UnlockMethodCache.java revision ecc798e6668046c2f67cf30c6ab1db2eba80cab1 
1/*
2 * Copyright (C) 2014 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.systemui.statusbar.phone;
18
19import android.content.Context;
20
21import com.android.internal.widget.LockPatternUtils;
22import com.android.keyguard.KeyguardUpdateMonitor;
23import com.android.keyguard.KeyguardUpdateMonitorCallback;
24
25import java.util.ArrayList;
26
27/**
28 * Caches whether the current unlock method is insecure, taking trust into account. This information
29 * might be a little bit out of date and should not be used for actual security decisions; it should
30 * be only used for visual indications.
31 */
32public class UnlockMethodCache {
33
34    private static UnlockMethodCache sInstance;
35
36    private final LockPatternUtils mLockPatternUtils;
37    private final KeyguardUpdateMonitor mKeyguardUpdateMonitor;
38    private final ArrayList<OnUnlockMethodChangedListener> mListeners = new ArrayList<>();
39    private boolean mMethodInsecure;
40
41    private UnlockMethodCache(Context ctx) {
42        mLockPatternUtils = new LockPatternUtils(ctx);
43        mKeyguardUpdateMonitor = KeyguardUpdateMonitor.getInstance(ctx);
44        KeyguardUpdateMonitor.getInstance(ctx).registerCallback(mCallback);
45        updateMethodSecure(true /* updateAlways */);
46    }
47
48    public static UnlockMethodCache getInstance(Context context) {
49        if (sInstance == null) {
50            sInstance = new UnlockMethodCache(context);
51        }
52        return sInstance;
53    }
54
55    /**
56     * @return whether the current security method is secure, i. e. the bouncer will be shown
57     */
58    public boolean isMethodInsecure() {
59        return mMethodInsecure;
60    }
61
62    public void addListener(OnUnlockMethodChangedListener listener) {
63        mListeners.add(listener);
64    }
65
66    public void removeListener(OnUnlockMethodChangedListener listener) {
67        mListeners.remove(listener);
68    }
69
70    private void updateMethodSecure(boolean updateAlways) {
71        int user = mLockPatternUtils.getCurrentUser();
72        boolean methodInsecure = !mLockPatternUtils.isSecure() ||
73                mKeyguardUpdateMonitor.getUserHasTrust(user);
74        boolean changed = methodInsecure != mMethodInsecure;
75        if (changed || updateAlways) {
76            mMethodInsecure = methodInsecure;
77            notifyListeners(mMethodInsecure);
78        }
79    }
80
81    private void notifyListeners(boolean secure) {
82        for (OnUnlockMethodChangedListener listener : mListeners) {
83            listener.onMethodSecureChanged(secure);
84        }
85    }
86
87    private final KeyguardUpdateMonitorCallback mCallback = new KeyguardUpdateMonitorCallback() {
88        @Override
89        public void onUserSwitchComplete(int userId) {
90            updateMethodSecure(false /* updateAlways */);
91        }
92
93        @Override
94        public void onTrustChanged(int userId) {
95            updateMethodSecure(false /* updateAlways */);
96        }
97
98        @Override
99        public void onScreenTurnedOn() {
100            updateMethodSecure(false /* updateAlways */);
101        }
102    };
103
104    public static interface OnUnlockMethodChangedListener {
105        void onMethodSecureChanged(boolean methodSecure);
106    }
107}
108