1/*
2 * Copyright (C) 2016 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.tv.experiments;
18
19import android.support.annotation.VisibleForTesting;
20
21/**
22 * Experiments return values based on user, device and other criteria.
23 */
24public final class ExperimentFlag<T> {
25
26    private static boolean sAllowOverrides = false;
27
28    @VisibleForTesting
29    public static void initForTest() {
30        sAllowOverrides = true;
31    }
32
33    /** Returns a boolean experiment */
34    public static ExperimentFlag<Boolean> createFlag(
35            boolean defaultValue) {
36        return new ExperimentFlag<>(
37                defaultValue);
38    }
39
40    private final T mDefaultValue;
41
42    private T mOverrideValue = null;
43    private boolean mOverridden = false;
44
45    private ExperimentFlag(
46            T defaultValue) {
47        mDefaultValue = defaultValue;
48    }
49
50    /** Returns value for this experiment */
51    public T get() {
52        return sAllowOverrides && mOverridden ? mOverrideValue : mDefaultValue;
53    }
54
55    @VisibleForTesting
56    public void override(T t) {
57        if (sAllowOverrides) {
58            mOverridden = true;
59            mOverrideValue = t;
60        }
61    }
62
63    @VisibleForTesting
64    public void resetOverride() {
65        mOverridden = false;
66    }
67
68
69
70}
71