net.sourceforge.phpeclipse.ui/src/net/sourceforge/phpdt/internal/ui/text/JavaHeuristicScanner.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2004 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package net.sourceforge.phpdt.internal.ui.text;
  12
  13 import java.util.Arrays;
  14
  15 import net.sourceforge.phpdt.internal.compiler.parser.Scanner;
  16 import net.sourceforge.phpeclipse.phpeditor.php.PHPDocumentPartitioner;
  17
  18 //incastrix
  19 //import org.eclipse.jface.text.Assert;
  20 import org.eclipse.core.runtime.Assert;
  21 import org.eclipse.jface.text.BadLocationException;
  22 import org.eclipse.jface.text.IDocument;
  23 import org.eclipse.jface.text.IRegion;
  24 import org.eclipse.jface.text.ITypedRegion;
  25 import org.eclipse.jface.text.Region;
  26 import org.eclipse.jface.text.TextUtilities;
  27
  28 /**
  29  * Utility methods for heuristic based Java manipulations in an incomplete Java
  30  * source file.
  31  *
  32  * <p>
  33  * An instance holds some internal position in the document and is therefore not
  34  * threadsafe.
  35  * </p>
  36  *
  37  * @since 3.0
  38  */
  39 public class JavaHeuristicScanner implements Symbols {
  40         /**
  41          * Returned by all methods when the requested position could not be found,
  42          * or if a {@link BadLocationException} was thrown while scanning.
  43          */
  44         public static final int NOT_FOUND = -1;
  45
  46         /**
  47          * Special bound parameter that means either -1 (backward scanning) or
  48          * <code>fDocument.getLength()</code> (forward scanning).
  49          */
  50         public static final int UNBOUND = -2;
  51
  52         /* character constants */
  53         private static final char LBRACE = '{';
  54
  55         private static final char RBRACE = '}';
  56
  57         private static final char LPAREN = '(';
  58
  59         private static final char RPAREN = ')';
  60
  61         private static final char SEMICOLON = ';';
  62
  63         private static final char COLON = ':';
  64
  65         private static final char COMMA = ',';
  66
  67         private static final char LBRACKET = '[';
  68
  69         private static final char RBRACKET = ']';
  70
  71         private static final char QUESTIONMARK = '?';
  72
  73         private static final char EQUAL = '=';
  74
  75         /**
  76          * Specifies the stop condition, upon which the <code>scanXXX</code>
  77          * methods will decide whether to keep scanning or not. This interface may
  78          * implemented by clients.
  79          */
  80         public interface StopCondition {
  81                 /**
  82                  * Instructs the scanner to return the current position.
  83                  *
  84                  * @param ch
  85                  *            the char at the current position
  86                  * @param position
  87                  *            the current position
  88                  * @param forward
  89                  *            the iteration direction
  90                  * @return <code>true</code> if the stop condition is met.
  91                  */
  92                 boolean stop(char ch, int position, boolean forward);
  93         }
  94
  95         /**
  96          * Stops upon a non-whitespace (as defined by
  97          * {@link Character#isWhitespace(char)}) character.
  98          */
  99         private static class NonWhitespace implements StopCondition {
 100                 /*
 101                  * @see net.sourceforge.phpdt.internal.ui.text.JavaHeuristicScanner.StopCondition#stop(char)
 102                  */
 103                 public boolean stop(char ch, int position, boolean forward) {
 104                         return !Character.isWhitespace(ch);
 105                 }
 106         }
 107
 108         /**
 109          * Stops upon a non-whitespace character in the default partition.
 110          *
 111          * @see NonWhitespace
 112          */
 113         private class NonWhitespaceDefaultPartition extends NonWhitespace {
 114                 /*
 115                  * @see net.sourceforge.phpdt.internal.ui.text.JavaHeuristicScanner.StopCondition#stop(char)
 116                  */
 117                 public boolean stop(char ch, int position, boolean forward) {
 118                         return super.stop(ch, position, true)
 119                                         && isDefaultPartition(position);
 120                 }
 121         }
 122
 123         /**
 124          * Stops upon a non-java identifier (as defined by
 125          * {@link Scanner#isPHPIdentifierPart(char)}) character.
 126          */
 127         private static class NonJavaIdentifierPart implements StopCondition {
 128                 /*
 129                  * @see net.sourceforge.phpdt.internal.ui.text.JavaHeuristicScanner.StopCondition#stop(char)
 130                  */
 131                 public boolean stop(char ch, int position, boolean forward) {
 132                         return !Scanner.isPHPIdentifierPart(ch);
 133                 }
 134         }
 135
 136         /**
 137          * Stops upon a non-java identifier character in the default partition.
