else if (d instanceof BitmapDrawable) { BitmapDrawable bd = (BitmapDrawable) d; return bd.getBitmap() != null && isGrayscaleIcon(bd.getBitmap()); } else if (d instanceof AnimationDrawable) { AnimationDrawable ad = (AnimationDrawable) d; int count = ad.getNumberOfFrames(); return count > 0 && isGrayscaleIcon(ad.getFrame(0)); } else if (d instanceof VectorDrawable) { // We just assume you're doing the right thing if using vectors return true; } else { return false; } } public boolean isGrayscaleIcon(Context context, Icon icon) { if (icon == null) { return false; } switch (icon.getType()) { case Icon.TYPE_BITMAP: return isGrayscaleIcon(icon.getBitmap()); case Icon.TYPE_RESOURCE: return isGrayscaleIcon(context, icon.getResId()); default: return false; } } /** * Checks whether a drawable with a resoure id is a small grayscale icon. * Grayscale here means "very close to a perfect gray"; icon means "no larger than 64dp". * * @param context The context to load the drawable from. * @return True if the bitmap is grayscale; false if it is color or too large to examine. */ public boolean isGrayscaleIcon(Context context, int drawableResId) { if (drawableResId != 0) { try { return isGrayscaleIcon(context.getDrawable(drawableResId)); } catch (Resources.NotFoundException ex) { Log.e(TAG, "Drawable not found: " + drawableResId); return false; } } else { return false; } } /** * Inverts all the grayscale colors set by {@link android.text.style.TextAppearanceSpan}s on * the text. * * @param charSequence The text to process. * @return The color inverted text. */ public CharSequence invertCharSequenceColors(CharSequence charSequence) { if (charSequence instanceof Spanned) { Spanned ss = (Spanned) charSequence; Object[] spans = ss.getSpans(0, ss.length(), Object.class); SpannableStringBuilder builder = new SpannableStringBuilder(ss.toString()); for (Object span : spans) { Object resultSpan = span; if (span instanceof TextAppearanceSpan) { resultSpan = processTextAppearanceSpan((TextAppearanceSpan) span); } builder.setSpan(resultSpan, ss.getSpanStart(span), ss.getSpanEnd(span), ss.getSpanFlags(span)); } return builder; } return charSequence; } private TextAppearanceSpan processTextAppearanceSpan(TextAppearanceSpan span) { ColorStateList colorStateList = span.getTextColor(); if (colorStateList != null) { int[] colors = colorStateList.getColors(); boolean changed = false; for (int i = 0; i < colors.length; i++) { if (ImageUtils.isGrayscale(colors[i])) { // Allocate a new array so we don't change the colors in the old color state // list. if (!changed) { colors = Arrays.copyOf(colors, colors.length); } colors[i] = processColor(colors[i]); changed = true; } } if (changed) { return new TextAppearanceSpan( span.getFamily(), span.getTextStyle(), span.getTextSize(), new ColorStateList(colorStateList.getStates(), colors), span.getLinkTextColor()); } } return span; } private int processColor(int color) { return Color.argb(Color.alpha(color), 255 - Color.red(color), 255 - Color.green(color), 255 - Color.blue(color)); } /** * Finds a suitable color such that there's enough contrast. * * @param color the color to start searching from. * @param other the color to ensure contrast against. Assumed to be lighter than {@param color} * @param findFg if true, we assume {@param color} is a foreground, otherwise a background. * @param minRatio the minimum contrast ratio required. * @return a color with the same hue as {@param color}, potentially darkened to meet the * contrast ratio. */ private static int findContrastColor(int color, int other, boolean findFg, double minRatio) { int fg = findFg ? color : other; int bg = findFg ? other : color; if (ColorUtilsFromCompat.calculateContrast(fg, bg) >= minRatio) { return color; } double[] lab = new double[3]; ColorUtilsFromCompat.colorToLAB(findFg ? fg : bg, lab); double low = 0, high = lab[0]; final double a = lab[1], b = lab[2]; for (int i = 0; i < 15 && high - low > 0.00001; i++) { final double l = (low + high) / 2; if (findFg) { fg = ColorUtilsFromCompat.LABToColor(l, a, b); } else { bg = ColorUtilsFromCompat.LABToColor(l, a, b); } if (ColorUtilsFromCompat.calculateContrast(fg, bg) > minRatio) { low = l; } else { high = l; } } return ColorUtilsFromCompat.LABToColor(low, a, b); } /** * Finds a text