1 /* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.inputmethod.latin; 18 19 import android.graphics.Color; 20 import android.inputmethodservice.InputMethodService; 21 import android.os.Build; 22 import android.text.SpannableStringBuilder; 23 import android.text.Spanned; 24 import android.text.TextUtils; 25 import android.text.style.BackgroundColorSpan; 26 import android.util.Log; 27 import android.view.KeyEvent; 28 import android.view.inputmethod.CompletionInfo; 29 import android.view.inputmethod.CorrectionInfo; 30 import android.view.inputmethod.ExtractedText; 31 import android.view.inputmethod.ExtractedTextRequest; 32 import android.view.inputmethod.InputConnection; 33 import android.view.inputmethod.InputMethodManager; 34 35 import com.android.inputmethod.compat.InputConnectionCompatUtils; 36 import com.android.inputmethod.latin.settings.SpacingAndPunctuations; 37 import com.android.inputmethod.latin.utils.CapsModeUtils; 38 import com.android.inputmethod.latin.utils.DebugLogUtils; 39 import com.android.inputmethod.latin.utils.PrevWordsInfoUtils; 40 import com.android.inputmethod.latin.utils.ScriptUtils; 41 import com.android.inputmethod.latin.utils.SpannableStringUtils; 42 import com.android.inputmethod.latin.utils.StringUtils; 43 import com.android.inputmethod.latin.utils.TextRange; 44 45 import java.util.Arrays; 46 47 /** 48 * Enrichment class for InputConnection to simplify interaction and add functionality. 49 * 50 * This class serves as a wrapper to be able to simply add hooks to any calls to the underlying 51 * InputConnection. It also keeps track of a number of things to avoid having to call upon IPC 52 * all the time to find out what text is in the buffer, when we need it to determine caps mode 53 * for example. 54 */ 55 public final class RichInputConnection { 56 private static final String TAG = RichInputConnection.class.getSimpleName(); 57 private static final boolean DBG = false; 58 private static final boolean DEBUG_PREVIOUS_TEXT = false; 59 private static final boolean DEBUG_BATCH_NESTING = false; 60 // Provision for long words and separators between the words. 61 private static final int LOOKBACK_CHARACTER_NUM = Constants.DICTIONARY_MAX_WORD_LENGTH 62 * (Constants.MAX_PREV_WORD_COUNT_FOR_N_GRAM + 1) /* words */ 63 + Constants.MAX_PREV_WORD_COUNT_FOR_N_GRAM /* separators */; 64 private static final int INVALID_CURSOR_POSITION = -1; 65 66 /** 67 * This variable contains an expected value for the selection start position. This is where the 68 * cursor or selection start may end up after all the keyboard-triggered updates have passed. We 69 * keep this to compare it to the actual selection start to guess whether the move was caused by 70 * a keyboard command or not. 71 * It's not really the selection start position: the selection start may not be there yet, and 72 * in some cases, it may never arrive there. 73 */ 74 private int mExpectedSelStart = INVALID_CURSOR_POSITION; // in chars, not code points 75 /** 76 * The expected selection end. Only differs from mExpectedSelStart if a non-empty selection is 77 * expected. The same caveats as mExpectedSelStart apply. 78 */ 79 private int mExpectedSelEnd = INVALID_CURSOR_POSITION; // in chars, not code points 80 /** 81 * This contains the committed text immediately preceding the cursor and the composing 82 * text if any. It is refreshed when the cursor moves by calling upon the TextView. 83 */ 84 private final StringBuilder mCommittedTextBeforeComposingText = new StringBuilder(); 85 /** 86 * This contains the currently composing text, as LatinIME thinks the TextView is seeing it. 87 */ 88 private final StringBuilder mComposingText = new StringBuilder(); 89 90 /** 91 * This variable is a temporary object used in 92 * {@link #commitTextWithBackgroundColor(CharSequence, int, int)} to avoid object creation. 93 */ 94 private SpannableStringBuilder mTempObjectForCommitText = new SpannableStringBuilder(); 95 /** 96 * This variable is used to track whether the last committed text had the background color or 97 * not. 98 * TODO: Omit this flag if possible. 99 */ 100 private boolean mLastCommittedTextHasBackgroundColor = false; 101 102 private final InputMethodService mParent; 103 InputConnection mIC; 104 int mNestLevel; RichInputConnection(final InputMethodService parent)105 public RichInputConnection(final InputMethodService parent) { 106 mParent = parent; 107 mIC = null; 108 mNestLevel = 0; 109 } 110 checkConsistencyForDebug()111 private void checkConsistencyForDebug() { 112 final ExtractedTextRequest r = new ExtractedTextRequest(); 113 r.hintMaxChars = 0; 114 r.hintMaxLines = 0; 115 r.token = 1; 116 r.flags = 0; 117 final ExtractedText et = mIC.getExtractedText(r, 0); 118 final CharSequence beforeCursor = getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE, 119 0); 120 final StringBuilder internal = new StringBuilder(mCommittedTextBeforeComposingText) 121 .append(mComposingText); 122 if (null == et || null == beforeCursor) return; 123 final int actualLength = Math.min(beforeCursor.length(), internal.length()); 124 if (internal.length() > actualLength) { 125 internal.delete(0, internal.length() - actualLength); 126 } 127 final String reference = (beforeCursor.length() <= actualLength) ? beforeCursor.toString() 128 : beforeCursor.subSequence(beforeCursor.length() - actualLength, 129 beforeCursor.length()).toString(); 130 if (et.selectionStart != mExpectedSelStart 131 || !