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

898 lines
43 KiB
Java

/*
* 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.latin.settings.SpacingAndPunctuations;
import com.android.inputmethod.latin.utils.CapsModeUtils;
import com.android.inputmethod.latin.utils.DebugLogUtils;
import com.android.inputmethod.latin.utils.SpannableStringUtils;
import com.android.inputmethod.latin.utils.StringUtils;
import com.android.inputmethod.latin.utils.TextRange;
import com.android.inputmethod.research.ResearchLogger;
import java.util.Arrays;
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 an expected value for the selection start position. This is where the
* cursor or selection start may end up after all the keyboard-triggered updates have passed. We
* keep this to compare it to the actual selection start to guess whether the move was caused by
* a keyboard command or not.
* It's not really the selection start position: the selection start may not be there yet, and
* in some cases, it may never arrive there.
*/
private int mExpectedSelStart = INVALID_CURSOR_POSITION; // in chars, not code points
/**
* The expected selection end. Only differs from mExpectedSelStart if a non-empty selection is
* expected. The same caveats as mExpectedSelStart apply.
*/
private int mExpectedSelEnd = 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 final StringBuilder mCommittedTextBeforeComposingText = new StringBuilder();
/**
* This contains the currently composing text, as LatinIME thinks the TextView is seeing it.
*/
private final StringBuilder mComposingText = new StringBuilder();
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(Constants.EDITOR_CONTENTS_CACHE_SIZE,
0);
final StringBuilder internal = new StringBuilder(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 != mExpectedSelStart
|| !(reference.equals(internal.toString()))) {
final String context = "Expected selection start = " + mExpectedSelStart
+ "\nActual selection start = " + et.selectionStart
+ "\nExpected text = " + internal.length() + " " + internal
+ "\nActual text = " + reference.length() + " " + reference;
((LatinIME)mParent).debugDumpStateAndCrashWithException(context);
} else {
Log.e(TAG, DebugLogUtils.getStackTrace(2));
Log.e(TAG, "Exp <> Actual : " + mExpectedSelStart + " <> " + 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();
}
/**
* Reset the cached text and retrieve it again from the editor.
*
* This should be called when the cursor moved. It's possible that we can't connect to
* the application when doing this; notably, this happens sometimes during rotation, probably
* because of a race condition in the framework. In this case, we just can't retrieve the
* data, so we empty the cache and note that we don't know the new cursor position, and we
* return false so that the caller knows about this and can retry later.
*
* @param newSelStart the new position of the selection start, as received from the system.
* @param newSelEnd the new position of the selection end, as received from the system.
* @param shouldFinishComposition whether we should finish the composition in progress.
* @return true if we were able to connect to the editor successfully, false otherwise. When
* this method returns false, the caches could not be correctly refreshed so they were only
* reset: the caller should try again later to return to normal operation.
*/
public boolean resetCachesUponCursorMoveAndReturnSuccess(final int newSelStart,
final int newSelEnd, final boolean shouldFinishComposition) {
mExpectedSelStart = newSelStart;
mExpectedSelEnd = newSelEnd;
mComposingText.setLength(0);
final boolean didReloadTextSuccessfully = reloadTextCache();
if (!didReloadTextSuccessfully) {
Log.d(TAG, "Will try to retrieve text later.");
return false;
}
if (null != mIC && shouldFinishComposition) {
mIC.finishComposingText();
if (ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
ResearchLogger.richInputConnection_finishComposingText();
}
}
return true;
}
/**
* Reload the cached text from the InputConnection.
