/* * Copyright (C) 2011 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.widget; import android.content.Context; import android.text.Editable; import android.text.Selection; import android.text.SpannableStringBuilder; import android.text.Spanned; import android.text.TextUtils; import android.text.method.WordIterator; import android.text.style.SpellCheckSpan; import android.text.style.SuggestionSpan; import android.util.Log; import android.util.LruCache; import android.view.textservice.SentenceSuggestionsInfo; import android.view.textservice.SpellCheckerSession; import android.view.textservice.SpellCheckerSession.SpellCheckerSessionListener; import android.view.textservice.SuggestionsInfo; import android.view.textservice.TextInfo; import android.view.textservice.TextServicesManager; import com.android.internal.util.ArrayUtils; import java.text.BreakIterator; import java.util.Locale; /** * Helper class for TextView. Bridge between the TextView and the Dictionnary service. * * @hide */ public class SpellChecker implements SpellCheckerSessionListener { private static final String TAG = SpellChecker.class.getSimpleName(); private static final boolean DBG = false; // No more than this number of words will be parsed on each iteration to ensure a minimum // lock of the UI thread public static final int MAX_NUMBER_OF_WORDS = 50; // Rough estimate, such that the word iterator interval usually does not need to be shifted public static final int AVERAGE_WORD_LENGTH = 7; // When parsing, use a character window of that size. Will be shifted if needed public static final int WORD_ITERATOR_INTERVAL = AVERAGE_WORD_LENGTH * MAX_NUMBER_OF_WORDS; // Pause between each spell check to keep the UI smooth private final static int SPELL_PAUSE_DURATION = 400; // milliseconds private static final int MIN_SENTENCE_LENGTH = 50; private static final int USE_SPAN_RANGE = -1; private final TextView mTextView; SpellCheckerSession mSpellCheckerSession; // We assume that the sentence level spell check will always provide better results than words. // Although word SC has a sequential option. private boolean mIsSentenceSpellCheckSupported; final int mCookie; // Paired arrays for the (id, spellCheckSpan) pair. A negative id means the associated // SpellCheckSpan has been recycled and can be-reused. // Contains null SpellCheckSpans after index mLength. private int[] mIds; private SpellCheckSpan[] mSpellCheckSpans; // The mLength first elements of the above arrays have been initialized private int mLength; // Parsers on chunck of text, cutting text into words that will be checked private SpellParser[] mSpellParsers = new SpellParser[0]; private int mSpanSequenceCounter = 0; private Locale mCurrentLocale; // Shared by all SpellParsers. Cannot be shared with TextView since it may be used // concurrently due to the asynchronous nature of onGetSuggestions. private WordIterator mWordIterator; private TextServicesManager mTextServicesManager; private Runnable mSpellRunnable; private static final int SUGGESTION_SPAN_CACHE_SIZE = 10; private final LruCache mSuggestionSpanCache = new LruCache(SUGGESTION_SPAN_CACHE_SIZE); public SpellChecker(TextView textView) { mTextView = textView; // Arbitrary: these arrays will automatically double their sizes on demand final int size = ArrayUtils.idealObjectArraySize(1); mIds = new int[size]; mSpellCheckSpans = new SpellCheckSpan[size]; setLocale(mTextView.getTextServicesLocale()); mCookie = hashCode(); } private void resetSession() { closeSession(); mTextServicesManager = (TextServicesManager) mTextView.getContext(). getSystemService(Context.TEXT_SERVICES_MANAGER_SERVICE); if (!mTextServicesManager.isSpellCheckerEnabled() || mTextServicesManager.getCurrentSpellCheckerSubtype(true) == null) { mSpellCheckerSession = null; } else { mSpellCheckerSession = mTextServicesManager.newSpellCheckerSession( null /* Bundle not currently used by the textServicesManager */, mCurrentLocale, this, false /* means any available languages from current spell checker */); mIsSentenceSpellCheckSupported = true; } // Restore SpellCheckSpans in pool for (int i = 0; i < mLength; i++) { mIds[i] = -1; } mLength = 0; // Remove existing misspelled SuggestionSpans mTextView.removeMisspelledSpans((Editable) mTextView.getText()); mSuggestionSpanCache.evictAll(); } private void setLocale(Locale locale) { mCurrentLocale = locale; resetSession(); // Change SpellParsers' wordIterator locale mWordIterator = new WordIterator(locale); // This class is the listener for locale change: warn other locale-aware objects mTextView.onLocaleChanged(); } /** * @return true if a spell checker session has successfully been created. Returns false if not, * for instance when spell checking has been disabled in settings. */ private boolean isSessionActive() { return mSpellCheckerSession != null; } public void closeSession() { if (mSpellCheckerSession != null) { mSpellCheckerSession.close(); } final int length = mSpellParsers.length; for (int i = 0; i < length; i++) { mSpellParsers[i].stop(); } if (mSpellRunnable != null) { mTextView.removeCallbacks(mSpellRunnable); } } private int nextSpellCheckSpanIndex() { for (int i = 0; i < mLength; i++) { if (mIds[i] < 0) return i; } if (mLength == mSpellCheckSpans.length) { final int newSize = mLength * 2; int[] newIds = new int[newSize]; SpellCheckSpan[] newSpellCheckSpans = new SpellCheckSpan[newSize]; System.arraycopy(mIds, 0, newIds, 0, mLength); System.arraycopy(mSpellCheckSpans, 0, newSpellCheckSpans, 0, mLength); mIds = newIds; mSpellCheckSpans = newSpellCheckSpans; } mSpellCheckSpans[mLength] = new SpellCheckSpan(); mLength++; return mLength - 1; } private void addSpellCheckSpan(Editable editable, int start, int end) { final int index = nextSpellCheckSpanIndex(); SpellCheckSpan spellCheckSpan = mSpellCheckSpans[index]; editable.setSpan(spellCheckSpan, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); spellCheckSpan.setSpellCheckInProgress(false); mIds[index] = mSpanSequenceCounter++; } public void onSpellCheckSpanRemoved(SpellCheckSpan spellCheckSpan) { // Recycle any removed SpellCheckSpan (from this code or during text edition) for (int i = 0; i < mLength; i++) { if (mSpellCheckSpans[i] == spellCheckSpan) { mIds[i] = -1; return; } } } public void onSelectionChanged() { spellCheck(); } public void spellCheck(int start, int end) { if (DBG) { Log.d(TAG, "Start spell-checking: " + start + ", " + end); } final Locale locale = mTextView.getTextServicesLocale(); final boolean isSessionActive = isSessionActive(); if (mCurrentLocale == null || (!(mCurrentLocale.equals(locale)))) { setLocale(locale); // Re-check the entire text start = 0; end = mTextView.getText().length(); } else { final boolean spellCheckerActivated = mTextServicesManager.isSpellCheckerEnabled(); if (isSessionActive != spellCheckerActivated) { // Spell checker has been turned of or off since last spellCheck resetSession(); } } if (!isSessionActive) return; // Find first available SpellParser from pool final int length = mSpellParsers.length; for (int i = 0; i < length; i++) { final SpellParser spellParser = mSpellParsers[i]; if (spellParser.isFinished()) { spellParser.parse(start, end); return; } } if (DBG) { Log.d(TAG, "new spell parser."); } // No available parser found in pool, create a new one SpellParser[] newSpellParsers = new SpellParser[length + 1]; System.arraycopy(mSpellParsers, 0, newSpellParsers, 0, length); mSpellParsers = newSpellParsers; SpellParser spellParser = new