 138          *
 139          * @see NonJavaIdentifierPart
 140          */
 141         private class NonJavaIdentifierPartDefaultPartition extends
 142                         NonJavaIdentifierPart {
 143                 /*
 144                  * @see net.sourceforge.phpdt.internal.ui.text.JavaHeuristicScanner.StopCondition#stop(char)
 145                  */
 146                 public boolean stop(char ch, int position, boolean forward) {
 147                         return super.stop(ch, position, true)
 148                                         || !isDefaultPartition(position);
 149                 }
 150         }
 151
 152         /**
 153          * Stops upon a character in the default partition that matches the given
 154          * character list.
 155          */
 156         private class CharacterMatch implements StopCondition {
 157                 private final char[] fChars;
 158
 159                 /**
 160                  * Creates a new instance.
 161                  *
 162                  * @param ch
 163                  *            the single character to match
 164                  */
 165                 public CharacterMatch(char ch) {
 166                         this(new char[] { ch });
 167                 }
 168
 169                 /**
 170                  * Creates a new instance.
 171                  *
 172                  * @param chars
 173                  *            the chars to match.
 174                  */
 175                 public CharacterMatch(char[] chars) {
 176                         Assert.isNotNull(chars);
 177                         Assert.isTrue(chars.length > 0);
 178                         fChars = chars;
 179                         Arrays.sort(chars);
 180                 }
 181
 182                 /*
 183                  * @see net.sourceforge.phpdt.internal.ui.text.JavaHeuristicScanner.StopCondition#stop(char,
 184                  *      int)
 185                  */
 186                 public boolean stop(char ch, int position, boolean forward) {
 187                         return Arrays.binarySearch(fChars, ch) >= 0
 188                                         && isDefaultPartition(position);
 189                 }
 190         }
 191
 192         /**
 193          * Acts like character match, but skips all scopes introduced by
 194          * parenthesis, brackets, and braces.
 195          */
 196         protected class SkippingScopeMatch extends CharacterMatch {
 197                 private char fOpening, fClosing;
 198
 199                 private int fDepth = 0;
 200
 201                 /**
 202                  * Creates a new instance.
 203                  *
 204                  * @param ch
 205                  *            the single character to match
 206                  */
 207                 public SkippingScopeMatch(char ch) {
 208                         super(ch);
 209                 }
 210
 211                 /**
 212                  * Creates a new instance.
 213                  *
 214                  * @param chars
 215                  *            the chars to match.
 216                  */
 217                 public SkippingScopeMatch(char[] chars) {
 218                         super(chars);
 219                 }
 220
 221                 /*
 222                  * @see net.sourceforge.phpdt.internal.ui.text.JavaHeuristicScanner.StopCondition#stop(char,
 223                  *      int)
 224                  */
 225                 public boolean stop(char ch, int position, boolean forward) {
 226
 227                         if (fDepth == 0 && super.stop(ch, position, true))
 228                                 return true;
 229                         else if (ch == fOpening)
 230                                 fDepth++;
 231                         else if (ch == fClosing) {
 232                                 fDepth--;
 233                                 if (fDepth == 0) {
 234                                         fOpening = 0;
 235                                         fClosing = 0;
 236                                 }
 237                         } else if (fDepth == 0) {
 238                                 fDepth = 1;
 239                                 if (forward) {
 240
 241                                         switch (ch) {
 242                                         case LBRACE:
 243                                                 fOpening = LBRACE;
 244                                                 fClosing = RBRACE;
 245                                                 break;
 246                                         case LPAREN:
 247                                                 fOpening = LPAREN;
 248                                                 fClosing = RPAREN;
 249                                                 break;
 250                                         case LBRACKET:
 251                                                 fOpening = LBRACKET;
 252                                                 fClosing = RBRACKET;
 253                                                 break;
 254                                         }
 255
 256                                 } else {
 257                                         switch (ch) {
 258                                         case RBRACE:
 259                                                 fOpening = RBRACE;
 260                                                 fClosing = LBRACE;
 261                                                 break;
 262                                         case RPAREN:
 263                                                 fOpening = RPAREN;
 264                                                 fClosing = LPAREN;
 265                                                 break;
 266                                         case RBRACKET:
 267                                                 fOpening = RBRACKET;
 268                                                 fClosing = LBRACKET;
 269                                                 break;
 270                                         }
 271
 272                                 }
 273                         }
 274
 275                         return false;
 276
 277                 }
 278
 279         }
 280
 281         /** The document being scanned. */
 282         private IDocument fDocument;
 283
 284         /** The partitioning being used for scanning. */
 285         private String fPartitioning;
 286
 287         /** The partition to scan in. */
 288         private String fPartition;
 289
 290         /* internal scan state */
 291
 292         /** the most recently read character. */
 293         private char fChar;
 294
 295         /** the most recently read position. */
 296         private int fPos;
 297
 298         /* preset stop conditions */
 299         private final StopCondition fNonWSDefaultPart = new NonWhitespaceDefaultPartition();
 300
 301         private final static StopCondition fNonWS = new NonWhitespace();
 302
 303         private final StopCondition fNonIdent = new NonJavaIdentifierPartDefaultPartition();
 304
 305         /**
 306          * Creates a new instance.
