1/*
2 * Copyright (C) 2012 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.server.wm;
18
19import android.app.ActivityManagerNative;
20import android.app.admin.DevicePolicyManager;
21import android.content.Context;
22import android.os.Handler;
23import android.os.IBinder;
24import android.os.Message;
25import android.os.RemoteException;
26import android.os.TokenWatcher;
27import android.util.Log;
28import android.util.Pair;
29import android.view.WindowManagerPolicy;
30
31public class KeyguardDisableHandler extends Handler {
32    private static final String TAG = "KeyguardDisableHandler";
33
34    private static final int ALLOW_DISABLE_YES = 1;
35    private static final int ALLOW_DISABLE_NO = 0;
36    private static final int ALLOW_DISABLE_UNKNOWN = -1; // check with DevicePolicyManager
37    private int mAllowDisableKeyguard = ALLOW_DISABLE_UNKNOWN; // sync'd by mKeyguardTokenWatcher
38
39    // Message.what constants
40    static final int KEYGUARD_DISABLE = 1;
41    static final int KEYGUARD_REENABLE = 2;
42    static final int KEYGUARD_POLICY_CHANGED = 3;
43
44    final Context mContext;
45    final WindowManagerPolicy mPolicy;
46    KeyguardTokenWatcher mKeyguardTokenWatcher;
47
48    public KeyguardDisableHandler(final Context context, final WindowManagerPolicy policy) {
49        mContext = context;
50        mPolicy = policy;
51    }
52
53    @SuppressWarnings("unchecked")
54    @Override
55    public void handleMessage(Message msg) {
56        if (mKeyguardTokenWatcher == null) {
57            mKeyguardTokenWatcher = new KeyguardTokenWatcher(this);
58        }
59
60        switch (msg.what) {
61            case KEYGUARD_DISABLE:
62                final Pair<IBinder, String> pair = (Pair<IBinder, String>)msg.obj;
63                mKeyguardTokenWatcher.acquire(pair.first, pair.second);
64                break;
65
66            case KEYGUARD_REENABLE:
67                mKeyguardTokenWatcher.release((IBinder)msg.obj);
68                break;
69
70            case KEYGUARD_POLICY_CHANGED:
71                mAllowDisableKeyguard = ALLOW_DISABLE_UNKNOWN;
72                if (mKeyguardTokenWatcher.isAcquired()) {
73                    // If we are currently disabled we need to know if the keyguard
74                    // should be re-enabled, so determine the allow state immediately.
75                    mKeyguardTokenWatcher.updateAllowState();
76                    if (mAllowDisableKeyguard != ALLOW_DISABLE_YES) {
77                        mPolicy.enableKeyguard(true);
78                    }
79                } else {
80                    // lazily evaluate this next time we're asked to disable keyguard
81                    mPolicy.enableKeyguard(true);
82                }
83                break;
84        }
85    }
86
87    class KeyguardTokenWatcher extends TokenWatcher {
88
89        public KeyguardTokenWatcher(final Handler handler) {
90            super(handler, TAG);
91        }
92
93        public void updateAllowState() {
94            // We fail safe and prevent disabling keyguard in the unlikely event this gets
95            // called before DevicePolicyManagerService has started.
96            DevicePolicyManager dpm = (DevicePolicyManager) mContext.getSystemService(
97                    Context.DEVICE_POLICY_SERVICE);
98            if (dpm != null) {
99                try {
100                    mAllowDisableKeyguard = dpm.getPasswordQuality(null,
101                            ActivityManagerNative.getDefault().getCurrentUser().id)
102                            == DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED ?
103                                    ALLOW_DISABLE_YES : ALLOW_DISABLE_NO;
104                } catch (RemoteException re) {
105                    // Nothing much we can do
106                }
107            }
108        }
109
110        @Override
111        public void acquired() {
112            if (mAllowDisableKeyguard == ALLOW_DISABLE_UNKNOWN) {
113                updateAllowState();
114            }
115            if (mAllowDisableKeyguard == ALLOW_DISABLE_YES) {
116                mPolicy.enableKeyguard(false);
117            } else {
118                Log.v(TAG, "Not disabling keyguard since device policy is enforced");
119            }
120        }
121
122        @Override
123        public void released() {
124            mPolicy.enableKeyguard(true);
125        }
126    }
127}
128