SpellParser(); mSpellParsers[length] = spellParser; spellParser.parse(start, end); } private void spellCheck() { if (mSpellCheckerSession == null) return; Editable editable = (Editable) mTextView.getText(); final int selectionStart = Selection.getSelectionStart(editable); final int selectionEnd = Selection.getSelectionEnd(editable); TextInfo[] textInfos = new TextInfo[mLength]; int textInfosCount = 0; for (int i = 0; i < mLength; i++) { final SpellCheckSpan spellCheckSpan = mSpellCheckSpans[i]; if (mIds[i] < 0 || spellCheckSpan.isSpellCheckInProgress()) continue; final int start = editable.getSpanStart(spellCheckSpan); final int end = editable.getSpanEnd(spellCheckSpan); // Do not check this word if the user is currently editing it final boolean isEditing; if (mIsSentenceSpellCheckSupported) { // Allow the overlap of the cursor and the first boundary of the spell check span // no to skip the spell check of the following word because the // following word will never be spell-checked even if the user finishes composing isEditing = selectionEnd <= start || selectionStart > end; } else { isEditing = selectionEnd < start || selectionStart > end; } if (start >= 0 && end > start && isEditing) { final String word = (editable instanceof SpannableStringBuilder) ? ((SpannableStringBuilder) editable).substring(start, end) : editable.subSequence(start, end).toString(); spellCheckSpan.setSpellCheckInProgress(true); textInfos[textInfosCount++] = new TextInfo(word, mCookie, mIds[i]); if (DBG) { Log.d(TAG, "create TextInfo: (" + i + "/" + mLength + ")" + word + ", cookie = " + mCookie + ", seq = " + mIds[i] + ", sel start = " + selectionStart + ", sel end = " + selectionEnd + ", start = " + start + ", end = " + end); } } } if (textInfosCount > 0) { if (textInfosCount < textInfos.length) { TextInfo[] textInfosCopy = new TextInfo[textInfosCount]; System.arraycopy(textInfos, 0, textInfosCopy, 0, textInfosCount); textInfos = textInfosCopy; } if (mIsSentenceSpellCheckSupported) { mSpellCheckerSession.getSentenceSuggestions( textInfos, SuggestionSpan.SUGGESTIONS_MAX_SIZE); } else { mSpellCheckerSession.getSuggestions(textInfos, SuggestionSpan.SUGGESTIONS_MAX_SIZE, false /* TODO Set sequentialWords to true for initial spell check */); } } } private SpellCheckSpan onGetSuggestionsInternal( SuggestionsInfo suggestionsInfo, int offset, int length) { if (suggestionsInfo == null || suggestionsInfo.getCookie() != mCookie) { return null; } final Editable editable = (Editable) mTextView.getText(); final int sequenceNumber = suggestionsInfo.getSequence(); for (int k = 0; k < mLength; ++k) { if (sequenceNumber == mIds[k]) { final int attributes = suggestionsInfo.getSuggestionsAttributes(); final boolean isInDictionary = ((attributes & SuggestionsInfo.RESULT_ATTR_IN_THE_DICTIONARY) > 0); final boolean looksLikeTypo = ((attributes & SuggestionsInfo.RESULT_ATTR_LOOKS_LIKE_TYPO) > 0); final SpellCheckSpan spellCheckSpan = mSpellCheckSpans[k]; //TODO: we need to change that rule for results from a sentence-level spell // checker that will probably be in dictionary. if (!isInDictionary && looksLikeTypo) { createMisspelledSuggestionSpan( editable, suggestionsInfo, spellCheckSpan, offset, length); } else { // Valid word -- isInDictionary || !looksLikeTypo if (mIsSentenceSpellCheckSupported) { // Allow the spell checker to remove existing misspelled span by // overwriting the span over the same place final int spellCheckSpanStart = editable.getSpanStart(spellCheckSpan); final int spellCheckSpanEnd = editable.getSpanEnd(spellCheckSpan); final int start; final int end; if (offset != USE_SPAN_RANGE && length != USE_SPAN_RANGE) { start = spellCheckSpanStart + offset; end = start + length; } else { start = spellCheckSpanStart; end = spellCheckSpanEnd; } if (spellCheckSpanStart >= 0 && spellCheckSpanEnd > spellCheckSpanStart && end > start) { final Long key = Long.valueOf(TextUtils.packRangeInLong(start, end)); final SuggestionSpan tempSuggestionSpan = mSuggestionSpanCache.get(key); if (tempSuggestionSpan != null) { if (DBG) { Log.i(TAG, "Remove existing misspelled span. " + editable.subSequence(start, end)); } editable.removeSpan(tempSuggestionSpan); mSuggestionSpanCache.remove(key); } } } } return spellCheckSpan; } } return null; } @Override public void onGetSuggestions(SuggestionsInfo[] results) { final Editable editable = (Editable) mTextView.getText(); for (int i = 0; i < results.length; ++i) { final SpellCheckSpan spellCheckSpan = onGetSuggestionsInternal(results[i], USE_SPAN_RANGE, USE_SPAN_RANGE); if (spellCheckSpan != null) { // onSpellCheckSpanRemoved will recycle this span in the pool editable.removeSpan(spellCheckSpan); } } scheduleNewSpellCheck(); } @Override public void onGetSentenceSuggestions(SentenceSuggestionsInfo[] results) { final Editable editable = (Editable) mTextView.getText(); for (int i = 0; i < results.length; ++i) { final SentenceSuggestionsInfo ssi = results[i]; if (ssi == null) { continue; } SpellCheckSpan spellCheckSpan = null; for (int j = 0; j < ssi.getSuggestionsCount(); ++j) { final SuggestionsInfo suggestionsInfo = ssi.getSuggestionsInfoAt(j); if (suggestionsInfo == null) { continue; } final int offset = ssi.getOffsetAt(j); final int length = ssi.getLengthAt(j); final SpellCheckSpan scs = onGetSuggestionsInternal( suggestionsInfo, offset, length); if (spellCheckSpan == null && scs != null) { // the spellCheckSpan is shared by all the "SuggestionsInfo"s in the same // SentenceSuggestionsInfo. Removal is deferred after this loop. spellCheckSpan = scs; } } if (spellCheckSpan != null) { // onSpellCheckSpanRemoved will recycle this span in the pool editable.removeSpan(spellCheckSpan); } } scheduleNewSpellCheck(); } private void scheduleNewSpellCheck() { if (DBG) { Log.i(TAG, "schedule new spell check."); } if (mSpellRunnable == null) { mSpellRunnable = new Runnable() { @Override public void run() { final int length = mSpellParsers.length; for (int i = 0; i < length; i++) { final SpellParser spellParser = mSpellParsers[i]; if (!spellParser.isFinished()) { spellParser.parse(); break; // run one spell parser at a time to bound running time } } } }; } else { mTextView.removeCallbacks(mSpellRunnable); } mTextView.postDelayed(mSpellRunnable, SPELL_PAUSE_DURATION); } private void createMisspelledSuggestionSpan(Editable editable, SuggestionsInfo suggestionsInfo, SpellCheckSpan spellCheckSpan, int offset, int length) { final int spellCheckSpanStart = editable.getSpanStart(spellCheckSpan); final int spellCheckSpanEnd = editable.getSpanEnd(spellCheckSpan); if (spellCheckSpanStart < 0 || spellCheckSpanEnd <= spellCheckSpanStart) return; // span was removed in the meantime final int start; final int end; if (offset != USE_SPAN_RANGE && length != USE_SPAN_RANGE) { start = spellCheckSpanStart + offset; end = start + length; } else { start = spellCheckSpanStart; end = spellCheckSpanEnd; } final int suggestionsCount = suggestionsInfo.getSuggestionsCount(); String[] suggestions; if (suggestionsCount > 0) { suggestions = new String[suggestionsCount]; for (int i = 0; i < suggestionsCount; i++) { suggestions[i] = suggestionsInfo.getSuggestionAt(i); } } else { suggestions = ArrayUtils.emptyArray(String.class); } SuggestionSpan suggestionSpan = new SuggestionSpan(mTextView.getContext(), suggestions, SuggestionSpan.FLAG_EASY_CORRECT | SuggestionSpan.FLAG_MISSPELLED); // TODO: Remove mIsSentenceSpellCheckSupported by extracting an interface // to share the logic of word level spell checker and sentence level