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