| /* |
| * Copyright (C) 2017 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.graphics; |
| |
| import android.graphics.Color; |
| import android.support.test.filters.SmallTest; |
| |
| import org.junit.Test; |
| |
| import static org.junit.Assert.assertTrue; |
| |
| @SmallTest |
| public class ColorUtilsTest { |
| |
| @Test |
| public void calculateMinimumBackgroundAlpha_satisfiestContrast() { |
| |
| int alpha = ColorUtils.calculateMinimumBackgroundAlpha(Color.WHITE, Color.BLACK, 4.5f); |
| assertTrue("Alpha doesn't need to be 255 to satisfy contrast", alpha < 255); |
| |
| int worstCase = ColorUtils.blendARGB(Color.WHITE, Color.BLACK, alpha/255f); |
| worstCase = ColorUtils.setAlphaComponent(worstCase, 255); |
| double contrast = ColorUtils.calculateContrast(Color.WHITE, worstCase); |
| assertTrue("Blended color should satisfy contrast", contrast >= 4.5); |
| |
| } |
| } |