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   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.phpdt.internal.core.Assert;
  17 import net.sourceforge.phpdt.internal.ui.text.SmartBackspaceManager.UndoSpec;
  18 import net.sourceforge.phpdt.ui.PreferenceConstants;
  19 //import net.sourceforge.phpeclipse.PHPeclipsePlugin;
  20 import net.sourceforge.phpeclipse.phpeditor.PHPUnitEditor;
  21 import net.sourceforge.phpeclipse.ui.WebUI;
  22
  23 import org.eclipse.jface.preference.IPreferenceStore;
  24 import org.eclipse.jface.text.BadLocationException;
  25 import org.eclipse.jface.text.DocumentCommand;
  26 import org.eclipse.jface.text.IAutoEditStrategy;
  27 import org.eclipse.jface.text.IDocument;
  28 import org.eclipse.jface.text.IRegion;
  29 import org.eclipse.jface.text.ITextSelection;
  30 import org.eclipse.jface.text.ITypedRegion;
  31 import org.eclipse.jface.text.Region;
  32 import org.eclipse.jface.text.TextSelection;
  33 import org.eclipse.jface.text.TextUtilities;
  34 import org.eclipse.text.edits.DeleteEdit;
  35 import org.eclipse.text.edits.MalformedTreeException;
  36 import org.eclipse.text.edits.ReplaceEdit;
  37 import org.eclipse.text.edits.TextEdit;
  38 import org.eclipse.ui.IEditorPart;
  39 import org.eclipse.ui.IWorkbenchPage;
  40 import org.eclipse.ui.texteditor.ITextEditorExtension2;
  41 import org.eclipse.ui.texteditor.ITextEditorExtension3;
  42
  43 /**
  44  * Modifies <code>DocumentCommand</code>s inserting semicolons and opening
  45  * braces to place them smartly, i.e. moving them to the end of a line if that
  46  * is what the user expects.
  47  *
  48  * <p>
  49  * In practice, semicolons and braces (and the caret) are moved to the end of
  50  * the line if they are typed anywhere except for semicolons in a
  51  * <code>for</code> statements definition. If the line contains a semicolon or
  52  * brace after the current caret position, the cursor is moved after it.
  53  * </p>
  54  *
  55  * @see org.eclipse.jface.text.DocumentCommand
  56  * @since 3.0
  57  */
  58 public class SmartSemicolonAutoEditStrategy implements IAutoEditStrategy {
  59
  60         /** String representation of a semicolon. */
  61         private static final String SEMICOLON = ";"; //$NON-NLS-1$
  62
  63         /** Char representation of a semicolon. */
  64         private static final char SEMICHAR = ';';
  65
  66         /** String represenattion of a opening brace. */
  67         private static final String BRACE = "{"; //$NON-NLS-1$
  68
  69         /** Char representation of a opening brace */
  70         private static final char BRACECHAR = '{';
  71
  72         private char fCharacter;
  73
  74         private String fPartitioning;
  75
  76         /**
  77          * Creates a new SmartSemicolonAutoEditStrategy.
  78          *
  79          * @param partitioning
  80          *            the document partitioning
  81          */
  82         public SmartSemicolonAutoEditStrategy(String partitioning) {
  83                 fPartitioning = partitioning;
  84         }
  85
  86         /*
  87          * @see org.eclipse.jface.text.IAutoEditStrategy#customizeDocumentCommand(org.eclipse.jface.text.IDocument,
  88          *      org.eclipse.jface.text.DocumentCommand)
  89          */
  90         public void customizeDocumentCommand(IDocument document,
  91                         DocumentCommand command) {
  92                 // 0: early pruning
  93                 // also customize if <code>doit</code> is false (so it works in code
  94                 // completion situations)
  95                 // if (!command.doit)
  96                 // return;
  97
  98                 if (command.text == null)
  99                         return;
 100
 101                 if (command.text.equals(SEMICOLON))
 102                         fCharacter = SEMICHAR;
 103                 else if (command.text.equals(BRACE))
 104                         fCharacter = BRACECHAR;
 105                 else
 106                         return;
 107
 108                 IPreferenceStore store = WebUI.getDefault()
 109                                 .getPreferenceStore();
 110                 if (fCharacter == SEMICHAR
 111                                 && !store
 112                                                 .getBoolean(PreferenceConstants.EDITOR_SMART_SEMICOLON))
 113                         return;
 114                 if (fCharacter == BRACECHAR
 115                                 && !store
 116                                                 .getBoolean(PreferenceConstants.EDITOR_SMART_OPENING_BRACE))
 117                         return;
 118
 119                 IWorkbenchPage page = WebUI.getActivePage();
 120                 if (page == null)
 121                         return;
 122                 IEditorPart part = page.getActiveEditor();
 123                 if (!(part instanceof PHPUnitEditor))
 124                         return;
 125                 PHPUnitEditor editor = (PHPUnitEditor) part;
 126                 if (editor.getInsertMode() != ITextEditorExtension3.SMART_INSERT
 127                                 || !editor.isEditable())
 128                         return;
 129                 ITextEditorExtension2 extension = (ITextEditorExtension2) editor
 130                                 .getAdapter(ITextEditorExtension2.class);
 131                 if (extension != null && !extension.validateEditorInputState())
 132                         return;
 133                 if (isMultilineSelection(document, command))
 134                         return;
 135
 136                 // 1: find concerned line / position in java code, location in statement
 137                 int pos = command.offset;
 138                 ITextSelection line;
 139                 try {
 140                         IRegion l = document.getLineInformationOfOffset(pos);
 141                         line = new TextSelection(document, l.getOffset(), l.getLength());
 142                 } catch (BadLocationException e) {
 143                         return;
 144                 }
 145
 146                 // 2: choose action based on findings (is for-Statement?)
 147                 // for now: compute the best position to insert the new character
 148                 int positionInLine = computeCharacterPosition(document, line, pos
 149                                 - line.getOffset(), fCharacter, fPartitioning);
 150                 int position = positionInLine + line.getOffset();
 151
 152                 // never position before the current position!