 307          *
 308          * @param document
 309          *            the document to scan
 310          * @param partitioning
 311          *            the partitioning to use for scanning
 312          * @param partition
 313          *            the partition to scan in
 314          */
 315         public JavaHeuristicScanner(IDocument document, String partitioning,
 316                         String partition) {
 317                 Assert.isNotNull(document);
 318                 Assert.isNotNull(partitioning);
 319                 Assert.isNotNull(partition);
 320                 fDocument = document;
 321                 fPartitioning = partitioning;
 322                 fPartition = partition;
 323         }
 324
 325         /**
 326          * Calls
 327          * <code>this(document, IJavaPartitions.JAVA_PARTITIONING, IDocument.DEFAULT_CONTENT_TYPE)</code>.
 328          *
 329          * @param document
 330          *            the document to scan.
 331          */
 332         public JavaHeuristicScanner(IDocument document) {
 333 //              this(document, IPHPPartitions.PHP_PARTITIONING,
 334 //                              IDocument.DEFAULT_CONTENT_TYPE);
 335                 this(document, IPHPPartitions.PHP_PARTITIONING,
 336                                 PHPDocumentPartitioner.PHP_SCRIPT_CODE);
 337         }
 338
 339         /**
 340          * Returns the most recent internal scan position.
 341          *
 342          * @return the most recent internal scan position.
 343          */
 344         public int getPosition() {
 345                 return fPos;
 346         }
 347
 348         /**
 349          * Returns the next token in forward direction, starting at
 350          * <code>start</code>, and not extending further than <code>bound</code>.
 351          * The return value is one of the constants defined in {@link Symbols}.
 352          * After a call, {@link #getPosition()} will return the position just after
 353          * the scanned token (i.e. the next position that will be scanned).
 354          *
 355          * @param start
 356          *            the first character position in the document to consider
 357          * @param bound
 358          *            the first position not to consider any more
 359          * @return a constant from {@link Symbols} describing the next token
 360          */
 361         public int nextToken(int start, int bound) {
 362                 int pos = scanForward(start, bound, fNonWSDefaultPart);
 363                 if (pos == NOT_FOUND)
 364                         return TokenEOF;
 365
 366                 fPos++;
 367
 368                 switch (fChar) {
 369                 case LBRACE:
 370                         return TokenLBRACE;
 371                 case RBRACE:
 372                         return TokenRBRACE;
 373                 case LBRACKET:
 374                         return TokenLBRACKET;
 375                 case RBRACKET:
 376                         return TokenRBRACKET;
 377                 case LPAREN:
 378                         return TokenLPAREN;
 379                 case RPAREN:
 380                         return TokenRPAREN;
 381                 case SEMICOLON:
 382                         return TokenSEMICOLON;
 383                 case COMMA:
 384                         return TokenCOMMA;
 385                 case QUESTIONMARK:
 386                         return TokenQUESTIONMARK;
 387                 case EQUAL:
 388                         try {
 389                                 if (fDocument.getChar(fPos) == '>') {
 390                                         fPos++;
 391                                         return TokenOTHER;
 392                                 }
 393                         } catch (BadLocationException e) {
 394                         }
 395                         return TokenEQUAL;
 396                 case '<':
 397                         try {
 398                                 if (fDocument.get(fPos, 4).equalsIgnoreCase("?php")) {
 399                                         fPos += 4;
 400                                         return TokenEOF;
 401                                 } else if (fDocument.getChar(fPos) == '?') {
 402                                         fPos++;
 403                                         return TokenEOF;
 404                                 }
 405                         } catch (BadLocationException e) {
 406                         }
 407                 }
 408
 409                 // else
 410                 if (Scanner.isPHPIdentifierPart(fChar)) {
 411                         // assume an ident or keyword
 412                         int from = pos, to;
 413                         pos = scanForward(pos + 1, bound, fNonIdent);
 414                         if (pos == NOT_FOUND)
 415                                 to = bound == UNBOUND ? fDocument.getLength() : bound;
 416                         else
 417                                 to = pos;
 418
 419                         String identOrKeyword;
 420                         try {
 421                                 identOrKeyword = fDocument.get(from, to - from);
 422                         } catch (BadLocationException e) {
 423                                 return TokenEOF;
 424                         }
 425
 426                         return getToken(identOrKeyword);
 427
 428                 } else {
 429                         // operators, number literals etc
 430                         return TokenOTHER;
 431                 }
 432         }
 433
 434         /**
 435          * Returns the next token in backward direction, starting at
 436          * <code>start</code>, and not extending further than <code>bound</code>.