(reference.equals(internal.toString()))) { 132 final String context = "Expected selection start = " + mExpectedSelStart 133 + "\nActual selection start = " + et.selectionStart 134 + "\nExpected text = " + internal.length() + " " + internal 135 + "\nActual text = " + reference.length() + " " + reference; 136 ((LatinIME)mParent).debugDumpStateAndCrashWithException(context); 137 } else { 138 Log.e(TAG, DebugLogUtils.getStackTrace(2)); 139 Log.e(TAG, "Exp <> Actual : " + mExpectedSelStart + " <> " + et.selectionStart); 140 } 141 } 142 beginBatchEdit()143 public void beginBatchEdit() { 144 if (++mNestLevel == 1) { 145 mIC = mParent.getCurrentInputConnection(); 146 if (null != mIC) { 147 mIC.beginBatchEdit(); 148 } 149 } else { 150 if (DBG) { 151 throw new RuntimeException("Nest level too deep"); 152 } else { 153 Log.e(TAG, "Nest level too deep : " + mNestLevel); 154 } 155 } 156 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 157 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 158 } 159 endBatchEdit()160 public void endBatchEdit() { 161 if (mNestLevel <= 0) Log.e(TAG, "Batch edit not in progress!"); // TODO: exception instead 162 if (--mNestLevel == 0 && null != mIC) { 163 mIC.endBatchEdit(); 164 } 165 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 166 } 167 168 /** 169 * Reset the cached text and retrieve it again from the editor. 170 * 171 * This should be called when the cursor moved. It's possible that we can't connect to 172 * the application when doing this; notably, this happens sometimes during rotation, probably 173 * because of a race condition in the framework. In this case, we just can't retrieve the 174 * data, so we empty the cache and note that we don't know the new cursor position, and we 175 * return false so that the caller knows about this and can retry later. 176 * 177 * @param newSelStart the new position of the selection start, as received from the system. 178 * @param newSelEnd the new position of the selection end, as received from the system. 179 * @param shouldFinishComposition whether we should finish the composition in progress. 180 * @return true if we were able to connect to the editor successfully, false otherwise. When 181 * this method returns false, the caches could not be correctly refreshed so they were only 182 * reset: the caller should try again later to return to normal operation. 183 */ resetCachesUponCursorMoveAndReturnSuccess(final int newSelStart, final int newSelEnd, final boolean shouldFinishComposition)184 public boolean resetCachesUponCursorMoveAndReturnSuccess(final int newSelStart, 185 final int newSelEnd, final boolean shouldFinishComposition) { 186 mExpectedSelStart = newSelStart; 187 mExpectedSelEnd = newSelEnd; 188 mComposingText.setLength(0); 189 final boolean didReloadTextSuccessfully = reloadTextCache(); 190 if (!didReloadTextSuccessfully) { 191 Log.d(TAG, "Will try to retrieve text later."); 192 return false; 193 } 194 if (null != mIC && shouldFinishComposition) { 195 mIC.finishComposingText(); 196 } 197 return true; 198 } 199 200 /** 201 * Reload the cached text from the InputConnection. 202 * 203 * @return true if successful 204 */ reloadTextCache()205 private boolean reloadTextCache() { 206 mCommittedTextBeforeComposingText.setLength(0); 207 mIC = mParent.getCurrentInputConnection(); 208 // Call upon the inputconnection directly since our own method is using the cache, and 209 // we want to refresh it. 210 final CharSequence textBeforeCursor = null == mIC ? null : 211 mIC.getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE, 0); 212 if (null == textBeforeCursor) { 213 // For some reason the app thinks we are not connected to it. This looks like a 214 // framework bug... Fall back to ground state and return false. 215 mExpectedSelStart = INVALID_CURSOR_POSITION; 216 mExpectedSelEnd = INVALID_CURSOR_POSITION; 217 Log.e(TAG, "Unable to connect to the editor to retrieve text."); 218 return false; 219 } 220 mCommittedTextBeforeComposingText.append(textBeforeCursor); 221 return true; 222 } 223 checkBatchEdit()224 private void checkBatchEdit() { 225 if (mNestLevel != 1) { 226 // TODO: exception instead 227 Log.e(TAG, "Batch edit level incorrect : " + mNestLevel); 228 Log.e(TAG, DebugLogUtils.getStackTrace(4)); 229 } 230 } 231 finishComposingText()232 public void finishComposingText() { 233 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 234 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 235 // TODO: this is not correct! The cursor is not necessarily after the composing text. 236 // In the practice right now this is only called when input ends so it will be reset so 237 // it works, but it's wrong and should be fixed. 238 mCommittedTextBeforeComposingText.append(mComposingText); 239 mComposingText.setLength(0); 240 // TODO: Clear this flag in setComposingRegion() and setComposingText() as well if needed. 241 mLastCommittedTextHasBackgroundColor = false; 242 if (null != mIC) { 243 mIC.finishComposingText(); 244 } 245 } 246 247 /** 248 * Synonym of {@code commitTextWithBackgroundColor(text, newCursorPosition, Color.TRANSPARENT}. 249 * @param text The text to commit. This may include styles. 250 * See {@link InputConnection#commitText(CharSequence, int)}. 251 * @param newCursorPosition The new cursor position around the text. 252 * See {@link InputConnection#commitText(CharSequence, int)}. 253 */ commitText(final CharSequence text, final int newCursorPosition)254 public void commitText(final CharSequence text, final int newCursorPosition) { 255 commitTextWithBackgroundColor(text, newCursorPosition, Color.TRANSPARENT, text.length()); 256 } 257 258 /** 259 * Calls {@link InputConnection#commitText(CharSequence, int)} with the given background color. 260 * @param text The text to commit. This may include styles. 261 * See {@link InputConnection#commitText(CharSequence, int)}. 262 * @param newCursorPosition The new cursor position around the text. 263 * See {@link InputConnection#commitText(CharSequence, int)}. 