1/*
2 * Copyright (C) 2009 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
17package com.android.settings;
18
19import android.app.AlertDialog;
20import android.app.Service;
21import android.content.DialogInterface;
22import android.content.Intent;
23import android.content.pm.ApplicationInfo;
24import android.content.pm.PackageManager;
25import android.content.pm.PackageManager.NameNotFoundException;
26import android.content.pm.ServiceInfo;
27import android.net.Uri;
28import android.os.Bundle;
29import android.os.SystemProperties;
30import android.preference.CheckBoxPreference;
31import android.preference.Preference;
32import android.preference.PreferenceActivity;
33import android.preference.PreferenceCategory;
34import android.preference.PreferenceGroup;
35import android.preference.PreferenceScreen;
36import android.provider.Settings;
37import android.text.TextUtils;
38import android.view.KeyCharacterMap;
39import android.view.KeyEvent;
40import android.view.accessibility.AccessibilityManager;
41
42import java.util.HashSet;
43import java.util.LinkedHashMap;
44import java.util.List;
45import java.util.Map;
46
47/**
48 * Activity with the accessibility settings.
49 */
50public class AccessibilitySettings extends PreferenceActivity {
51    private static final String DEFAULT_SCREENREADER_MARKET_LINK =
52        "market://search?q=pname:com.google.android.marvin.talkback";
53
54    private final String TOGGLE_ACCESSIBILITY_SERVICE_CHECKBOX =
55        "toggle_accessibility_service_checkbox";
56
57    private static final String ACCESSIBILITY_SERVICES_CATEGORY =
58        "accessibility_services_category";
59
60    private static final String POWER_BUTTON_CATEGORY =
61        "power_button_category";
62
63    private final String POWER_BUTTON_ENDS_CALL_CHECKBOX =
64        "power_button_ends_call";
65
66    private CheckBoxPreference mToggleCheckBox;
67
68    private PreferenceCategory mPowerButtonCategory;
69    private CheckBoxPreference mPowerButtonEndsCallCheckBox;
70
71    private Map<String, ServiceInfo> mAccessibilityServices =
72        new LinkedHashMap<String, ServiceInfo>();
73
74    private TextUtils.SimpleStringSplitter mStringColonSplitter =
75        new TextUtils.SimpleStringSplitter(':');
76
77    private PreferenceGroup mAccessibilityServicesCategory;
78
79    @Override
80    protected void onCreate(Bundle icicle) {
81        super.onCreate(icicle);
82        addPreferencesFromResource(R.xml.accessibility_settings);
83
84        mToggleCheckBox = (CheckBoxPreference) findPreference(
85            TOGGLE_ACCESSIBILITY_SERVICE_CHECKBOX);
86
87        mPowerButtonCategory = (PreferenceCategory) findPreference(POWER_BUTTON_CATEGORY);
88        mPowerButtonEndsCallCheckBox = (CheckBoxPreference) findPreference(
89            POWER_BUTTON_ENDS_CALL_CHECKBOX);
90
91        addAccessibilitServicePreferences();
92    }
93
94    @Override
95    protected void onResume() {
96        super.onResume();
97
98        final HashSet<String> enabled = new HashSet<String>();
99        String settingValue = Settings.Secure.getString(getContentResolver(),
100                Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES);
101        if (settingValue != null) {
102            TextUtils.SimpleStringSplitter splitter = mStringColonSplitter;
103            splitter.setString(settingValue);
104            while (splitter.hasNext()) {
105                enabled.add(splitter.next());
106            }
107        }
108
109        Map<String, ServiceInfo> accessibilityServices = mAccessibilityServices;
110
111        for (String key : accessibilityServices.keySet()) {
112            CheckBoxPreference preference = (CheckBoxPreference) findPreference(key);
113            if (preference != null) {
114                preference.setChecked(enabled.contains(key));
115            }
116        }
117
118        int serviceState = Settings.Secure.getInt(getContentResolver(),
119            Settings.Secure.ACCESSIBILITY_ENABLED, 0);
120
121        if (!accessibilityServices.isEmpty()) {
122            if (serviceState == 1) {
123                mToggleCheckBox.setChecked(true);
124            } else {
125                setAccessibilityServicePreferencesState(false);
126            }
127            mToggleCheckBox.setEnabled(true);
128        } else {
129            if (serviceState == 1) {
130                // no service and accessibility is enabled => disable
131                Settings.Secure.putInt(getContentResolver(),
132                    Settings.Secure.ACCESSIBILITY_ENABLED, 0);
133            }
134            mToggleCheckBox.setEnabled(false);
135            // Notify user that they do not have any accessibility apps
136            // installed and direct them to Market to get TalkBack
137            displayNoAppsAlert();
138        }
139
140        if (KeyCharacterMap.deviceHasKey(KeyEvent.KEYCODE_POWER)) {
141            int incallPowerBehavior = Settings.Secure.getInt(getContentResolver(),
142                    Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR,
143                    Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR_DEFAULT);
144            // The checkbox is labeled "Power button ends call"; thus the in-call
145            // Power button behavior is INCALL_POWER_BUTTON_BEHAVIOR_HANGUP if
146            // checked, and INCALL_POWER_BUTTON_BEHAVIOR_SCREEN_OFF if unchecked.