 437          * The return value is one of the constants defined in {@link Symbols}.
 438          * After a call, {@link #getPosition()} will return the position just before
 439          * the scanned token starts (i.e. the next position that will be scanned).
 440          *
 441          * @param start
 442          *            the first character position in the document to consider
 443          * @param bound
 444          *            the first position not to consider any more
 445          * @return a constant from {@link Symbols} describing the previous token
 446          */
 447         public int previousToken(int start, int bound) {
 448                 int pos = scanBackward(start, bound, fNonWSDefaultPart);
 449                 if (pos == NOT_FOUND)
 450                         return TokenEOF;
 451
 452                 fPos--;
 453
 454                 switch (fChar) {
 455                 case LBRACE:
 456                         return TokenLBRACE;
 457                 case RBRACE:
 458                         return TokenRBRACE;
 459                 case LBRACKET:
 460                         return TokenLBRACKET;
 461                 case RBRACKET:
 462                         return TokenRBRACKET;
 463                 case LPAREN:
 464                         return TokenLPAREN;
 465                 case RPAREN:
 466                         return TokenRPAREN;
 467                 case SEMICOLON:
 468                         return TokenSEMICOLON;
 469                 case COLON:
 470                         return TokenCOLON;
 471                 case COMMA:
 472                         return TokenCOMMA;
 473                 case QUESTIONMARK:
 474                         return TokenQUESTIONMARK;
 475                 case EQUAL:
 476                         return TokenEQUAL;
 477                 case '>':
 478                         try {
 479                                 switch (fDocument.getChar(fPos)) {
 480                                 case '=':
 481                                         fPos--;
 482                                         return TokenOTHER;
 483                                 case '?':
 484                                         fPos--;
 485                                         return TokenEOF;
 486                                 }
 487                         } catch (BadLocationException e) {
 488                         }
 489                 }
 490
 491                 // else
 492                 if (Scanner.isPHPIdentifierPart(fChar)) {
 493                         // assume an ident or keyword
 494                         int from, to = pos + 1;
 495                         pos = scanBackward(pos - 1, bound, fNonIdent);
 496                         if (pos == NOT_FOUND)
 497                                 from = bound == UNBOUND ? 0 : bound + 1;
 498                         else
 499                                 from = pos + 1;
 500
 501                         String identOrKeyword;
 502                         try {
 503                                 identOrKeyword = fDocument.get(from, to - from);
 504                         } catch (BadLocationException e) {
 505                                 return TokenEOF;
 506                         }
 507
 508                         return getToken(identOrKeyword);
 509
 510                 } else {
 511                         // operators, number literals etc
 512                         return TokenOTHER;
 513                 }
 514
 515         }
 516
 517         /**
 518          * Returns one of the keyword constants or <code>TokenIDENT</code> for a
 519          * scanned identifier.
 520          *
 521          * @param s
 522          *            a scanned identifier
 523          * @return one of the constants defined in {@link Symbols}
 524          */
 525         private int getToken(String s) {
 526                 Assert.isNotNull(s);
 527
 528                 switch (s.length()) {
 529                 case 2:
 530                         if ("if".equals(s)) //$NON-NLS-1$
 531                                 return TokenIF;
 532                         if ("do".equals(s)) //$NON-NLS-1$
 533                                 return TokenDO;
 534                         break;
 535                 case 3:
 536                         if ("for".equals(s)) //$NON-NLS-1$
 537                                 return TokenFOR;
 538                         if ("try".equals(s)) //$NON-NLS-1$
 539                                 return TokenTRY;
 540                         if ("new".equals(s)) //$NON-NLS-1$
 541                                 return TokenNEW;
 542                         break;
 543                 case 4:
 544                         if ("case".equals(s)) //$NON-NLS-1$
 545                                 return TokenCASE;
 546                         if ("else".equals(s)) //$NON-NLS-1$
 547                                 return TokenELSE;
 548                         if ("goto".equals(s)) //$NON-NLS-1$
 549                                 return TokenGOTO;
 550                         break;
 551                 case 5:
 552                         if ("break".equals(s)) //$NON-NLS-1$
 553                                 return TokenBREAK;
 554                         if ("catch".equals(s)) //$NON-NLS-1$
 555                                 return TokenCATCH;
 556                         if ("while".equals(s)) //$NON-NLS-1$
 557                                 return TokenWHILE;
 558                         break;
 559                 case 6:
 560                         if ("return".equals(s)) //$NON-NLS-1$
 561                                 return TokenRETURN;
 562                         if ("static".equals(s)) //$NON-NLS-1$
 563                                 return TokenSTATIC;
 564                         if ("switch".equals(s)) //$NON-NLS-1$
 565                                 return TokenSWITCH;
 566                         break;
 567                 case 7:
 568                         if ("default".equals(s)) //$NON-NLS-1$
 569                                 return TokenDEFAULT;
 570                         if ("finally".equals(s)) //$NON-NLS-1$
 571                                 return TokenFINALLY;
 572                         break;
 573                 case 12:
 574                         if ("synchronized".equals(s)) //$NON-NLS-1$
 575                                 return TokenSYNCHRONIZED;
 576                         break;
 577                 }
 578                 return TokenIDENT;
 579         }
 580
 581         /**
 582          * Returns the position of the closing peer character (forward search). Any
 583          * scopes introduced by opening peers are skipped. All peers accounted for
 584          * must reside in the default partition.
