SuggestionSpanUtils.java revision aa300bb73a970a42ffb8bc8c5419c22191a7c08a 
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
17package com.android.inputmethod.compat;
18
19import com.android.inputmethod.latin.LatinImeLogger;
20import com.android.inputmethod.latin.SuggestedWords;
21import com.android.inputmethod.latin.SuggestionSpanPickedNotificationReceiver;
22
23import android.content.Context;
24import android.text.Spannable;
25import android.text.SpannableString;
26import android.text.Spanned;
27import android.text.TextUtils;
28import android.util.Log;
29
30import java.lang.reflect.Constructor;
31import java.lang.reflect.Field;
32import java.util.ArrayList;
33import java.util.Locale;
34
35public class SuggestionSpanUtils {
36    private static final String TAG = SuggestionSpanUtils.class.getSimpleName();
37    // TODO: Use reflection to get field values
38    public static final String ACTION_SUGGESTION_PICKED =
39            "android.text.style.SUGGESTION_PICKED";
40    public static final String SUGGESTION_SPAN_PICKED_AFTER = "after";
41    public static final String SUGGESTION_SPAN_PICKED_BEFORE = "before";
42    public static final String SUGGESTION_SPAN_PICKED_HASHCODE = "hashcode";
43    public static final boolean SUGGESTION_SPAN_IS_SUPPORTED;
44
45    private static final Class<?> CLASS_SuggestionSpan = CompatUtils
46            .getClass("android.text.style.SuggestionSpan");
47    private static final Class<?>[] INPUT_TYPE_SuggestionSpan = new Class<?>[] {
48            Context.class, Locale.class, String[].class, int.class, Class.class };
49    private static final Constructor<?> CONSTRUCTOR_SuggestionSpan = CompatUtils
50            .getConstructor(CLASS_SuggestionSpan, INPUT_TYPE_SuggestionSpan);
51    public static final Field FIELD_FLAG_EASY_CORRECT =
52            CompatUtils.getField(CLASS_SuggestionSpan, "FLAG_EASY_CORRECT");
53    public static final Field FIELD_FLAG_MISSPELLED =
54            CompatUtils.getField(CLASS_SuggestionSpan, "FLAG_MISSPELLED");
55    public static final Field FIELD_FLAG_AUTO_CORRECTION =
56            CompatUtils.getField(CLASS_SuggestionSpan, "FLAG_AUTO_CORRECTION");
57    public static final Field FIELD_SUGGESTIONS_MAX_SIZE
58            = CompatUtils.getField(CLASS_SuggestionSpan, "SUGGESTIONS_MAX_SIZE");
59    public static final Integer OBJ_FLAG_EASY_CORRECT = (Integer) CompatUtils
60            .getFieldValue(null, null, FIELD_FLAG_EASY_CORRECT);
61    public static final Integer OBJ_FLAG_MISSPELLED = (Integer) CompatUtils
62            .getFieldValue(null, null, FIELD_FLAG_MISSPELLED);
63    public static final Integer OBJ_FLAG_AUTO_CORRECTION = (Integer) CompatUtils
64            .getFieldValue(null, null, FIELD_FLAG_AUTO_CORRECTION);
65    public static final Integer OBJ_SUGGESTIONS_MAX_SIZE = (Integer) CompatUtils
66            .getFieldValue(null, null, FIELD_SUGGESTIONS_MAX_SIZE);
67
68    static {
69        SUGGESTION_SPAN_IS_SUPPORTED =
70                CLASS_SuggestionSpan != null && CONSTRUCTOR_SuggestionSpan != null;
71        if (LatinImeLogger.sDBG) {
72            if (SUGGESTION_SPAN_IS_SUPPORTED
73                    && (OBJ_FLAG_AUTO_CORRECTION == null || OBJ_SUGGESTIONS_MAX_SIZE == null
74                            || OBJ_FLAG_MISSPELLED == null || OBJ_FLAG_EASY_CORRECT == null)) {
75                throw new RuntimeException("Field is accidentially null.");
76            }
77        }
78    }
79
80    private SuggestionSpanUtils() {
81        // This utility class is not publicly instantiable.
82    }
83
84    public static CharSequence getTextWithAutoCorrectionIndicatorUnderline(
85            Context context, CharSequence text) {
86        if (TextUtils.isEmpty(text) || CONSTRUCTOR_SuggestionSpan == null
87                || OBJ_FLAG_AUTO_CORRECTION == null || OBJ_SUGGESTIONS_MAX_SIZE == null
88                || OBJ_FLAG_MISSPELLED == null || OBJ_FLAG_EASY_CORRECT == null) {
89            return text;
90        }
91        final Spannable spannable = text instanceof Spannable
92                ? (Spannable) text : new SpannableString(text);
93        final Object[] args =
94                { context, null, new String[] {}, (int)OBJ_FLAG_AUTO_CORRECTION,
95                        (Class<?>) SuggestionSpanPickedNotificationReceiver.class };
96        final Object ss = CompatUtils.newInstance(CONSTRUCTOR_SuggestionSpan, args);
97        if (ss == null) {
98            Log.w(TAG, "Suggestion span was not created.");
99            return text;
100        }
101        spannable.setSpan(ss, 0, text.length(),
102                Spanned.SPAN_EXCLUSIVE_EXCLUSIVE | Spanned.SPAN_COMPOSING);
103        return spannable;
104    }
105
106    public static CharSequence getTextWithSuggestionSpan(Context context,
107            CharSequence pickedWord, SuggestedWords suggestedWords) {
108        if (TextUtils.isEmpty(pickedWord) || CONSTRUCTOR_SuggestionSpan == null
109                || suggestedWords == null || suggestedWords.size() == 0
110                || OBJ_SUGGESTIONS_MAX_SIZE == null) {
111            return pickedWord;
112        }
113
114        final Spannable spannable;
115        if (pickedWord instanceof Spannable) {
116            spannable = (Spannable) pickedWord;
117        } else {
118            spannable = new SpannableString(pickedWord);
119        }
120        final ArrayList<String> suggestionsList = new ArrayList<String>();
121        boolean sameAsTyped = false;
122        for (int i = 0; i < suggestedWords.size(); ++i) {
123            if (suggestionsList.size() >= OBJ_SUGGESTIONS_MAX_SIZE) {
124                break;
125            }
126            final CharSequence word = suggestedWords.getWord(i);
127            if (!TextUtils.equals(pickedWord, word)) {
128                suggestionsList.add(word.toString());
129            } else if (i == 0) {
130                sameAsTyped = true;
131            }
132        }
133        // TODO: Share the implementation for checking typed word validity between the IME
134        // and the spell checker.
135        final int flag = (sameAsTyped && !suggestedWords.mTypedWordValid)
136                ? (OBJ_FLAG_EASY_CORRECT | OBJ_FLAG_MISSPELLED)
137                : 0;
138
139        // TODO: We should avoid adding suggestion span candidates that came from the bigram
140        // prediction.
141        final Object[] args =
142                { context, null, suggestionsList.toArray(new String[suggestionsList.size()]), flag,
143                        (Class<?>) SuggestionSpanPickedNotificationReceiver.class };
144        final Object ss = CompatUtils.newInstance(CONSTRUCTOR_SuggestionSpan, args);
145        if (ss == null) {
146            return pickedWord;
147        }
148        spannable.setSpan(ss, 0, pickedWord.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
149        return spannable;
150    }
151}
152