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      1 /*
      2  * Copyright (C) 2016 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.accessibility;
     18 
     19 import android.accessibilityservice.AccessibilityServiceInfo;
     20 import android.app.Activity;
     21 import android.app.AlertDialog;
     22 import android.app.Dialog;
     23 import android.content.Context;
     24 import android.content.DialogInterface;
     25 import android.os.storage.StorageManager;
     26 import android.text.BidiFormatter;
     27 import android.view.LayoutInflater;
     28 import android.view.MotionEvent;
     29 import android.view.View;
     30 import android.view.Window;
     31 import android.view.WindowManager;
     32 import android.widget.ImageView;
     33 import android.widget.LinearLayout;
     34 import android.widget.TextView;
     35 import android.widget.Toast;
     36 
     37 import com.android.settings.R;
     38 
     39 import java.util.List;
     40 import java.util.Locale;
     41 
     42 import static android.view.WindowManager.LayoutParams.PRIVATE_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;
     43 
     44 /**
     45  * Utility class for creating the dialog that asks users for explicit permission to grant
     46  * all of the requested capabilities to an accessibility service before the service is enabled
     47  */
     48 public class AccessibilityServiceWarning {
     49     public static Dialog createCapabilitiesDialog(Activity parentActivity,
     50             AccessibilityServiceInfo info, DialogInterface.OnClickListener listener) {
     51         final AlertDialog ad = new AlertDialog.Builder(parentActivity)
     52                 .setTitle(parentActivity.getString(R.string.enable_service_title,
     53                         getServiceName(parentActivity, info)))
     54                 .setView(createEnableDialogContentView(parentActivity, info))
     55                 .setPositiveButton(android.R.string.ok, listener)
     56                 .setNegativeButton(android.R.string.cancel, listener)
     57                 .create();
     58 
     59         final View.OnTouchListener filterTouchListener = (View v, MotionEvent event) -> {
     60             // Filter obscured touches by consuming them.
     61             if (((event.getFlags() & MotionEvent.FLAG_WINDOW_IS_OBSCURED) != 0)
     62                     || ((event.getFlags() & MotionEvent.FLAG_WINDOW_IS_PARTIALLY_OBSCURED) != 0)) {
     63                 if (event.getAction() == MotionEvent.ACTION_UP) {
     64                     Toast.makeText(v.getContext(), R.string.touch_filtered_warning,
     65                             Toast.LENGTH_SHORT).show();
     66                 }
     67                 return true;
     68             }
     69             return false;
     70         };
     71 
     72         Window window = ad.getWindow();
     73         WindowManager.LayoutParams params = window.getAttributes();
     74         params.privateFlags |= PRIVATE_FLAG_HIDE_NON_SYSTEM_OVERLAY_WINDOWS;
     75         window.setAttributes(params);
     76         ad.create();
     77         ad.getButton(AlertDialog.BUTTON_POSITIVE).setOnTouchListener(filterTouchListener);
     78         ad.setCanceledOnTouchOutside(true);
     79 
     80         return ad;
     81     }
     82 
     83     /**
     84      * Return whether the device is encrypted with legacy full disk encryption. Newer devices
     85      * should be using File Based Encryption.
     86      *
     87      * @return true if device is encrypted
     88      */
     89     private static boolean isFullDiskEncrypted() {
     90         return StorageManager.isNonDefaultBlockEncrypted();
     91     }
     92 
     93     /**
     94      * Get a content View for a dialog to confirm that they want to enable a service.
     95      *
     96      * @param context A valid context
     97      * @param info The info about a service
     98      * @return A content view suitable for viewing
     99      */
    100     private static View createEnableDialogContentView(Context context,
    101             AccessibilityServiceInfo info) {
    102         LayoutInflater inflater = (LayoutInflater) context.getSystemService(
    103                 Context.LAYOUT_INFLATER_SERVICE);
    104 
    105         View content = inflater.inflate(R.layout.enable_accessibility_service_dialog_content,
    106                 null);
    107 
    108         TextView encryptionWarningView = (TextView) content.findViewById(
    109                 R.id.encryption_warning);
    110         if (isFullDiskEncrypted()) {
    111             String text = context.getString(R.string.enable_service_encryption_warning,
    112                     getServiceName(context, info));
    113             encryptionWarningView.setText(text);
    114             encryptionWarningView.setVisibility(View.VISIBLE);
    115         } else {
    116             encryptionWarningView.setVisibility(View.GONE);
    117         }
    118 
    119         TextView capabilitiesHeaderView = (TextView) content.findViewById(
    120                 R.id.capabilities_header);
    121         capabilitiesHeaderView.setText(context.getString(R.string.capabilities_list_title,
    122                 getServiceName(context, info)));
    123 
    124         LinearLayout capabilitiesView = (LinearLayout) content.findViewById(R.id.capabilities);
    125 
    126         // This capability is implicit for all services.
    127         View capabilityView = inflater.inflate(
    128                 com.android.internal.R.layout.app_permission_item_old, null);
    129 
    130         ImageView imageView = (ImageView) capabilityView.findViewById(
    131                 com.android.internal.R.id.perm_icon);
    132         imageView.setImageDrawable(context.getDrawable(
    133                 com.android.internal.R.drawable.ic_text_dot));
    134 
    135         TextView labelView = (TextView) capabilityView.findViewById(
    136                 com.android.internal.R.id.permission_group);
    137         labelView.setText(context.getString(
    138                 R.string.capability_title_receiveAccessibilityEvents));
    139 
    140         TextView descriptionView = (TextView) capabilityView.findViewById(
    141                 com.android.internal.R.id.permission_list);
    142         descriptionView.setText(
    143                 context.getString(R.string.capability_desc_receiveAccessibilityEvents));
    144 
    145         List<AccessibilityServiceInfo.CapabilityInfo> capabilities =
    146                 info.getCapabilityInfos(context);
    147 
    148         capabilitiesView.addView(capabilityView);
    149 
    150         // Service-specific capabilities.
    151         final int capabilityCount = capabilities.size();
    152         for (int i = 0; i < capabilityCount; i++) {
    153             AccessibilityServiceInfo.CapabilityInfo capability = capabilities.get(i);
    154 
    155             capabilityView = inflater.inflate(
    156                     com.android.internal.R.layout.app_permission_item_old, null);
    157 
    158             imageView = (ImageView) capabilityView.findViewById(
    159                     com.android.internal.R.id.perm_icon);
    160             imageView.setImageDrawable(context.getDrawable(
    161                     com.android.internal.R.drawable.ic_text_dot));
    162 
    163             labelView = (TextView) capabilityView.findViewById(
    164                     com.android.internal.R.id.permission_group);
    165             labelView.setText(context.getString(capability.titleResId));
    166 
    167             descriptionView = (TextView) capabilityView.findViewById(
    168                     com.android.internal.R.id.permission_list);
    169             descriptionView.setText(context.getString(capability.descResId));
    170 
    171             capabilitiesView.addView(capabilityView);
    172         }
    173 
    174         return content;
    175     }
    176 
    177     // Get the service name and bidi wrap it to protect from bidi side effects.
    178     private static CharSequence getServiceName(Context context, AccessibilityServiceInfo info) {
    179         final Locale locale = context.getResources().getConfiguration().getLocales().get(0);
    180         final CharSequence label =
    181                 info.getResolveInfo().loadLabel(context.getPackageManager());
    182         return BidiFormatter.getInstance(locale).unicodeWrap(label);
    183     }
    184 }
    185