 585          *
 586          * <p>
 587          * Note that <code>start</code> must not point to the opening peer, but to
 588          * the first character being searched.
 589          * </p>
 590          *
 591          * @param start
 592          *            the start position
 593          * @param openingPeer
 594          *            the opening peer character (e.g. '{')
 595          * @param closingPeer
 596          *            the closing peer character (e.g. '}')
 597          * @return the matching peer character position, or <code>NOT_FOUND</code>
 598          */
 599         public int findClosingPeer(int start, final char openingPeer,
 600                         final char closingPeer) {
 601                 Assert.isNotNull(fDocument);
 602                 Assert.isTrue(start >= 0);
 603
 604                 try {
 605                         int depth = 1;
 606                         start -= 1;
 607                         while (true) {
 608                                 start = scanForward(start + 1, UNBOUND, new CharacterMatch(
 609                                                 new char[] { openingPeer, closingPeer }));
 610                                 if (start == NOT_FOUND)
 611                                         return NOT_FOUND;
 612
 613                                 if (fDocument.getChar(start) == openingPeer)
 614                                         depth++;
 615                                 else
 616                                         depth--;
 617
 618                                 if (depth == 0)
 619                                         return start;
 620                         }
 621
 622                 } catch (BadLocationException e) {
 623                         return NOT_FOUND;
 624                 }
 625         }
 626
 627         /**
 628          * Returns the position of the opening peer character (backward search). Any
 629          * scopes introduced by closing peers are skipped. All peers accounted for
 630          * must reside in the default partition.
 631          *
 632          * <p>
 633          * Note that <code>start</code> must not point to the closing peer, but to
 634          * the first character being searched.
 635          * </p>
 636          *
 637          * @param start
 638          *            the start position
 639          * @param openingPeer
 640          *            the opening peer character (e.g. '{')
 641          * @param closingPeer
 642          *            the closing peer character (e.g. '}')
 643          * @return the matching peer character position, or <code>NOT_FOUND</code>
 644          */
 645         public int findOpeningPeer(int start, char openingPeer, char closingPeer) {
 646                 Assert.isTrue(start < fDocument.getLength());
 647
 648                 try {
 649                         int depth = 1;
 650                         start += 1;
 651                         while (true) {
 652                                 start = scanBackward(start - 1, UNBOUND, new CharacterMatch(
 653                                                 new char[] { openingPeer, closingPeer }));
 654                                 if (start == NOT_FOUND)
 655                                         return NOT_FOUND;
 656
 657                                 if (fDocument.getChar(start) == closingPeer)
 658                                         depth++;
 659                                 else
 660                                         depth--;
 661
 662                                 if (depth == 0)
 663                                         return start;
 664                         }
 665
 666                 } catch (BadLocationException e) {
 667                         return NOT_FOUND;
 668                 }
 669         }
 670
 671         /**
 672          * Computes the surrounding block around <code>offset</code>. The search
 673          * is started at the beginning of <code>offset</code>, i.e. an opening
 674          * brace at <code>offset</code> will not be part of the surrounding block,
 675          * but a closing brace will.
 676          *
 677          * @param offset
 678          *            the offset for which the surrounding block is computed
 679          * @return a region describing the surrounding block, or <code>null</code>
 680          *         if none can be found
 681          */
 682         public IRegion findSurroundingBlock(int offset) {
 683                 if (offset < 1 || offset >= fDocument.getLength())
 684                         return null;
 685
 686                 int begin = findOpeningPeer(offset - 1, LBRACE, RBRACE);
 687                 int end = findClosingPeer(offset, LBRACE, RBRACE);
 688                 if (begin == NOT_FOUND || end == NOT_FOUND)
 689                         return null;
 690                 return new Region(begin, end + 1 - begin);
 691         }
 692
 693         /**
 694          * Finds the smallest position in <code>fDocument</code> such that the
 695          * position is &gt;= <code>position</code> and &lt; <code>bound</code>
 696          * and <code>Character.isWhitespace(fDocument.getChar(pos))</code>
 697          * evaluates to <code>false</code> and the position is in the default
 698          * partition.
