LatinIME/java/src/com/android/inputmethod/latin/RichInputConnection.java

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/*
* Copyright (C) 2012 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 com.android.inputmethod.latin;
import android.inputmethodservice.InputMethodService;
import android.text.TextUtils;
import android.util.Log;
import android.view.KeyEvent;
import android.view.inputmethod.CompletionInfo;
import android.view.inputmethod.CorrectionInfo;
import android.view.inputmethod.ExtractedText;
import android.view.inputmethod.ExtractedTextRequest;
import android.view.inputmethod.InputConnection;
import com.android.inputmethod.latin.define.ProductionFlag;
import com.android.inputmethod.research.ResearchLogger;
import java.util.Locale;
import java.util.regex.Pattern;
/**
* Enrichment class for InputConnection to simplify interaction and add functionality.
*
* This class serves as a wrapper to be able to simply add hooks to any calls to the underlying
* InputConnection. It also keeps track of a number of things to avoid having to call upon IPC
* all the time to find out what text is in the buffer, when we need it to determine caps mode
* for example.
*/
public final class RichInputConnection {
private static final String TAG = RichInputConnection.class.getSimpleName();
private static final boolean DBG = false;
private static final boolean DEBUG_PREVIOUS_TEXT = false;
private static final boolean DEBUG_BATCH_NESTING = false;
// Provision for a long word pair and a separator
private static final int LOOKBACK_CHARACTER_NUM = Constants.Dictionary.MAX_WORD_LENGTH * 2 + 1;
private static final Pattern spaceRegex = Pattern.compile("\\s+");
private static final int INVALID_CURSOR_POSITION = -1;
/**
* This variable contains the value LatinIME thinks the cursor position should be at now.
* This is a few steps in advance of what the TextView thinks it is, because TextView will
* only know after the IPC calls gets through.
*/
private int mCurrentCursorPosition = INVALID_CURSOR_POSITION; // in chars, not code points
/**
* This contains the committed text immediately preceding the cursor and the composing
* text if any. It is refreshed when the cursor moves by calling upon the TextView.
*/
private StringBuilder mCommittedTextBeforeComposingText = new StringBuilder();
/**
* This contains the currently composing text, as LatinIME thinks the TextView is seeing it.
*/
private StringBuilder mComposingText = new StringBuilder();
// A hint on how many characters to cache from the TextView. A good value of this is given by
// how many characters we need to be able to almost always find the caps mode.
private static final int DEFAULT_TEXT_CACHE_SIZE = 100;
private final InputMethodService mParent;
InputConnection mIC;
int mNestLevel;
public RichInputConnection(final InputMethodService parent) {
mParent = parent;
mIC = null;
mNestLevel = 0;
}
private void checkConsistencyForDebug() {
final ExtractedTextRequest r = new ExtractedTextRequest();
r.hintMaxChars = 0;
r.hintMaxLines = 0;
r.token = 1;
r.flags = 0;
final ExtractedText et = mIC.getExtractedText(r, 0);
final CharSequence beforeCursor = getTextBeforeCursor(DEFAULT_TEXT_CACHE_SIZE, 0);
final StringBuilder internal = new StringBuilder().append(mCommittedTextBeforeComposingText)
.append(mComposingText);
if (null == et || null == beforeCursor) return;
final int actualLength = Math.min(beforeCursor.length(), internal.length());
if (internal.length() > actualLength) {
internal.delete(0, internal.length() - actualLength);
}
final String reference = (beforeCursor.length() <= actualLength) ? beforeCursor.toString()
: beforeCursor.subSequence(beforeCursor.length() - actualLength,
beforeCursor.length()).toString();
if (et.selectionStart != mCurrentCursorPosition
|| !(reference.equals(internal.toString()))) {
final String context = "Expected cursor position = " + mCurrentCursorPosition
+ "\nActual cursor position = " + et.selectionStart