264 * @param color The background color to be attached. Set {@link Color#TRANSPARENT} to disable 265 * the background color. Note that this method specifies {@link BackgroundColorSpan} with 266 * {@link Spanned#SPAN_COMPOSING} flag, meaning that the background color persists until 267 * {@link #finishComposingText()} is called. 268 * @param coloredTextLength the length of text, in Java chars, which should be rendered with 269 * the given background color. 270 */ commitTextWithBackgroundColor(final CharSequence text, final int newCursorPosition, final int color, final int coloredTextLength)271 public void commitTextWithBackgroundColor(final CharSequence text, final int newCursorPosition, 272 final int color, final int coloredTextLength) { 273 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 274 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 275 mCommittedTextBeforeComposingText.append(text); 276 // TODO: the following is exceedingly error-prone. Right now when the cursor is in the 277 // middle of the composing word mComposingText only holds the part of the composing text 278 // that is before the cursor, so this actually works, but it's terribly confusing. Fix this. 279 mExpectedSelStart += text.length() - mComposingText.length(); 280 mExpectedSelEnd = mExpectedSelStart; 281 mComposingText.setLength(0); 282 mLastCommittedTextHasBackgroundColor = false; 283 if (null != mIC) { 284 if (color == Color.TRANSPARENT) { 285 mIC.commitText(text, newCursorPosition); 286 } else { 287 mTempObjectForCommitText.clear(); 288 mTempObjectForCommitText.append(text); 289 final BackgroundColorSpan backgroundColorSpan = new BackgroundColorSpan(color); 290 final int spanLength = Math.min(coloredTextLength, text.length()); 291 mTempObjectForCommitText.setSpan(backgroundColorSpan, 0, spanLength, 292 Spanned.SPAN_COMPOSING | Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); 293 mIC.commitText(mTempObjectForCommitText, newCursorPosition); 294 mLastCommittedTextHasBackgroundColor = true; 295 } 296 } 297 } 298 299 /** 300 * Removes the background color from the highlighted text if necessary. Should be called while 301 * there is no on-going composing text. 302 * 303 * <p>CAVEAT: This method internally calls {@link InputConnection#finishComposingText()}. 304 * Be careful of any unexpected side effects.</p> 305 */ removeBackgroundColorFromHighlightedTextIfNecessary()306 public void removeBackgroundColorFromHighlightedTextIfNecessary() { 307 // TODO: We haven't yet full tested if we really need to check this flag or not. Omit this 308 // flag if everything works fine without this condition. 309 if (!mLastCommittedTextHasBackgroundColor) { 310 return; 311 } 312 if (mComposingText.length() > 0) { 313 Log.e(TAG, "clearSpansWithComposingFlags should be called when composing text is " + 314 "empty. mComposingText=" + mComposingText); 315 return; 316 } 317 finishComposingText(); 318 } 319 getSelectedText(final int flags)320 public CharSequence getSelectedText(final int flags) { 321 return (null == mIC) ? null : mIC.getSelectedText(flags); 322 } 323 canDeleteCharacters()324 public boolean canDeleteCharacters() { 325 return mExpectedSelStart > 0; 326 } 327 328 /** 329 * Gets the caps modes we should be in after this specific string. 330 * 331 * This returns a bit set of TextUtils#CAP_MODE_*, masked by the inputType argument. 332 * This method also supports faking an additional space after the string passed in argument, 333 * to support cases where a space will be added automatically, like in phantom space 334 * state for example. 335 * Note that for English, we are using American typography rules (which are not specific to 336 * American English, it's just the most common set of rules for English). 337 * 338 * @param inputType a mask of the caps modes to test for. 339 * @param spacingAndPunctuations the values of the settings to use for locale and separators. 340 * @param hasSpaceBefore if we should consider there should be a space after the string. 341 * @return the caps modes that should be on as a set of bits 342 */ getCursorCapsMode(final int inputType, final SpacingAndPunctuations spacingAndPunctuations, final boolean hasSpaceBefore)343 public int getCursorCapsMode(final int inputType, 344 final SpacingAndPunctuations spacingAndPunctuations, final boolean hasSpaceBefore) { 345 mIC = mParent.getCurrentInputConnection(); 346 if (null == mIC) return Constants.TextUtils.CAP_MODE_OFF; 347 if (!TextUtils.isEmpty(mComposingText)) { 348 if (hasSpaceBefore) { 349 // If we have some composing text and a space before, then we should have 350 // MODE_CHARACTERS and MODE_WORDS on. 351 return (TextUtils.CAP_MODE_CHARACTERS | TextUtils.CAP_MODE_WORDS) & inputType; 352 } else { 353 // We have some composing text - we should be in MODE_CHARACTERS only. 354 return TextUtils.CAP_MODE_CHARACTERS & inputType; 355 } 356 } 357 // TODO: this will generally work, but there may be cases where the buffer contains SOME 358 // information but not enough to determine the caps mode accurately. This may happen after 359 // heavy pressing of delete, for example DEFAULT_TEXT_CACHE_SIZE - 5 times or so. 360 // getCapsMode should be updated to be able to return a "not enough info" result so that 361 // we can get more context only when needed. 