Java tutorial
/* * 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.contacts.util; import android.app.Activity; import android.content.res.Resources; import android.content.res.TypedArray; import android.os.Parcel; import android.os.Parcelable; import android.os.Trace; import android.support.v4.content.ContextCompat; import com.android.contacts.R; import com.android.contacts.activities.PeopleActivity; public class MaterialColorMapUtils { private final TypedArray sPrimaryColors; private final TypedArray sSecondaryColors; public MaterialColorMapUtils(Resources resources) { sPrimaryColors = resources.obtainTypedArray(com.android.contacts.R.array.letter_tile_colors); sSecondaryColors = resources.obtainTypedArray(com.android.contacts.R.array.letter_tile_colors_dark); } public static class MaterialPalette implements Parcelable { public MaterialPalette(int primaryColor, int secondaryColor) { mPrimaryColor = primaryColor; mSecondaryColor = secondaryColor; } public final int mPrimaryColor; public final int mSecondaryColor; @Override public boolean equals(Object obj) { if (this == obj) { return true; } if (obj == null) { return false; } if (getClass() != obj.getClass()) { return false; } MaterialPalette other = (MaterialPalette) obj; if (mPrimaryColor != other.mPrimaryColor) { return false; } if (mSecondaryColor != other.mSecondaryColor) { return false; } return true; } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + mPrimaryColor; result = prime * result + mSecondaryColor; return result; } @Override public int describeContents() { return 0; } @Override public void writeToParcel(Parcel dest, int flags) { dest.writeInt(mPrimaryColor); dest.writeInt(mSecondaryColor); } private MaterialPalette(Parcel in) { mPrimaryColor = in.readInt(); mSecondaryColor = in.readInt(); } public static final Creator<MaterialPalette> CREATOR = new Creator<MaterialPalette>() { @Override public MaterialPalette createFromParcel(Parcel in) { return new MaterialPalette(in); } @Override public MaterialPalette[] newArray(int size) { return new MaterialPalette[size]; } }; } /** * Return primary and secondary colors from the Material color palette that are similar to * {@param color}. */ public MaterialPalette calculatePrimaryAndSecondaryColor(int color) { Trace.beginSection("calculatePrimaryAndSecondaryColor"); final float colorHue = hue(color); float minimumDistance = Float.MAX_VALUE; int indexBestMatch = 0; for (int i = 0; i < sPrimaryColors.length(); i++) { final int primaryColor = sPrimaryColors.getColor(i, 0); final float comparedHue = hue(primaryColor); // No need to be perceptually accurate when calculating color distances since // we are only mapping to 15 colors. Being slightly inaccurate isn't going to change // the mapping very often. final float distance = Math.abs(comparedHue - colorHue); if (distance < minimumDistance) { minimumDistance = distance; indexBestMatch = i; } } Trace.endSection(); return new MaterialPalette(sPrimaryColors.getColor(indexBestMatch, 0), sSecondaryColors.getColor(indexBestMatch, 0)); } public static MaterialPalette getDefaultPrimaryAndSecondaryColors(Resources resources) { final int primaryColor = resources.getColor(R.color.quickcontact_default_photo_tint_color); final int secondaryColor = resources.getColor(R.color.quickcontact_default_photo_tint_color_dark); return new MaterialPalette(primaryColor, secondaryColor); } /** * Returns the hue component of a color int. * * @return A value between 0.0f and 1.0f */ public static float hue(int color) { int r = (color >> 16) & 0xFF; int g = (color >> 8) & 0xFF; int b = color & 0xFF; int V = Math.max(b, Math.max(r, g)); int temp = Math.min(b, Math.min(r, g)); float H; if (V == temp) { H = 0; } else { final float vtemp = V - temp; final float cr = (V - r) / vtemp; final float cg = (V - g) / vtemp; final float cb = (V - b) / vtemp; if (r == V) { H = cb - cg; } else if (g == V) { H = 2 + cr - cb; } else { H = 4 + cg - cr; } H /= 6.f; if (H < 0) { H++; } } return H; } /** * Returns status bar color for group view and non-group views. */ public static int getStatusBarColor(Activity activity) { final boolean isGroupView = activity instanceof PeopleActivity && ((PeopleActivity) activity).isGroupView(); return isGroupView ? ContextCompat.getColor(activity, R.color.group_primary_color_dark) : ContextCompat.getColor(activity, R.color.primary_color_dark); } /** * Returns toolbar color for group view and non-group views. */ public static int getToolBarColor(Activity activity) { final boolean isGroupView = activity instanceof PeopleActivity && ((PeopleActivity) activity).isGroupView(); return isGroupView ? ContextCompat.getColor(activity, R.color.group_primary_color) : ContextCompat.getColor(activity, R.color.primary_color); } }