+ "\nExpected text = " + internal.length() + " " + internal
+ "\nActual text = " + reference.length() + " " + reference;
((LatinIME)mParent).debugDumpStateAndCrashWithException(context);
} else {
Log.e(TAG, Utils.getStackTrace(2));
Log.e(TAG, "Exp <> Actual : " + mCurrentCursorPosition + " <> " + et.selectionStart);
}
}
public void beginBatchEdit() {
if (++mNestLevel == 1) {
mIC = mParent.getCurrentInputConnection();
if (null != mIC) {
mIC.beginBatchEdit();
}
} else {
if (DBG) {
throw new RuntimeException("Nest level too deep");
} else {
Log.e(TAG, "Nest level too deep : " + mNestLevel);
}
}
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
}
public void endBatchEdit() {
if (mNestLevel <= 0) Log.e(TAG, "Batch edit not in progress!"); // TODO: exception instead
if (--mNestLevel == 0 && null != mIC) {
mIC.endBatchEdit();
}
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
}
public void resetCachesUponCursorMove(final int newCursorPosition) {
mCurrentCursorPosition = newCursorPosition;
mComposingText.setLength(0);
mCommittedTextBeforeComposingText.setLength(0);
final CharSequence textBeforeCursor = getTextBeforeCursor(DEFAULT_TEXT_CACHE_SIZE, 0);
if (null != textBeforeCursor) mCommittedTextBeforeComposingText.append(textBeforeCursor);
if (null != mIC) {
mIC.finishComposingText();
if (ProductionFlag.IS_EXPERIMENTAL) {
ResearchLogger.richInputConnection_finishComposingText();
}
}
}
private void checkBatchEdit() {
if (mNestLevel != 1) {
// TODO: exception instead
Log.e(TAG, "Batch edit level incorrect : " + mNestLevel);
Log.e(TAG, Utils.getStackTrace(4));
}
}
public void finishComposingText() {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
mCommittedTextBeforeComposingText.append(mComposingText);
mCurrentCursorPosition += mComposingText.length();
mComposingText.setLength(0);
if (null != mIC) {
mIC.finishComposingText();
if (ProductionFlag.IS_EXPERIMENTAL) {
ResearchLogger.richInputConnection_finishComposingText();
}
}
}
public void commitText(final CharSequence text, final int i) {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
mCommittedTextBeforeComposingText.append(text);
mCurrentCursorPosition += text.length() - mComposingText.length();
mComposingText.setLength(0);
if (null != mIC) {
mIC.commitText(text, i);
}
}
/**
* Gets the caps modes we should be in after this specific string.
*
* This returns a bit set of TextUtils#CAP_MODE_*, masked by the inputType argument.
* This method also supports faking an additional space after the string passed in argument,
* to support cases where a space will be added automatically, like in phantom space
* state for example.
* Note that for English, we are using American typography rules (which are not specific to
* American English, it's just the most common set of rules for English).
*
* @param inputType a mask of the caps modes to test for.
* @param locale what language should be considered.
* @param hasSpaceBefore if we should consider there should be a space after the string.
* @return the caps modes that should be on as a set of bits
*/
public int getCursorCapsMode(final int inputType, final Locale locale,
final boolean hasSpaceBefore) {
mIC = mParent.getCurrentInputConnection();
if (null == mIC) return Constants.TextUtils.CAP_MODE_OFF;
if (!TextUtils.isEmpty(mComposingText)) {
if (hasSpaceBefore) {
// If we have some composing text and a space before, then we should have
// MODE_CHARACTERS and MODE_WORDS on.
return (TextUtils.CAP_MODE_CHARACTERS | TextUtils.CAP_MODE_WORDS) & inputType;
} else {
// We have some composing text - we should be in MODE_CHARACTERS only.
return TextUtils.CAP_MODE_CHARACTERS & inputType;
}
}
// TODO: this will generally work, but there may be cases where the buffer contains SOME
// information but not enough to determine the caps mode accurately. This may happen after
// heavy pressing of delete, for example DEFAULT_TEXT_CACHE_SIZE - 5 times or so.