 153                 if (position < pos)
 154                         return;
 155
 156                 // never double already existing content
 157                 if (alreadyPresent(document, fCharacter, position))
 158                         return;
 159
 160                 // don't do special processing if what we do is actually the normal
 161                 // behaviour
 162                 String insertion = adjustSpacing(document, position, fCharacter);
 163                 if (command.offset == position && insertion.equals(command.text))
 164                         return;
 165
 166                 try {
 167
 168                         final SmartBackspaceManager manager = (SmartBackspaceManager) editor
 169                                         .getAdapter(SmartBackspaceManager.class);
 170                         if (manager != null
 171                                         && WebUI.getDefault().getPreferenceStore()
 172                                                         .getBoolean(
 173                                                                         PreferenceConstants.EDITOR_SMART_BACKSPACE)) {
 174                                 TextEdit e1 = new ReplaceEdit(command.offset, command.text
 175                                                 .length(), document.get(command.offset, command.length));
 176                                 UndoSpec s1 = new UndoSpec(command.offset
 177                                                 + command.text.length(), new Region(command.offset, 0),
 178                                                 new TextEdit[] { e1 }, 0, null);
 179
 180                                 DeleteEdit smart = new DeleteEdit(position, insertion.length());
 181                                 ReplaceEdit raw = new ReplaceEdit(command.offset,
 182                                                 command.length, command.text);
 183                                 UndoSpec s2 = new UndoSpec(position + insertion.length(),
 184                                                 new Region(command.offset + command.text.length(), 0),
 185                                                 new TextEdit[] { smart, raw }, 2, s1);
 186                                 manager.register(s2);
 187                         }
 188
 189                         // 3: modify command
 190                         command.offset = position;
 191                         command.length = 0;
 192                         command.caretOffset = position;
 193                         command.text = insertion;
 194                         command.doit = true;
 195                         command.owner = null;
 196                 } catch (MalformedTreeException e) {
 197                         WebUI.log(e);
 198                 } catch (BadLocationException e) {
 199                         WebUI.log(e);
 200                 }
 201
 202         }
 203
 204         /**
 205          * Returns <code>true</code> if the document command is applied on a multi
 206          * line selection, <code>false</code> otherwise.
 207          *
 208          * @param document
 209          *            the document
 210          * @param command
 211          *            the command
 212          * @return <code>true</code> if <code>command</code> is a multiline
 213          *         command
 214          */
 215         private boolean isMultilineSelection(IDocument document,
 216                         DocumentCommand command) {
 217                 try {
 218                         return document.getNumberOfLines(command.offset, command.length) > 1;
 219                 } catch (BadLocationException e) {
 220                         // ignore
 221                         return false;
 222                 }
 223         }
 224
 225         /**
 226          * Adds a space before a brace if it is inserted after a parenthesis, equal
 227          * sign, or one of the keywords <code>try, else, do</code>.
 228          *
 229          * @param document
 230          *            the document we are working on
 231          * @param position
 232          *            the insert position of <code>character</code>
 233          * @param character
 234          *            the character to be inserted
 235          * @return a <code>String</code> consisting of <code>character</code>
 236          *         plus any additional spacing
 237          */
 238         private String adjustSpacing(IDocument doc, int position, char character) {
 239                 if (character == BRACECHAR) {
 240                         if (position > 0 && position <= doc.getLength()) {
 241                                 int pos = position - 1;
 242                                 if (looksLike(doc, pos, ")") //$NON-NLS-1$
 243                                                 || looksLike(doc, pos, "=") //$NON-NLS-1$
 244                                                 || looksLike(doc, pos, "]") //$NON-NLS-1$
 245                                                 || looksLike(doc, pos, "try") //$NON-NLS-1$
 246                                                 || looksLike(doc, pos, "else") //$NON-NLS-1$
 247                                                 || looksLike(doc, pos, "synchronized") //$NON-NLS-1$
 248                                                 || looksLike(doc, pos, "static") //$NON-NLS-1$
 249                                                 || looksLike(doc, pos, "finally") //$NON-NLS-1$
 250                                                 || looksLike(doc, pos, "do")) //$NON-NLS-1$
 251                                         return new String(new char[] { ' ', character });
 252                         }
 253                 }
 254
 255                 return new String(new char[] { character });
 256         }
 257
 258         /**
 259          * Checks whether a character to be inserted is already present at the
 260          * insert location (perhaps separated by some whitespace from
 261          * <code>position</code>.
 262          *
 263          * @param document
 264          *            the document we are working on
 265          * @param position
 266          *            the insert position of <code>ch</code>
 267          * @param character
 268          *            the character to be inserted
 269          * @return <code>true</code> if <code>ch</code> is already present at
 270          *         <code>location</code>, <code>false</code> otherwise
 271          */
 272         private boolean alreadyPresent(IDocument document, char ch, int position) {
 273                 int pos = firstNonWhitespaceForward(document, position, fPartitioning,
 274                                 document.getLength());
 275                 try {
 276                         if (pos != -1 && document.getChar(pos) == ch)
 277                                 return true;
 278                 } catch (BadLocationException e) {
 279                 }
 280
 281                 return false;
 282         }
 283
 284         /**
 285          * Computes the next insert position of the given character in the current
 286          * line.