color with sufficient contrast over bg that has the same hue as the original * color, assuming it is for large text. */ private static int ensureLargeTextContrast(int color, int bg) { return findContrastColor(color, bg, true, 3); } /** * Finds a text color with sufficient contrast over bg that has the same hue as the original * color. */ private static int ensureTextContrast(int color, int bg) { return findContrastColor(color, bg, true, 4.5); } /** Finds a background color for a text view with given text color and hint text color, that * has the same hue as the original color. */ public static int ensureTextBackgroundColor(int color, int textColor, int hintColor) { color = findContrastColor(color, hintColor, false, 3.0); return findContrastColor(color, textColor, false, 4.5); } private static String contrastChange(int colorOld, int colorNew, int bg) { return String.format("from %.2f:1 to %.2f:1", ColorUtilsFromCompat.calculateContrast(colorOld, bg), ColorUtilsFromCompat.calculateContrast(colorNew, bg)); } /** * Resolves {@param color} to an actual color if it is {@link Notification#COLOR_DEFAULT} */ public static int resolveColor(Context context, int color) { if (color == Notification.COLOR_DEFAULT) { return context.getColor(com.android.internal.R.color.notification_icon_default_color); } return color; } /** * Resolves a Notification's color such that it has enough contrast to be used as the * color for the Notification's action and header text. * * @param notificationColor the color of the notification or {@link Notification#COLOR_DEFAULT} * @return a color of the same hue with enough contrast against the backgrounds. */ public static int resolveContrastColor(Context context, int notificationColor) { final int resolvedColor = resolveColor(context, notificationColor); final int actionBg = context.getColor( com.android.internal.R.color.notification_action_list); final int notiBg = context.getColor( com.android.internal.R.color.notification_material_background_color); int color = resolvedColor; color = NotificationColorUtil.ensureLargeTextContrast(color, actionBg); color = NotificationColorUtil.ensureTextContrast(color, notiBg); if (color != resolvedColor) { if (DEBUG){ Log.w(TAG, String.format( "Enhanced contrast of notification for %s %s (over action)" + " and %s (over background) by changing #%s to %s", context.getPackageName(), NotificationColorUtil.contrastChange(resolvedColor, color, actionBg), NotificationColorUtil.contrastChange(resolvedColor, color, notiBg), Integer.toHexString(resolvedColor), Integer.toHexString(color))); } } return color; } /** * Framework copy of functions needed from android.support.v4.graphics.ColorUtils. */ private static class ColorUtilsFromCompat { private static final double XYZ_WHITE_REFERENCE_X = 95.047; private static final double XYZ_WHITE_REFERENCE_Y = 100; private static final double XYZ_WHITE_REFERENCE_Z = 108.883; private static final double XYZ_EPSILON = 0.008856; private static final double XYZ_KAPPA = 903.3; private static final int MIN_ALPHA_SEARCH_MAX_ITERATIONS = 10; private static final int MIN_ALPHA_SEARCH_PRECISION = 1; private static final ThreadLocal TEMP_ARRAY = new ThreadLocal<>(); private ColorUtilsFromCompat() {} /** * Composite two potentially translucent colors over each other and returns the result. */ public static int compositeColors(@ColorInt int foreground, @ColorInt int background) { int bgAlpha = Color.alpha(background); int fgAlpha = Color.alpha(foreground); int a = compositeAlpha(fgAlpha, bgAlpha); int r = compositeComponent(Color.red(foreground), fgAlpha, Color.red(background), bgAlpha, a); int g = compositeComponent(Color.green(foreground), fgAlpha, Color.green(background), bgAlpha, a); int b = compositeComponent(Color.blue(foreground), fgAlpha, Color.blue(background), bgAlpha, a); return Color.argb(a, r, g, b); } private static int compositeAlpha(int foregroundAlpha, int backgroundAlpha) { return 0xFF - (((0xFF - backgroundAlpha) * (0xFF - foregroundAlpha)) / 0xFF); } private static int compositeComponent(int fgC, int fgA, int bgC, int bgA, int a) { if (a == 0) return 0; return ((0xFF * fgC * fgA) + (bgC * bgA * (0xFF - fgA))) / (a * 0xFF); } /** * Returns the luminance of a color as a float between {@code 0.0} and {@code 1.0}. *