147            boolean powerButtonCheckboxEnabled =
148                    (incallPowerBehavior == Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR_HANGUP);
149            mPowerButtonEndsCallCheckBox.setChecked(powerButtonCheckboxEnabled);
150            mPowerButtonEndsCallCheckBox.setEnabled(true);
151        } else {
152            // No POWER key on the current device; this entire category is irrelevant.
153            getPreferenceScreen().removePreference(mPowerButtonCategory);
154        }
155    }
156
157    @Override
158    protected void onPause() {
159        super.onPause();
160
161        persistEnabledAccessibilityServices();
162    }
163
164    /**
165     * Sets the state of the preferences for enabling/disabling
166     * AccessibilityServices.
167     *
168     * @param isEnabled If to enable or disable the preferences.
169     */
170    private void setAccessibilityServicePreferencesState(boolean isEnabled) {
171        if (mAccessibilityServicesCategory == null) {
172            return;
173        }
174
175        int count = mAccessibilityServicesCategory.getPreferenceCount();
176        for (int i = 0; i < count; i++) {
177            Preference pref = mAccessibilityServicesCategory.getPreference(i);
178            pref.setEnabled(isEnabled);
179        }
180    }
181
182    @Override
183    public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
184        final String key = preference.getKey();
185
186        if (TOGGLE_ACCESSIBILITY_SERVICE_CHECKBOX.equals(key)) {
187            boolean isChecked = ((CheckBoxPreference) preference).isChecked();
188            handleEnableAccessibilityStateChange((CheckBoxPreference) preference);
189        } else if (POWER_BUTTON_ENDS_CALL_CHECKBOX.equals(key)) {
190            boolean isChecked = ((CheckBoxPreference) preference).isChecked();
191            // The checkbox is labeled "Power button ends call"; thus the in-call
192            // Power button behavior is INCALL_POWER_BUTTON_BEHAVIOR_HANGUP if
193            // checked, and INCALL_POWER_BUTTON_BEHAVIOR_SCREEN_OFF if unchecked.
194            Settings.Secure.putInt(getContentResolver(),
195                    Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR,
196                    (isChecked ? Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR_HANGUP
197                            : Settings.Secure.INCALL_POWER_BUTTON_BEHAVIOR_SCREEN_OFF));
198        } else if (preference instanceof CheckBoxPreference) {
199            handleEnableAccessibilityServiceStateChange((CheckBoxPreference) preference);
200        }
201
202        return super.onPreferenceTreeClick(preferenceScreen, preference);
203    }
204
205    /**
206     * Handles the change of the accessibility enabled setting state.
207     *
208     * @param preference The preference for enabling/disabling accessibility.
209     */
210    private void handleEnableAccessibilityStateChange(CheckBoxPreference preference) {
211        if (preference.isChecked()) {
212            Settings.Secure.putInt(getContentResolver(),
213                Settings.Secure.ACCESSIBILITY_ENABLED, 1);
214            setAccessibilityServicePreferencesState(true);
215        } else {
216            final CheckBoxPreference checkBoxPreference = preference;
217            AlertDialog dialog = (new AlertDialog.Builder(this))
218                .setTitle(android.R.string.dialog_alert_title)
219                .setIcon(android.R.drawable.ic_dialog_alert)
220                .setMessage(getString(R.string.accessibility_service_disable_warning))
221                .setCancelable(true)
222                .setPositiveButton(android.R.string.ok,
223                    new DialogInterface.OnClickListener() {
224                        public void onClick(DialogInterface dialog, int which) {
225                            Settings.Secure.putInt(getContentResolver(),
226                                Settings.Secure.ACCESSIBILITY_ENABLED, 0);
227                            setAccessibilityServicePreferencesState(false);
228                        }
229                })
230                .setNegativeButton(android.R.string.cancel,
231                    new DialogInterface.OnClickListener() {
232                        public void onClick(DialogInterface dialog, int which) {
233                            checkBoxPreference.setChecked(true);
234                        }
235                })
236                .create();
237            dialog.show();
238        }
239    }
240
241    /**
242     * Handles the change of the preference for enabling/disabling an AccessibilityService.
243     *
244     * @param preference The preference.
