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      1 /*
      2  * Copyright (C) 2008 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.settings;
     18 
     19 import com.android.internal.widget.LockPatternUtils;
     20 
     21 import android.app.Activity;
     22 import android.app.AlertDialog;
     23 import android.app.Fragment;
     24 import android.app.admin.DevicePolicyManager;
     25 import android.content.BroadcastReceiver;
     26 import android.content.Context;
     27 import android.content.Intent;
     28 import android.content.IntentFilter;
     29 import android.content.res.Resources;
     30 import android.os.BatteryManager;
     31 import android.os.Bundle;
     32 import android.preference.Preference;
     33 import android.preference.PreferenceActivity;
     34 import android.text.TextUtils;
     35 import android.view.LayoutInflater;
     36 import android.view.View;
     37 import android.view.ViewGroup;
     38 import android.widget.Button;
     39 
     40 public class CryptKeeperSettings extends Fragment {
     41     private static final String TAG = "CryptKeeper";
     42 
     43     private static final int KEYGUARD_REQUEST = 55;
     44 
     45     // This is the minimum acceptable password quality.  If the current password quality is
     46     // lower than this, encryption should not be activated.
     47     static final int MIN_PASSWORD_QUALITY = DevicePolicyManager.PASSWORD_QUALITY_NUMERIC;
     48 
     49     // Minimum battery charge level (in percent) to launch encryption.  If the battery charge is
     50     // lower than this, encryption should not be activated.
     51     private static final int MIN_BATTERY_LEVEL = 80;
     52 
     53     private View mContentView;
     54     private Button mInitiateButton;
     55     private View mPowerWarning;
     56     private View mBatteryWarning;
     57     private IntentFilter mIntentFilter;
     58 
     59     private BroadcastReceiver mIntentReceiver = new BroadcastReceiver() {
     60         @Override
     61         public void onReceive(Context context, Intent intent) {
     62             String action = intent.getAction();
     63             if (action.equals(Intent.ACTION_BATTERY_CHANGED)) {
     64                 int level = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 0);
     65                 int plugged = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, 0);
     66                 int invalidCharger = intent.getIntExtra(BatteryManager.EXTRA_INVALID_CHARGER, 0);
     67 
     68                 boolean levelOk = level >= MIN_BATTERY_LEVEL;
     69                 boolean pluggedOk =
     70                     (plugged == BatteryManager.BATTERY_PLUGGED_AC ||
     71                      plugged == BatteryManager.BATTERY_PLUGGED_USB) &&
     72                      invalidCharger == 0;
     73 
     74                 // Update UI elements based on power/battery status
     75                 mInitiateButton.setEnabled(levelOk && pluggedOk);
     76                 mPowerWarning.setVisibility(pluggedOk ? View.GONE : View.VISIBLE );
     77                 mBatteryWarning.setVisibility(levelOk ? View.GONE : View.VISIBLE);
     78             }
     79         }
     80     };
     81 
     82     /**
     83      * If the user clicks to begin the reset sequence, we next require a
     84      * keyguard confirmation if the user has currently enabled one.  If there
     85      * is no keyguard available, we prompt the user to set a password.