362 if (TextUtils.isEmpty(mCommittedTextBeforeComposingText) && 0 != mExpectedSelStart) { 363 if (!reloadTextCache()) { 364 Log.w(TAG, "Unable to connect to the editor. " 365 + "Setting caps mode without knowing text."); 366 } 367 } 368 // This never calls InputConnection#getCapsMode - in fact, it's a static method that 369 // never blocks or initiates IPC. 370 return CapsModeUtils.getCapsMode(mCommittedTextBeforeComposingText, inputType, 371 spacingAndPunctuations, hasSpaceBefore); 372 } 373 getCodePointBeforeCursor()374 public int getCodePointBeforeCursor() { 375 final int length = mCommittedTextBeforeComposingText.length(); 376 if (length < 1) return Constants.NOT_A_CODE; 377 return Character.codePointBefore(mCommittedTextBeforeComposingText, length); 378 } 379 getTextBeforeCursor(final int n, final int flags)380 public CharSequence getTextBeforeCursor(final int n, final int flags) { 381 final int cachedLength = 382 mCommittedTextBeforeComposingText.length() + mComposingText.length(); 383 // If we have enough characters to satisfy the request, or if we have all characters in 384 // the text field, then we can return the cached version right away. 385 // However, if we don't have an expected cursor position, then we should always 386 // go fetch the cache again (as it happens, INVALID_CURSOR_POSITION < 0, so we need to 387 // test for this explicitly) 388 if (INVALID_CURSOR_POSITION != mExpectedSelStart 389 && (cachedLength >= n || cachedLength >= mExpectedSelStart)) { 390 final StringBuilder s = new StringBuilder(mCommittedTextBeforeComposingText); 391 // We call #toString() here to create a temporary object. 392 // In some situations, this method is called on a worker thread, and it's possible 393 // the main thread touches the contents of mComposingText while this worker thread 394 // is suspended, because mComposingText is a StringBuilder. This may lead to crashes, 395 // so we call #toString() on it. That will result in the return value being strictly 396 // speaking wrong, but since this is used for basing bigram probability off, and 397 // it's only going to matter for one getSuggestions call, it's fine in the practice. 398 s.append(mComposingText.toString()); 399 if (s.length() > n) { 400 s.delete(0, s.length() - n); 401 } 402 return s; 403 } 404 mIC = mParent.getCurrentInputConnection(); 405 return (null == mIC) ? null : mIC.getTextBeforeCursor(n, flags); 406 } 407 getTextAfterCursor(final int n, final int flags)408 public CharSequence getTextAfterCursor(final int n, final int flags) { 409 mIC = mParent.getCurrentInputConnection(); 410 return (null == mIC) ? null : mIC.getTextAfterCursor(n, flags); 411 } 412 deleteSurroundingText(final int beforeLength, final int afterLength)413 public void deleteSurroundingText(final int beforeLength, final int afterLength) { 414 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 415 // TODO: the following is incorrect if the cursor is not immediately after the composition. 416 // Right now we never come here in this case because we reset the composing state before we 417 // come here in this case, but we need to fix this. 418 final int remainingChars = mComposingText.length() - beforeLength; 419 if (remainingChars >= 0) { 420 mComposingText.setLength(remainingChars); 421 } else { 422 mComposingText.setLength(0); 423 // Never cut under 0 424 final int len = Math.max(mCommittedTextBeforeComposingText.length() 425 + remainingChars, 0); 426 mCommittedTextBeforeComposingText.setLength(len); 427 } 428 if (mExpectedSelStart > beforeLength) { 429 mExpectedSelStart -= beforeLength; 430 mExpectedSelEnd -= beforeLength; 431 } else { 432 // There are fewer characters before the cursor in the buffer than we are being asked to 433 // delete. Only delete what is there, and update the end with the amount deleted. 434 mExpectedSelEnd -= mExpectedSelStart; 435 mExpectedSelStart = 0; 436 } 437 if (null != mIC) { 438 mIC.deleteSurroundingText(beforeLength, afterLength); 439 } 440 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 441 } 442 performEditorAction(final int actionId)443 public void performEditorAction(final int actionId) { 444 mIC = mParent.getCurrentInputConnection(); 445 if (null != mIC) { 446 mIC.performEditorAction(actionId); 447 } 448 } 449 sendKeyEvent(final KeyEvent keyEvent)450 public void sendKeyEvent(final KeyEvent keyEvent) { 451 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 452 if (keyEvent.getAction() == KeyEvent.ACTION_DOWN) { 453 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 454 // This method is only called for enter or backspace when speaking to old applications 455 // (target SDK <= 15 (Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1)), or for digits. 456 // When talking to new applications we never use this method because it's inherently 457 // racy and has unpredictable results, but for backward compatibility we continue 458 // sending the key events for only Enter and Backspace because some applications 459 // mistakenly catch them to do some stuff. 460 switch (keyEvent.getKeyCode()) { 461 case KeyEvent.KEYCODE_ENTER: 462 mCommittedTextBeforeComposingText.append("\n"); 463 mExpectedSelStart += 1; 464 mExpectedSelEnd = mExpectedSelStart; 465 break; 466 case KeyEvent.KEYCODE_DEL: 467 if (0 == mComposingText.length()) { 468 if (mCommittedTextBeforeComposingText.length() > 0) { 469 mCommittedTextBeforeComposingText.delete( 470 mCommittedTextBeforeComposingText.length() - 1, 471 mCommittedTextBeforeComposingText.length()); 472 } 473 } else { 474 mComposingText.delete(mComposingText.length() - 1, mComposingText.length()); 475 } 476 if (mExpectedSelStart > 0 && mExpectedSelStart == mExpectedSelEnd) { 477 // TODO: Handle surrogate pairs. 