SpellCheckerService.java revision 142d7575b52d03d46246e3b142e22ebc32d45a84 
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
5 * use this file except in compliance with the License. You may obtain a copy of
6 * 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, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations under
14 * the License.
15 */
16
17package android.service.textservice;
18
19import com.android.internal.textservice.ISpellCheckerService;
20import com.android.internal.textservice.ISpellCheckerSession;
21import com.android.internal.textservice.ISpellCheckerSessionListener;
22
23import android.app.Service;
24import android.content.Intent;
25import android.os.IBinder;
26import android.os.RemoteException;
27import android.view.textservice.SuggestionsInfo;
28import android.view.textservice.TextInfo;
29
30import java.lang.ref.WeakReference;
31
32/**
33 * SpellCheckerService provides an abstract base class for a spell checker.
34 * This class combines a service to the system with the spell checker service interface that
35 * spell checker must implement.
36 */
37public abstract class SpellCheckerService extends Service {
38    private static final String TAG = SpellCheckerService.class.getSimpleName();
39    public static final String SERVICE_INTERFACE =
40            "android.service.textservice.SpellCheckerService";
41
42    private final SpellCheckerServiceBinder mBinder = new SpellCheckerServiceBinder(this);
43
44    /**
45     * Get suggestions for specified text in TextInfo.
46     * This function will run on the incoming IPC thread. So, this is not called on the main thread,
47     * but will be called in series on another thread.
48     * @param textInfo the text metadata
49     * @param suggestionsLimit the number of limit of suggestions returned
50     * @param locale the locale for getting suggestions
51     * @return SuggestionInfo which contains suggestions for textInfo
52     */
53    public abstract SuggestionsInfo getSuggestions(
54            TextInfo textInfo, int suggestionsLimit, String locale);
55
56    /**
57     * A batch process of onGetSuggestions.
58     * This function will run on the incoming IPC thread. So, this is not called on the main thread,
59     * but will be called in series on another thread.
60     * @param textInfos an array of the text metadata
61     * @param locale the locale for getting suggestions
62     * @param suggestionsLimit the number of limit of suggestions returned
63     * @param sequentialWords true if textInfos can be treated as sequential words.
64     * @return an array of SuggestionInfo of onGetSuggestions
65     */
66    public SuggestionsInfo[] getSuggestionsMultiple(
67            TextInfo[] textInfos, String locale, int suggestionsLimit, boolean sequentialWords) {
68        final int length = textInfos.length;
69        final SuggestionsInfo[] retval = new SuggestionsInfo[length];
70        for (int i = 0; i < length; ++i) {
71            retval[i] = getSuggestions(textInfos[i], suggestionsLimit, locale);
72            retval[i].setCookieAndSequence(textInfos[i].getCookie(), textInfos[i].getSequence());
73        }
74        return retval;
75    }
76
77    /**
78     * Request to abort all tasks executed in SpellChecker.
79     * This function will run on the incoming IPC thread. So, this is not called on the main thread,
80     * but will be called in series on another thread.
81     */
82    public void cancel() {}
83
84    /**
85     * Implement to return the implementation of the internal spell checker
86     * service interface. Subclasses should not override.
87     */
88    @Override
89    public final IBinder onBind(final Intent intent) {
90        return mBinder;
91    }
92
93    private static class SpellCheckerSessionImpl extends ISpellCheckerSession.Stub {
94        private final WeakReference<SpellCheckerService> mInternalServiceRef;
95        private final String mLocale;
96        private final ISpellCheckerSessionListener mListener;
97
98        public SpellCheckerSessionImpl(
99                SpellCheckerService service, String locale, ISpellCheckerSessionListener listener) {
100            mInternalServiceRef = new WeakReference<SpellCheckerService>(service);
101            mLocale = locale;
102            mListener = listener;
103        }
104
105        @Override
106        public void getSuggestionsMultiple(
107                TextInfo[] textInfos, int suggestionsLimit, boolean sequentialWords) {
108            final SpellCheckerService service = mInternalServiceRef.get();
109            if (service == null) return;
110            try {
111                mListener.onGetSuggestions(
112                        service.getSuggestionsMultiple(textInfos, mLocale,
113                                suggestionsLimit, sequentialWords));
114            } catch (RemoteException e) {
115            }
116        }
117
118        @Override
119        public void cancel() {
120            final SpellCheckerService service = mInternalServiceRef.get();
121            if (service == null) return;
122            service.cancel();
123        }
124    }
125
126    private static class SpellCheckerServiceBinder extends ISpellCheckerService.Stub {
127        private final WeakReference<SpellCheckerService> mInternalServiceRef;
128
129        public SpellCheckerServiceBinder(SpellCheckerService service) {
130            mInternalServiceRef = new WeakReference<SpellCheckerService>(service);
131        }
132
133        @Override
134        public ISpellCheckerSession getISpellCheckerSession(
135                String locale, ISpellCheckerSessionListener listener) {
136            final SpellCheckerService service = mInternalServiceRef.get();
137            if (service == null) return null;
138            return new SpellCheckerSessionImpl(service, locale, listener);
139        }
140    }
141}
142