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 17 package com.android.tv.common.feature; 18 19 import android.content.Context; 20 import com.android.tv.common.BooleanSystemProperty; 21 22 /** 23 * Feature controlled by system property. 24 * 25 * <p>See {@link BooleanSystemProperty} for instructions on how to set using adb. 26 */ 27 public final class PropertyFeature implements Feature { 28 create(String key, boolean defaultValue)29 public static PropertyFeature create(String key, boolean defaultValue) { 30 return new PropertyFeature(key, defaultValue); 31 } 32 33 private final BooleanSystemProperty mProperty; 34 35 /** 36 * Create System Property backed feature. 37 * 38 * @param key the system property key. Length must be <= 31 characters. 39 * @param defaultValue the value to return if the property is undefined or empty. 40 */ PropertyFeature(String key, boolean defaultValue)41 private PropertyFeature(String key, boolean defaultValue) { 42 if (key.length() > 31) { 43 // Since Features are initialized at startup and the keys are static go ahead and kill 44 // the application. 45 throw new IllegalArgumentException( 46 "Property keys have a max length of 31 characters but '" 47 + key 48 + "' is " 49 + key.length() 50 + " characters."); 51 } 52 mProperty = new BooleanSystemProperty(key, defaultValue); 53 } 54 55 @Override isEnabled(Context context)56 public boolean isEnabled(Context context) { 57 return mProperty.getValue(); 58 } 59 60 @Override toString()61 public String toString() { 62 return mProperty.toString(); 63 } 64 } 65