Defined as the Y component in the XYZ representation of {@code color}.

*/ @FloatRange(from = 0.0, to = 1.0) public static double calculateLuminance(@ColorInt int color) { final double[] result = getTempDouble3Array(); colorToXYZ(color, result); // Luminance is the Y component return result[1] / 100; } /** * Returns the contrast ratio between {@code foreground} and {@code background}. * {@code background} must be opaque. *

* Formula defined * here. */ public static double calculateContrast(@ColorInt int foreground, @ColorInt int background) { if (Color.alpha(background) != 255) { throw new IllegalArgumentException("background can not be translucent: #" + Integer.toHexString(background)); } if (Color.alpha(foreground) < 255) { // If the foreground is translucent, composite the foreground over the background foreground = compositeColors(foreground, background); } final double luminance1 = calculateLuminance(foreground) + 0.05; final double luminance2 = calculateLuminance(background) + 0.05; // Now return the lighter luminance divided by the darker luminance return Math.max(luminance1, luminance2) / Math.min(luminance1, luminance2); } /** * Convert the ARGB color to its CIE Lab representative components. * * @param color the ARGB color to convert. The alpha component is ignored * @param outLab 3-element array which holds the resulting LAB components */ public static void colorToLAB(@ColorInt int color, @NonNull double[] outLab) { RGBToLAB(Color.red(color), Color.green(color), Color.blue(color), outLab); } /** * Convert RGB components to its CIE Lab representative components. * *

    *
  • outLab[0] is L [0 ...1)
    • *
  • outLab[1] is a [-128...127)
    • *
  • outLab[2] is b [-128...127)
    • *
* * @param r red component value [0..255] * @param g green component value [0..255] * @param b blue component value [0..255] * @param outLab 3-element array which holds the resulting LAB components */ public static void RGBToLAB(@IntRange(from = 0x0, to = 0xFF) int r, @IntRange(from = 0x0, to = 0xFF) int g, @IntRange(from = 0x0, to = 0xFF) int b, @NonNull double[] outLab) { // First we convert RGB to XYZ RGBToXYZ(r, g, b, outLab); // outLab now contains XYZ XYZToLAB(outLab[0], outLab[1], outLab[2], outLab); // outLab now contains LAB representation } /** * Convert the ARGB color to it's CIE XYZ representative components. * *

The resulting XYZ representation will use the D65 illuminant and the CIE * 2° Standard Observer (1931).

* *
    *
  • outXyz[0] is X [0 ...95.047)
    • *
  • outXyz[1] is Y [0...100)
    • *
  • outXyz[2] is Z [0...108.883)
    • *
* * @param color the ARGB color to convert. The alpha component is ignored * @param outXyz 3-element array which holds the resulting LAB components */ public static void colorToXYZ(@ColorInt int color, @NonNull double[] outXyz) { RGBToXYZ(Color.red(color), Color.green(color), Color.blue(color), outXyz); } /** * Convert RGB components to it's CIE XYZ representative components. * *

The resulting XYZ representation will use the D65 illuminant and the CIE * 2° Standard Observer (1931).

* *
    *
  • outXyz[0] is X [0 ...95.047)
    • *
  • outXyz[1] is Y [0...100)
    • *
  • outXyz[2] is Z [0...108.883)
    • *
* * @param r red component value [0..255] * @param g green component value [0..255] * @param b blue component value [0..255] * @param outXyz 3-element array which holds the resulting XYZ components */ public static void RGBToXYZ(@IntRange(from = 0x0, to = 0xFF) int r, @IntRange(from = 0x0, to = 0xFF) int g, @IntRange(from = 0x0, to = 0xFF) int b, @NonNull double[] outXyz) { if (outXyz.length != 3) { throw new IllegalArgumentException("outXyz must have a length of 3."); } double sr = r / 255.0; sr = sr < 0.04045 ? sr / 12.92 : Math.pow((sr + 0.055) / 1.055, 2.4); double sg = g / 255.0; sg = sg < 0.04045 ? sg / 12.92 : Math.pow((sg + 0.055) / 1.055, 2.4); double sb = b / 255.0; sb = sb < 0.04045 ? sb / 12.92 : Math.pow((sb + 0.055) / 1.055, 2.4); outXyz[0] = 100 * (sr * 0.4124 + sg * 0.3576 + sb * 0.1805); outXyz[1] = 100 * (sr * 0.2126 + sg * 0.7152 + sb * 0.0722); outXyz[2] = 100 * (sr * 0.0193 + sg * 0.1192 + sb * 0.9505); } /** * Converts a color from CIE XYZ to CIE Lab representation. * *

This method expects the XYZ representation to use the D65 illuminant and the CIE * 2° Standard Observer (1931).