// getCapsMode should be updated to be able to return a "not enough info" result so that
// we can get more context only when needed.
if (TextUtils.isEmpty(mCommittedTextBeforeComposingText) && 0 != mCurrentCursorPosition) {
mCommittedTextBeforeComposingText.append(
getTextBeforeCursor(DEFAULT_TEXT_CACHE_SIZE, 0));
}
// This never calls InputConnection#getCapsMode - in fact, it's a static method that
// never blocks or initiates IPC.
return StringUtils.getCapsMode(mCommittedTextBeforeComposingText, inputType, locale,
hasSpaceBefore);
}
public int getCodePointBeforeCursor() {
if (mCommittedTextBeforeComposingText.length() < 1) return Constants.NOT_A_CODE;
return Character.codePointBefore(mCommittedTextBeforeComposingText,
mCommittedTextBeforeComposingText.length());
}
public CharSequence getTextBeforeCursor(final int i, final int j) {
// TODO: use mCommittedTextBeforeComposingText if possible to improve performance
mIC = mParent.getCurrentInputConnection();
if (null != mIC) return mIC.getTextBeforeCursor(i, j);
return null;
}
public CharSequence getTextAfterCursor(final int i, final int j) {
mIC = mParent.getCurrentInputConnection();
if (null != mIC) return mIC.getTextAfterCursor(i, j);
return null;
}
public void deleteSurroundingText(final int i, final int j) {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
final int remainingChars = mComposingText.length() - i;
if (remainingChars >= 0) {
mComposingText.setLength(remainingChars);
} else {
mComposingText.setLength(0);
// Never cut under 0
final int len = Math.max(mCommittedTextBeforeComposingText.length()
+ remainingChars, 0);
mCommittedTextBeforeComposingText.setLength(len);
}
if (mCurrentCursorPosition > i) {
mCurrentCursorPosition -= i;
} else {
mCurrentCursorPosition = 0;
}
if (null != mIC) {
mIC.deleteSurroundingText(i, j);
if (ProductionFlag.IS_EXPERIMENTAL) {
ResearchLogger.richInputConnection_deleteSurroundingText(i, j);
}
}
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
}
public void performEditorAction(final int actionId) {
mIC = mParent.getCurrentInputConnection();
if (null != mIC) {
mIC.performEditorAction(actionId);
if (ProductionFlag.IS_EXPERIMENTAL) {
ResearchLogger.richInputConnection_performEditorAction(actionId);
}
}
}
public void sendKeyEvent(final KeyEvent keyEvent) {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (keyEvent.getAction() == KeyEvent.ACTION_DOWN) {
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
// This method is only called for enter or backspace when speaking to old
// applications (target SDK <= 15), or for digits.
// When talking to new applications we never use this method because it's inherently
// racy and has unpredictable results, but for backward compatibility we continue
// sending the key events for only Enter and Backspace because some applications
// mistakenly catch them to do some stuff.