 699          *
 700          * @param position
 701          *            the first character position in <code>fDocument</code> to be
 702          *            considered
 703          * @param bound
 704          *            the first position in <code>fDocument</code> to not consider
 705          *            any more, with <code>bound</code> &gt; <code>position</code>,
 706          *            or <code>UNBOUND</code>
 707          * @return the smallest position of a non-whitespace character in [<code>position</code>,
 708          *         <code>bound</code>) that resides in a Java partition, or
 709          *         <code>NOT_FOUND</code> if none can be found
 710          */
 711         public int findNonWhitespaceForward(int position, int bound) {
 712                 return scanForward(position, bound, fNonWSDefaultPart);
 713         }
 714
 715         /**
 716          * Finds the smallest position in <code>fDocument</code> such that the
 717          * position is &gt;= <code>position</code> and &lt; <code>bound</code>
 718          * and <code>Character.isWhitespace(fDocument.getChar(pos))</code>
 719          * evaluates to <code>false</code>.
 720          *
 721          * @param position
 722          *            the first character position in <code>fDocument</code> to be
 723          *            considered
 724          * @param bound
 725          *            the first position in <code>fDocument</code> to not consider
 726          *            any more, with <code>bound</code> &gt; <code>position</code>,
 727          *            or <code>UNBOUND</code>
 728          * @return the smallest position of a non-whitespace character in [<code>position</code>,
 729          *         <code>bound</code>), or <code>NOT_FOUND</code> if none can
 730          *         be found
 731          */
 732         public int findNonWhitespaceForwardInAnyPartition(int position, int bound) {
 733                 return scanForward(position, bound, fNonWS);
 734         }
 735
 736         /**
 737          * Finds the highest position in <code>fDocument</code> such that the
 738          * position is &lt;= <code>position</code> and &gt; <code>bound</code>
 739          * and <code>Character.isWhitespace(fDocument.getChar(pos))</code>
 740          * evaluates to <code>false</code> and the position is in the default
 741          * partition.
 742          *
 743          * @param position
 744          *            the first character position in <code>fDocument</code> to be
 745          *            considered
 746          * @param bound
 747          *            the first position in <code>fDocument</code> to not consider
 748          *            any more, with <code>bound</code> &lt; <code>position</code>,
 749          *            or <code>UNBOUND</code>
 750          * @return the highest position of a non-whitespace character in (<code>bound</code>,
 751          *         <code>position</code>] that resides in a Java partition, or
 752          *         <code>NOT_FOUND</code> if none can be found
 753          */
 754         public int findNonWhitespaceBackward(int position, int bound) {
 755                 return scanBackward(position, bound, fNonWSDefaultPart);
 756         }
 757
 758         /**
 759          * Finds the lowest position <code>p</code> in <code>fDocument</code>
 760          * such that <code>start</code> &lt;= p &lt; <code>bound</code> and
 761          * <code>condition.stop(fDocument.getChar(p), p)</code> evaluates to
 762          * <code>true</code>.
 763          *
 764          * @param start
 765          *            the first character position in <code>fDocument</code> to be
 766          *            considered
 767          * @param bound
 768          *            the first position in <code>fDocument</code> to not consider
 769          *            any more, with <code>bound</code> &gt; <code>start</code>,
 770          *            or <code>UNBOUND</code>
 771          * @param condition
 772          *            the <code>StopCondition</code> to check
 773          * @return the lowest position in [<code>start</code>,
 774          *         <code>bound</code>) for which <code>condition</code> holds,
 775          *         or <code>NOT_FOUND</code> if none can be found
 776          */
 777         public int scanForward(int start, int bound, StopCondition condition) {
 778                 Assert.isTrue(start >= 0);
 779
 780                 if (bound == UNBOUND)
 781                         bound = fDocument.getLength();
 782
 783                 Assert.isTrue(bound <= fDocument.getLength());
 784
 785                 try {
 786                         fPos = start;
 787                         while (fPos < bound) {
 788
 789                                 fChar = fDocument.getChar(fPos);
 790                                 // omit closing tag
 791                                 if (fChar == '?') {
 792                                         if (fPos < fDocument.getLength() - 1) {
 793                                                 if (fDocument.get(fPos - 1, 2).equalsIgnoreCase("?>")) {
 794                                                         fPos++;
 795                                                         return NOT_FOUND;
 796                                                 }
 797                                         }
 798                                 }
 799                                 if (condition.stop(fChar, fPos, true))
 800                                         return fPos;
 801
 802                                 fPos++;
 803                         }
 804                 } catch (BadLocationException e) {
 805                 }
 806                 return NOT_FOUND;
 807         }
 808
 809         /**
 810          * Finds the lowest position in <code>fDocument</code> such that the
 811          * position is &gt;= <code>position</code> and &lt; <code>bound</code>
 812          * and <code>fDocument.getChar(position) == ch</code> evaluates to
 813          * <code>true</code> and the position is in the default partition.
