1 /*
2  * Copyright (C) 2019 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.car.themeplayground;
18 
19 import android.app.Activity;
20 import android.content.Intent;
21 
22 import java.util.Objects;
23 
24 /**
25  * Utility class for changing the theme of the app at run time.
26  */
27 public class Utils {
28     static String sThemeName = "";
29     private static int sThemeResId = 0;
30 
31     /**
32      * Set the theme of the Activity, and restart it by creating a new Activity of the same type.
33      */
changeToTheme(Activity activity, String themeName, int themeResId)34     public static void changeToTheme(Activity activity, String themeName, int themeResId) {
35         sThemeName = Objects.requireNonNull(themeName, "Theme name can not be null");
36         sThemeResId = themeResId;
37         activity.finish();
38         activity.startActivity(new Intent(activity, activity.getClass()));
39     }
40 
41     /** Set the theme of the activity, according to the configuration. */
onActivityCreateSetTheme(Activity activity)42     public static void onActivityCreateSetTheme(Activity activity) {
43         if (Objects.equals(sThemeName, "")) {
44             activity.setTheme(android.R.style.Theme_DeviceDefault);
45         } else {
46             activity.setTheme(sThemeResId);
47         }
48     }
49 }
50