SpellChecker.java revision 0eea6681519277310e1733d791bfc0342b8e5cea
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 android.widget; 18 19import android.content.Context; 20import android.text.Editable; 21import android.text.Selection; 22import android.text.Spanned; 23import android.text.style.SpellCheckSpan; 24import android.text.style.SuggestionSpan; 25import android.util.Log; 26import android.view.textservice.SpellCheckerSession; 27import android.view.textservice.SpellCheckerSession.SpellCheckerSessionListener; 28import android.view.textservice.SuggestionsInfo; 29import android.view.textservice.TextInfo; 30import android.view.textservice.TextServicesManager; 31 32import com.android.internal.util.ArrayUtils; 33 34import java.util.Locale; 35 36 37/** 38 * Helper class for TextView. Bridge between the TextView and the Dictionnary service. 39 * 40 * @hide 41 */ 42public class SpellChecker implements SpellCheckerSessionListener { 43 private static final String LOG_TAG = "SpellChecker"; 44 private static final boolean DEBUG_SPELL_CHECK = false; 45 private static final int DELAY_BEFORE_SPELL_CHECK = 400; // milliseconds 46 47 private final TextView mTextView; 48 49 final SpellCheckerSession mSpellCheckerSession; 50 final int mCookie; 51 52 // Paired arrays for the (id, spellCheckSpan) pair. mIndex is the next available position 53 private int[] mIds; 54 private SpellCheckSpan[] mSpellCheckSpans; 55 // The actual current number of used slots in the above arrays 56 private int mLength; 57 58 private int mSpanSequenceCounter = 0; 59 private Runnable mChecker; 60 61 public SpellChecker(TextView textView) { 62 mTextView = textView; 63 64 final TextServicesManager textServicesManager = (TextServicesManager) textView.getContext(). 65 getSystemService(Context.TEXT_SERVICES_MANAGER_SERVICE); 66 mSpellCheckerSession = textServicesManager.newSpellCheckerSession( 67 null /* not currently used by the textServicesManager */, Locale.getDefault(), 68 this, true /* means use the languages defined in Settings */); 69 mCookie = hashCode(); 70 71 // Arbitrary: 4 simultaneous spell check spans. Will automatically double size on demand 72 final int size = ArrayUtils.idealObjectArraySize(4); 73 mIds = new int[size]; 74 mSpellCheckSpans = new SpellCheckSpan[size]; 75 mLength = 0; 76 } 77 78 public void addSpellCheckSpan(SpellCheckSpan spellCheckSpan) { 79 int length = mIds.length; 80 if (mLength >= length) { 81 final int newSize = length * 2; 82 int[] newIds = new int[newSize]; 83 SpellCheckSpan[] newSpellCheckSpans = new SpellCheckSpan[newSize]; 84 System.arraycopy(mIds, 0, newIds, 0, length); 85 System.arraycopy(mSpellCheckSpans, 0, newSpellCheckSpans, 0, length); 86 mIds = newIds; 87 mSpellCheckSpans = newSpellCheckSpans; 88 } 89 90 mIds[mLength] = mSpanSequenceCounter++; 91 mSpellCheckSpans[mLength] = spellCheckSpan; 92 mLength++; 93 94 if (DEBUG_SPELL_CHECK) { 95 final Editable mText = (Editable) mTextView.getText(); 96 int start = mText.getSpanStart(spellCheckSpan); 97 int end = mText.getSpanEnd(spellCheckSpan); 98 if (start >= 0 && end >= 0) { 99 Log.d(LOG_TAG, "Schedule check " + mText.subSequence(start, end)); 100 } else { 101 Log.d(LOG_TAG, "Schedule check EMPTY!"); 102 } 103 } 104 105 scheduleSpellCheck(); 106 } 107 108 public void removeSpellCheckSpan(SpellCheckSpan spellCheckSpan) { 109 for (int i = 0; i < mLength; i++) { 110 if (mSpellCheckSpans[i] == spellCheckSpan) { 111 removeAtIndex(i); 112 return; 113 } 114 } 115 } 116 117 private void removeAtIndex(int i) { 118 System.arraycopy(mIds, i + 1, mIds, i, mLength - i - 1); 119 System.arraycopy(mSpellCheckSpans, i + 1, mSpellCheckSpans, i, mLength - i - 1); 120 mLength--; 121 } 122 123 public void onSelectionChanged() { 124 scheduleSpellCheck(); 125 } 126 127 private void scheduleSpellCheck() { 128 if (mLength == 0) return; 129 if (mSpellCheckerSession == null) return; 130 131 if (mChecker != null) { 132 mTextView.removeCallbacks(mChecker); 133 } 134 if (mChecker == null) { 135 mChecker = new Runnable() { 136 