1 /*
2  * Copyright (C) 2017 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.dashboard;
18 
19 import static com.android.settingslib.RestrictedLockUtils.EnforcedAdmin;
20 
21 import android.app.Activity;
22 import android.content.BroadcastReceiver;
23 import android.content.Context;
24 import android.content.Intent;
25 import android.content.IntentFilter;
26 import android.content.RestrictionsManager;
27 import android.os.Bundle;
28 import android.os.PersistableBundle;
29 import android.os.UserHandle;
30 import android.os.UserManager;
31 import android.view.View;
32 import android.widget.TextView;
33 
34 import androidx.appcompat.app.AlertDialog;
35 
36 import com.android.settings.R;
37 import com.android.settings.RestrictedSettingsFragment;
38 import com.android.settings.enterprise.ActionDisabledByAdminDialogHelper;
39 import com.android.settingslib.RestrictedLockUtilsInternal;
40 
41 /**
42  * Base class for settings screens that should be pin protected when in restricted mode or
43  * that will display an admin support message in case an admin has disabled the options.
44  * The constructor for this class will take the restriction key that this screen should be
45  * locked by.  If {@link RestrictionsManager.hasRestrictionsProvider()} and
46  * {@link UserManager.hasUserRestriction()}, then the user will have to enter the restrictions
47  * pin before seeing the Settings screen.
48  *
49  * {@link RestrictionsManager.hasRestrictionsProvider()} returns true, pass in
50  * {@link RESTRICT_IF_OVERRIDABLE} to the constructor instead of a restrictions key.
51  *
52  * This fragment is a replacement of {@link RestrictedSettingsFragment} but extends
53  * from {@link DashboardFragment}, so we could also use
54  * {@link com.android.settingslib.core.AbstractPreferenceController} in this fragment.
55  */
56 public abstract class RestrictedDashboardFragment extends DashboardFragment {
57 
58     protected static final String RESTRICT_IF_OVERRIDABLE = "restrict_if_overridable";
59 
60     // No RestrictedSettingsFragment screens should use this number in startActivityForResult.
61     private static final int REQUEST_PIN_CHALLENGE = 12309;
62 
63     private static final String KEY_CHALLENGE_SUCCEEDED = "chsc";
64     private static final String KEY_CHALLENGE_REQUESTED = "chrq";
65 
66     // If the restriction PIN is entered correctly.
67     private boolean mChallengeSucceeded;
68     private boolean mChallengeRequested;
69 
70     private UserManager mUserManager;
71     private RestrictionsManager mRestrictionsManager;
72 
73     private final String mRestrictionKey;
74     private EnforcedAdmin mEnforcedAdmin;
75     private TextView mEmptyTextView;
76 
77     private boolean mOnlyAvailableForAdmins = false;
78     private boolean mIsAdminUser;
79 
80     // Receiver to clear pin status when the screen is turned off.
81     private BroadcastReceiver mScreenOffReceiver = new BroadcastReceiver() {
82         @Override
83         public void onReceive(Context context, Intent intent) {
84             if (!mChallengeRequested) {
85                 mChallengeSucceeded = false;
86                 mChallengeRequested = false;
87             }
88         }
89     };
90     private AlertDialog mActionDisabledDialog;
91 
92     /**
93      * @param restrictionKey The restriction key to check before pin protecting
94      *            this settings page. Pass in {@link RESTRICT_IF_OVERRIDABLE} if it should
95      *            be protected whenever a restrictions provider is set. Pass in
96      *            null if it should never be protected.
97      */
RestrictedDashboardFragment(String restrictionKey)98     public RestrictedDashboardFragment(String restrictionKey) {
99         mRestrictionKey = restrictionKey;
100     }
101 
102     @Override
onCreate(Bundle icicle)103     public void onCreate(Bundle icicle) {
104         super.onCreate(icicle);
105 
106         mRestrictionsManager = (RestrictionsManager) getSystemService(Context.RESTRICTIONS_SERVICE);
107         mUserManager = (UserManager) getSystemService(Context.USER_SERVICE);
108         mIsAdminUser = mUserManager.isAdminUser();
109 
110         if (icicle != null) {
111             mChallengeSucceeded = icicle.getBoolean(KEY_CHALLENGE_SUCCEEDED, false);
112             mChallengeRequested = icicle.getBoolean(KEY_CHALLENGE_REQUESTED, false);
113         }
114 
115         IntentFilter offFilter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
116         offFilter.addAction(Intent.ACTION_USER_PRESENT);
117         getActivity().registerReceiver(mScreenOffReceiver, offFilter);
118     }
119 
120     @Override
onActivityCreated(Bundle savedInstanceState)121     public void onActivityCreated(Bundle savedInstanceState) {
122         super.onActivityCreated(savedInstanceState);
123         mEmptyTextView = initEmptyTextView();
124     }
125 
126     @Override
onSaveInstanceState(Bundle outState)127     public void onSaveInstanceState(Bundle outState) {
128         super.onSaveInstanceState(outState);
129 
130         if (getActivity().isChangingConfigurations()) {
131             outState.putBoolean(KEY_CHALLENGE_REQUESTED, mChallengeRequested);
132             outState.putBoolean(KEY_CHALLENGE_SUCCEEDED, mChallengeSucceeded);
133         }
134     }
135 
136     @Override
onResume()137     public void onResume() {
138         super.onResume();
139 
140         if (shouldBeProviderProtected(mRestrictionKey)) {
