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      1 /*
      2  * Copyright (C) 2014 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 
     17 package com.android.contacts.common.util;
     18 
     19 import com.android.contacts.common.R;
     20 
     21 import android.content.res.Resources;
     22 import android.content.res.TypedArray;
     23 import android.os.Trace;
     24 
     25 public class MaterialColorMapUtils {
     26 
     27     private final TypedArray sPrimaryColors;
     28     private final TypedArray sSecondaryColors;
     29 
     30     public MaterialColorMapUtils(Resources resources) {
     31         sPrimaryColors = resources.obtainTypedArray(
     32                 com.android.contacts.common.R.array.letter_tile_colors);
     33         sSecondaryColors = resources.obtainTypedArray(
     34                 com.android.contacts.common.R.array.letter_tile_colors_dark);
     35     }
     36 
     37     public static class MaterialPalette {
     38         public MaterialPalette(int primaryColor, int secondaryColor) {
     39             mPrimaryColor = primaryColor;
     40             mSecondaryColor = secondaryColor;
     41         }
     42         public final int mPrimaryColor;
     43         public final int mSecondaryColor;
     44     }
     45 
     46     /**
     47      * Return primary and secondary colors from the Material color palette that are similar to
     48      * {@param color}.
     49      */
     50     public MaterialPalette calculatePrimaryAndSecondaryColor(int color) {
     51         Trace.beginSection("calculatePrimaryAndSecondaryColor");
     52 
     53         final float colorHue = hue(color);
     54         float minimumDistance = Float.MAX_VALUE;
     55         int indexBestMatch = 0;
     56         for (int i = 0; i < sPrimaryColors.length(); i++) {
     57             final int primaryColor = sPrimaryColors.getColor(i, 0);
     58             final float comparedHue = hue(primaryColor);
     59             // No need to be perceptually accurate when calculating color distances since
     60             // we are only mapping to 15 colors. Being slightly inaccurate isn't going to change
     61             // the mapping very often.
     62             final float distance = Math.abs(comparedHue - colorHue);
     63             if (distance < minimumDistance) {
     64                 minimumDistance = distance;
     65                 indexBestMatch = i;
     66             }
     67         }
     68 
     69         Trace.endSection();
     70         return new MaterialPalette(sPrimaryColors.getColor(indexBestMatch, 0),
     71                 sSecondaryColors.getColor(indexBestMatch, 0));
     72     }
     73 
     74     public static MaterialPalette getDefaultPrimaryAndSecondaryColors(Resources resources) {
     75         final int primaryColor = resources.getColor(
     76                 R.color.quickcontact_default_photo_tint_color);
     77         final int secondaryColor = resources.getColor(
     78                 R.color.quickcontact_default_photo_tint_color_dark);
     79         return new MaterialPalette(primaryColor, secondaryColor);
     80     }
     81 
     82     /**
     83      * Returns the hue component of a color int.
     84      *
     85      * @return A value between 0.0f and 1.0f
     86      */
     87     public static float hue(int color) {
     88         int r = (color >> 16) & 0xFF;
     89         int g = (color >> 8) & 0xFF;
     90         int b = color & 0xFF;
     91 
     92         int V = Math.max(b, Math.max(r, g));
     93         int temp = Math.min(b, Math.min(r, g));
     94 
     95         float H;
     96 
     97         if (V == temp) {
     98             H = 0;
     99         } else {
    100             final float vtemp = V - temp;
    101             final float cr = (V - r) / vtemp;
    102             final float cg = (V - g) / vtemp;
    103             final float cb = (V - b) / vtemp;
    104 
    105             if (r == V) {
    106                 H = cb - cg;
    107             } else if (g == V) {
    108                 H = 2 + cr - cb;
    109             } else {
    110                 H = 4 + cg - cr;
    111             }
    112 
    113             H /= 6.f;
    114             if (H < 0) {
    115                 H++;
    116             }
    117         }
    118 
    119         return H;
    120     }
    121 }
    122