*
* @return true if successful
*/
private boolean reloadTextCache() {
mCommittedTextBeforeComposingText.setLength(0);
mIC = mParent.getCurrentInputConnection();
// Call upon the inputconnection directly since our own method is using the cache, and
// we want to refresh it.
final CharSequence textBeforeCursor = null == mIC ? null :
mIC.getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE, 0);
if (null == textBeforeCursor) {
// For some reason the app thinks we are not connected to it. This looks like a
// framework bug... Fall back to ground state and return false.
mExpectedSelStart = INVALID_CURSOR_POSITION;
mExpectedSelEnd = INVALID_CURSOR_POSITION;
Log.e(TAG, "Unable to connect to the editor to retrieve text.");
return false;
}
mCommittedTextBeforeComposingText.append(textBeforeCursor);
return true;
}
private void checkBatchEdit() {
if (mNestLevel != 1) {
// TODO: exception instead
Log.e(TAG, "Batch edit level incorrect : " + mNestLevel);
Log.e(TAG, DebugLogUtils.getStackTrace(4));
}
}
public void finishComposingText() {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
// TODO: this is not correct! The cursor is not necessarily after the composing text.
// In the practice right now this is only called when input ends so it will be reset so
// it works, but it's wrong and should be fixed.
mCommittedTextBeforeComposingText.append(mComposingText);
mComposingText.setLength(0);
if (null != mIC) {
mIC.finishComposingText();
if (ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
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);
// TODO: the following is exceedingly error-prone. Right now when the cursor is in the
// middle of the composing word mComposingText only holds the part of the composing text
// that is before the cursor, so this actually works, but it's terribly confusing. Fix this.
mExpectedSelStart += text.length() - mComposingText.length();
mExpectedSelEnd = mExpectedSelStart;
mComposingText.setLength(0);
if (null != mIC) {
mIC.commitText(text, i);
}
}
public CharSequence getSelectedText(final int flags) {
return (null == mIC) ? null : mIC.getSelectedText(flags);
}
public boolean canDeleteCharacters() {
return mExpectedSelStart > 0;
}
/**
* 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 spacingAndPunctuations the values of the settings to use for locale and separators.
* @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 SpacingAndPunctuations spacingAndPunctuations, 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 != mExpectedSelStart) {
if (!reloadTextCache()) {
Log.w(TAG, "Unable to connect to the editor. "
+ "Setting caps mode without knowing text.");
}
}
// This never calls InputConnection#getCapsMode - in fact, it's a static method that
// never blocks or initiates IPC.
return CapsModeUtils.getCapsMode(mCommittedTextBeforeComposingText, inputType,
spacingAndPunctuations, hasSpaceBefore);
}
public int getCodePointBeforeCursor() {
final int length = mCommittedTextBeforeComposingText.length();
if (length < 1) return Constants.NOT_A_CODE;
return Character.codePointBefore(mCommittedTextBeforeComposingText, length);
}
public CharSequence getTextBeforeCursor(final int n, final int flags) {
final int cachedLength =
mCommittedTextBeforeComposingText.length() + mComposingText.length();
// If we have enough characters to satisfy the request, or if we have all characters in
// the text field, then we can return the cached version right away.
// However, if we don't have an expected cursor position, then we should always
// go fetch the cache again (as it happens, INVALID_CURSOR_POSITION < 0, so we need to
// test for this explicitly)
if (INVALID_CURSOR_POSITION != mExpectedSelStart
&& (cachedLength >= n || cachedLength >= mExpectedSelStart)) {
final StringBuilder s = new StringBuilder(mCommittedTextBeforeComposingText);
// We call #toString() here to create a temporary object.
// In some situations, this method is called on a worker thread, and it's possible
// the main thread touches the contents of mComposingText while this worker thread
// is suspended, because mComposingText is a StringBuilder. This may lead to crashes,
// so we call #toString() on it. That will result in the return value being strictly
// speaking wrong, but since this is used for basing bigram probability off, and
// it's only going to matter for one getSuggestions call, it's fine in the practice.
s.append(mComposingText.toString());
if (s.length() > n) {
s.delete(0, s.length() - n);
}
return s;
}
mIC = mParent.getCurrentInputConnection();
return (null == mIC) ? null : mIC.getTextBeforeCursor(n, flags);
}
public CharSequence getTextAfterCursor(final int n, final int flags) {
mIC = mParent.getCurrentInputConnection();
return (null == mIC) ? null : mIC.getTextAfterCursor(n, flags);
}
public void deleteSurroundingText(final int beforeLength, final int afterLength) {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
// TODO: the following is incorrect if the cursor is not immediately after the composition.