switch (keyEvent.getKeyCode()) {
case KeyEvent.KEYCODE_ENTER:
mCommittedTextBeforeComposingText.append("\n");
mCurrentCursorPosition += 1;
break;
case KeyEvent.KEYCODE_DEL:
if (0 == mComposingText.length()) {
if (mCommittedTextBeforeComposingText.length() > 0) {
mCommittedTextBeforeComposingText.delete(
mCommittedTextBeforeComposingText.length() - 1,
mCommittedTextBeforeComposingText.length());
}
} else {
mComposingText.delete(mComposingText.length() - 1, mComposingText.length());
}
if (mCurrentCursorPosition > 0) mCurrentCursorPosition -= 1;
break;
case KeyEvent.KEYCODE_UNKNOWN:
if (null != keyEvent.getCharacters()) {
mCommittedTextBeforeComposingText.append(keyEvent.getCharacters());
mCurrentCursorPosition += keyEvent.getCharacters().length();
}
break;
default:
final String text = new String(new int[] { keyEvent.getUnicodeChar() }, 0, 1);
mCommittedTextBeforeComposingText.append(text);
mCurrentCursorPosition += text.length();
break;
}
}
if (null != mIC) {
mIC.sendKeyEvent(keyEvent);
if (ProductionFlag.IS_EXPERIMENTAL) {
ResearchLogger.richInputConnection_sendKeyEvent(keyEvent);
}
}
}
public void setComposingRegion(final int start, final int end) {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
mCurrentCursorPosition = end;
final CharSequence textBeforeCursor =
getTextBeforeCursor(DEFAULT_TEXT_CACHE_SIZE + (end - start), 0);
final int indexOfStartOfComposingText =
Math.max(textBeforeCursor.length() - (end - start), 0);
mComposingText.append(textBeforeCursor.subSequence(indexOfStartOfComposingText,
textBeforeCursor.length()));
mCommittedTextBeforeComposingText.setLength(0);
mCommittedTextBeforeComposingText.append(
textBeforeCursor.subSequence(0, indexOfStartOfComposingText));
if (null != mIC) {
mIC.setComposingRegion(start, end);
}
}
public void setComposingText(final CharSequence text, final int i) {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
mCurrentCursorPosition += text.length() - mComposingText.length();
mComposingText.setLength(0);
mComposingText.append(text);
// TODO: support values of i != 1. At this time, this is never called with i != 1.
if (null != mIC) {
mIC.setComposingText(text, i);
if (ProductionFlag.IS_EXPERIMENTAL) {
ResearchLogger.richInputConnection_setComposingText(text, i);
}
}
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
}
public void setSelection(final int from, final int to) {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
if (null != mIC) {
mIC.setSelection(from, to);
if (ProductionFlag.IS_EXPERIMENTAL) {
ResearchLogger.richInputConnection_setSelection(from, to);
}
}
mCurrentCursorPosition = from;
mCommittedTextBeforeComposingText.setLength(0);
mCommittedTextBeforeComposingText.append(getTextBeforeCursor(DEFAULT_TEXT_CACHE_SIZE, 0));
}
public void commitCorrection(final CorrectionInfo correctionInfo) {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
// This has no effect on the text field and does not change its content. It only makes
// TextView flash the text for a second based on indices contained in the argument.
if (null != mIC) {
mIC.commitCorrection(correctionInfo);
}
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
}
public void commitCompletion(final CompletionInfo completionInfo) {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
final CharSequence text = completionInfo.getText();
mCommittedTextBeforeComposingText.append(text);
mCurrentCursorPosition += text.length() - mComposingText.length();
mComposingText.setLength(0);
if (null != mIC) {
mIC.commitCompletion(completionInfo);
if (ProductionFlag.IS_EXPERIMENTAL) {
ResearchLogger.richInputConnection_commitCompletion(completionInfo);
}
}
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
}
@SuppressWarnings("unused")
public String getNthPreviousWord(final String sentenceSeperators, final int n) {
mIC = mParent.getCurrentInputConnection();
if (null == mIC) return null;
final CharSequence prev = mIC.getTextBeforeCursor(LOOKBACK_CHARACTER_NUM, 0);
if (DEBUG_PREVIOUS_TEXT && null != prev) {
final int checkLength = LOOKBACK_CHARACTER_NUM - 1;
final String reference = prev.length() <= checkLength ? prev.toString()
: prev.subSequence(prev.length() - checkLength, prev.length()).toString();
final StringBuilder internal = new StringBuilder()
.append(mCommittedTextBeforeComposingText).append(mComposingText);
if (internal.length() > checkLength) {
internal.delete(0, internal.length() - checkLength);
if (!(reference.equals(internal.toString()))) {
final String context =
"Expected text = " + internal + "\nActual text = " + reference;
((LatinIME)mParent).debugDumpStateAndCrashWithException(context);
}
}
}
return getNthPreviousWord(prev, sentenceSeperators, n);
}
/**
* Represents a range of text, relative to the current cursor position.
