Fix ContrastColorUtil.findContrastColorAgainstDark to return the valid color (4c0e8a62) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/util/ContrastColorUtil.java

+10 −9

Original line number	Diff line number	Diff line
		@@ -291,10 +291,10 @@ public class ContrastColorUtil {
		* 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 other the color to ensure contrast against. Assumed to be lighter than {@code color}
		* @param findFg if true, we assume {@code 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
		* @return a color with the same hue as {@code color}, potentially darkened to meet the
		* contrast ratio.
		*/
		public static int findContrastColor(int color, int other, boolean findFg, double minRatio) {
		@@ -331,7 +331,7 @@ public class ContrastColorUtil {
		* @param color the color to start searching from.
		* @param backgroundColor the color to ensure contrast against.
		* @param minRatio the minimum contrast ratio required.
		* @return the same color as {@param color} with potentially modified alpha to meet contrast
		* @return the same color as {@code color} with potentially modified alpha to meet contrast
		*/
		public static int findAlphaToMeetContrast(int color, int backgroundColor, double minRatio) {
		int fg = color;
		@@ -361,10 +361,10 @@ public class ContrastColorUtil {
		* 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 darker than {@param color}
		* @param findFg if true, we assume {@param color} is a foreground, otherwise a background.
		* @param other the color to ensure contrast against. Assumed to be darker than {@code color}
		* @param findFg if true, we assume {@code 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
		* @return a color with the same hue as {@code color}, potentially lightened to meet the
		* contrast ratio.
		*/
		public static int findContrastColorAgainstDark(int color, int other, boolean findFg,
		@@ -393,7 +393,8 @@ public class ContrastColorUtil {
		low = l;
		}
		}
		return findFg ? fg : bg;
		hsl[2] = high;
		return ColorUtilsFromCompat.HSLToColor(hsl);
		}

		public static int ensureTextContrastOnBlack(int color) {
		@@ -452,7 +453,7 @@ public class ContrastColorUtil {
		}

		/**
		* Resolves {@param color} to an actual color if it is {@link Notification#COLOR_DEFAULT}
		* Resolves {@code color} to an actual color if it is {@link Notification#COLOR_DEFAULT}
		*/
		public static int resolveColor(Context context, int color, boolean defaultBackgroundIsDark) {
		if (color == Notification.COLOR_DEFAULT) {

core/tests/coretests/src/com/android/internal/util/ContrastColorUtilTest.java

0 → 100644

+99 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 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 static androidx.core.graphics.ColorUtils.calculateContrast;

		import static com.google.common.truth.Truth.assertThat;

		import android.graphics.Color;

		import androidx.test.filters.SmallTest;

		import junit.framework.TestCase;

		public class ContrastColorUtilTest extends TestCase {

		@SmallTest
		public void testEnsureTextContrastAgainstDark() {
		int darkBg = 0xFF35302A;

		int blueContrastColor = ContrastColorUtil.ensureTextContrast(Color.BLUE, darkBg, true);
		assertContrastIsWithinRange(blueContrastColor, darkBg, 4.5, 4.75);

		int redContrastColor = ContrastColorUtil.ensureTextContrast(Color.RED, darkBg, true);
		assertContrastIsWithinRange(redContrastColor, darkBg, 4.5, 4.75);

		final int darkGreen = 0xff008800;
		int greenContrastColor = ContrastColorUtil.ensureTextContrast(darkGreen, darkBg, true);
		assertContrastIsWithinRange(greenContrastColor, darkBg, 4.5, 4.75);

		int grayContrastColor = ContrastColorUtil.ensureTextContrast(Color.DKGRAY, darkBg, true);
		assertContrastIsWithinRange(grayContrastColor, darkBg, 4.5, 4.75);

		int selfContrastColor = ContrastColorUtil.ensureTextContrast(darkBg, darkBg, true);
		assertContrastIsWithinRange(selfContrastColor, darkBg, 4.5, 4.75);
		}

		@SmallTest
		public void testEnsureTextContrastAgainstLight() {
		int lightBg = 0xFFFFF8F2;

		final int lightBlue = 0xff8888ff;
		int blueContrastColor = ContrastColorUtil.ensureTextContrast(lightBlue, lightBg, false);
		assertContrastIsWithinRange(blueContrastColor, lightBg, 4.5, 4.75);

		int redContrastColor = ContrastColorUtil.ensureTextContrast(Color.RED, lightBg, false);
		assertContrastIsWithinRange(redContrastColor, lightBg, 4.5, 4.75);

		int greenContrastColor = ContrastColorUtil.ensureTextContrast(Color.GREEN, lightBg, false);
		assertContrastIsWithinRange(greenContrastColor, lightBg, 4.5, 4.75);

		int grayContrastColor = ContrastColorUtil.ensureTextContrast(Color.LTGRAY, lightBg, false);
		assertContrastIsWithinRange(grayContrastColor, lightBg, 4.5, 4.75);

		int selfContrastColor = ContrastColorUtil.ensureTextContrast(lightBg, lightBg, false);
		assertContrastIsWithinRange(selfContrastColor, lightBg, 4.5, 4.75);
		}

		private void assertContrastIsWithinRange(int foreground, int background,
		double minContrast, double maxContrast) {
		assertContrastIsAtLeast(foreground, background, minContrast);
		assertContrastIsAtMost(foreground, background, maxContrast);
		}

		private void assertContrastIsAtLeast(int foreground, int background, double minContrast) {
		try {
		assertThat(calculateContrast(foreground, background)).isAtLeast(minContrast);
		} catch (AssertionError e) {
		throw new AssertionError(
		String.format("Insufficient contrast: foreground=#%08x background=#%08x",
		foreground, background), e);
		}
		}

		private void assertContrastIsAtMost(int foreground, int background, double maxContrast) {
		try {
		assertThat(calculateContrast(foreground, background)).isAtMost(maxContrast);
		} catch (AssertionError e) {
		throw new AssertionError(
		String.format("Excessive contrast: foreground=#%08x background=#%08x",
		foreground, background), e);
		}
		}

		}