478 mExpectedSelStart -= 1; 479 } 480 mExpectedSelEnd = mExpectedSelStart; 481 break; 482 case KeyEvent.KEYCODE_UNKNOWN: 483 if (null != keyEvent.getCharacters()) { 484 mCommittedTextBeforeComposingText.append(keyEvent.getCharacters()); 485 mExpectedSelStart += keyEvent.getCharacters().length(); 486 mExpectedSelEnd = mExpectedSelStart; 487 } 488 break; 489 default: 490 final String text = StringUtils.newSingleCodePointString(keyEvent.getUnicodeChar()); 491 mCommittedTextBeforeComposingText.append(text); 492 mExpectedSelStart += text.length(); 493 mExpectedSelEnd = mExpectedSelStart; 494 break; 495 } 496 } 497 if (null != mIC) { 498 mIC.sendKeyEvent(keyEvent); 499 } 500 } 501 setComposingRegion(final int start, final int end)502 public void setComposingRegion(final int start, final int end) { 503 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 504 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 505 final CharSequence textBeforeCursor = 506 getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE + (end - start), 0); 507 mCommittedTextBeforeComposingText.setLength(0); 508 if (!TextUtils.isEmpty(textBeforeCursor)) { 509 // The cursor is not necessarily at the end of the composing text, but we have its 510 // position in mExpectedSelStart and mExpectedSelEnd. In this case we want the start 511 // of the text, so we should use mExpectedSelStart. In other words, the composing 512 // text starts (mExpectedSelStart - start) characters before the end of textBeforeCursor 513 final int indexOfStartOfComposingText = 514 Math.max(textBeforeCursor.length() - (mExpectedSelStart - start), 0); 515 mComposingText.append(textBeforeCursor.subSequence(indexOfStartOfComposingText, 516 textBeforeCursor.length())); 517 mCommittedTextBeforeComposingText.append( 518 textBeforeCursor.subSequence(0, indexOfStartOfComposingText)); 519 } 520 if (null != mIC) { 521 mIC.setComposingRegion(start, end); 522 } 523 } 524 setComposingText(final CharSequence text, final int newCursorPosition)525 public void setComposingText(final CharSequence text, final int newCursorPosition) { 526 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 527 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 528 mExpectedSelStart += text.length() - mComposingText.length(); 529 mExpectedSelEnd = mExpectedSelStart; 530 mComposingText.setLength(0); 531 mComposingText.append(text); 532 // TODO: support values of newCursorPosition != 1. At this time, this is never called with 533 // newCursorPosition != 1. 534 if (null != mIC) { 535 mIC.setComposingText(text, newCursorPosition); 536 } 537 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 538 } 539 540 /** 541 * Set the selection of the text editor. 542 * 543 * Calls through to {@link InputConnection#setSelection(int, int)}. 544 * 545 * @param start the character index where the selection should start. 546 * @param end the character index where the selection should end. 547 * @return Returns true on success, false on failure: either the input connection is no longer 548 * valid when setting the selection or when retrieving the text cache at that point, or 549 * invalid arguments were passed. 550 */ setSelection(final int start, final int end)551 public boolean setSelection(final int start, final int end) { 552 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 553 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 554 if (start < 0 || end < 0) { 555 return false; 556 } 557 mExpectedSelStart = start; 558 mExpectedSelEnd = end; 559 if (null != mIC) { 560 final boolean isIcValid = mIC.setSelection(start, end); 561 if (!isIcValid) { 562 return false; 563 } 564 } 565 return reloadTextCache(); 566 } 567 commitCorrection(final CorrectionInfo correctionInfo)568 public void commitCorrection(final CorrectionInfo correctionInfo) { 569 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 570 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 571 // This has no effect on the text field and does not change its content. It only makes 572 // TextView flash the text for a second based on indices contained in the argument. 573 if (null != mIC) { 574 mIC.commitCorrection(correctionInfo); 575 } 576 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 577 } 578 commitCompletion(final CompletionInfo completionInfo)579 public void commitCompletion(final CompletionInfo completionInfo) { 580 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 581 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 582 CharSequence text = completionInfo.getText(); 583 // text should never be null, but just in case, it's better to insert nothing than to crash 584 if (null == text) text = ""; 585 mCommittedTextBeforeComposingText.append(text); 586 mExpectedSelStart += text.length() - mComposingText.length(); 587 mExpectedSelEnd = mExpectedSelStart; 588 mComposingText.setLength(0); 589 if (null != mIC) { 590 mIC.commitCompletion(completionInfo); 591 } 592 if (DEBUG_PREVIOUS_TEXT) checkConsistencyForDebug(); 593 } 594 595 @SuppressWarnings("unused") getPrevWordsInfoFromNthPreviousWord( final SpacingAndPunctuations spacingAndPunctuations, final int n)596 public PrevWordsInfo getPrevWordsInfoFromNthPreviousWord( 597 final SpacingAndPunctuations spacingAndPunctuations, final int n) { 598 mIC = mParent.getCurrentInputConnection(); 599 if (null == mIC) { 600 return PrevWordsInfo.EMPTY_PREV_WORDS_INFO; 601 } 602 final CharSequence prev = getTextBeforeCursor(LOOKBACK_CHARACTER_NUM, 0); 603 if (DEBUG_PREVIOUS_TEXT && null != prev) { 604 final int checkLength = LOOKBACK_CHARACTER_NUM - 1; 605 final String reference = prev.length() <= checkLength ? prev.toString() 606 : prev.subSequence(prev.length() - checkLength, prev.length()).toString(); 607 // TODO: right now the following works because mComposingText holds the part of the 608 // composing text that is before the cursor, but this is very confusing. We should 609 // fix it. 610 final StringBuilder internal = new StringBuilder() 611 .append(mCommittedTextBeforeComposingText).append(mComposingText); 612 if (internal.length() > checkLength) { 613 internal.delete(0, internal.length() - checkLength); 614 if (!