AccessibilityManager.java revision 7953e7d89b1d4d7297176fbb6aeea882577df8e6 
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 android.view.accessibility;
18
19import android.content.Context;
20import android.content.pm.ServiceInfo;
21
22import java.util.Collections;
23import java.util.List;
24
25/**
26 * System level service that serves as an event dispatch for {@link AccessibilityEvent}s.
27 * Such events are generated when something notable happens in the user interface,
28 * for example an {@link android.app.Activity} starts, the focus or selection of a
29 * {@link android.view.View} changes etc. Parties interested in handling accessibility
30 * events implement and register an accessibility service which extends
31 * {@link android.accessibilityservice.AccessibilityService}.
32 *
33 * @see AccessibilityEvent
34 * @see android.accessibilityservice.AccessibilityService
35 * @see android.content.Context#getSystemService
36 */
37public final class AccessibilityManager {
38    private static AccessibilityManager sInstance = new AccessibilityManager();
39
40    /**
41     * Get an AccessibilityManager instance (create one if necessary).
42     *
43     * @hide
44     */
45    public static AccessibilityManager getInstance(Context context) {
46        return sInstance;
47    }
48
49    /**
50     * Create an instance.
51     *
52     * @param context A {@link Context}.
53     */
54    private AccessibilityManager() {
55    }
56
57    /**
58     * Returns if the {@link AccessibilityManager} is enabled.
59     *
60     * @return True if this {@link AccessibilityManager} is enabled, false otherwise.
61     */
62    public boolean isEnabled() {
63        return false;
64    }
65
66    /**
67     * Sends an {@link AccessibilityEvent}. If this {@link AccessibilityManager} is not
68     * enabled the call is a NOOP.
69     *
70     * @param event The {@link AccessibilityEvent}.
71     *
72     * @throws IllegalStateException if a client tries to send an {@link AccessibilityEvent}
73     *         while accessibility is not enabled.
74     */
75    public void sendAccessibilityEvent(AccessibilityEvent event) {
76    }
77
78    /**
79     * Requests interruption of the accessibility feedback from all accessibility services.
80     */
81    public void interrupt() {
82    }
83
84    /**
85     * Returns the {@link ServiceInfo}s of the installed accessibility services.
86     *
87     * @return An unmodifiable list with {@link ServiceInfo}s.
88     */
89    public List<ServiceInfo> getAccessibilityServiceList() {
90        List<ServiceInfo> services = null;
91        return Collections.unmodifiableList(services);
92    }
93}
94