*/
public static final class Range {
/** Characters before selection start */
public final int mCharsBefore;
/**
* Characters after selection start, including one trailing word
* separator.
*/
public final int mCharsAfter;
/** The actual characters that make up a word */
public final String mWord;
public Range(int charsBefore, int charsAfter, String word) {
if (charsBefore < 0 || charsAfter < 0) {
throw new IndexOutOfBoundsException();
}
this.mCharsBefore = charsBefore;
this.mCharsAfter = charsAfter;
this.mWord = word;
}
}
private static boolean isSeparator(int code, String sep) {
return sep.indexOf(code) != -1;
}
// Get the nth word before cursor. n = 1 retrieves the word immediately before the cursor,
// n = 2 retrieves the word before that, and so on. This splits on whitespace only.
// Also, it won't return words that end in a separator (if the nth word before the cursor
// ends in a separator, it returns null).
// Example :
// (n = 1) "abc def|" -> def
// (n = 1) "abc def |" -> def
// (n = 1) "abc def. |" -> null
// (n = 1) "abc def . |" -> null
// (n = 2) "abc def|" -> abc
// (n = 2) "abc def |" -> abc
// (n = 2) "abc def. |" -> abc
// (n = 2) "abc def . |" -> def
// (n = 2) "abc|" -> null
// (n = 2) "abc |" -> null
// (n = 2) "abc. def|" -> null
public static String getNthPreviousWord(final CharSequence prev,
final String sentenceSeperators, final int n) {
if (prev == null) return null;
final String[] w = spaceRegex.split(prev);
// If we can't find n words, or we found an empty word, return null.
if (w.length < n) return null;
final String nthPrevWord = w[w.length - n];
final int length = nthPrevWord.length();
if (length <= 0) return null;
// If ends in a separator, return null
final char lastChar = nthPrevWord.charAt(length - 1);
if (sentenceSeperators.contains(String.valueOf(lastChar))) return null;
return nthPrevWord;
}
/**
* @param separators characters which may separate words
* @return the word that surrounds the cursor, including up to one trailing
* separator. For example, if the field contains "he|llo world", where |
* represents the cursor, then "hello " will be returned.
*/
public String getWordAtCursor(String separators) {
// getWordRangeAtCursor returns null if the connection is null
Range r = getWordRangeAtCursor(separators, 0);
return (r == null) ? null : r.mWord;
}
private int getCursorPosition() {
mIC = mParent.getCurrentInputConnection();
if (null == mIC) return INVALID_CURSOR_POSITION;
final ExtractedText extracted = mIC.getExtractedText(new ExtractedTextRequest(), 0);
if (extracted == null) {
return INVALID_CURSOR_POSITION;
}
return extracted.startOffset + extracted.selectionStart;
}
/**
* Returns the text surrounding the cursor.
*
* @param sep a string of characters that split words.
* @param additionalPrecedingWordsCount the number of words before the current word that should
* be included in the returned range
* @return a range containing the text surrounding the cursor
*/
public Range getWordRangeAtCursor(final String sep, final int additionalPrecedingWordsCount) {
mIC = mParent.getCurrentInputConnection();
if (mIC == null || sep == null) {
return null;
}
final CharSequence before = mIC.getTextBeforeCursor(1000, 0);
final CharSequence after = mIC.getTextAfterCursor(1000, 0);
if (before == null || after == null) {
return null;
}
// Going backward, alternate skipping non-separators and separators until enough words
// have been read.
