1 /*
2  * Copyright (C) 2013 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.settings;
18 
19 import android.app.Activity;
20 import android.content.BroadcastReceiver;
21 import android.content.Context;
22 import android.content.Intent;
23 import android.content.IntentFilter;
24 import android.content.RestrictionsManager;
25 import android.os.Bundle;
26 import android.os.PersistableBundle;
27 import android.os.UserManager;
28 
29 /**
30  * Base class for settings screens that should be pin protected when in restricted mode.
31  * The constructor for this class will take the restriction key that this screen should be
32  * locked by.  If {@link RestrictionsManager.hasRestrictionsProvider()} and
33  * {@link UserManager.hasUserRestriction()}, then the user will have to enter the restrictions
34  * pin before seeing the Settings screen.
35  *
36  * If this settings screen should be pin protected whenever
37  * {@link RestrictionsManager.hasRestrictionsProvider()} returns true, pass in
38  * {@link RESTRICT_IF_OVERRIDABLE} to the constructor instead of a restrictions key.
39  */
40 public class RestrictedSettingsFragment extends SettingsPreferenceFragment {
41 
42     protected static final String RESTRICT_IF_OVERRIDABLE = "restrict_if_overridable";
43 
44     // No RestrictedSettingsFragment screens should use this number in startActivityForResult.
45     private static final int REQUEST_PIN_CHALLENGE = 12309;
46 
47     private static final String KEY_CHALLENGE_SUCCEEDED = "chsc";
48     private static final String KEY_CHALLENGE_REQUESTED = "chrq";
49 
50     // If the restriction PIN is entered correctly.
51     private boolean mChallengeSucceeded;
52     private boolean mChallengeRequested;
53 
54     private UserManager mUserManager;
55     private RestrictionsManager mRestrictionsManager;
56 
57     private final String mRestrictionKey;
58 
59     // Receiver to clear pin status when the screen is turned off.
60     private BroadcastReceiver mScreenOffReceiver = new BroadcastReceiver() {
61         @Override
62         public void onReceive(Context context, Intent intent) {
63             if (!mChallengeRequested) {
64                 mChallengeSucceeded = false;
65                 mChallengeRequested = false;
66             }
67         }
68     };
69 
70     /**
71      * @param restrictionKey The restriction key to check before pin protecting
72      *            this settings page. Pass in {@link RESTRICT_IF_OVERRIDABLE} if it should
73      *            be protected whenever a restrictions provider is set. Pass in
74      *            null if it should never be protected.
75      */
RestrictedSettingsFragment(String restrictionKey)76     public RestrictedSettingsFragment(String restrictionKey) {
77         mRestrictionKey = restrictionKey;
78     }
79 
80     @Override
onCreate(Bundle icicle)81     public void onCreate(Bundle icicle) {
82         super.onCreate(icicle);
83 
84         mRestrictionsManager = (RestrictionsManager) getSystemService(Context.RESTRICTIONS_SERVICE);
85         mUserManager = (UserManager) getSystemService(Context.USER_SERVICE);
86 
87         if (icicle != null) {
88             mChallengeSucceeded = icicle.getBoolean(KEY_CHALLENGE_SUCCEEDED, false);
89             mChallengeRequested = icicle.getBoolean(KEY_CHALLENGE_REQUESTED, false);
90         }
91 
92         IntentFilter offFilter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
93         offFilter.addAction(Intent.ACTION_USER_PRESENT);
94         getActivity().registerReceiver(mScreenOffReceiver, offFilter);
95     }
96 
97     @Override
onSaveInstanceState(Bundle outState)98     public void onSaveInstanceState(Bundle outState) {
99         super.onSaveInstanceState(outState);
100 
101         if (getActivity().isChangingConfigurations()) {
102             outState.putBoolean(KEY_CHALLENGE_REQUESTED, mChallengeRequested);
103             outState.putBoolean(KEY_CHALLENGE_SUCCEEDED, mChallengeSucceeded);
104         }
105     }
106 
107     @Override
onResume()108     public void onResume() {
109         super.onResume();
110 
111         if (shouldBeProviderProtected(mRestrictionKey)) {
112             ensurePin();
113         }
114     }
115 
116     @Override
onDestroy()117     public void onDestroy() {
118         getActivity().unregisterReceiver(mScreenOffReceiver);
119         super.onDestroy();
120     }
121 
122     @Override
onActivityResult(int requestCode, int resultCode, Intent data)123     public void onActivityResult(int requestCode, int resultCode, Intent data) {
124         if (requestCode == REQUEST_PIN_CHALLENGE) {
125             if (resultCode == Activity.RESULT_OK) {
126                 mChallengeSucceeded = true;
127                 mChallengeRequested = false;
128             } else {
129                 mChallengeSucceeded = false;
130             }
131             return;
132         }
133 
134         super.onActivityResult(requestCode, resultCode, data);
135     }
136 
ensurePin()137     private void ensurePin() {
138         if (!mChallengeSucceeded && !mChallengeRequested
139                 && mRestrictionsManager.hasRestrictionsProvider()) {
140             Intent intent = mRestrictionsManager.createLocalApprovalIntent();
141             if (intent != null) {
142                 mChallengeRequested = true;
143                 mChallengeSucceeded = false;
144                 PersistableBundle request = new PersistableBundle();
145                 request.putString(RestrictionsManager.REQUEST_KEY_MESSAGE,
146                         getResources().getString(R.string.restr_pin_enter_admin_pin));
147                 intent.putExtra(RestrictionsManager.EXTRA_REQUEST_BUNDLE, request);
148                 startActivityForResult(intent, REQUEST_PIN_CHALLENGE);
149             }
150         }
151     }
152 
153     /**
154      * Returns true if this activity is restricted, but no restrictions provider has been set.
155      * Used to determine if the settings UI should disable UI.
156      */
isRestrictedAndNotProviderProtected()157     protected boolean isRestrictedAndNotProviderProtected() {
158         if (mRestrictionKey == null || RESTRICT_IF_OVERRIDABLE.equals(mRestrictionKey)) {
159             return false;
160         }
161         return mUserManager.hasUserRestriction(mRestrictionKey)
162                 && !mRestrictionsManager.hasRestrictionsProvider();
163     }
164 
hasChallengeSucceeded()165     protected boolean hasChallengeSucceeded() {
166         return (mChallengeRequested && mChallengeSucceeded) || !mChallengeRequested;
167     }
168 
169     /**
170      * Returns true if this restrictions key is locked down.
171      */
shouldBeProviderProtected(String restrictionKey)172     protected boolean shouldBeProviderProtected(String restrictionKey) {
173         if (restrictionKey == null) {
174             return false;
175         }
176         boolean restricted = RESTRICT_IF_OVERRIDABLE.equals(restrictionKey)
177                 || mUserManager.hasUserRestriction(mRestrictionKey);
178         return restricted && mRestrictionsManager.hasRestrictionsProvider();
179     }
180 
181     /**
182      * Returns whether restricted or actionable UI elements should be removed or disabled.
183      */
isUiRestricted()184     protected boolean isUiRestricted() {
185         return isRestrictedAndNotProviderProtected() || !hasChallengeSucceeded();
186     }
187 }
188