public void run() { 137 spellCheck(); 138 } 139 }; 140 } 141 mTextView.postDelayed(mChecker, DELAY_BEFORE_SPELL_CHECK); 142 } 143 144 private void spellCheck() { 145 final Editable editable = (Editable) mTextView.getText(); 146 final int selectionStart = Selection.getSelectionStart(editable); 147 final int selectionEnd = Selection.getSelectionEnd(editable); 148 149 TextInfo[] textInfos = new TextInfo[mLength]; 150 int textInfosCount = 0; 151 152 for (int i = 0; i < mLength; i++) { 153 SpellCheckSpan spellCheckSpan = mSpellCheckSpans[i]; 154 155 if (spellCheckSpan.isSpellCheckInProgress()) continue; 156 157 final int start = editable.getSpanStart(spellCheckSpan); 158 final int end = editable.getSpanEnd(spellCheckSpan); 159 160 // Do not check this word if the user is currently editing it 161 if (start >= 0 && end > start && (selectionEnd < start || selectionStart > end)) { 162 final String word = editable.subSequence(start, end).toString(); 163 spellCheckSpan.setSpellCheckInProgress(); 164 textInfos[textInfosCount++] = new TextInfo(word, mCookie, mIds[i]); 165 } 166 } 167 168 if (textInfosCount > 0) { 169 if (textInfosCount < mLength) { 170 TextInfo[] textInfosCopy = new TextInfo[textInfosCount]; 171 System.arraycopy(textInfos, 0, textInfosCopy, 0, textInfosCount); 172 textInfos = textInfosCopy; 173 } 174 mSpellCheckerSession.getSuggestions(textInfos, SuggestionSpan.SUGGESTIONS_MAX_SIZE, 175 false /* TODO Set sequentialWords to true for initial spell check */); 176 } 177 } 178 179 @Override 180 public void onGetSuggestions(SuggestionsInfo[] results) { 181 final Editable editable = (Editable) mTextView.getText(); 182 for (int i = 0; i < results.length; i++) { 183 SuggestionsInfo suggestionsInfo = results[i]; 184 if (suggestionsInfo.getCookie() != mCookie) continue; 185 186 final int sequenceNumber = suggestionsInfo.getSequence(); 187 // Starting from the end, to limit the number of array copy while removing 188 for (int j = mLength - 1; j >= 0; j--) { 189 if (sequenceNumber == mIds[j]) { 190 SpellCheckSpan spellCheckSpan = mSpellCheckSpans[j]; 191 final int attributes = suggestionsInfo.getSuggestionsAttributes(); 192 boolean isInDictionary = 193 ((attributes & SuggestionsInfo.RESULT_ATTR_IN_THE_DICTIONARY) > 0); 194 boolean looksLikeTypo = 195 ((attributes & SuggestionsInfo.RESULT_ATTR_LOOKS_LIKE_TYPO) > 0); 196 197 if (DEBUG_SPELL_CHECK) { 198 final int start = editable.getSpanStart(spellCheckSpan); 199 final int end = editable.getSpanEnd(spellCheckSpan); 200 Log.d(LOG_TAG, "Result sequence=" + suggestionsInfo.getSequence() + " " + 201 editable.subSequence(start, end) + 202 "\t" + (isInDictionary?"IN_DICT" : "NOT_DICT") + 203 "\t" + (looksLikeTypo?"TYPO" : "NOT_TYPO")); 204 } 205 206 if (!isInDictionary && looksLikeTypo) { 207 String[] suggestions = getSuggestions(suggestionsInfo); 208 if (suggestions.length > 0) { 209 SuggestionSpan suggestionSpan = new SuggestionSpan( 210 mTextView.getContext(), suggestions, 211 SuggestionSpan.FLAG_EASY_CORRECT | 212 SuggestionSpan.FLAG_MISSPELLED); 213 final int start = editable.getSpanStart(spellCheckSpan); 214 final int end = editable.getSpanEnd(spellCheckSpan); 215 editable.setSpan(suggestionSpan, start, end, 216 Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); 217 // TODO limit to the word rectangle region 218 mTextView.invalidate(); 219 220 if (DEBUG_SPELL_CHECK) { 221 String suggestionsString = ""; 222 for (String s : suggestions) { suggestionsString += s + "|"; } 223 Log.d(LOG_TAG, " Suggestions for " + sequenceNumber + " " + 224 editable.subSequence(start, end)+ " " + suggestionsString); 225 } 226 } 227 } 228 editable.removeSpan(spellCheckSpan); 229 } 230 } 231 } 232 } 233 234 private static String[] getSuggestions(SuggestionsInfo suggestionsInfo) { 235 final int len = Math.max(0, suggestionsInfo.getSuggestionsCount()); 236 String[] suggestions = new String[len]; 237 for (int j = 0; j < len; ++j) { 238 suggestions[j] = suggestionsInfo.getSuggestionAt(j); 239 } 240 return suggestions; 241 } 242} 243