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      1 /*
      2  * Copyright (C) 2014 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 
     17 package com.android.inputmethod.latin.spellcheck;
     18 
     19 import android.annotation.TargetApi;
     20 import android.content.res.Resources;
     21 import android.os.Build;
     22 import android.view.textservice.SentenceSuggestionsInfo;
     23 import android.view.textservice.SuggestionsInfo;
     24 import android.view.textservice.TextInfo;
     25 
     26 import com.android.inputmethod.compat.TextInfoCompatUtils;
     27 import com.android.inputmethod.latin.common.Constants;
     28 import com.android.inputmethod.latin.settings.SpacingAndPunctuations;
     29 import com.android.inputmethod.latin.utils.RunInLocale;
     30 
     31 import java.util.ArrayList;
     32 import java.util.Locale;
     33 
     34 /**
     35  * This code is mostly lifted directly from android.service.textservice.SpellCheckerService in
     36  * the framework; maybe that should be protected instead, so that implementers don't have to
     37  * rewrite everything for any small change.
     38  */
     39 public class SentenceLevelAdapter {
     40     private static class EmptySentenceSuggestionsInfosInitializationHolder {
     41         public static final SentenceSuggestionsInfo[] EMPTY_SENTENCE_SUGGESTIONS_INFOS =
     42                 new SentenceSuggestionsInfo[]{};
     43     }
     44     private static final SuggestionsInfo EMPTY_SUGGESTIONS_INFO = new SuggestionsInfo(0, null);
     45 
     46     public static SentenceSuggestionsInfo[] getEmptySentenceSuggestionsInfo() {
     47         return EmptySentenceSuggestionsInfosInitializationHolder.EMPTY_SENTENCE_SUGGESTIONS_INFOS;
     48     }
     49 
     50     /**
     51      * Container for split TextInfo parameters
     52      */
     53     public static class SentenceWordItem {
     54         public final TextInfo mTextInfo;
     55         public final int mStart;
     56         public final int mLength;
     57         public SentenceWordItem(TextInfo ti, int start, int end) {
     58             mTextInfo = ti;
     59             mStart = start;
     60             mLength = end - start;
     61         }
     62     }
     63 
     64     /**
     65      * Container for originally queried TextInfo and parameters
     66      */
     67     public static class SentenceTextInfoParams {
     68         final TextInfo mOriginalTextInfo;
     69         final ArrayList<SentenceWordItem> mItems;
     70         final int mSize;
     71         public SentenceTextInfoParams(TextInfo ti, ArrayList<SentenceWordItem> items) {
     72             mOriginalTextInfo = ti;
     73             mItems = items;
     74             mSize = items.size();
     75         }
     76     }
     77 
     78     private static class WordIterator {
     79         private final SpacingAndPunctuations mSpacingAndPunctuations;
     80         public WordIterator(final Resources res, final Locale locale) {
     81             final RunInLocale<SpacingAndPunctuations> job =
     82                     new RunInLocale<SpacingAndPunctuations>() {
     83                 @Override
     84                 protected SpacingAndPunctuations job(final Resources r) {
     85                     return new SpacingAndPunctuations(r);
     86                 }
     87             };
     88             mSpacingAndPunctuations = job.runInLocale(res, locale);
     89         }
     90 
     91         public int getEndOfWord(final CharSequence sequence, final int fromIndex) {
     92             final int length = sequence.length();
     93             int index = fromIndex < 0 ? 0 : Character.offsetByCodePoints(sequence, fromIndex, 1);
     94             while (index < length) {
     95                 final int codePoint = Character.codePointAt(sequence, index);
     96                 if (mSpacingAndPunctuations.isWordSeparator(codePoint)) {
     97                     // If it's a period, we want to stop here only if it's followed by another
     98                     // word separator. In all other cases we stop here.