(reference.equals(internal.toString()))) { 615 final String context = 616 "Expected text = " + internal + "\nActual text = " + reference; 617 ((LatinIME)mParent).debugDumpStateAndCrashWithException(context); 618 } 619 } 620 } 621 return PrevWordsInfoUtils.getPrevWordsInfoFromNthPreviousWord( 622 prev, spacingAndPunctuations, n); 623 } 624 isSeparator(final int code, final int[] sortedSeparators)625 private static boolean isSeparator(final int code, final int[] sortedSeparators) { 626 return Arrays.binarySearch(sortedSeparators, code) >= 0; 627 } 628 isPartOfCompositionForScript(final int codePoint, final SpacingAndPunctuations spacingAndPunctuations, final int scriptId)629 private static boolean isPartOfCompositionForScript(final int codePoint, 630 final SpacingAndPunctuations spacingAndPunctuations, final int scriptId) { 631 // We always consider word connectors part of compositions. 632 return spacingAndPunctuations.isWordConnector(codePoint) 633 // Otherwise, it's part of composition if it's part of script and not a separator. 634 || (!spacingAndPunctuations.isWordSeparator(codePoint) 635 && ScriptUtils.isLetterPartOfScript(codePoint, scriptId)); 636 } 637 638 /** 639 * Returns the text surrounding the cursor. 640 * 641 * @param spacingAndPunctuations the rules for spacing and punctuation 642 * @param scriptId the script we consider to be writing words, as one of ScriptUtils.SCRIPT_* 643 * @return a range containing the text surrounding the cursor 644 */ getWordRangeAtCursor(final SpacingAndPunctuations spacingAndPunctuations, final int scriptId)645 public TextRange getWordRangeAtCursor(final SpacingAndPunctuations spacingAndPunctuations, 646 final int scriptId) { 647 mIC = mParent.getCurrentInputConnection(); 648 if (mIC == null) { 649 return null; 650 } 651 final CharSequence before = mIC.getTextBeforeCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE, 652 InputConnection.GET_TEXT_WITH_STYLES); 653 final CharSequence after = mIC.getTextAfterCursor(Constants.EDITOR_CONTENTS_CACHE_SIZE, 654 InputConnection.GET_TEXT_WITH_STYLES); 655 if (before == null || after == null) { 656 return null; 657 } 658 659 // Going backward, find the first breaking point (separator) 660 int startIndexInBefore = before.length(); 661 while (startIndexInBefore > 0) { 662 final int codePoint = Character.codePointBefore(before, startIndexInBefore); 663 if (!isPartOfCompositionForScript(codePoint, spacingAndPunctuations, scriptId)) { 664 break; 665 } 666 --startIndexInBefore; 667 if (Character.isSupplementaryCodePoint(codePoint)) { 668 --startIndexInBefore; 669 } 670 } 671 672 // Find last word separator after the cursor 673 int endIndexInAfter = -1; 674 while (++endIndexInAfter < after.length()) { 675 final int codePoint = Character.codePointAt(after, endIndexInAfter); 676 if (!isPartOfCompositionForScript(codePoint, spacingAndPunctuations, scriptId)) { 677 break; 678 } 679 if (Character.isSupplementaryCodePoint(codePoint)) { 680 ++endIndexInAfter; 681 } 682 } 683 684 final boolean hasUrlSpans = 685 SpannableStringUtils.hasUrlSpans(before, startIndexInBefore, before.length()) 686 || SpannableStringUtils.hasUrlSpans(after, 0, endIndexInAfter); 687 // We don't use TextUtils#concat because it copies all spans without respect to their 688 // nature. If the text includes a PARAGRAPH span and it has been split, then 689 // TextUtils#concat will crash when it tries to concat both sides of it. 690 return new TextRange( 691 SpannableStringUtils.concatWithNonParagraphSuggestionSpansOnly(before, after), 692 startIndexInBefore, before.length() + endIndexInAfter, before.length(), 693 hasUrlSpans); 694 } 695 isCursorTouchingWord(final SpacingAndPunctuations spacingAndPunctuations)696 public boolean isCursorTouchingWord(final SpacingAndPunctuations spacingAndPunctuations) { 697 if (isCursorFollowedByWordCharacter(spacingAndPunctuations)) { 698 // If what's after the cursor is a word character, then we're touching a word. 699 return true; 700 } 701 final String textBeforeCursor = mCommittedTextBeforeComposingText.toString(); 702 int indexOfCodePointInJavaChars = textBeforeCursor.length(); 703 int consideredCodePoint = 0 == indexOfCodePointInJavaChars ? Constants.NOT_A_CODE 704 : textBeforeCursor.codePointBefore(indexOfCodePointInJavaChars); 705 // Search for the first non word-connector char 706 if (spacingAndPunctuations.isWordConnector(consideredCodePoint)) { 707 indexOfCodePointInJavaChars -= Character.charCount(consideredCodePoint); 708 consideredCodePoint = 0 == indexOfCodePointInJavaChars ? Constants.NOT_A_CODE 709 : textBeforeCursor.codePointBefore(indexOfCodePointInJavaChars); 710 } 711 return !(Constants.NOT_A_CODE == consideredCodePoint 712 || spacingAndPunctuations.isWordSeparator(consideredCodePoint) 713 || spacingAndPunctuations.isWordConnector(consideredCodePoint)); 714 } 715 isCursorFollowedByWordCharacter( final SpacingAndPunctuations spacingAndPunctuations)716 public boolean isCursorFollowedByWordCharacter( 717 final SpacingAndPunctuations spacingAndPunctuations) { 718 final CharSequence after = getTextAfterCursor(1, 0); 719 if (TextUtils.isEmpty(after)) { 720 return false; 721 } 722 final int codePointAfterCursor = Character.codePointAt(after, 0); 723 if (spacingAndPunctuations.isWordSeparator(codePointAfterCursor) 724 || spacingAndPunctuations.isWordConnector(codePointAfterCursor)) { 725 return false; 726 } 727 return true; 728 } 729 removeTrailingSpace()730 public void removeTrailingSpace() { 731 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 732 final int codePointBeforeCursor = getCodePointBeforeCursor(); 733 if (Constants.CODE_SPACE == codePointBeforeCursor) { 734 deleteSurroundingText(1, 0); 735 } 736 } 737 sameAsTextBeforeCursor(final CharSequence text)738 public boolean sameAsTextBeforeCursor(final CharSequence text) { 739 final CharSequence beforeText = getTextBeforeCursor(text.length(), 0); 740 return TextUtils.equals(text, beforeText); 741 } 742 revertDoubleSpacePeriod()743 public boolean revertDoubleSpacePeriod() { 744 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 745 // Here we test whether we indeed have a period and a space before us. This should not 746 // be needed, but it's there just in case something went wrong. 