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
17package com.android.settings;
18
19import android.app.Activity;
20import android.content.BroadcastReceiver;
21import android.content.Context;
22import android.content.Intent;
23import android.content.IntentFilter;
24import android.content.RestrictionsManager;
25import android.os.Bundle;
26import android.os.PersistableBundle;
27import 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 */
40public abstract 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     */
76    public RestrictedSettingsFragment(String restrictionKey) {
77        mRestrictionKey = restrictionKey;
78    }
79
80    @Override
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
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
108    public void onResume() {
109        super.onResume();
110
111        if (shouldBeProviderProtected(mRestrictionKey)) {
112            ensurePin();
113        }
114    }
115
116    @Override
117    public void onDestroy() {
118        getActivity().unregisterReceiver(mScreenOffReceiver);
119        super.onDestroy();
120    }
121
122    @Override
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
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     */
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
165    protected boolean hasChallengeSucceeded() {
166        return (mChallengeRequested && mChallengeSucceeded) || !mChallengeRequested;
167    }
168
169    /**
170     * Returns true if this restrictions key is locked down.
171     */
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     */
184    protected boolean isUiRestricted() {
185        return isRestrictedAndNotProviderProtected() || !hasChallengeSucceeded();
186    }
187}
188