 814          *
 815          * @param position
 816          *            the first character position in <code>fDocument</code> to be
 817          *            considered
 818          * @param bound
 819          *            the first position in <code>fDocument</code> to not consider
 820          *            any more, with <code>bound</code> &gt; <code>position</code>,
 821          *            or <code>UNBOUND</code>
 822          * @param ch
 823          *            the <code>char</code> to search for
 824          * @return the lowest position of <code>ch</code> in (<code>bound</code>,
 825          *         <code>position</code>] that resides in a Java partition, or
 826          *         <code>NOT_FOUND</code> if none can be found
 827          */
 828         public int scanForward(int position, int bound, char ch) {
 829                 return scanForward(position, bound, new CharacterMatch(ch));
 830         }
 831
 832         /**
 833          * Finds the lowest position in <code>fDocument</code> such that the
 834          * position is &gt;= <code>position</code> and &lt; <code>bound</code>
 835          * and <code>fDocument.getChar(position) == ch</code> evaluates to
 836          * <code>true</code> for at least one ch in <code>chars</code> and the
 837          * position is in the default partition.
 838          *
 839          * @param position
 840          *            the first character position in <code>fDocument</code> to be
 841          *            considered
 842          * @param bound
 843          *            the first position in <code>fDocument</code> to not consider
 844          *            any more, with <code>bound</code> &gt; <code>position</code>,
 845          *            or <code>UNBOUND</code>
 846          * @param chars
 847          *            an array of <code>char</code> to search for
 848          * @return the lowest position of a non-whitespace character in [<code>position</code>,
 849          *         <code>bound</code>) that resides in a Java partition, or
 850          *         <code>NOT_FOUND</code> if none can be found
 851          */
 852         public int scanForward(int position, int bound, char[] chars) {
 853                 return scanForward(position, bound, new CharacterMatch(chars));
 854         }
 855
 856         /**
 857          * Finds the highest position <code>p</code> in <code>fDocument</code>
 858          * such that <code>bound</code> &lt; <code>p</code> &lt;=
 859          * <code>start</code> and
 860          * <code>condition.stop(fDocument.getChar(p), p)</code> evaluates to
 861          * <code>true</code>.
 862          *
 863          * @param start
 864          *            the first character position in <code>fDocument</code> to be
 865          *            considered
 866          * @param bound
 867          *            the first position in <code>fDocument</code> to not consider
 868          *            any more, with <code>bound</code> &lt; <code>start</code>,
 869          *            or <code>UNBOUND</code>
 870          * @param condition
 871          *            the <code>StopCondition</code> to check
 872          * @return the highest position in (<code>bound</code>,
 873          *         <code>start</code> for which <code>condition</code> holds, or
 874          *         <code>NOT_FOUND</code> if none can be found
 875          */
 876         public int scanBackward(int start, int bound, StopCondition condition) {
 877                 if (bound == UNBOUND)
 878                         bound = -1;
 879
 880                 Assert.isTrue(bound >= -1);
 881                 Assert.isTrue(start < fDocument.getLength());
 882
 883                 try {
 884                         fPos = start;
 885                         while (fPos > bound) {
 886
 887                                 fChar = fDocument.getChar(fPos);
 888                                 // omit opening tag
 889                                 if (fChar == 'p' || fChar == 'P') {
 890                                         if (fPos >= 4) {
 891                                                 if (fDocument.get(fPos - 4, 5).equalsIgnoreCase("<?php")) {
 892                                                         fPos -= 4;
 893                                                         return NOT_FOUND;
 894                                                 }
 895                                         }
 896                                 } else if (fChar == '?') {
 897                                         if (fPos >= 1) {
 898                                                 if (fDocument.get(fPos - 1, 2).equalsIgnoreCase("<?")) {
 899                                                         fPos--;
 900                                                         return NOT_FOUND;
 901                                                 }
 902                                         }
 903                                 }
 904                                 if (condition.stop(fChar, fPos, false))
 905                                         return fPos;
 906
 907                                 fPos--;
 908                         }
 909                 } catch (BadLocationException e) {
 910                 }
 911                 return NOT_FOUND;
 912         }
 913
 914         /**
 915          * Finds the highest position in <code>fDocument</code> such that the
 916          * position is &lt;= <code>position</code> and &gt; <code>bound</code>
 917          * and <code>fDocument.getChar(position) == ch</code> evaluates to
 918          * <code>true</code> for at least one ch in <code>chars</code> and the
 919          * position is in the default partition.