int count = additionalPrecedingWordsCount;
int start = before.length();
boolean isStoppingAtWhitespace = true; // toggles to indicate what to stop at
while (true) { // see comments below for why this is guaranteed to halt
while (start > 0) {
final int codePoint = Character.codePointBefore(before, start);
if (isStoppingAtWhitespace == isSeparator(codePoint, sep)) {
break; // inner loop
}
--start;
if (Character.isSupplementaryCodePoint(codePoint)) {
--start;
}
}
// isStoppingAtWhitespace is true every other time through the loop,
// so additionalPrecedingWordsCount is guaranteed to become < 0, which
// guarantees outer loop termination
if (isStoppingAtWhitespace && (--count < 0)) {
break; // outer loop
}
isStoppingAtWhitespace = !isStoppingAtWhitespace;
}
// Find last word separator after the cursor
int end = -1;
while (++end < after.length()) {
final int codePoint = Character.codePointAt(after, end);
if (isSeparator(codePoint, sep)) {
break;
}
if (Character.isSupplementaryCodePoint(codePoint)) {
++end;
}
}
final int cursor = getCursorPosition();
if (start >= 0 && cursor + end <= after.length() + before.length()) {
String word = before.toString().substring(start, before.length())
+ after.toString().substring(0, end);
return new Range(before.length() - start, end, word);
}
return null;
}
public boolean isCursorTouchingWord(final SettingsValues settingsValues) {
final CharSequence before = getTextBeforeCursor(1, 0);
final CharSequence after = getTextAfterCursor(1, 0);
if (!TextUtils.isEmpty(before) && !settingsValues.isWordSeparator(before.charAt(0))
&& !settingsValues.isSymbolExcludedFromWordSeparators(before.charAt(0))) {
return true;
}
if (!TextUtils.isEmpty(after) && !settingsValues.isWordSeparator(after.charAt(0))
&& !settingsValues.isSymbolExcludedFromWordSeparators(after.charAt(0))) {
return true;
}
return false;
}
public void removeTrailingSpace() {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
final CharSequence lastOne = getTextBeforeCursor(1, 0);
if (lastOne != null && lastOne.length() == 1
&& lastOne.charAt(0) == Constants.CODE_SPACE) {
deleteSurroundingText(1, 0);
}
}
public boolean sameAsTextBeforeCursor(final CharSequence text) {
final CharSequence beforeText = getTextBeforeCursor(text.length(), 0);
return TextUtils.equals(text, beforeText);
}
/* (non-javadoc)
* Returns the word before the cursor if the cursor is at the end of a word, null otherwise
*/
public CharSequence getWordBeforeCursorIfAtEndOfWord(final SettingsValues settings) {
// Bail out if the cursor is in the middle of a word (cursor must be followed by whitespace,
// separator or end of line/text)
// Example: "test|"<EOL> "te|st" get rejected here
final CharSequence textAfterCursor = getTextAfterCursor(1, 0);
if (!TextUtils.isEmpty(textAfterCursor)
&& !settings.isWordSeparator(textAfterCursor.charAt(0))) return null;
// Bail out if word before cursor is 0-length or a single non letter (like an apostrophe)
// Example: " -|" gets rejected here but "e-|" and "e|" are okay
CharSequence word = getWordAtCursor(settings.mWordSeparators);
// We don't suggest on leading single quotes, so we have to remove them from the word if
// it starts with single quotes.
while (!TextUtils.isEmpty(word) && Constants.CODE_SINGLE_QUOTE == word.charAt(0)) {
word = word.subSequence(1, word.length());
}
if (TextUtils.isEmpty(word)) return null;
// Find the last code point of the string
final int lastCodePoint = Character.codePointBefore(word, word.length());
// If for some reason the text field contains non-unicode binary data, or if the
// charsequence is exactly one char long and the contents is a low surrogate, return null.
if (!Character.isDefined(lastCodePoint)) return null;
// Bail out if the cursor is not at the end of a word (cursor must be preceded by
// non-whitespace, non-separator, non-start-of-text)
// Example ("|" is the cursor here) : <SOL>"|a" " |a" " | " all get rejected here.