// Right now we never come here in this case because we reset the composing state before we
// come here in this case, but we need to fix this.
final int remainingChars = mComposingText.length() - beforeLength;
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 (mExpectedSelStart > beforeLength) {
mExpectedSelStart -= beforeLength;
mExpectedSelEnd -= beforeLength;
} else {
// There are fewer characters before the cursor in the buffer than we are being asked to
// delete. Only delete what is there, and update the end with the amount deleted.
mExpectedSelEnd -= mExpectedSelStart;
mExpectedSelStart = 0;
}
if (null != mIC) {
mIC.deleteSurroundingText(beforeLength, afterLength);
if (ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
ResearchLogger.richInputConnection_deleteSurroundingText(beforeLength, afterLength);
}
}
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
}
public void performEditorAction(final int actionId) {
mIC = mParent.getCurrentInputConnection();
if (null != mIC) {
mIC.performEditorAction(actionId);
if (ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
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 (Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1)), 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");
mExpectedSelStart += 1;
mExpectedSelEnd = mExpectedSelStart;
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 (mExpectedSelStart > 0 && mExpectedSelStart == mExpectedSelEnd) {
// TODO: Handle surrogate pairs.
mExpectedSelStart -= 1;
}
mExpectedSelEnd = mExpectedSelStart;
break;
case KeyEvent.KEYCODE_UNKNOWN:
if (null != keyEvent.getCharacters()) {
mCommittedTextBeforeComposingText.append(keyEvent.getCharacters());
mExpectedSelStart += keyEvent.getCharacters().length();
mExpectedSelEnd = mExpectedSelStart;
}
break;
default:
final String text = StringUtils.newSingleCodePointString(keyEvent.getUnicodeChar());
mCommittedTextBeforeComposingText.append(text);
mExpectedSelStart += text.length();
mExpectedSelEnd = mExpectedSelStart;
break;
}
}
if (null != mIC) {
mIC.sendKeyEvent(keyEvent);
if (ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
ResearchLogger.richInputConnection_sendKeyEvent(keyEvent);
}
}
}
public void setComposingRegion(final int start, final int end) {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
final CharSequence textBeforeCursor =
getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE + (end - start), 0);
mCommittedTextBeforeComposingText.setLength(0);
if (!TextUtils.isEmpty(textBeforeCursor)) {
// The cursor is not necessarily at the end of the composing text, but we have its
// position in mExpectedSelStart and mExpectedSelEnd. In this case we want the start
// of the text, so we should use mExpectedSelStart. In other words, the composing
// text starts (mExpectedSelStart - start) characters before the end of textBeforeCursor
final int indexOfStartOfComposingText =
Math.max(textBeforeCursor.length() - (mExpectedSelStart - start), 0);
mComposingText.append(textBeforeCursor.subSequence(indexOfStartOfComposingText,
textBeforeCursor.length()));
mCommittedTextBeforeComposingText.append(
textBeforeCursor.subSequence(0, indexOfStartOfComposingText));
}
if (null != mIC) {
mIC.setComposingRegion(start, end);
}
}
public void setComposingText(final CharSequence text, final int newCursorPosition) {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
mExpectedSelStart += text.length() - mComposingText.length();
mExpectedSelEnd = mExpectedSelStart;
mComposingText.setLength(0);
mComposingText.append(text);
// TODO: support values of newCursorPosition != 1. At this time, this is never called with
// newCursorPosition != 1.
if (null != mIC) {
mIC.setComposingText(text, newCursorPosition);
if (ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
ResearchLogger.richInputConnection_setComposingText(text, newCursorPosition);
}
}
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
}
/**
* Set the selection of the text editor.