     99                     if (Constants.CODE_PERIOD == codePoint) {
    100                         final int indexOfNextCodePoint =
    101                                 index + Character.charCount(Constants.CODE_PERIOD);
    102                         if (indexOfNextCodePoint < length
    103                                 && mSpacingAndPunctuations.isWordSeparator(
    104                                         Character.codePointAt(sequence, indexOfNextCodePoint))) {
    105                             return index;
    106                         }
    107                     } else {
    108                         return index;
    109                     }
    110                 }
    111                 index += Character.charCount(codePoint);
    112             }
    113             return index;
    114         }
    115 
    116         public int getBeginningOfNextWord(final CharSequence sequence, final int fromIndex) {
    117             final int length = sequence.length();
    118             if (fromIndex >= length) {
    119                 return -1;
    120             }
    121             int index = fromIndex < 0 ? 0 : Character.offsetByCodePoints(sequence, fromIndex, 1);
    122             while (index < length) {
    123                 final int codePoint = Character.codePointAt(sequence, index);
    124                 if (!mSpacingAndPunctuations.isWordSeparator(codePoint)) {
    125                     return index;
    126                 }
    127                 index += Character.charCount(codePoint);
    128             }
    129             return -1;
    130         }
    131     }
    132 
    133     private final WordIterator mWordIterator;
    134     public SentenceLevelAdapter(final Resources res, final Locale locale) {
    135         mWordIterator = new WordIterator(res, locale);
    136     }
    137 
    138     public SentenceTextInfoParams getSplitWords(TextInfo originalTextInfo) {
    139         final WordIterator wordIterator = mWordIterator;
    140         final CharSequence originalText =
    141                 TextInfoCompatUtils.getCharSequenceOrString(originalTextInfo);
    142         final int cookie = originalTextInfo.getCookie();
    143         final int start = -1;
    144         final int end = originalText.length();
    145         final ArrayList<SentenceWordItem> wordItems = new ArrayList<>();
    146         int wordStart = wordIterator.getBeginningOfNextWord(originalText, start);
    147         int wordEnd = wordIterator.getEndOfWord(originalText, wordStart);
    148         while (wordStart <= end && wordEnd != -1 && wordStart != -1) {
    149             if (wordEnd >= start && wordEnd > wordStart) {
    150                 final TextInfo ti = TextInfoCompatUtils.newInstance(originalText, wordStart,
    151                         wordEnd, cookie, originalText.subSequence(wordStart, wordEnd).hashCode());
    152                 wordItems.add(new SentenceWordItem(ti, wordStart, wordEnd));
    153             }
    154             wordStart = wordIterator.getBeginningOfNextWord(originalText, wordEnd);
    155             if (wordStart == -1) {
    156                 break;
    157             }
    158             wordEnd = wordIterator.getEndOfWord(originalText, wordStart);
    159         }
    160         return new SentenceTextInfoParams(originalTextInfo, wordItems);
    161     }
    162 
    163     @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    164     public static SentenceSuggestionsInfo reconstructSuggestions(
    165             SentenceTextInfoParams originalTextInfoParams, SuggestionsInfo[] results) {
    166         if (results == null || results.length == 0) {
    167             return null;
    168         }
    169         if (originalTextInfoParams == null) {
    170             return null;
    171         }
    172         final int originalCookie = originalTextInfoParams.mOriginalTextInfo.getCookie();
    173         final int originalSequence =
    174                 originalTextInfoParams.mOriginalTextInfo.getSequence();
    175 
    176         final int querySize = originalTextInfoParams.mSize;
    177         final int[] offsets = new int[querySize];
    178         final int[] lengths = new int[querySize];
    179         final SuggestionsInfo[] reconstructedSuggestions = new SuggestionsInfo[querySize];
    180         for (int i = 0; i < querySize; ++i) {
    181             final SentenceWordItem item = originalTextInfoParams.mItems.get(i);
    182             SuggestionsInfo result = null;
    183             for (int j = 0; j < results.length; ++j) {
    184                 final SuggestionsInfo cur = results[j];
    185                 if (cur != null && cur.getSequence() == item.mTextInfo.getSequence()) {
    186                     result = cur;
    187                     result.setCookieAndSequence(originalCookie, originalSequence);
    188                     break;
    189                 }
    190             }
    191             offsets[i] = item.mStart;
    192             lengths[i] = item.mLength;
    193             reconstructedSuggestions[i] = result != null ? result : EMPTY_SUGGESTIONS_INFO;
    194         }
    195         return new SentenceSuggestionsInfo(reconstructedSuggestions, offsets, lengths);
    196     }
    197 }
    198