 287          *
 288          * @param document
 289          *            the document we are working on
 290          * @param line
 291          *            the line where the change is being made
 292          * @param offset
 293          *            the position of the caret in the line when
 294          *            <code>character</code> was typed
 295          * @param character
 296          *            the character to look for
 297          * @param partitioning
 298          *            the document partitioning
 299          * @return the position where <code>character</code> should be inserted /
 300          *         replaced
 301          */
 302         protected static int computeCharacterPosition(IDocument document,
 303                         ITextSelection line, int offset, char character, String partitioning) {
 304                 String text = line.getText();
 305                 if (text == null)
 306                         return 0;
 307
 308                 int insertPos;
 309                 if (character == BRACECHAR) {
 310
 311                         insertPos = computeArrayInitializationPos(document, line, offset,
 312                                         partitioning);
 313
 314                         if (insertPos == -1) {
 315                                 insertPos = computeAfterTryDoElse(document, line, offset);
 316                         }
 317
 318                         if (insertPos == -1) {
 319                                 insertPos = computeAfterParenthesis(document, line, offset,
 320                                                 partitioning);
 321                         }
 322
 323                 } else if (character == SEMICHAR) {
 324
 325                         if (isForStatement(text, offset)) {
 326                                 insertPos = -1; // don't do anything in for statements, as semis
 327                                                                 // are vital part of these
 328                         } else {
 329                                 int nextPartitionPos = nextPartitionOrLineEnd(document, line,
 330                                                 offset, partitioning);
 331                                 insertPos = startOfWhitespaceBeforeOffset(text,
 332                                                 nextPartitionPos);
 333                                 // if there is a semi present, return its location as
 334                                 // alreadyPresent() will take it out this way.
 335                                 if (insertPos > 0 && text.charAt(insertPos - 1) == character)
 336                                         insertPos = insertPos - 1;
 337                         }
 338
 339                 } else {
 340                         Assert.isTrue(false);
 341                         return -1;
 342                 }
 343
 344                 return insertPos;
 345         }
 346
 347         /**
 348          * Computes an insert position for an opening brace if <code>offset</code>
 349          * maps to a position in <code>document</code> that looks like being the
 350          * RHS of an assignment or like an array definition.
 351          *
 352          * @param document
 353          *            the document being modified
 354          * @param line
 355          *            the current line under investigation
 356          * @param offset
 357          *            the offset of the caret position, relative to the line start.
 358          * @param partitioning
 359          *            the document partitioning
 360          * @return an insert position relative to the line start if
 361          *         <code>line</code> looks like being an array initialization at
 362          *         <code>offset</code>, -1 otherwise
 363          */
 364         private static int computeArrayInitializationPos(IDocument document,
 365                         ITextSelection line, int offset, String partitioning) {
 366                 // search backward while WS, find = (not != <= >= ==) in default
 367                 // partition
 368                 int pos = offset + line.getOffset();
 369
 370                 if (pos == 0)
 371                         return -1;
 372
 373                 int p = firstNonWhitespaceBackward(document, pos - 1, partitioning, -1);
 374
 375                 if (p == -1)
 376                         return -1;
 377
 378                 try {
 379
 380                         char ch = document.getChar(p);
 381                         if (ch != '=' && ch != ']')
 382                                 return -1;
 383
 384                         if (p == 0)
 385                                 return offset;
 386
 387                         p = firstNonWhitespaceBackward(document, p - 1, partitioning, -1);
 388                         if (p == -1)
 389                                 return -1;
 390
 391                         ch = document.getChar(p);
 392                         if (Scanner.isPHPIdentifierPart(ch) || ch == ']' || ch == '[')
 393                                 return offset;
 394
 395                 } catch (BadLocationException e) {
 396                 }
 397                 return -1;
 398         }
 399
 400         /**
 401          * Computes an insert position for an opening brace if <code>offset</code>
 402          * maps to a position in <code>document</code> involving a keyword taking
 403          * a block after it. These are: <code>try</code>, <code>do</code>,
 404          * <code>synchronized</code>, <code>static</code>,
 405          * <code>finally</code>, or <code>else</code>.
 406          *
 407          * @param document
 408          *            the document being modified
 409          * @param line
 410          *            the current line under investigation
 411          * @param offset
 412          *            the offset of the caret position, relative to the line start.
 413          * @return an insert position relative to the line start if
 414          *         <code>line</code> contains one of the above keywords at or
 415          *         before <code>offset</code>, -1 otherwise
 416          */
 417         private static int computeAfterTryDoElse(IDocument doc,
 418                         ITextSelection line, int offset) {
 419                 // search backward while WS, find 'try', 'do', 'else' in default
 420                 // partition
 421                 int p = offset + line.getOffset();
 422                 p = firstWhitespaceToRight(doc, p);
 423                 if (p == -1)
 424                         return -1;
 425                 p--;
 426
 427                 if (looksLike(doc, p, "try") //$NON-NLS-1$
 428                                 || looksLike(doc, p, "do") //$NON-NLS-1$
 429                                 || looksLike(doc, p, "synchronized") //$NON-NLS-1$
 430                                 || looksLike(doc, p, "static") //$NON-NLS-1$
 431                                 || looksLike(doc, p, "finally") //$NON-NLS-1$
 432                                 || looksLike(doc, p, "else")) //$NON-NLS-1$
 433                         return p + 1 - line.getOffset();
 434
 435                 return -1;
 436         }
 437
 438         /**
 439          * Computes an insert position for an opening brace if <code>offset</code>
 440          * maps to a position in <code>document</code> with a expression in
 441          * parenthesis that will take a block after the closing parenthesis.
 442          *
 443          * @param document
 444          *            the document being modified
 445          * @param line
 446          *            the current line under investigation
 447          * @param offset
 448          *            the offset of the caret position, relative to the line start.