747 final CharSequence textBeforeCursor = getTextBeforeCursor(2, 0); 748 if (!TextUtils.equals(Constants.STRING_PERIOD_AND_SPACE, textBeforeCursor)) { 749 // Theoretically we should not be coming here if there isn't ". " before the 750 // cursor, but the application may be changing the text while we are typing, so 751 // anything goes. We should not crash. 752 Log.d(TAG, "Tried to revert double-space combo but we didn't find " 753 + "\"" + Constants.STRING_PERIOD_AND_SPACE + "\" just before the cursor."); 754 return false; 755 } 756 // Double-space results in ". ". A backspace to cancel this should result in a single 757 // space in the text field, so we replace ". " with a single space. 758 deleteSurroundingText(2, 0); 759 final String singleSpace = " "; 760 commitText(singleSpace, 1); 761 return true; 762 } 763 revertSwapPunctuation()764 public boolean revertSwapPunctuation() { 765 if (DEBUG_BATCH_NESTING) checkBatchEdit(); 766 // Here we test whether we indeed have a space and something else before us. This should not 767 // be needed, but it's there just in case something went wrong. 768 final CharSequence textBeforeCursor = getTextBeforeCursor(2, 0); 769 // NOTE: This does not work with surrogate pairs. Hopefully when the keyboard is able to 770 // enter surrogate pairs this code will have been removed. 771 if (TextUtils.isEmpty(textBeforeCursor) 772 || (Constants.CODE_SPACE != textBeforeCursor.charAt(1))) { 773 // We may only come here if the application is changing the text while we are typing. 774 // This is quite a broken case, but not logically impossible, so we shouldn't crash, 775 // but some debugging log may be in order. 776 Log.d(TAG, "Tried to revert a swap of punctuation but we didn't " 777 + "find a space just before the cursor."); 778 return false; 779 } 780 deleteSurroundingText(2, 0); 781 final String text = " " + textBeforeCursor.subSequence(0, 1); 782 commitText(text, 1); 783 return true; 784 } 785 786 /** 787 * Heuristic to determine if this is an expected update of the cursor. 788 * 789 * Sometimes updates to the cursor position are late because of their asynchronous nature. 790 * This method tries to determine if this update is one, based on the values of the cursor 791 * position in the update, and the currently expected position of the cursor according to 792 * LatinIME's internal accounting. If this is not a belated expected update, then it should 793 * mean that the user moved the cursor explicitly. 794 * This is quite robust, but of course it's not perfect. In particular, it will fail in the 795 * case we get an update A, the user types in N characters so as to move the cursor to A+N but 796 * we don't get those, and then the user places the cursor between A and A+N, and we get only 797 * this update and not the ones in-between. This is almost impossible to achieve even trying 798 * very very hard. 799 * 800 * @param oldSelStart The value of the old selection in the update. 801 * @param newSelStart The value of the new selection in the update. 802 * @param oldSelEnd The value of the old selection end in the update. 803 * @param newSelEnd The value of the new selection end in the update. 804 * @return whether this is a belated expected update or not. 805 */ isBelatedExpectedUpdate(final int oldSelStart, final int newSelStart, final int oldSelEnd, final int newSelEnd)806 public boolean isBelatedExpectedUpdate(final int oldSelStart, final int newSelStart, 807 final int oldSelEnd, final int newSelEnd) { 808 // This update is "belated" if we are expecting it. That is, mExpectedSelStart and 809 // mExpectedSelEnd match the new values that the TextView is updating TO. 810 if (mExpectedSelStart == newSelStart && mExpectedSelEnd == newSelEnd) return true; 811 // This update is not belated if mExpectedSelStart and mExpectedSelEnd match the old 812 // values, and one of newSelStart or newSelEnd is updated to a different value. In this 813 // case, it is likely that something other than the IME has moved the selection endpoint 814 // to the new value. 815 if (mExpectedSelStart == oldSelStart && mExpectedSelEnd == oldSelEnd 816 && (oldSelStart != newSelStart || oldSelEnd != newSelEnd)) return false; 817 // If neither of the above two cases hold, then the system may be having trouble keeping up 818 // with updates. If 1) the selection is a cursor, 2) newSelStart is between oldSelStart 819 // and mExpectedSelStart, and 3) newSelEnd is between oldSelEnd and mExpectedSelEnd, then 820 // assume a belated update. 821 return (newSelStart == newSelEnd) 822 && (newSelStart - oldSelStart) * (mExpectedSelStart - newSelStart) >= 0 823 && (newSelEnd - oldSelEnd) * (mExpectedSelEnd - newSelEnd) >= 0; 824 } 825 826 /** 827 * Looks at the text just before the cursor to find out if it looks like a URL. 828 * 829 * The weakest point here is, if we don't have enough text bufferized, we may fail to realize 830 * we are in URL situation, but other places in this class have the same limitation and it 831 * does not matter too much in the practice. 