1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file
5  * except in compliance with the License. You may obtain a copy of the License at
6  *
7  *      http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software distributed under the
10  * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
11  * KIND, either express or implied. See the License for the specific language governing
12  * permissions and limitations under the License.
13  */
14 
15 package com.android.systemui;
16 
17 import java.util.ArrayList;
18 
19 import javax.inject.Inject;
20 import javax.inject.Singleton;
21 
22 /**
23  * Created by {@link Dependency} on SystemUI startup. Add tasks which need to be executed only
24  * after all other dependencies have been created.
25  */
26 @Singleton
27 public class InitController {
28 
29     /**
30      * If a task is added after all tasks are executed, then we've done something terribly wrong
31      */
32     private boolean mTasksExecuted = false;
33 
34     private final ArrayList<Runnable> mTasks = new ArrayList<>();
35 
36     @Inject
InitController()37     public InitController() {
38     }
39 
40     /**
41      * Add a task to be executed after {@link Dependency#start()}
42      * @param runnable the task to be executed
43      */
addPostInitTask(Runnable runnable)44     public void addPostInitTask(Runnable runnable) {
45         if (mTasksExecuted) {
46             throw new IllegalStateException("post init tasks have already been executed!");
47         }
48         mTasks.add(runnable);
49     }
50 
51     /**
52      * Run post-init tasks and remove them from the tasks list
53      */
executePostInitTasks()54     public void executePostInitTasks() {
55         while (!mTasks.isEmpty()) {
56             mTasks.remove(0).run();
57         }
58 
59         mTasksExecuted = true;
60     }
61 }
62