 920          *
 921          * @param position
 922          *            the first character position in <code>fDocument</code> to be
 923          *            considered
 924          * @param bound
 925          *            the first position in <code>fDocument</code> to not consider
 926          *            any more, with <code>bound</code> &lt; <code>position</code>,
 927          *            or <code>UNBOUND</code>
 928          * @param ch
 929          *            the <code>char</code> to search for
 930          * @return the highest position of one element in <code>chars</code> in (<code>bound</code>,
 931          *         <code>position</code>] that resides in a Java partition, or
 932          *         <code>NOT_FOUND</code> if none can be found
 933          */
 934         public int scanBackward(int position, int bound, char ch) {
 935                 return scanBackward(position, bound, new CharacterMatch(ch));
 936         }
 937
 938         /**
 939          * Finds the highest position in <code>fDocument</code> such that the
 940          * position is &lt;= <code>position</code> and &gt; <code>bound</code>
 941          * and <code>fDocument.getChar(position) == ch</code> evaluates to
 942          * <code>true</code> for at least one ch in <code>chars</code> and the
 943          * position is in the default partition.
 944          *
 945          * @param position
 946          *            the first character position in <code>fDocument</code> to be
 947          *            considered
 948          * @param bound
 949          *            the first position in <code>fDocument</code> to not consider
 950          *            any more, with <code>bound</code> &lt; <code>position</code>,
 951          *            or <code>UNBOUND</code>
 952          * @param chars
 953          *            an array of <code>char</code> to search for
 954          * @return the highest position of one element in <code>chars</code> in (<code>bound</code>,
 955          *         <code>position</code>] that resides in a Java partition, or
 956          *         <code>NOT_FOUND</code> if none can be found
 957          */
 958         public int scanBackward(int position, int bound, char[] chars) {
 959                 return scanBackward(position, bound, new CharacterMatch(chars));
 960         }
 961
 962         /**
 963          * Checks whether <code>position</code> resides in a default (Java)
 964          * partition of <code>fDocument</code>.
 965          *
 966          * @param position
 967          *            the position to be checked
 968          * @return <code>true</code> if <code>position</code> is in the default
 969          *         partition of <code>fDocument</code>, <code>false</code>
 970          *         otherwise
 971          */
 972         public boolean isDefaultPartition(int position) {
 973                 Assert.isTrue(position >= 0);
 974                 Assert.isTrue(position <= fDocument.getLength());
 975
 976                 try {
 977                         ITypedRegion region = TextUtilities.getPartition(fDocument,
 978                                         fPartitioning, position, false);
 979                         return region.getType().equals(fPartition);
 980
 981                 } catch (BadLocationException e) {
 982                 }
 983
 984                 return false;
 985         }
 986
 987         /**
 988          * Checks if the line seems to be an open condition not followed by a block
 989          * (i.e. an if, while, or for statement with just one following statement,
 990          * see example below).
 991          *
 992          * <pre>
 993          * if (condition)
 994          *      doStuff();
 995          * </pre>
 996          *
 997          * <p>
 998          * Algorithm: if the last non-WS, non-Comment code on the line is an if
 999          * (condition), while (condition), for( expression), do, else, and there is
1000          * no statement after that
1001          * </p>
1002          *
1003          * @param position
1004          *            the insert position of the new character
1005          * @param bound
1006          *            the lowest position to consider
1007          * @return <code>true</code> if the code is a conditional statement or
1008          *         loop without a block, <code>false</code> otherwise
1009          */
1010         public boolean isBracelessBlockStart(int position, int bound) {
1011                 if (position < 1)
1012                         return false;
1013
1014                 switch (previousToken(position, bound)) {
1015                 case TokenDO:
1016                 case TokenELSE:
1017                         return true;
1018                 case TokenRPAREN:
1019                         position = findOpeningPeer(fPos, LPAREN, RPAREN);
1020                         if (position > 0) {
1021                                 switch (previousToken(position - 1, bound)) {
1022                                 case TokenIF:
1023                                 case TokenFOR:
1024                                 case TokenWHILE:
1025                                         return true;
1026                                 }
1027                         }
1028                 }
1029
1030                 return false;
1031         }
1032 }