832 */ textBeforeCursorLooksLikeURL()833 public boolean textBeforeCursorLooksLikeURL() { 834 return StringUtils.lastPartLooksLikeURL(mCommittedTextBeforeComposingText); 835 } 836 837 /** 838 * Looks at the text just before the cursor to find out if we are inside a double quote. 839 * 840 * As with #textBeforeCursorLooksLikeURL, this is dependent on how much text we have cached. 841 * However this won't be a concrete problem in most situations, as the cache is almost always 842 * long enough for this use. 843 */ isInsideDoubleQuoteOrAfterDigit()844 public boolean isInsideDoubleQuoteOrAfterDigit() { 845 return StringUtils.isInsideDoubleQuoteOrAfterDigit(mCommittedTextBeforeComposingText); 846 } 847 848 /** 849 * Try to get the text from the editor to expose lies the framework may have been 850 * telling us. Concretely, when the device rotates, the frameworks tells us about where the 851 * cursor used to be initially in the editor at the time it first received the focus; this 852 * may be completely different from the place it is upon rotation. Since we don't have any 853 * means to get the real value, try at least to ask the text view for some characters and 854 * detect the most damaging cases: when the cursor position is declared to be much smaller 855 * than it really is. 856 */ tryFixLyingCursorPosition()857 public void tryFixLyingCursorPosition() { 858 final CharSequence textBeforeCursor = getTextBeforeCursor( 859 Constants.EDITOR_CONTENTS_CACHE_SIZE, 0); 860 if (null == textBeforeCursor) { 861 mExpectedSelStart = mExpectedSelEnd = Constants.NOT_A_CURSOR_POSITION; 862 } else { 863 final int textLength = textBeforeCursor.length(); 864 if (textLength < Constants.EDITOR_CONTENTS_CACHE_SIZE 865 && (textLength > mExpectedSelStart 866 || mExpectedSelStart < Constants.EDITOR_CONTENTS_CACHE_SIZE)) { 867 // It should not be possible to have only one of those variables be 868 // NOT_A_CURSOR_POSITION, so if they are equal, either the selection is zero-sized 869 // (simple cursor, no selection) or there is no cursor/we don't know its pos 870 final boolean wasEqual = mExpectedSelStart == mExpectedSelEnd; 871 mExpectedSelStart = textLength; 872 // We can't figure out the value of mLastSelectionEnd :( 873 // But at least if it's smaller than mLastSelectionStart something is wrong, 874 // and if they used to be equal we also don't want to make it look like there is a 875 // selection. 876 if (wasEqual || mExpectedSelStart > mExpectedSelEnd) { 877 mExpectedSelEnd = mExpectedSelStart; 878 } 879 } 880 } 881 } 882 getExpectedSelectionStart()883 public int getExpectedSelectionStart() { 884 return mExpectedSelStart; 885 } 886 getExpectedSelectionEnd()887 public int getExpectedSelectionEnd() { 888 return mExpectedSelEnd; 889 } 890 891 /** 892 * @return whether there is a selection currently active. 893 */ hasSelection()894 public boolean hasSelection() { 895 return mExpectedSelEnd != mExpectedSelStart; 896 } 897 isCursorPositionKnown()898 public boolean isCursorPositionKnown() { 899 return INVALID_CURSOR_POSITION != mExpectedSelStart; 900 } 901 902 /** 903 * Work around a bug that was present before Jelly Bean upon rotation. 904 * 905 * Before Jelly Bean, there is a bug where setComposingRegion and other committing 906 * functions on the input connection get ignored until the cursor moves. This method works 907 * around the bug by wiggling the cursor first, which reactivates the connection and has 908 * the subsequent methods work, then restoring it to its original position. 909 * 910 * On platforms on which this method is not present, this is a no-op. 911 */ maybeMoveTheCursorAroundAndRestoreToWorkaroundABug()912 public void maybeMoveTheCursorAroundAndRestoreToWorkaroundABug() { 913 if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) { 914 if (mExpectedSelStart > 0) { 915 mIC.setSelection(mExpectedSelStart - 1, mExpectedSelStart - 1); 916 } else { 917 mIC.setSelection(mExpectedSelStart + 1, mExpectedSelStart + 1); 918 } 919 mIC.setSelection(mExpectedSelStart, mExpectedSelEnd); 920 } 921 } 922 923 private boolean mCursorAnchorInfoMonitorEnabled = false; 924 925 /** 926 * Requests the editor to call back {@link InputMethodManager#updateCursorAnchorInfo}. 927 * @param enableMonitor {@code true} to request the editor to call back the method whenever the 928 * cursor/anchor position is changed. 929 * @param requestImmediateCallback {@code true} to request the editor to call back the method 930 * as soon as possible to notify the current cursor/anchor position to the input method. 931 * @return {@code true} if the request is accepted. Returns {@code false} otherwise, which 932 * includes "not implemented" or "rejected" or "temporarily unavailable" or whatever which 933 * prevents the application from fulfilling the request. (TODO: Improve the API when it turns 934 * out that we actually need more detailed error codes) 935 */ requestCursorUpdates(final boolean enableMonitor, final boolean requestImmediateCallback)936 public boolean requestCursorUpdates(final boolean enableMonitor, 937 final boolean requestImmediateCallback) { 938 mIC = mParent.getCurrentInputConnection(); 939 final boolean scheduled; 940 if (null != mIC) { 941 scheduled = InputConnectionCompatUtils.requestCursorUpdates(mIC, enableMonitor, 942 requestImmediateCallback); 943 } else { 944 scheduled = false; 945 } 946 mCursorAnchorInfoMonitorEnabled = (scheduled && enableMonitor); 947 return scheduled; 948 } 949 950 /** 951 * @return {@code true} if the application reported that the monitor mode of 952 * {@link InputMethodService#onUpdateCursorAnchorInfo(CursorAnchorInfo)} is currently enabled. 953 */ isCursorAnchorInfoMonitorEnabled()954 public boolean isCursorAnchorInfoMonitorEnabled() { 955 return mCursorAnchorInfoMonitorEnabled; 956 } 957 } 958