 449          * @param partitioning
 450          *            the document partitioning
 451          * @return an insert position relative to the line start if
 452          *         <code>line</code> contains a parenthesized expression that can
 453          *         be followed by a block, -1 otherwise
 454          */
 455         private static int computeAfterParenthesis(IDocument document,
 456                         ITextSelection line, int offset, String partitioning) {
 457                 // find the opening parenthesis for every closing parenthesis on the
 458                 // current line after offset
 459                 // return the position behind the closing parenthesis if it looks like a
 460                 // method declaration
 461                 // or an expression for an if, while, for, catch statement
 462                 int pos = offset + line.getOffset();
 463                 int length = line.getOffset() + line.getLength();
 464                 int scanTo = scanForward(document, pos, partitioning, length, '}');
 465                 if (scanTo == -1)
 466                         scanTo = length;
 467
 468                 int closingParen = findClosingParenToLeft(document, pos, partitioning) - 1;
 469
 470                 while (true) {
 471                         int startScan = closingParen + 1;
 472                         closingParen = scanForward(document, startScan, partitioning,
 473                                         scanTo, ')');
 474                         if (closingParen == -1)
 475                                 break;
 476
 477                         int openingParen = findOpeningParenMatch(document, closingParen,
 478                                         partitioning);
 479
 480                         // no way an expression at the beginning of the document can mean
 481                         // anything
 482                         if (openingParen < 1)
 483                                 break;
 484
 485                         // only select insert positions for parenthesis currently embracing
 486                         // the caret
 487                         if (openingParen > pos)
 488                                 continue;
 489
 490                         if (looksLikeAnonymousClassDef(document, openingParen - 1,
 491                                         partitioning))
 492                                 return closingParen + 1 - line.getOffset();
 493
 494                         if (looksLikeIfWhileForCatch(document, openingParen - 1,
 495                                         partitioning))
 496                                 return closingParen + 1 - line.getOffset();
 497
 498                         if (looksLikeMethodDecl(document, openingParen - 1, partitioning))
 499                                 return closingParen + 1 - line.getOffset();
 500
 501                 }
 502
 503                 return -1;
 504         }
 505
 506         /**
 507          * Finds a closing parenthesis to the left of <code>position</code> in
 508          * document, where that parenthesis is only separated by whitespace from
 509          * <code>position</code>. If no such parenthesis can be found,
 510          * <code>position</code> is returned.
 511          *
 512          * @param document
 513          *            the document being modified
 514          * @param position
 515          *            the first character position in <code>document</code> to be
 516          *            considered
 517          * @param partitioning
 518          *            the document partitioning
 519          * @return the position of a closing parenthesis left to
 520          *         <code>position</code> separated only by whitespace, or
 521          *         <code>position</code> if no parenthesis can be found
 522          */
 523         private static int findClosingParenToLeft(IDocument document, int position,
 524                         String partitioning) {
 525                 final char CLOSING_PAREN = ')';
 526                 try {
 527                         if (position < 1)
 528                                 return position;
 529
 530                         int nonWS = firstNonWhitespaceBackward(document, position - 1,
 531                                         partitioning, -1);
 532                         if (nonWS != -1 && document.getChar(nonWS) == CLOSING_PAREN)
 533                                 return nonWS;
 534                 } catch (BadLocationException e1) {
 535                 }
 536                 return position;
 537         }
 538
 539         /**
 540          * Finds the first whitespace character position to the right of (and
 541          * including) <code>position</code>.
 542          *
 543          * @param document
 544          *            the document being modified
 545          * @param position
 546          *            the first character position in <code>document</code> to be
 547          *            considered
 548          * @return the position of a whitespace character greater or equal than
 549          *         <code>position</code> separated only by whitespace, or -1 if
 550          *         none found
 551          */
 552         private static int firstWhitespaceToRight(IDocument document, int position) {
 553                 int length = document.getLength();
 554                 Assert.isTrue(position >= 0);
 555                 Assert.isTrue(position <= length);
 556
 557                 try {
 558                         while (position < length) {
 559                                 char ch = document.getChar(position);
 560                                 if (Character.isWhitespace(ch))
 561                                         return position;
 562                                 position++;
 563                         }
 564                         return position;
 565                 } catch (BadLocationException e) {
 566                 }
 567                 return -1;
 568         }
 569
 570         /**
 571          * Finds the highest position in <code>document</code> such that the
 572          * position is &lt;= <code>position</code> and &gt; <code>bound</code>
 573          * and <code>Character.isWhitespace(document.getChar(pos))</code>
 574          * evaluates to <code>false</code> and the position is in the default
 575          * partition.
 576          *
 577          * @param document
 578          *            the document being modified
 579          * @param position
 580          *            the first character position in <code>document</code> to be
 581          *            considered
 582          * @param partitioning
 583          *            the document partitioning
 584          * @param bound
 585          *            the first position in <code>document</code> to not consider
 586          *            any more, with <code>bound</code> &gt; <code>position</code>
 587          * @return the highest position of one element in <code>chars</code> in [<code>position</code>,
 588          *         <code>scanTo</code>) that resides in a Java partition, or
 589          *         <code>-1</code> if none can be found
 590          */
 591         private static int firstNonWhitespaceBackward(IDocument document,
 592                         int position, String partitioning, int bound) {
 593                 Assert.isTrue(position < document.getLength());
 594                 Assert.isTrue(bound >= -1);
 595
 596                 try {
 597                         while (position > bound) {
 598                                 char ch = document.getChar(position);
 599                                 if (!Character.isWhitespace(ch)
 600                                                 && isDefaultPartition(document, position, partitioning))
 601                                         return position;
 602                                 position--;
 603                         }
 604                 } catch (BadLocationException e) {
 605                 }
 606                 return -1;
 607         }
 608
 609         /**
 610          * Finds the smallest position in <code>document</code> such that the
 611          * position is &gt;= <code>position</code> and &lt; <code>bound</code>
 612          * and <code>Character.isWhitespace(document.getChar(pos))</code>
 613          * evaluates to <code>false</code> and the position is in the default
 614          * partition.
 615          *
 616          * @param document
 617          *            the document being modified
 618          * @param position
 619          *            the first character position in <code>document</code> to be
 620          *            considered
 621          * @param partitioning
 622          *            the document partitioning
 623          * @param bound
 624          *            the first position in <code>document</code> to not consider
 625          *            any more, with <code>bound</code> &gt; <code>position</code>
 626          * @return the smallest position of one element in <code>chars</code> in [<code>position</code>,
 627          *         <code>scanTo</code>) that resides in a Java partition, or
 628          *         <code>-1</code> if none can be found
 629          */
 630         private static int firstNonWhitespaceForward(IDocument document,
 631                         int position, String partitioning, int bound) {
 632                 Assert.isTrue(position >= 0);
 633                 Assert.isTrue(bound <= document.getLength());
 634
 635                 try {
 636                         while (position < bound) {
 637                                 char ch = document.getChar(position);
 638                                 if (!Character.isWhitespace(ch)
 639                                                 && isDefaultPartition(document, position, partitioning))
 640                                         return position;
 641                                 position++;
 642                         }
 643                 } catch (BadLocationException e) {
 644                 }
 645                 return -1;
 646         }
 647
 648         /**
 649          * Finds the highest position in <code>document</code> such that the
 650          * position is &lt;= <code>position</code> and &gt; <code>bound</code>
 651          * and <code>document.getChar(position) == ch</code> evaluates to
 652          * <code>true</code> for at least one ch in <code>chars</code> and the
 653          * position is in the default partition.