if (settings.isWordSeparator(lastCodePoint)) return null;
final char firstChar = word.charAt(0); // we just tested that word is not empty
if (word.length() == 1 && !Character.isLetter(firstChar)) return null;
// We only suggest on words that start with a letter or a symbol that is excluded from
// word separators (see #handleCharacterWhileInBatchEdit).
if (!(Character.isLetter(firstChar)
|| settings.isSymbolExcludedFromWordSeparators(firstChar))) {
return null;
}
return word;
}
public boolean revertDoubleSpace() {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
// Here we test whether we indeed have a period and a space before us. This should not
// be needed, but it's there just in case something went wrong.
final CharSequence textBeforeCursor = getTextBeforeCursor(2, 0);
if (!". ".equals(textBeforeCursor)) {
// Theoretically we should not be coming here if there isn't ". " before the
// cursor, but the application may be changing the text while we are typing, so
// anything goes. We should not crash.
Log.d(TAG, "Tried to revert double-space combo but we didn't find "
+ "\". \" just before the cursor.");
return false;
}
deleteSurroundingText(2, 0);
final String doubleSpace = " ";
commitText(doubleSpace, 1);
if (ProductionFlag.IS_EXPERIMENTAL) {
ResearchLogger.getInstance().onWordComplete(doubleSpace, Long.MAX_VALUE);
}
return true;
}
public boolean revertSwapPunctuation() {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
// Here we test whether we indeed have a space and something else before us. This should not
// be needed, but it's there just in case something went wrong.
final CharSequence textBeforeCursor = getTextBeforeCursor(2, 0);
// NOTE: This does not work with surrogate pairs. Hopefully when the keyboard is able to
// enter surrogate pairs this code will have been removed.
if (TextUtils.isEmpty(textBeforeCursor)
|| (Constants.CODE_SPACE != textBeforeCursor.charAt(1))) {
// We may only come here if the application is changing the text while we are typing.
// This is quite a broken case, but not logically impossible, so we shouldn't crash,
// but some debugging log may be in order.
Log.d(TAG, "Tried to revert a swap of punctuation but we didn't "
+ "find a space just before the cursor.");
return false;
}
deleteSurroundingText(2, 0);
final String text = " " + textBeforeCursor.subSequence(0, 1);
commitText(text, 1);
if (ProductionFlag.IS_EXPERIMENTAL) {
ResearchLogger.getInstance().onWordComplete(text, Long.MAX_VALUE);
}
return true;
}
/**
* Heuristic to determine if this is an expected update of the cursor.
*
* Sometimes updates to the cursor position are late because of their asynchronous nature.
* This method tries to determine if this update is one, based on the values of the cursor
* position in the update, and the currently expected position of the cursor according to
* LatinIME's internal accounting. If this is not a belated expected update, then it should
* mean that the user moved the cursor explicitly.
* This is quite robust, but of course it's not perfect. In particular, it will fail in the
* case we get an update A, the user types in N characters so as to move the cursor to A+N but
* we don't get those, and then the user places the cursor between A and A+N, and we get only
* this update and not the ones in-between. This is almost impossible to achieve even trying
* very very hard.
*
* @param oldSelStart The value of the old cursor position in the update.
* @param newSelStart The value of the new cursor position in the update.
* @return whether this is a belated expected update or not.
*/
public boolean isBelatedExpectedUpdate(final int oldSelStart, final int newSelStart) {
// If this is an update that arrives at our expected position, it's a belated update.
if (newSelStart == mCurrentCursorPosition) return true;
// If this is an update that moves the cursor from our expected position, it must be
// an explicit move.
if (oldSelStart == mCurrentCursorPosition) return false;
// The following returns true if newSelStart is between oldSelStart and
// mCurrentCursorPosition. We assume that if the updated position is between the old
// position and the expected position, then it must be a belated update.
return (newSelStart - oldSelStart) * (mCurrentCursorPosition - newSelStart) >= 0;
}
}