141             ensurePin();
142         }
143     }
144 
145     @Override
onDestroy()146     public void onDestroy() {
147         getActivity().unregisterReceiver(mScreenOffReceiver);
148         super.onDestroy();
149     }
150 
151     @Override
onActivityResult(int requestCode, int resultCode, Intent data)152     public void onActivityResult(int requestCode, int resultCode, Intent data) {
153         if (requestCode == REQUEST_PIN_CHALLENGE) {
154             if (resultCode == Activity.RESULT_OK) {
155                 mChallengeSucceeded = true;
156                 mChallengeRequested = false;
157             } else {
158                 mChallengeSucceeded = false;
159             }
160             return;
161         }
162 
163         super.onActivityResult(requestCode, resultCode, data);
164     }
165 
ensurePin()166     private void ensurePin() {
167         if (!mChallengeSucceeded && !mChallengeRequested
168                 && mRestrictionsManager.hasRestrictionsProvider()) {
169             Intent intent = mRestrictionsManager.createLocalApprovalIntent();
170             if (intent != null) {
171                 mChallengeRequested = true;
172                 mChallengeSucceeded = false;
173                 PersistableBundle request = new PersistableBundle();
174                 request.putString(RestrictionsManager.REQUEST_KEY_MESSAGE,
175                         getResources().getString(R.string.restr_pin_enter_admin_pin));
176                 intent.putExtra(RestrictionsManager.EXTRA_REQUEST_BUNDLE, request);
177                 startActivityForResult(intent, REQUEST_PIN_CHALLENGE);
178             }
179         }
180     }
181 
182     /**
183      * Returns true if this activity is restricted, but no restrictions provider has been set.
184      * Used to determine if the settings UI should disable UI.
185      */
isRestrictedAndNotProviderProtected()186     protected boolean isRestrictedAndNotProviderProtected() {
187         if (mRestrictionKey == null || RESTRICT_IF_OVERRIDABLE.equals(mRestrictionKey)) {
188             return false;
189         }
190         return mUserManager.hasUserRestriction(mRestrictionKey)
191                 && !mRestrictionsManager.hasRestrictionsProvider();
192     }
193 
hasChallengeSucceeded()194     protected boolean hasChallengeSucceeded() {
195         return (mChallengeRequested && mChallengeSucceeded) || !mChallengeRequested;
196     }
197 
198     /**
199      * Returns true if this restrictions key is locked down.
200      */
shouldBeProviderProtected(String restrictionKey)201     protected boolean shouldBeProviderProtected(String restrictionKey) {
202         if (restrictionKey == null) {
203             return false;
204         }
205         boolean restricted = RESTRICT_IF_OVERRIDABLE.equals(restrictionKey)
206                 || mUserManager.hasUserRestriction(mRestrictionKey);
207         return restricted && mRestrictionsManager.hasRestrictionsProvider();
208     }
209 
initEmptyTextView()210     protected TextView initEmptyTextView() {
211         TextView emptyView = (TextView) getActivity().findViewById(android.R.id.empty);
212         return emptyView;
213     }
214 
getRestrictionEnforcedAdmin()215     public EnforcedAdmin getRestrictionEnforcedAdmin() {
216         mEnforcedAdmin = RestrictedLockUtilsInternal.checkIfRestrictionEnforced(getActivity(),
217                 mRestrictionKey, UserHandle.myUserId());
218         if (mEnforcedAdmin != null && mEnforcedAdmin.user == null) {
219             mEnforcedAdmin.user = UserHandle.of(UserHandle.myUserId());
220         }
221         return mEnforcedAdmin;
222     }
223 
getEmptyTextView()224     public TextView getEmptyTextView() {
225         return mEmptyTextView;
226     }
227 
228     @Override
onDataSetChanged()229     protected void onDataSetChanged() {
230         highlightPreferenceIfNeeded();
231         if (isUiRestrictedByOnlyAdmin()
232                 && (mActionDisabledDialog == null || !mActionDisabledDialog.isShowing())) {
233             final EnforcedAdmin admin = getRestrictionEnforcedAdmin();
234             mActionDisabledDialog = new ActionDisabledByAdminDialogHelper(getActivity())
235                     .prepareDialogBuilder(mRestrictionKey, admin)
236                     .setOnDismissListener(__ -> getActivity().finish())
237                     .show();
238             setEmptyView(new View(getContext()));
239         } else if (mEmptyTextView != null) {
240             setEmptyView(mEmptyTextView);
241         }
242         super.onDataSetChanged();
243     }
244 
setIfOnlyAvailableForAdmins(boolean onlyForAdmins)245     public void setIfOnlyAvailableForAdmins(boolean onlyForAdmins) {
246         mOnlyAvailableForAdmins = onlyForAdmins;
247     }
248 
249     /**
250      * Returns whether restricted or actionable UI elements should be removed or disabled.
251      */
isUiRestricted()252     protected boolean isUiRestricted() {
253         return isRestrictedAndNotProviderProtected() || !hasChallengeSucceeded()
254                 || (!mIsAdminUser && mOnlyAvailableForAdmins);
255     }
256 
isUiRestrictedByOnlyAdmin()257     protected boolean isUiRestrictedByOnlyAdmin() {
258         return isUiRestricted() && !mUserManager.hasBaseUserRestriction(mRestrictionKey,
259                 UserHandle.of(UserHandle.myUserId())) && (mIsAdminUser || !mOnlyAvailableForAdmins);
260     }
261 }
262