1 /*
<lambda>null2  * 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.permissioncontroller.permission.data
18 
19 import android.app.Application
20 import android.content.pm.PackageManager
21 import com.android.permissioncontroller.PermissionControllerApplication
22 
23 /** Serves as a single shared Permission Change Listener for all AppPermissionGroupLiveDatas. */
24 object PermissionListenerMultiplexer : PackageManager.OnPermissionsChangedListener {
25 
26     private val app: Application = PermissionControllerApplication.get()
27     /**
28      * Map<UID, list of PermissionChangeCallbacks that wish to be informed when permissions are
29      * updated for that UID>
30      */
31     private val callbacks = mutableMapOf<Int, MutableList<PermissionChangeCallback>>()
32     private val pm = app.applicationContext.packageManager
33 
34     override fun onPermissionsChanged(uid: Int) {
35         callbacks[uid]?.toList()?.forEach { callback -> callback.onPermissionChange() }
36     }
37 
38     fun addOrReplaceCallback(oldUid: Int?, newUid: Int, callback: PermissionChangeCallback) {
39         if (oldUid != null) {
40             removeCallback(oldUid, callback)
41         }
42         addCallback(newUid, callback)
43     }
44 
45     fun addCallback(uid: Int, callback: PermissionChangeCallback) {
46         val wasEmpty = callbacks.isEmpty()
47 
48         callbacks.getOrPut(uid, { mutableListOf() }).add(callback)
49 
50         if (wasEmpty) {
51             pm.addOnPermissionsChangeListener(this)
52         }
53     }
54 
55     fun removeCallback(uid: Int, callback: PermissionChangeCallback) {
56         if (!callbacks.contains(uid)) {
57             return
58         }
59 
60         if (!callbacks[uid]!!.remove(callback)) {
61             return
62         }
63 
64         if (callbacks[uid]!!.isEmpty()) {
65             callbacks.remove(uid)
66         }
67 
68         if (callbacks.isEmpty()) {
69             pm.removeOnPermissionsChangeListener(this)
70         }
71     }
72 
73     interface PermissionChangeCallback {
74         fun onPermissionChange()
75     }
76 }
77