 654          *
 655          * @param document
 656          *            the document being modified
 657          * @param position
 658          *            the first character position in <code>document</code> to be
 659          *            considered
 660          * @param partitioning
 661          *            the document partitioning
 662          * @param bound
 663          *            the first position in <code>document</code> to not consider
 664          *            any more, with <code>scanTo</code> &gt;
 665          *            <code>position</code>
 666          * @param chars
 667          *            an array of <code>char</code> to search for
 668          * @return the highest position of one element in <code>chars</code> in (<code>bound</code>,
 669          *         <code>position</code>] that resides in a Java partition, or
 670          *         <code>-1</code> if none can be found
 671          */
 672         private static int scanBackward(IDocument document, int position,
 673                         String partitioning, int bound, char[] chars) {
 674                 Assert.isTrue(bound >= -1);
 675                 Assert.isTrue(position < document.getLength());
 676
 677                 Arrays.sort(chars);
 678
 679                 try {
 680                         while (position > bound) {
 681
 682                                 if (Arrays.binarySearch(chars, document.getChar(position)) >= 0
 683                                                 && isDefaultPartition(document, position, partitioning))
 684                                         return position;
 685
 686                                 position--;
 687                         }
 688                 } catch (BadLocationException e) {
 689                 }
 690                 return -1;
 691         }
 692
 693         // /**
 694         // * Finds the highest position in <code>document</code> such that the
 695         // position is &lt;= <code>position</code>
 696         // * and &gt; <code>bound</code> and <code>document.getChar(position) ==
 697         // ch</code> evaluates to <code>true</code>
 698         // * and the position is in the default partition.
 699         // *
 700         // * @param document the document being modified
 701         // * @param position the first character position in <code>document</code>
 702         // to be considered
 703         // * @param bound the first position in <code>document</code> to not
 704         // consider any more, with <code>scanTo</code> &gt; <code>position</code>
 705         // * @param chars an array of <code>char</code> to search for
 706         // * @return the highest position of one element in <code>chars</code> in
 707         // [<code>position</code>, <code>scanTo</code>) that resides in a Java
 708         // partition, or <code>-1</code> if none can be found
 709         // */
 710         // private static int scanBackward(IDocument document, int position, int
 711         // bound, char ch) {
 712         // return scanBackward(document, position, bound, new char[] {ch});
 713         // }
 714         //
 715         /**
 716          * Finds the lowest position in <code>document</code> such that the
 717          * position is &gt;= <code>position</code> and &lt; <code>bound</code>
 718          * and <code>document.getChar(position) == ch</code> evaluates to
 719          * <code>true</code> for at least one ch in <code>chars</code> and the
 720          * position is in the default partition.
 721          *
 722          * @param document
 723          *            the document being modified
 724          * @param position
 725          *            the first character position in <code>document</code> to be
 726          *            considered
 727          * @param partitioning
 728          *            the document partitioning
 729          * @param bound
 730          *            the first position in <code>document</code> to not consider
 731          *            any more, with <code>scanTo</code> &gt;
 732          *            <code>position</code>
 733          * @param chars
 734          *            an array of <code>char</code> to search for
 735          * @return the lowest position of one element in <code>chars</code> in [<code>position</code>,
 736          *         <code>bound</code>) that resides in a Java partition, or
 737          *         <code>-1</code> if none can be found
 738          */
 739         private static int scanForward(IDocument document, int position,
 740                         String partitioning, int bound, char[] chars) {
 741                 Assert.isTrue(position >= 0);
 742                 Assert.isTrue(bound <= document.getLength());
 743
 744                 Arrays.sort(chars);
 745
 746                 try {
 747                         while (position < bound) {
 748
 749                                 if (Arrays.binarySearch(chars, document.getChar(position)) >= 0
 750                                                 && isDefaultPartition(document, position, partitioning))
 751                                         return position;
 752
 753                                 position++;
 754                         }
 755                 } catch (BadLocationException e) {
 756                 }
 757                 return -1;
 758         }
 759
 760         /**
 761          * Finds the lowest position in <code>document</code> such that the
 762          * position is &gt;= <code>position</code> and &lt; <code>bound</code>
 763          * and <code>document.getChar(position) == ch</code> evaluates to
 764          * <code>true</code> and the position is in the default partition.
 765          *
 766          * @param document
 767          *            the document being modified
 768          * @param position
 769          *            the first character position in <code>document</code> to be
 770          *            considered
 771          * @param partitioning
 772          *            the document partitioning
 773          * @param bound
 774          *            the first position in <code>document</code> to not consider
 775          *            any more, with <code>scanTo</code> &gt;
 776          *            <code>position</code>
 777          * @param chars
 778          *            an array of <code>char</code> to search for
 779          * @return the lowest position of one element in <code>chars</code> in [<code>position</code>,
 780          *         <code>bound</code>) that resides in a Java partition, or
 781          *         <code>-1</code> if none can be found
 782          */
 783         private static int scanForward(IDocument document, int position,
 784                         String partitioning, int bound, char ch) {
 785                 return scanForward(document, position, partitioning, bound,
 786                                 new char[] { ch });
 787         }
 788
 789         /**
 790          * Checks whether the content of <code>document</code> in the range (<code>offset</code>,
 791          * <code>length</code>) contains the <code>new</code> keyword.
 792          *
 793          * @param document
 794          *            the document being modified
 795          * @param offset
 796          *            the first character position in <code>document</code> to be
 797          *            considered
 798          * @param length
 799          *            the length of the character range to be considered
 800          * @param partitioning
 801          *            the document partitioning
 802          * @return <code>true</code> if the specified character range contains a
 803          *         <code>new</code> keyword, <code>false</code> otherwise.