*
* Calls through to {@link InputConnection#setSelection(int, int)}.
*
* @param start the character index where the selection should start.
* @param end the character index where the selection should end.
* @return Returns true on success, false on failure: either the input connection is no longer
* valid when setting the selection or when retrieving the text cache at that point, or
* invalid arguments were passed.
*/
public boolean setSelection(final int start, final int end) {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
if (start < 0 || end < 0) {
return false;
}
mExpectedSelStart = start;
mExpectedSelEnd = end;
if (null != mIC) {
final boolean isIcValid = mIC.setSelection(start, end);
if (!isIcValid) {
return false;
}
if (ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
ResearchLogger.richInputConnection_setSelection(start, end);
}
}
return reloadTextCache();
}
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();
CharSequence text = completionInfo.getText();
// text should never be null, but just in case, it's better to insert nothing than to crash
if (null == text) text = "";
mCommittedTextBeforeComposingText.append(text);
mExpectedSelStart += text.length() - mComposingText.length();
mExpectedSelEnd = mExpectedSelStart;
mComposingText.setLength(0);
if (null != mIC) {
mIC.commitCompletion(completionInfo);
if (ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
ResearchLogger.richInputConnection_commitCompletion(completionInfo);
}
}
if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug();
}
@SuppressWarnings("unused")
public String getNthPreviousWord(final SpacingAndPunctuations spacingAndPunctuations,
final int n) {
mIC = mParent.getCurrentInputConnection();
if (null == mIC) return null;
final CharSequence prev = 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();
// TODO: right now the following works because mComposingText holds the part of the
// composing text that is before the cursor, but this is very confusing. We should
// fix it.
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, spacingAndPunctuations, n);
}
private static boolean isSeparator(final int code, final int[] sortedSeparators) {
return Arrays.binarySearch(sortedSeparators, code) >= 0;
}
// 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 SpacingAndPunctuations spacingAndPunctuations, 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 (spacingAndPunctuations.isWordSeparator(lastChar)
|| spacingAndPunctuations.isWordConnector(lastChar)) return null;
return nthPrevWord;
}
/**
* @param sortedSeparators a sorted array of code points 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 CharSequence getWordAtCursor(final int[] sortedSeparators) {
// getWordRangeAtCursor returns null if the connection is null
final TextRange r = getWordRangeAtCursor(sortedSeparators, 0);
return (r == null) ? null : r.mWord;
}
/**
* Returns the text surrounding the cursor.
*
* @param sortedSeparators a sorted array of code points 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 TextRange getWordRangeAtCursor(final int[] sortedSeparators,
final int additionalPrecedingWordsCount) {
mIC = mParent.getCurrentInputConnection();
if (mIC == null) {
return null;
}
final CharSequence before = mIC.getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE,
InputConnection.GET_TEXT_WITH_STYLES);
final CharSequence after = mIC.getTextAfterCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE,
InputConnection.GET_TEXT_WITH_STYLES);
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 startIndexInBefore = 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 (startIndexInBefore > 0) {
final int codePoint = Character.codePointBefore(before, startIndexInBefore);
if (isStoppingAtWhitespace == isSeparator(codePoint, sortedSeparators)) {
break; // inner loop
}
--startIndexInBefore;
if (Character.isSupplementaryCodePoint(codePoint)) {
--startIndexInBefore;
}
}
// 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 endIndexInAfter = -1;
while (++endIndexInAfter < after.length()) {
final int codePoint = Character.codePointAt(after, endIndexInAfter);
if (isSeparator(codePoint, sortedSeparators)) {
break;
}
if (Character.isSupplementaryCodePoint(codePoint)) {
++endIndexInAfter;
}
}
final boolean hasUrlSpans =
SpannableStringUtils.hasUrlSpans(before, startIndexInBefore, before.length())
|| SpannableStringUtils.hasUrlSpans(after, 0, endIndexInAfter);
// We don't use TextUtils#concat because it copies all spans without respect to their
// nature. If the text includes a PARAGRAPH span and it has been split, then
// TextUtils#concat will crash when it tries to concat both sides of it.