spell checker if (mIsSentenceSpellCheckSupported) { final Long key = Long.valueOf(TextUtils.packRangeInLong(start, end)); final SuggestionSpan tempSuggestionSpan = mSuggestionSpanCache.get(key); if (tempSuggestionSpan != null) { if (DBG) { Log.i(TAG, "Cached span on the same position is cleard. " + editable.subSequence(start, end)); } editable.removeSpan(tempSuggestionSpan); } mSuggestionSpanCache.put(key, suggestionSpan); } editable.setSpan(suggestionSpan, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); mTextView.invalidateRegion(start, end, false /* No cursor involved */); } private class SpellParser { private Object mRange = new Object(); public void parse(int start, int end) { final int max = mTextView.length(); final int parseEnd; if (end > max) { Log.w(TAG, "Parse invalid region, from " + start + " to " + end); parseEnd = max; } else { parseEnd = end; } if (parseEnd > start) { setRangeSpan((Editable) mTextView.getText(), start, parseEnd); parse(); } } public boolean isFinished() { return ((Editable) mTextView.getText()).getSpanStart(mRange) < 0; } public void stop() { removeRangeSpan((Editable) mTextView.getText()); } private void setRangeSpan(Editable editable, int start, int end) { if (DBG) { Log.d(TAG, "set next range span: " + start + ", " + end); } editable.setSpan(mRange, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); } private void removeRangeSpan(Editable editable) { if (DBG) { Log.d(TAG, "Remove range span." + editable.getSpanStart(editable) + editable.getSpanEnd(editable)); } editable.removeSpan(mRange); } public void parse() { Editable editable = (Editable) mTextView.getText(); // Iterate over the newly added text and schedule new SpellCheckSpans final int start; if (mIsSentenceSpellCheckSupported) { // TODO: Find the start position of the sentence. // Set span with the context start = Math.max( 0, editable.getSpanStart(mRange) - MIN_SENTENCE_LENGTH); } else { start = editable.getSpanStart(mRange); } final int end = editable.getSpanEnd(mRange); int wordIteratorWindowEnd = Math.min(end, start + WORD_ITERATOR_INTERVAL); mWordIterator.setCharSequence(editable, start, wordIteratorWindowEnd); // Move back to the beginning of the current word, if any int wordStart = mWordIterator.preceding(start); int wordEnd; if (wordStart == BreakIterator.DONE) { wordEnd = mWordIterator.following(start); if (wordEnd != BreakIterator.DONE) { wordStart = mWordIterator.getBeginning(wordEnd); } } else { wordEnd = mWordIterator.getEnd(wordStart); } if (wordEnd == BreakIterator.DONE) { if (DBG) { Log.i(TAG, "No more spell check."); } removeRangeSpan(editable); return; } // We need to expand by one character because we want to include the spans that // end/start at position start/end respectively. SpellCheckSpan[] spellCheckSpans = editable.getSpans(start - 1, end + 1, SpellCheckSpan.class); SuggestionSpan[] suggestionSpans = editable.getSpans(start - 1, end + 1, SuggestionSpan.class); int wordCount = 0; boolean scheduleOtherSpellCheck = false; if (mIsSentenceSpellCheckSupported) { if (wordIteratorWindowEnd < end) { if (DBG) { Log.i(TAG, "schedule other spell check."); } // Several batches needed on that region. Cut after last previous word scheduleOtherSpellCheck = true; } int spellCheckEnd = mWordIterator.preceding(wordIteratorWindowEnd); boolean correct = spellCheckEnd != BreakIterator.DONE; if (correct) { spellCheckEnd = mWordIterator.getEnd(spellCheckEnd); correct = spellCheckEnd != BreakIterator.DONE; } if (!correct) { if (DBG) { Log.i(TAG, "Incorrect range span."); } removeRangeSpan(editable); return; } do { // TODO: Find the start position of the sentence. int spellCheckStart = wordStart; boolean createSpellCheckSpan = true; // Cancel or merge overlapped spell check