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      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 
     17 package com.android.server.wm;
     18 
     19 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WITH_CLASS_NAME;
     20 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;
     21 
     22 import android.app.ActivityManager;
     23 import android.app.admin.DevicePolicyManager;
     24 import android.content.Context;
     25 import android.os.Handler;
     26 import android.os.IBinder;
     27 import android.os.Message;
     28 import android.os.RemoteException;
     29 import android.os.TokenWatcher;
     30 import android.util.Log;
     31 import android.util.Pair;
     32 
     33 import com.android.server.policy.WindowManagerPolicy;
     34 
     35 public class KeyguardDisableHandler extends Handler {
     36     private static final String TAG = TAG_WITH_CLASS_NAME ? "KeyguardDisableHandler" : TAG_WM;
     37 
     38     private static final int ALLOW_DISABLE_YES = 1;
     39     private static final int ALLOW_DISABLE_NO = 0;
     40     private static final int ALLOW_DISABLE_UNKNOWN = -1; // check with DevicePolicyManager
     41     private int mAllowDisableKeyguard = ALLOW_DISABLE_UNKNOWN; // sync'd by mKeyguardTokenWatcher
     42 
     43     // Message.what constants
     44     static final int KEYGUARD_DISABLE = 1;
     45     static final int KEYGUARD_REENABLE = 2;
     46     static final int KEYGUARD_POLICY_CHANGED = 3;
     47 
     48     final Context mContext;
     49     final WindowManagerPolicy mPolicy;
     50     KeyguardTokenWatcher mKeyguardTokenWatcher;
     51 
     52     public KeyguardDisableHandler(final Context context, final WindowManagerPolicy policy) {
     53         mContext = context;
     54         mPolicy = policy;
     55     }
     56 
     57     @SuppressWarnings("unchecked")
     58     @Override
     59     public void handleMessage(Message msg) {
     60         if (mKeyguardTokenWatcher == null) {
     61             mKeyguardTokenWatcher = new KeyguardTokenWatcher(this);
     62         }
     63 
     64         switch (msg.what) {
     65             case KEYGUARD_DISABLE:
     66                 final Pair<IBinder, String> pair = (Pair<IBinder, String>)msg.obj;
     67                 mKeyguardTokenWatcher.acquire(pair.first, pair.second);
     68                 break;
     69 
     70             case KEYGUARD_REENABLE:
     71                 mKeyguardTokenWatcher.release((IBinder)msg.obj);
     72                 break;
     73 
     74             case KEYGUARD_POLICY_CHANGED:
     75                 mAllowDisableKeyguard = ALLOW_DISABLE_UNKNOWN;
     76                 if (mKeyguardTokenWatcher.isAcquired()) {
     77                     // If we are currently disabled we need to know if the keyguard
     78                     // should be re-enabled, so determine the allow state immediately.
     79                     mKeyguardTokenWatcher.updateAllowState();
     80                     if (mAllowDisableKeyguard != ALLOW_DISABLE_YES) {
     81                         mPolicy.enableKeyguard(true);
     82                     }
     83                 } else {
     84                     // lazily evaluate this next time we're asked to disable keyguard
     85                     mPolicy.enableKeyguard(true);
     86                 }
     87                 break;
     88         }
     89     }
     90 
     91     class KeyguardTokenWatcher extends TokenWatcher {
     92 
     93         public KeyguardTokenWatcher(final Handler handler) {
     94             super(handler, TAG);
     95         }
     96 
     97         public void updateAllowState() {
     98             // We fail safe and prevent disabling keyguard in the unlikely event this gets
     99             // called before DevicePolicyManagerService has started.
    100             DevicePolicyManager dpm = (DevicePolicyManager) mContext.getSystemService(
    101                     Context.DEVICE_POLICY_SERVICE);
    102             if (dpm != null) {
    103                 try {
    104                     mAllowDisableKeyguard = dpm.getPasswordQuality(null,
    105                             ActivityManager.getService().getCurrentUser().id)
    106                             == DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED ?
    107                                     ALLOW_DISABLE_YES : ALLOW_DISABLE_NO;
    108                 } catch (RemoteException re) {
    109                     // Nothing much we can do
    110                 }
    111             }
    112         }
    113 
    114         @Override
    115         public void acquired() {
    116             if (mAllowDisableKeyguard == ALLOW_DISABLE_UNKNOWN) {
    117                 updateAllowState();
    118             }
    119             if (mAllowDisableKeyguard == ALLOW_DISABLE_YES) {
    120                 mPolicy.enableKeyguard(false);
    121             } else {
    122                 Log.v(TAG, "Not disabling keyguard since device policy is enforced");
    123             }
    124         }
    125 
    126         @Override
    127         public void released() {
    128             mPolicy.enableKeyguard(true);
    129         }
    130     }
    131 }
    132