return new TextRange(
SpannableStringUtils.concatWithNonParagraphSuggestionSpansOnly(before, after),
startIndexInBefore, before.length() + endIndexInAfter, before.length(),
hasUrlSpans);
}
public boolean isCursorTouchingWord(final SpacingAndPunctuations spacingAndPunctuations) {
if (isCursorFollowedByWordCharacter(spacingAndPunctuations)) {
// If what's after the cursor is a word character, then we're touching a word.
return true;
}
final String textBeforeCursor = mCommittedTextBeforeComposingText.toString();
int indexOfCodePointInJavaChars = textBeforeCursor.length();
int consideredCodePoint = 0 == indexOfCodePointInJavaChars ? Constants.NOT_A_CODE
: textBeforeCursor.codePointBefore(indexOfCodePointInJavaChars);
// Search for the first non word-connector char
if (spacingAndPunctuations.isWordConnector(consideredCodePoint)) {
indexOfCodePointInJavaChars -= Character.charCount(consideredCodePoint);
consideredCodePoint = 0 == indexOfCodePointInJavaChars ? Constants.NOT_A_CODE
: textBeforeCursor.codePointBefore(indexOfCodePointInJavaChars);
}
return !(Constants.NOT_A_CODE == consideredCodePoint
|| spacingAndPunctuations.isWordSeparator(consideredCodePoint)
|| spacingAndPunctuations.isWordConnector(consideredCodePoint));
}
public boolean isCursorFollowedByWordCharacter(
final SpacingAndPunctuations spacingAndPunctuations) {
final CharSequence after = getTextAfterCursor(1, 0);
if (TextUtils.isEmpty(after)) {
return false;
}
final int codePointAfterCursor = Character.codePointAt(after, 0);
if (spacingAndPunctuations.isWordSeparator(codePointAfterCursor)
|| spacingAndPunctuations.isWordConnector(codePointAfterCursor)) {
return false;
}
return true;
}
public void removeTrailingSpace() {
if (DEBUG_BATCH_NESTING) checkBatchEdit();
final int codePointBeforeCursor = getCodePointBeforeCursor();
if (Constants.CODE_SPACE == codePointBeforeCursor) {
deleteSurroundingText(1, 0);
}
}
public boolean sameAsTextBeforeCursor(final CharSequence text) {
final CharSequence beforeText = getTextBeforeCursor(text.length(), 0);
return TextUtils.equals(text, beforeText);
}
public boolean revertDoubleSpacePeriod() {
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);
final String periodSpace = ". ";
if (!TextUtils.equals(periodSpace, 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 "
+ "\"" + periodSpace + "\" just before the cursor.");
return false;
}
// Double-space results in ". ". A backspace to cancel this should result in a single
// space in the text field, so we replace ". " with a single space.
deleteSurroundingText(2, 0);
final String singleSpace = " ";
commitText(singleSpace, 1);
if (ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
ResearchLogger.richInputConnection_revertDoubleSpacePeriod();
}
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.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
ResearchLogger.richInputConnection_revertSwapPunctuation();
}
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 selection in the update.
* @param newSelStart The value of the new selection in the update.
* @param oldSelEnd The value of the old selection end in the update.
* @param newSelEnd The value of the new selection end in the update.
* @return whether this is a belated expected update or not.
