1/* 2 * Copyright (C) 2017 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 com.android.launcher3.util; 18 19import android.content.Context; 20import android.content.res.TypedArray; 21import android.graphics.Color; 22import android.graphics.ColorMatrix; 23import android.view.ContextThemeWrapper; 24 25/** 26 * Various utility methods associated with theming. 27 */ 28public class Themes { 29 30 public static int getColorAccent(Context context) { 31 return getAttrColor(context, android.R.attr.colorAccent); 32 } 33 34 public static int getColorPrimary(Context context, int theme) { 35 return getAttrColor(new ContextThemeWrapper(context, theme), android.R.attr.colorPrimary); 36 } 37 38 public static int getAttrColor(Context context, int attr) { 39 TypedArray ta = context.obtainStyledAttributes(new int[]{attr}); 40 int colorAccent = ta.getColor(0, 0); 41 ta.recycle(); 42 return colorAccent; 43 } 44 45 /** 46 * Returns the alpha corresponding to the theme attribute {@param attr}, in the range [0, 255]. 47 */ 48 public static int getAlpha(Context context, int attr) { 49 TypedArray ta = context.obtainStyledAttributes(new int[]{attr}); 50 float alpha = ta.getFloat(0, 0); 51 ta.recycle(); 52 return (int) (255 * alpha + 0.5f); 53 } 54 55 /** 56 * Scales a color matrix such that, when applied to color R G B A, it produces R' G' B' A' where 57 * R' = r * R 58 * G' = g * G 59 * B' = b * B 60 * A' = a * A 61 * 62 * The matrix will, for instance, turn white into r g b a, and black will remain black. 63 * 64 * @param color The color r g b a 65 * @param target The ColorMatrix to scale 66 */ 67 public static void setColorScaleOnMatrix(int color, ColorMatrix target) { 68 target.setScale(Color.red(color) / 255f, Color.green(color) / 255f, 69 Color.blue(color) / 255f, Color.alpha(color) / 255f); 70 } 71} 72