 804          */
 805         private static boolean isNewMatch(IDocument document, int offset,
 806                         int length, String partitioning) {
 807                 Assert.isTrue(length >= 0);
 808                 Assert.isTrue(offset >= 0);
 809                 Assert.isTrue(offset + length < document.getLength() + 1);
 810
 811                 try {
 812                         String text = document.get(offset, length);
 813                         int pos = text.indexOf("new"); //$NON-NLS-1$
 814
 815                         while (pos != -1
 816                                         && !isDefaultPartition(document, pos + offset, partitioning))
 817                                 pos = text.indexOf("new", pos + 2); //$NON-NLS-1$
 818
 819                         if (pos < 0)
 820                                 return false;
 821
 822                         if (pos != 0 && Scanner.isPHPIdentifierPart(text.charAt(pos - 1)))
 823                                 return false;
 824
 825                         if (pos + 3 < length
 826                                         && Scanner.isPHPIdentifierPart(text.charAt(pos + 3)))
 827                                 return false;
 828
 829                         return true;
 830
 831                 } catch (BadLocationException e) {
 832                 }
 833                 return false;
 834         }
 835
 836         /**
 837          * Checks whether the content of <code>document</code> at
 838          * <code>position</code> looks like an anonymous class definition.
 839          * <code>position</code> must be to the left of the opening parenthesis of
 840          * the definition's parameter list.
 841          *
 842          * @param document
 843          *            the document being modified
 844          * @param position
 845          *            the first character position in <code>document</code> to be
 846          *            considered
 847          * @param partitioning
 848          *            the document partitioning
 849          * @return <code>true</code> if the content of <code>document</code>
 850          *         looks like an anonymous class definition, <code>false</code>
 851          *         otherwise
 852          */
 853         private static boolean looksLikeAnonymousClassDef(IDocument document,
 854                         int position, String partitioning) {
 855                 int previousCommaOrParen = scanBackward(document, position - 1,
 856                                 partitioning, -1, new char[] { ',', '(' });
 857                 if (previousCommaOrParen == -1 || position < previousCommaOrParen + 5) // 2
 858                                                                                                                                                                 // for
 859                                                                                                                                                                 // borders,
 860                                                                                                                                                                 // 3
 861                                                                                                                                                                 // for
 862                                                                                                                                                                 // "new"
 863                         return false;
 864
 865                 if (isNewMatch(document, previousCommaOrParen + 1, position
 866                                 - previousCommaOrParen - 2, partitioning))
 867                         return true;
 868
 869                 return false;
 870         }
 871
 872         /**
 873          * Checks whether <code>position</code> resides in a default (Java)
 874          * partition of <code>document</code>.
 875          *
 876          * @param document
 877          *            the document being modified
 878          * @param position
 879          *            the position to be checked
 880          * @param partitioning
 881          *            the document partitioning
 882          * @return <code>true</code> if <code>position</code> is in the default
 883          *         partition of <code>document</code>, <code>false</code>
 884          *         otherwise
 885          */
 886         private static boolean isDefaultPartition(IDocument document, int position,
 887                         String partitioning) {
 888                 Assert.isTrue(position >= 0);
 889                 Assert.isTrue(position <= document.getLength());
 890
 891                 try {
 892                         // don't use getPartition2 since we're interested in the scanned
 893                         // character's partition
 894                         ITypedRegion region = TextUtilities.getPartition(document,
 895                                         partitioning, position, false);
 896                         return region.getType().equals(IDocument.DEFAULT_CONTENT_TYPE);
 897
 898                 } catch (BadLocationException e) {
 899                 }
 900
 901                 return false;
 902         }
 903
 904         /**
 905          * Finds the position of the parenthesis matching the closing parenthesis at
 906          * <code>position</code>.
 907          *
 908          * @param document
 909          *            the document being modified
 910          * @param position
 911          *            the position in <code>document</code> of a closing
 912          *            parenthesis
 913          * @param partitioning
 914          *            the document partitioning
 915          * @return the position in <code>document</code> of the matching
 916          *         parenthesis, or -1 if none can be found
 917          */
 918         private static int findOpeningParenMatch(IDocument document, int position,
 919                         String partitioning) {
 920                 final char CLOSING_PAREN = ')';
 921                 final char OPENING_PAREN = '(';
 922
 923                 Assert.isTrue(position < document.getLength());
 924                 Assert.isTrue(position >= 0);
 925                 Assert.isTrue(isDefaultPartition(document, position, partitioning));
 926
 927                 try {
 928
 929                         Assert.isTrue(document.getChar(position) == CLOSING_PAREN);
 930
 931                         int depth = 1;
 932                         while (true) {
 933                                 position = scanBackward(document, position - 1, partitioning,
 934                                                 -1, new char[] { CLOSING_PAREN, OPENING_PAREN });
 935                                 if (position == -1)
 936                                         return -1;
 937
 938                                 if (document.getChar(position) == CLOSING_PAREN)
 939                                         depth++;
 940                                 else
 941                                         depth--;
 942
 943                                 if (depth == 0)
 944                                         return position;
 945                         }
 946
 947                 } catch (BadLocationException e) {
 948                         return -1;
 949                 }
 950         }
 951
 952         /**
 953          * Checks whether, to the left of <code>position</code> and separated only
 954          * by whitespace, <code>document</code> contains a keyword taking a
 955          * parameter list and a block after it. These are: <code>if</code>,
 956          * <code>while</code>, <code>catch</code>, <code>for</code>,
 957          * <code>synchronized</code>, <code>switch</code>.