*/
public boolean isBelatedExpectedUpdate(final int oldSelStart, final int newSelStart,
final int oldSelEnd, final int newSelEnd) {
// This update is "belated" if we are expecting it. That is, mExpectedSelStart and
// mExpectedSelEnd match the new values that the TextView is updating TO.
if (mExpectedSelStart == newSelStart && mExpectedSelEnd == newSelEnd) return true;
// This update is not belated if mExpectedSelStart and mExpectedSelEnd match the old
// values, and one of newSelStart or newSelEnd is updated to a different value. In this
// case, it is likely that something other than the IME has moved the selection endpoint
// to the new value.
if (mExpectedSelStart == oldSelStart && mExpectedSelEnd == oldSelEnd
&& (oldSelStart != newSelStart || oldSelEnd != newSelEnd)) return false;
// If neither of the above two cases hold, then the system may be having trouble keeping up
// with updates. If 1) the selection is a cursor, 2) newSelStart is between oldSelStart
// and mExpectedSelStart, and 3) newSelEnd is between oldSelEnd and mExpectedSelEnd, then
// assume a belated update.
return (newSelStart == newSelEnd)
&& (newSelStart - oldSelStart) * (mExpectedSelStart - newSelStart) >= 0
&& (newSelEnd - oldSelEnd) * (mExpectedSelEnd - newSelEnd) >= 0;
}
/**
* Looks at the text just before the cursor to find out if it looks like a URL.
*
* The weakest point here is, if we don't have enough text bufferized, we may fail to realize
* we are in URL situation, but other places in this class have the same limitation and it
* does not matter too much in the practice.
*/
public boolean textBeforeCursorLooksLikeURL() {
return StringUtils.lastPartLooksLikeURL(mCommittedTextBeforeComposingText);
}
/**
* Looks at the text just before the cursor to find out if we are inside a double quote.
*
* As with #textBeforeCursorLooksLikeURL, this is dependent on how much text we have cached.
* However this won't be a concrete problem in most situations, as the cache is almost always
* long enough for this use.
*/
public boolean isInsideDoubleQuoteOrAfterDigit() {
return StringUtils.isInsideDoubleQuoteOrAfterDigit(mCommittedTextBeforeComposingText);
}
/**
* Try to get the text from the editor to expose lies the framework may have been
* telling us. Concretely, when the device rotates, the frameworks tells us about where the
* cursor used to be initially in the editor at the time it first received the focus; this
* may be completely different from the place it is upon rotation. Since we don't have any
* means to get the real value, try at least to ask the text view for some characters and
* detect the most damaging cases: when the cursor position is declared to be much smaller
* than it really is.
*/
public void tryFixLyingCursorPosition() {
final CharSequence textBeforeCursor = getTextBeforeCursor(
Constants.EDITOR_CONTENTS_CACHE_SIZE, 0);
if (null == textBeforeCursor) {
mExpectedSelStart = mExpectedSelEnd = Constants.NOT_A_CURSOR_POSITION;
} else {
final int textLength = textBeforeCursor.length();
if (textLength < Constants.EDITOR_CONTENTS_CACHE_SIZE
&& (textLength > mExpectedSelStart
|| mExpectedSelStart < Constants.EDITOR_CONTENTS_CACHE_SIZE)) {
// It should not be possible to have only one of those variables be
// NOT_A_CURSOR_POSITION, so if they are equal, either the selection is zero-sized
// (simple cursor, no selection) or there is no cursor/we don't know its pos
final boolean wasEqual = mExpectedSelStart == mExpectedSelEnd;
mExpectedSelStart = textLength;
// We can't figure out the value of mLastSelectionEnd :(
// But at least if it's smaller than mLastSelectionStart something is wrong,
// and if they used to be equal we also don't want to make it look like there is a
// selection.
if (wasEqual || mExpectedSelStart > mExpectedSelEnd) {
mExpectedSelEnd = mExpectedSelStart;
}
}
}
}
public int getExpectedSelectionStart() {
return mExpectedSelStart;
}
public int getExpectedSelectionEnd() {
return mExpectedSelEnd;
}
/**
* @return whether there is a selection currently active.
*/
public boolean hasSelection() {
return mExpectedSelEnd != mExpectedSelStart;
}
}