* *
    *
  • outLab[0] is L [0 ...1)
    • *
  • outLab[1] is a [-128...127)
    • *
  • outLab[2] is b [-128...127)
    • *
* * @param x X component value [0...95.047) * @param y Y component value [0...100) * @param z Z component value [0...108.883) * @param outLab 3-element array which holds the resulting Lab components */ public static void XYZToLAB(@FloatRange(from = 0f, to = XYZ_WHITE_REFERENCE_X) double x, @FloatRange(from = 0f, to = XYZ_WHITE_REFERENCE_Y) double y, @FloatRange(from = 0f, to = XYZ_WHITE_REFERENCE_Z) double z, @NonNull double[] outLab) { if (outLab.length != 3) { throw new IllegalArgumentException("outLab must have a length of 3."); } x = pivotXyzComponent(x / XYZ_WHITE_REFERENCE_X); y = pivotXyzComponent(y / XYZ_WHITE_REFERENCE_Y); z = pivotXyzComponent(z / XYZ_WHITE_REFERENCE_Z); outLab[0] = Math.max(0, 116 * y - 16); outLab[1] = 500 * (x - y); outLab[2] = 200 * (y - z); } /** * Converts a color from CIE Lab to CIE XYZ representation. * *

The resulting XYZ representation will use the D65 illuminant and the CIE * 2° Standard Observer (1931).

* *
    *
  • outXyz[0] is X [0 ...95.047)
    • *
  • outXyz[1] is Y [0...100)
    • *
  • outXyz[2] is Z [0...108.883)
    • *
* * @param l L component value [0...100) * @param a A component value [-128...127) * @param b B component value [-128...127) * @param outXyz 3-element array which holds the resulting XYZ components */ public static void LABToXYZ(@FloatRange(from = 0f, to = 100) final double l, @FloatRange(from = -128, to = 127) final double a, @FloatRange(from = -128, to = 127) final double b, @NonNull double[] outXyz) { final double fy = (l + 16) / 116; final double fx = a / 500 + fy; final double fz = fy - b / 200; double tmp = Math.pow(fx, 3); final double xr = tmp > XYZ_EPSILON ? tmp : (116 * fx - 16) / XYZ_KAPPA; final double yr = l > XYZ_KAPPA * XYZ_EPSILON ? Math.pow(fy, 3) : l / XYZ_KAPPA; tmp = Math.pow(fz, 3); final double zr = tmp > XYZ_EPSILON ? tmp : (116 * fz - 16) / XYZ_KAPPA; outXyz[0] = xr * XYZ_WHITE_REFERENCE_X; outXyz[1] = yr * XYZ_WHITE_REFERENCE_Y; outXyz[2] = zr * XYZ_WHITE_REFERENCE_Z; } /** * Converts a color from CIE XYZ to its RGB representation. * *

This method expects the XYZ representation to use the D65 illuminant and the CIE * 2° Standard Observer (1931).

* * @param x X component value [0...95.047) * @param y Y component value [0...100) * @param z Z component value [0...108.883) * @return int containing the RGB representation */ @ColorInt public static int XYZToColor(@FloatRange(from = 0f, to = XYZ_WHITE_REFERENCE_X) double x, @FloatRange(from = 0f, to = XYZ_WHITE_REFERENCE_Y) double y, @FloatRange(from = 0f, to = XYZ_WHITE_REFERENCE_Z) double z) { double r = (x * 3.2406 + y * -1.5372 + z * -0.4986) / 100; double g = (x * -0.9689 + y * 1.8758 + z * 0.0415) / 100; double b = (x * 0.0557 + y * -0.2040 + z * 1.0570) / 100; r = r > 0.0031308 ? 1.055 * Math.pow(r, 1 / 2.4) - 0.055 : 12.92 * r; g = g > 0.0031308 ? 1.055 * Math.pow(g, 1 / 2.4) - 0.055 : 12.92 * g; b = b > 0.0031308 ? 1.055 * Math.pow(b, 1 / 2.4) - 0.055 : 12.92 * b; return Color.rgb( constrain((int) Math.round(r * 255), 0, 255), constrain((int) Math.round(g * 255), 0, 255), constrain((int) Math.round(b * 255), 0, 255)); } /** * Converts a color from CIE Lab to its RGB representation. * * @param l L component value [0...100] * @param a A component value [-128...127] * @param b B component value [-128...127] * @return int containing the RGB representation */ @ColorInt public static int LABToColor(@FloatRange(from = 0f, to = 100) final double l, @FloatRange(from = -128, to = 127) final double a, @FloatRange(from = -128, to = 127) final double b) { final double[] result = getTempDouble3Array(); LABToXYZ(l, a, b, result); return XYZToColor(result[0], result[1], result[2]); } private static int constrain(int amount, int low, int high) { return amount < low ? low : (amount > high ? high : amount); } private static double pivotXyzComponent(double component) { return component > XYZ_EPSILON ? Math.pow(component, 1 / 3.0) : (XYZ_KAPPA * component + 16) / 116; } private static double[] getTempDouble3Array() { double[] result = TEMP_ARRAY.get(); if (result == null) { result = new double[3]; TEMP_ARRAY.set(result); } return result; } } }