1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.support.v4.graphics;
18
19import android.graphics.Color;
20import android.support.v4.graphics.ColorUtils;
21import android.test.AndroidTestCase;
22
23import java.util.ArrayList;
24
25/**
26 * @hide
27 */
28public class ColorUtilsTest extends AndroidTestCase {
29
30    // 0.5% of the max value
31    private static final float ALLOWED_OFFSET_HUE = 360 * 0.005f;
32    private static final float ALLOWED_OFFSET_SATURATION = 0.005f;
33    private static final float ALLOWED_OFFSET_LIGHTNESS = 0.005f;
34
35    private static final int ALLOWED_OFFSET_RGB_COMPONENT = 2;
36
37    private static final ArrayList<TestEntry> sEntryList = new ArrayList<>();
38
39    static {
40        sEntryList.add(new TestEntry(Color.BLACK).setHsl(0f, 0f, 0f));
41        sEntryList.add(new TestEntry(Color.WHITE).setHsl(0f, 0f, 1f));
42        sEntryList.add(new TestEntry(Color.BLUE).setHsl(240f, 1f, 0.5f));
43        sEntryList.add(new TestEntry(Color.GREEN).setHsl(120f, 1f, 0.5f));
44        sEntryList.add(new TestEntry(Color.RED).setHsl(0f, 1f, 0.5f));
45        sEntryList.add(new TestEntry(Color.CYAN).setHsl(180f, 1f, 0.5f));
46        sEntryList.add(new TestEntry(0x2196F3).setHsl(207f, 0.9f, 0.54f));
47        sEntryList.add(new TestEntry(0xD1C4E9).setHsl(261f, 0.46f, 0.84f));
48        sEntryList.add(new TestEntry(0x311B92).setHsl(251.09f, 0.687f, 0.339f));
49    }
50
51    public void testToHSL() {
52        for (TestEntry entry : sEntryList) {
53            testColorToHSL(entry.rgb, entry.hsl);
54        }
55    }
56
57    public void testFromHSL() {
58        for (TestEntry entry : sEntryList) {
59            testHSLToColor(entry.hsl, entry.rgb);
60        }
61    }
62
63    public void testToHslLimits() {
64        final float[] hsl = new float[3];
65
66        for (TestEntry entry : sEntryList) {
67            ColorUtils.colorToHSL(entry.rgb, hsl);
68
69            assertTrue(hsl[0] >= 0f && hsl[0] <= 360f);
70            assertTrue(hsl[1] >= 0f && hsl[1] <= 1f);
71            assertTrue(hsl[2] >= 0f && hsl[2] <= 1f);
72        }
73    }
74
75    private static void assertClose(String message, float expected, float actual,
76            float allowedOffset) {
77        StringBuilder sb = new StringBuilder(message);
78        sb.append(". Expected: ").append(expected).append(". Actual: ").append(actual);
79
80        assertTrue(sb.toString(), Math.abs(expected - actual) <= allowedOffset);
81    }
82
83    private static void assertClose(String message, int expected, int actual,
84            int allowedOffset) {
85        StringBuilder sb = new StringBuilder(message);
86        sb.append(". Expected: ").append(expected).append(". Actual: ").append(actual);
87
88        assertTrue(sb.toString(), Math.abs(expected - actual) <= allowedOffset);
89    }
90
91    private static void testColorToHSL(int color, float[] expectedHsl) {
92        float[] actualHSL = new float[3];
93        ColorUtils.colorToHSL(color, actualHSL);
94
95        assertClose("Hue not within offset", expectedHsl[0], actualHSL[0],
96                ALLOWED_OFFSET_HUE);
97        assertClose("Saturation not within offset", expectedHsl[1], actualHSL[1],
98                ALLOWED_OFFSET_SATURATION);
99        assertClose("Lightness not within offset", expectedHsl[2], actualHSL[2],
100                ALLOWED_OFFSET_LIGHTNESS);
101    }
102
103    private static void testHSLToColor(float[] hsl, int expectedRgb) {
104        final int actualRgb = ColorUtils.HSLToColor(hsl);
105
106        assertClose("Red not within offset",
107                Color.red(expectedRgb), Color.red(actualRgb), ALLOWED_OFFSET_RGB_COMPONENT);
108        assertClose("Green not within offset",
109                Color.green(expectedRgb), Color.green(actualRgb), ALLOWED_OFFSET_RGB_COMPONENT);
110        assertClose("Blue not within offset",
111                Color.blue(expectedRgb), Color.blue(actualRgb), ALLOWED_OFFSET_RGB_COMPONENT);
112    }
113
114    private static class TestEntry {
115        final int rgb;
116        final float[] hsl = new float[3];
117
118        TestEntry(int rgb) {
119            this.rgb = rgb;
120        }
121
122        TestEntry setHsl(float h, float s, float l) {
123            hsl[0] = h;
124            hsl[1] = s;
125            hsl[2] = l;
126            return this;
127        }
128    }
129}