 958          *
 959          * @param document
 960          *            the document being modified
 961          * @param position
 962          *            the first character position in <code>document</code> to be
 963          *            considered
 964          * @param partitioning
 965          *            the document partitioning
 966          * @return <code>true</code> if <code>document</code> contains any of
 967          *         the above keywords to the left of <code>position</code>,
 968          *         <code>false</code> otherwise
 969          */
 970         private static boolean looksLikeIfWhileForCatch(IDocument document,
 971                         int position, String partitioning) {
 972                 position = firstNonWhitespaceBackward(document, position, partitioning,
 973                                 -1);
 974                 if (position == -1)
 975                         return false;
 976
 977                 return looksLike(document, position, "if") //$NON-NLS-1$
 978                                 || looksLike(document, position, "while") //$NON-NLS-1$
 979                                 || looksLike(document, position, "catch") //$NON-NLS-1$
 980                                 || looksLike(document, position, "synchronized") //$NON-NLS-1$
 981                                 || looksLike(document, position, "switch") //$NON-NLS-1$
 982                                 || looksLike(document, position, "for"); //$NON-NLS-1$
 983         }
 984
 985         /**
 986          * Checks whether code>document</code> contains the <code>String</code> <code>like</code>
 987          * such that its last character is at <code>position</code>. If <code>like</code>
 988          * starts with a identifier part (as determined by
 989          * {@link Scanner#isPHPIdentifierPart(char)}), it is also made sure that
 990          * <code>like</code> is preceded by some non-identifier character or
 991          * stands at the document start.
 992          *
 993          * @param document
 994          *            the document being modified
 995          * @param position
 996          *            the first character position in <code>document</code> to be
 997          *            considered
 998          * @param like
 999          *            the <code>String</code> to look for.
1000          * @return <code>true</code> if <code>document</code> contains <code>like</code>
1001          *         such that it ends at <code>position</code>, <code>false</code>
1002          *         otherwise
1003          */
1004         private static boolean looksLike(IDocument document, int position,
1005                         String like) {
1006                 int length = like.length();
1007                 if (position < length - 1)
1008                         return false;
1009
1010                 try {
1011                         if (!like.equals(document.get(position - length + 1, length)))
1012                                 return false;
1013
1014                         if (position >= length
1015                                         && Scanner.isPHPIdentifierPart(like.charAt(0))
1016                                         && Scanner.isPHPIdentifierPart(document.getChar(position
1017                                                         - length)))
1018                                 return false;
1019
1020                 } catch (BadLocationException e) {
1021                         return false;
1022                 }
1023
1024                 return true;
1025         }
1026
1027         /**
1028          * Checks whether the content of <code>document</code> at
1029          * <code>position</code> looks like a method declaration header (i.e. only
1030          * the return type and method name). <code>position</code> must be just
1031          * left of the opening parenthesis of the parameter list.
1032          *
1033          * @param document
1034          *            the document being modified
1035          * @param position
1036          *            the first character position in <code>document</code> to be
1037          *            considered
1038          * @param partitioning
1039          *            the document partitioning
1040          * @return <code>true</code> if the content of <code>document</code>
1041          *         looks like a method definition, <code>false</code> otherwise
1042          */
1043         private static boolean looksLikeMethodDecl(IDocument document,
1044                         int position, String partitioning) {
1045
1046                 // method name
1047                 position = eatIdentToLeft(document, position, partitioning);
1048                 if (position < 1)
1049                         return false;
1050
1051                 position = eatBrackets(document, position - 1, partitioning);
1052                 if (position < 1)
1053                         return false;
1054
1055                 position = eatIdentToLeft(document, position - 1, partitioning);
1056
1057                 return position != -1;
1058         }
1059
1060         /**
1061          * From <code>position</code> to the left, eats any whitespace and then a
1062          * pair of brackets as used to declare an array return type like
1063          *
1064          * <pre>
1065          * String [ ]
1066          * </pre>. The return value is either the position of the opening bracket
1067          * or <code>position</code> if no pair of brackets can be parsed.
1068          *
1069          * @param document
1070          *            the document being modified
1071          * @param position
1072          *            the first character position in <code>document</code> to be
1073          *            considered
1074          * @param partitioning
1075          *            the document partitioning
1076          * @return the smallest character position of bracket pair or
1077          *         <code>position</code>
1078          */
1079         private static int eatBrackets(IDocument document, int position,
1080                         String partitioning) {
1081                 // accept array return type
1082                 int pos = firstNonWhitespaceBackward(document, position, partitioning,
1083                                 -1);
1084                 try {
1085                         if (pos > 1 && document.getChar(pos) == ']') {
1086                                 pos = firstNonWhitespaceBackward(document, pos - 1,
1087                                                 partitioning, -1);
1088                                 if (pos > 0 && document.getChar(pos) == '[')
1089                                         return pos;
1090                         }
1091                 } catch (BadLocationException e) {
1092                         // won't happen
1093                 }
1094                 return position;
1095         }
1096
1097         /**
1098          * From <code>position</code> to the left, eats any whitespace and the
1099          * first identifier, returning the position of the first identifier
1100          * character (in normal read order).
1101          * <p>
1102          * When called on a document with content <code>" some string  "</code> and
1103          * positionition 13, the return value will be 6 (the first letter in
1104          * <code>string</code>).
1105          * </p>
1106          *
1107          * @param document
1108          *            the document being modified
1109          * @param position
1110          *            the first character position in <code>document</code> to be
1111          *            considered
1112          * @param partitioning
1113          *            the document partitioning
1114          * @return the smallest character position of an identifier or -1 if none
1115          *         can be found; always &lt;= <code>position</code>
1116          */
1117         private static int eatIdentToLeft(IDocument document, int position,
1118                         String partitioning) {
1119                 if (position < 0)
1120                         return -1;
1121                 Assert.isTrue(position < document.getLength());
1122
1123                 int p = firstNonWhitespaceBackward(document, position, partitioning, -1);
1124                 if (p == -1)
1125                         return -1;
1126
1127                 try {
1128                         while (p >= 0) {
1129
1130                                 char ch = document.getChar(p);
1131                                 if (Scanner.isPHPIdentifierPart(ch)) {
1132                                         p--;
1133                                         continue;
1134                                 }
1135
1136                                 // length must be > 0
1137                                 if (Character.isWhitespace(ch) && p != position)
1138                                         return p + 1;
1139                                 else
1140                                         return -1;
1141
1142                         }
1143
1144                         // start of document reached
1145                         return 0;
1146
1147                 } catch (BadLocationException e) {
1148                 }
1149                 return -1;
1150         }
1151
1152         /**
1153          * Returns a position in the first java partition after the last non-empty
1154          * and non-comment partition. There is no non-whitespace from the returned
1155          * position to the end of the partition it is contained in.