spans for (int i = 0; i < mLength; ++i) { final SpellCheckSpan spellCheckSpan = mSpellCheckSpans[i]; if (mIds[i] < 0 || spellCheckSpan.isSpellCheckInProgress()) { continue; } final int spanStart = editable.getSpanStart(spellCheckSpan); final int spanEnd = editable.getSpanEnd(spellCheckSpan); if (spanEnd < spellCheckStart || spellCheckEnd < spanStart) { // No need to merge continue; } if (spanStart <= spellCheckStart && spellCheckEnd <= spanEnd) { // There is a completely overlapped spell check span // skip this span createSpellCheckSpan = false; if (DBG) { Log.i(TAG, "The range is overrapped. Skip spell check."); } break; } // This spellCheckSpan is replaced by the one we are creating editable.removeSpan(spellCheckSpan); spellCheckStart = Math.min(spanStart, spellCheckStart); spellCheckEnd = Math.max(spanEnd, spellCheckEnd); } if (DBG) { Log.d(TAG, "addSpellCheckSpan: " + ", End = " + spellCheckEnd + ", Start = " + spellCheckStart + ", next = " + scheduleOtherSpellCheck + "\n" + editable.subSequence(spellCheckStart, spellCheckEnd)); } // Stop spell checking when there are no characters in the range. if (spellCheckEnd < start) { break; } if (spellCheckEnd <= spellCheckStart) { Log.w(TAG, "Trying to spellcheck invalid region, from " + start + " to " + end); break; } if (createSpellCheckSpan) { addSpellCheckSpan(editable, spellCheckStart, spellCheckEnd); } } while (false); wordStart = spellCheckEnd; } else { while (wordStart <= end) { if (wordEnd >= start && wordEnd > wordStart) { if (wordCount >= MAX_NUMBER_OF_WORDS) { scheduleOtherSpellCheck = true; break; } // A new word has been created across the interval boundaries with this // edit. The previous spans (that ended on start / started on end) are // not valid anymore and must be removed. if (wordStart < start && wordEnd > start) { removeSpansAt(editable, start, spellCheckSpans); removeSpansAt(editable, start, suggestionSpans); } if (wordStart < end && wordEnd > end) { removeSpansAt(editable, end, spellCheckSpans); removeSpansAt(editable, end, suggestionSpans); } // Do not create new boundary spans if they already exist boolean createSpellCheckSpan = true; if (wordEnd == start) { for (int i = 0; i < spellCheckSpans.length; i++) { final int spanEnd = editable.getSpanEnd(spellCheckSpans[i]); if (spanEnd == start) { createSpellCheckSpan = false; break; } } } if (wordStart == end) { for (int i = 0; i < spellCheckSpans.length; i++) { final int spanStart = editable.getSpanStart(spellCheckSpans[i]); if (spanStart == end) { createSpellCheckSpan = false; break; } } } if (createSpellCheckSpan) { addSpellCheckSpan(editable, wordStart, wordEnd); } wordCount++; } // iterate word by word int originalWordEnd = wordEnd; wordEnd = mWordIterator.following(wordEnd); if ((wordIteratorWindowEnd < end) && (wordEnd == BreakIterator.DONE || wordEnd >= wordIteratorWindowEnd)) { wordIteratorWindowEnd = Math.min(end, originalWordEnd + WORD_ITERATOR_INTERVAL); mWordIterator.setCharSequence( editable, originalWordEnd, wordIteratorWindowEnd); wordEnd = mWordIterator.following(originalWordEnd); } if (wordEnd == BreakIterator.DONE) break; wordStart = mWordIterator.getBeginning(wordEnd); if (wordStart == BreakIterator.DONE) { break; } } } if (scheduleOtherSpellCheck) { // Update range span: start new spell check from last wordStart setRangeSpan(editable, wordStart, end); } else { removeRangeSpan(editable); } spellCheck(); } private void removeSpansAt(Editable editable, int offset, T[] spans) { final int length = spans.length; for (int i = 0; i < length; i++) { final T span = spans[i]; final int start = editable.getSpanStart(span); if (start > offset) continue; final int end = editable.getSpanEnd(span); if (end < offset) continue; editable.removeSpan(span); } } } }