245     */
246    private void handleEnableAccessibilityServiceStateChange(CheckBoxPreference preference) {
247        if (preference.isChecked()) {
248            final CheckBoxPreference checkBoxPreference = preference;
249            AlertDialog dialog = (new AlertDialog.Builder(this))
250                .setTitle(android.R.string.dialog_alert_title)
251                .setIcon(android.R.drawable.ic_dialog_alert)
252                .setMessage(getString(R.string.accessibility_service_security_warning,
253                    mAccessibilityServices.get(preference.getKey())
254                    .applicationInfo.loadLabel(getPackageManager())))
255                .setCancelable(true)
256                .setPositiveButton(android.R.string.ok,
257                        new DialogInterface.OnClickListener() {
258                            public void onClick(DialogInterface dialog, int which) {
259                                checkBoxPreference.setChecked(true);
260                                persistEnabledAccessibilityServices();
261                            }
262                })
263                .setNegativeButton(android.R.string.cancel,
264                        new DialogInterface.OnClickListener() {
265                            public void onClick(DialogInterface dialog, int which) {
266                                checkBoxPreference.setChecked(false);
267                            }
268                })
269                .create();
270            dialog.show();
271        } else {
272            persistEnabledAccessibilityServices();
273        }
274    }
275
276    /**
277     * Persists the Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES setting.
278     * The AccessibilityManagerService watches this property and manages the
279     * AccessibilityServices.
280     */
281    private void persistEnabledAccessibilityServices() {
282        StringBuilder builder = new StringBuilder(256);
283
284        int firstEnabled = -1;
285        for (String key : mAccessibilityServices.keySet()) {
286            CheckBoxPreference preference = (CheckBoxPreference) findPreference(key);
287            if (preference.isChecked()) {
288                 builder.append(key);
289                 builder.append(':');
290            }
291        }
292
293        Settings.Secure.putString(getContentResolver(),
294            Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES, builder.toString());
295    }
296
297    /**
298     * Adds {@link CheckBoxPreference} for enabling or disabling an accessibility services.
299     */
300    private void addAccessibilitServicePreferences() {
301        AccessibilityManager accessibilityManager =
302            (AccessibilityManager) getSystemService(Service.ACCESSIBILITY_SERVICE);
303
304        List<ServiceInfo> installedServices = accessibilityManager.getAccessibilityServiceList();
305
306        mAccessibilityServicesCategory =
307            (PreferenceGroup) findPreference(ACCESSIBILITY_SERVICES_CATEGORY);
308
309        if (installedServices.isEmpty()) {
310            getPreferenceScreen().removePreference(mAccessibilityServicesCategory);
311            mAccessibilityServicesCategory = null;
312            return;
313        }
314
315        for (int i = 0, count = installedServices.size(); i < count; ++i) {
316            ServiceInfo serviceInfo = installedServices.get(i);
317            String key = serviceInfo.packageName + "/" + serviceInfo.name;
318
319            mAccessibilityServices.put(key, serviceInfo);
320
321            CheckBoxPreference preference = new CheckBoxPreference(this);
322            preference.setKey(key);
323            preference.setTitle(serviceInfo.loadLabel(getPackageManager()));
324            mAccessibilityServicesCategory.addPreference(preference);
325        }
326    }
327
328    /**
329     * Displays a message telling the user that they do not have any accessibility
330     * related apps installed and that they can get TalkBack (Google's free screen
331     * reader) from Market.
332     */
333    private void displayNoAppsAlert() {
334        try {
335            PackageManager pm = getPackageManager();
336            ApplicationInfo info = pm.getApplicationInfo("com.android.vending", 0);
337        } catch (NameNotFoundException e) {
338            // This is a no-op if the user does not have Android Market
339            return;
340        }
341        AlertDialog.Builder noAppsAlert = new AlertDialog.Builder(this);
342        noAppsAlert.setTitle(R.string.accessibility_service_no_apps_title);
343        noAppsAlert.setMessage(R.string.accessibility_service_no_apps_message);
344
345        noAppsAlert.setPositiveButton(android.R.string.ok,
346            new DialogInterface.OnClickListener() {
347                public void onClick(DialogInterface dialog, int which) {
348                    String screenreaderMarketLink =
349                        SystemProperties.get("ro.screenreader.market",
350                                DEFAULT_SCREENREADER_MARKET_LINK);
351                    Uri marketUri = Uri.parse(screenreaderMarketLink);
352                    Intent marketIntent = new Intent(Intent.ACTION_VIEW, marketUri);
353                    startActivity(marketIntent);
354                    finish();
355                }
356            });
357
358        noAppsAlert.setNegativeButton(android.R.string.cancel,
359            new DialogInterface.OnClickListener() {
360                public void onClick(DialogInterface dialog, int which) {
361                }
362            });
363
364        noAppsAlert.show();
365    }
366}
367