     86      */
     87     private Button.OnClickListener mInitiateListener = new Button.OnClickListener() {
     88 
     89         public void onClick(View v) {
     90             if (!runKeyguardConfirmation(KEYGUARD_REQUEST)) {
     91                 // TODO replace (or follow) this dialog with an explicit launch into password UI
     92                 new AlertDialog.Builder(getActivity())
     93                     .setTitle(R.string.crypt_keeper_dialog_need_password_title)
     94                     .setIcon(android.R.drawable.ic_dialog_alert)
     95                     .setMessage(R.string.crypt_keeper_dialog_need_password_message)
     96                     .setPositiveButton(android.R.string.ok, null)
     97                     .create()
     98                     .show();
     99             }
    100         }
    101     };
    102 
    103     @Override
    104     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedState) {
    105         mContentView = inflater.inflate(R.layout.crypt_keeper_settings, null);
    106 
    107         mIntentFilter = new IntentFilter();
    108         mIntentFilter.addAction(Intent.ACTION_BATTERY_CHANGED);
    109 
    110         mInitiateButton = (Button) mContentView.findViewById(R.id.initiate_encrypt);
    111         mInitiateButton.setOnClickListener(mInitiateListener);
    112         mInitiateButton.setEnabled(false);
    113 
    114         mPowerWarning = mContentView.findViewById(R.id.warning_unplugged);
    115         mBatteryWarning = mContentView.findViewById(R.id.warning_low_charge);
    116 
    117         return mContentView;
    118     }
    119 
    120     @Override
    121     public void onResume() {
    122         super.onResume();
    123         getActivity().registerReceiver(mIntentReceiver, mIntentFilter);
    124     }
    125 
    126     @Override
    127     public void onPause() {
    128         super.onPause();
    129         getActivity().unregisterReceiver(mIntentReceiver);
    130     }
    131 
    132     /**
    133      * If encryption is already started, and this launched via a "start encryption" intent,
    134      * then exit immediately - it's already up and running, so there's no point in "starting" it.
    135      */
    136     @Override
    137     public void onActivityCreated(Bundle savedInstanceState) {
    138         super.onActivityCreated(savedInstanceState);
    139         Activity activity = getActivity();
    140         Intent intent = activity.getIntent();
    141         if (DevicePolicyManager.ACTION_START_ENCRYPTION.equals(intent.getAction())) {
    142             DevicePolicyManager dpm = (DevicePolicyManager)
    143                     activity.getSystemService(Context.DEVICE_POLICY_SERVICE);
    144             if (dpm != null) {
    145                 int status = dpm.getStorageEncryptionStatus();
    146                 if (status != DevicePolicyManager.ENCRYPTION_STATUS_INACTIVE) {
    147                     // There is nothing to do here, so simply finish() (which returns to caller)
    148                     activity.finish();
    149                 }
    150             }
    151         }
    152     }
    153 
    154     /**
    155      * Keyguard validation is run using the standard {@link ConfirmLockPattern}
    156      * component as a subactivity
    157      * @param request the request code to be returned once confirmation finishes
    158      * @return true if confirmation launched
    159      */
    160     private boolean runKeyguardConfirmation(int request) {
    161         // 1.  Confirm that we have a sufficient PIN/Password to continue
    162         int quality = new LockPatternUtils(getActivity()).getActivePasswordQuality();
    163         if (quality < MIN_PASSWORD_QUALITY) {
    164             return false;
    165         }
    166         // 2.  Ask the user to confirm the current PIN/Password
    167         Resources res = getActivity().getResources();
    168         return new ChooseLockSettingsHelper(getActivity(), this)
    169                 .launchConfirmationActivity(request,
    170                         res.getText(R.string.master_clear_gesture_prompt),
    171                         res.getText(R.string.master_clear_gesture_explanation));
    172     }
    173 
    174     @Override
    175     public void onActivityResult(int requestCode, int resultCode, Intent data) {
    176         super.onActivityResult(requestCode, resultCode, data);
    177 
    178         if (requestCode != KEYGUARD_REQUEST) {
    179             return;
    180         }
    181 
    182         // If the user entered a valid keyguard trace, present the final
    183         // confirmation prompt; otherwise, go back to the initial state.
    184         if (resultCode == Activity.RESULT_OK && data != null) {
    185             String password = data.getStringExtra(ChooseLockSettingsHelper.EXTRA_KEY_PASSWORD);
    186             if (!TextUtils.isEmpty(password)) {
    187                 showFinalConfirmation(password);
    188             }
    189         }
    190     }
    191 
    192     private void showFinalConfirmation(String password) {
    193         Preference preference = new Preference(getActivity());
    194         preference.setFragment(CryptKeeperConfirm.class.getName());
    195         preference.setTitle(R.string.crypt_keeper_confirm_title);
    196         preference.getExtras().putString("password", password);
    197         ((PreferenceActivity) getActivity()).onPreferenceStartFragment(null, preference);
    198     }
    199 }
    200 
    201