1156          *
1157          * @param document
1158          *            the document being modified
1159          * @param line
1160          *            the line under investigation
1161          * @param offset
1162          *            the caret offset into <code>line</code>
1163          * @param partitioning
1164          *            the document partitioning
1165          * @return the position of the next Java partition, or the end of
1166          *         <code>line</code>
1167          */
1168         private static int nextPartitionOrLineEnd(IDocument document,
1169                         ITextSelection line, int offset, String partitioning) {
1170                 // run relative to document
1171                 final int docOffset = offset + line.getOffset();
1172                 final int eol = line.getOffset() + line.getLength();
1173                 int nextPartitionPos = eol; // init with line end
1174                 int validPosition = docOffset;
1175
1176                 try {
1177                         ITypedRegion partition = TextUtilities.getPartition(document,
1178                                         partitioning, nextPartitionPos, true);
1179                         validPosition = getValidPositionForPartition(document, partition,
1180                                         eol);
1181                         while (validPosition == -1) {
1182                                 nextPartitionPos = partition.getOffset() - 1;
1183                                 if (nextPartitionPos < docOffset) {
1184                                         validPosition = docOffset;
1185                                         break;
1186                                 }
1187                                 partition = TextUtilities.getPartition(document, partitioning,
1188                                                 nextPartitionPos, false);
1189                                 validPosition = getValidPositionForPartition(document,
1190                                                 partition, eol);
1191                         }
1192                 } catch (BadLocationException e) {
1193                 }
1194
1195                 validPosition = Math.max(validPosition, docOffset);
1196                 // make relative to line
1197                 validPosition -= line.getOffset();
1198                 return validPosition;
1199         }
1200
1201         /**
1202          * Returns a valid insert location (except for whitespace) in
1203          * <code>partition</code> or -1 if there is no valid insert location. An
1204          * valid insert location is right after any java string or character
1205          * partition, or at the end of a java default partition, but never behind
1206          * <code>maxOffset</code>. Comment partitions or empty java partitions do
1207          * never yield valid insert positions.
1208          *
1209          * @param doc
1210          *            the document being modified
1211          * @param partition
1212          *            the current partition
1213          * @param maxOffset
1214          *            the maximum offset to consider
1215          * @return a valid insert location in <code>partition</code>, or -1 if
1216          *         there is no valid insert location
1217          */
1218         private static int getValidPositionForPartition(IDocument doc,
1219                         ITypedRegion partition, int maxOffset) {
1220                 final int INVALID = -1;
1221
1222                 if (IPHPPartitions.PHP_PHPDOC_COMMENT.equals(partition.getType()))
1223                         return INVALID;
1224                 if (IPHPPartitions.PHP_MULTILINE_COMMENT.equals(partition.getType()))
1225                         return INVALID;
1226                 if (IPHPPartitions.PHP_SINGLELINE_COMMENT.equals(partition.getType()))
1227                         return INVALID;
1228
1229                 int endOffset = Math.min(maxOffset, partition.getOffset()
1230                                 + partition.getLength());
1231
1232                 // if (IPHPPartitions.JAVA_CHARACTER.equals(partition.getType()))
1233                 // return endOffset;
1234                 if (IPHPPartitions.PHP_STRING_DQ.equals(partition.getType()))
1235                         return endOffset;
1236                 if (IPHPPartitions.PHP_STRING_SQ.equals(partition.getType()))
1237                         return endOffset;
1238                 if (IPHPPartitions.PHP_STRING_HEREDOC.equals(partition.getType()))
1239                         return endOffset;
1240                 if (IDocument.DEFAULT_CONTENT_TYPE.equals(partition.getType())) {
1241                         try {
1242                                 if (doc.get(partition.getOffset(),
1243                                                 endOffset - partition.getOffset()).trim().length() == 0)
1244                                         return INVALID;
1245                                 else
1246                                         return endOffset;
1247                         } catch (BadLocationException e) {
1248                                 return INVALID;
1249                         }
1250                 }
1251                 // default: we don't know anything about the partition - assume valid
1252                 return endOffset;
1253         }
1254
1255         /**
1256          * Determines whether the current line contains a for statement. Algorithm:
1257          * any "for" word in the line is a positive, "for" contained in a string
1258          * literal will produce a false positive.
1259          *
1260          * @param line
1261          *            the line where the change is being made
1262          * @param offset
1263          *            the position of the caret
1264          * @return <code>true</code> if <code>line</code> contains
1265          *         <code>for</code>, <code>false</code> otherwise
1266          */
1267         private static boolean isForStatement(String line, int offset) {
1268                 /* searching for (^|\s)for(\s|$) */
1269                 int forPos = line.indexOf("for"); //$NON-NLS-1$
1270                 if (forPos != -1) {
1271                         if ((forPos == 0 || !Scanner.isPHPIdentifierPart(line
1272                                         .charAt(forPos - 1)))
1273                                         && (line.length() == forPos + 3 || !Scanner
1274                                                         .isPHPIdentifierPart(line.charAt(forPos + 3))))
1275                                 return true;
1276                 }
1277                 return false;
1278         }
1279
1280         /**
1281          * Returns the position in <code>text</code> after which there comes only
1282          * whitespace, up to <code>offset</code>.
1283          *
1284          * @param text
1285          *            the text being searched
1286          * @param offset
1287          *            the maximum offset to search for
1288          * @return the smallest value <code>v</code> such that
1289          *         <code>text.substring(v, offset).trim() == 0</code>
1290          */
1291         private static int startOfWhitespaceBeforeOffset(String text, int offset) {
1292                 int i = Math.min(offset, text.length());
1293                 for (; i >= 1; i--) {
1294                         if (!Character.isWhitespace(text.charAt(i - 1)))
1295                                 break;
1296                 }
1297                 return i;
1298         }
1299 }