1/*
2 * Copyright (C) 2015 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.settingslib.accessibility;
18
19import android.accessibilityservice.AccessibilityServiceInfo;
20import android.content.ComponentName;
21import android.content.Context;
22import android.content.pm.ResolveInfo;
23import android.content.res.Configuration;
24import android.content.res.Resources;
25import android.os.UserHandle;
26import android.provider.Settings;
27import android.text.TextUtils;
28import android.util.ArraySet;
29import android.view.accessibility.AccessibilityManager;
30
31import java.util.Collections;
32import java.util.HashSet;
33import java.util.List;
34import java.util.Locale;
35import java.util.Set;
36
37public class AccessibilityUtils {
38    public static final char ENABLED_ACCESSIBILITY_SERVICES_SEPARATOR = ':';
39
40    final static TextUtils.SimpleStringSplitter sStringColonSplitter =
41            new TextUtils.SimpleStringSplitter(ENABLED_ACCESSIBILITY_SERVICES_SEPARATOR);
42
43    /**
44     * @return the set of enabled accessibility services. If there are no services,
45     * it returns the unmodifiable {@link Collections#emptySet()}.
46     */
47    public static Set<ComponentName> getEnabledServicesFromSettings(Context context) {
48        return getEnabledServicesFromSettings(context, UserHandle.myUserId());
49    }
50
51    /**
52     * @return the set of enabled accessibility services for {@param userId}. If there are no
53     * services, it returns the unmodifiable {@link Collections#emptySet()}.
54     */
55    public static Set<ComponentName> getEnabledServicesFromSettings(Context context, int userId) {
56        final String enabledServicesSetting = Settings.Secure.getStringForUser(
57                context.getContentResolver(), Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES,
58                userId);
59        if (enabledServicesSetting == null) {
60            return Collections.emptySet();
61        }
62
63        final Set<ComponentName> enabledServices = new HashSet<>();
64        final TextUtils.SimpleStringSplitter colonSplitter = sStringColonSplitter;
65        colonSplitter.setString(enabledServicesSetting);
66
67        while (colonSplitter.hasNext()) {
68            final String componentNameString = colonSplitter.next();
69            final ComponentName enabledService = ComponentName.unflattenFromString(
70                    componentNameString);
71            if (enabledService != null) {
72                enabledServices.add(enabledService);
73            }
74        }
75
76        return enabledServices;
77    }
78
79    /**
80     * @return a localized version of the text resource specified by resId
81     */
82    public static CharSequence getTextForLocale(Context context, Locale locale, int resId) {
83        final Resources res = context.getResources();
84        final Configuration config = new Configuration(res.getConfiguration());
85        config.setLocale(locale);
86        final Context langContext = context.createConfigurationContext(config);
87        return langContext.getText(resId);
88    }
89
90    /**
91     * Changes an accessibility component's state.
92     */
93    public static void setAccessibilityServiceState(Context context, ComponentName toggledService,
94            boolean enabled) {
95        setAccessibilityServiceState(context, toggledService, enabled, UserHandle.myUserId());
96    }
97
98    /**
99     * Changes an accessibility component's state for {@param userId}.
100     */
101    public static void setAccessibilityServiceState(Context context, ComponentName toggledService,
102            boolean enabled, int userId) {
103        // Parse the enabled services.
104        Set<ComponentName> enabledServices = AccessibilityUtils.getEnabledServicesFromSettings(
105                context, userId);
106
107        if (enabledServices.isEmpty()) {
108            enabledServices = new ArraySet<>(1);
109        }
110
111        // Determine enabled services and accessibility state.
112        boolean accessibilityEnabled = false;
113        if (enabled) {
114            enabledServices.add(toggledService);
115            // Enabling at least one service enables accessibility.
116            accessibilityEnabled = true;
117        } else {
118            enabledServices.remove(toggledService);
119            // Check how many enabled and installed services are present.
120            Set<ComponentName> installedServices = getInstalledServices(context);
121            for (ComponentName enabledService : enabledServices) {
122                if (installedServices.contains(enabledService)) {
123                    // Disabling the last service disables accessibility.
124                    accessibilityEnabled = true;
125                    break;
126                }
127            }
128        }
129
130        // Update the enabled services setting.
131        StringBuilder enabledServicesBuilder = new StringBuilder();
132        // Keep the enabled services even if they are not installed since we
133        // have no way to know whether the application restore process has
134        // completed. In general the system should be responsible for the
135        // clean up not settings.
136        for (ComponentName enabledService : enabledServices) {
137            enabledServicesBuilder.append(enabledService.flattenToString());
138            enabledServicesBuilder.append(
139                    AccessibilityUtils.ENABLED_ACCESSIBILITY_SERVICES_SEPARATOR);
140        }
141        final int enabledServicesBuilderLength = enabledServicesBuilder.length();
142        if (enabledServicesBuilderLength > 0) {
143            enabledServicesBuilder.deleteCharAt(enabledServicesBuilderLength - 1);
144        }
145        Settings.Secure.putStringForUser(context.getContentResolver(),
146                Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES,
147                enabledServicesBuilder.toString(), userId);
148    }
149
150    private static Set<ComponentName> getInstalledServices(Context context) {
151        final Set<ComponentName> installedServices = new HashSet<>();
152        installedServices.clear();
153
154        final List<AccessibilityServiceInfo> installedServiceInfos =
155                AccessibilityManager.getInstance(context)
156                        .getInstalledAccessibilityServiceList();
157        if (installedServiceInfos == null) {
158            return installedServices;
159        }
160
161        for (final AccessibilityServiceInfo info : installedServiceInfos) {
162            final ResolveInfo resolveInfo = info.getResolveInfo();
163            final ComponentName installedService = new ComponentName(
164                    resolveInfo.serviceInfo.packageName,
165                    resolveInfo.serviceInfo.name);
166            installedServices.add(installedService);
167        }
168        return installedServices;
169    }
170
171}
172