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      1 /*
      2  * Copyright (C) 2011 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.example.android.supportv4.accessibility;
     18 
     19 import android.accessibilityservice.AccessibilityServiceInfo;
     20 import android.app.Activity;
     21 import android.app.Service;
     22 import android.content.pm.ResolveInfo;
     23 import android.os.Bundle;
     24 import android.support.v4.accessibilityservice.AccessibilityServiceInfoCompat;
     25 import android.support.v4.view.accessibility.AccessibilityManagerCompat;
     26 import android.view.accessibility.AccessibilityManager;
     27 import android.widget.TextView;
     28 import android.widget.Toast;
     29 
     30 import com.example.android.supportv4.R;
     31 
     32 import java.util.List;
     33 
     34 /**
     35  * <p>
     36  * This class demonstrates how to use the support library to register
     37  * an AccessibilityManager.AccessibilityStateChangeListener introduced
     38  * in ICS to watch changes to the global accessibility state on the
     39  * device in a backwards compatible manner.
     40  * </p>
     41  * <p>
     42  * This class also demonstrates how to use the support library to query
     43  * information about enabled accessibility services via APIs introduced
     44  * in ICS in a backwards compatible manner.
     45  * </p>
     46  */
     47 public class AccessibilityManagerSupportActivity extends Activity {
     48 
     49     /** Handle to the accessibility manager service. */
     50     private AccessibilityManager mAccessibilityManager;
     51 
     52     /** Handle to the View showing accessibility services summary */
     53     private TextView mAccessibilityStateView;
     54 
     55     /**
     56      * {@inheritDoc}
     57      */
     58     @Override
     59     public void onCreate(Bundle savedInstanceState) {
     60         super.onCreate(savedInstanceState);
     61         setContentView(R.layout.accessibility_manager);
     62         mAccessibilityManager = (AccessibilityManager) getSystemService(
     63                 Service.ACCESSIBILITY_SERVICE);
     64         mAccessibilityStateView = findViewById(R.id.accessibility_state);
     65         registerAccessibilityStateChangeListener();
     66     }
     67 
     68     /**
     69      * {@inheritDoc}
     70      */
     71     @Override
     72     public void onResume() {
     73         super.onResume();
     74         updateAccessibilityStateView();
     75     }
     76 
     77     /**
     78      * Registers an AccessibilityStateChangeListener that show a Toast
     79      * when the global accessibility state on the device changes.
     80      */
     81     private void registerAccessibilityStateChangeListener() {
     82         // The AccessibilityStateChange listener APIs were added in ICS. Therefore to be
     83         // backwards compatible we use the APIs in the support library. Note that if the
     84         // platform API version is lower and the called API is not available no listener
     85         // is added and you will not receive a call of onAccessibilityStateChanged.
     86         AccessibilityManagerCompat.addAccessibilityStateChangeListener(mAccessibilityManager,
     87                 new AccessibilityManagerCompat.AccessibilityStateChangeListener() {
     88             @Override
     89             public void onAccessibilityStateChanged(boolean enabled) {
     90                 Toast.makeText(AccessibilityManagerSupportActivity.this,
     91                         getString(R.string.accessibility_manager_accessibility_state,
     92                                 Boolean.toString(enabled)),
     93                         Toast.LENGTH_SHORT).show();
     94             }
     95         });
     96     }
     97 
     98     /**
     99      * Updates the content of a TextView with description of the enabled
    100      * accessibility services.
    101      */
    102     private void updateAccessibilityStateView() {
    103         // The API for getting the enabled accessibility services based on feedback
    104         // type was added in ICS. Therefore to be backwards compatible we use the
    105         // APIs in the support library. Note that if the platform API version is lower
    106         // and the called API is not available an empty list of services is returned.
    107         List<AccessibilityServiceInfo> enabledServices =
    108             AccessibilityManagerCompat.getEnabledAccessibilityServiceList(mAccessibilityManager,
    109                     AccessibilityServiceInfo.FEEDBACK_SPOKEN);
    110         if (!enabledServices.isEmpty()) {
    111             StringBuilder builder = new StringBuilder();
    112             final int enabledServiceCount = enabledServices.size();
    113             for (int i = 0; i < enabledServiceCount; i++) {
    114                 AccessibilityServiceInfo service = enabledServices.get(i);
    115                 // Some new APIs were added in ICS for getting more information about
    116                 // an accessibility service. Again accessed them via the support library.
    117                 ResolveInfo resolveInfo = service.getResolveInfo();
    118                 String serviceDescription = getString(
    119                         R.string.accessibility_manager_enabled_service,
    120                         resolveInfo.loadLabel(getPackageManager()),
    121                         AccessibilityServiceInfoCompat.feedbackTypeToString(service.feedbackType),
    122                         AccessibilityServiceInfoCompat.loadDescription(
    123                                 service, getPackageManager()),
    124                         service.getSettingsActivityName());
    125                 builder.append(serviceDescription);
    126             }
    127             mAccessibilityStateView.setText(builder);
    128         } else {
    129             // Either no services or the platform API version is not high enough.
    130             mAccessibilityStateView.setText(getString(
    131                     R.string.accessibility_manager_no_enabled_services));
    132         }
    133     }
    134 }
    135