net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/ui/text/SmartSemicolonAutoEditStrategy.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 //incastrix
  17 //import net.sourceforge.phpdt.internal.corext.Assert;
  18 import org.eclipse.core.runtime.Assert;
  19 import net.sourceforge.phpdt.internal.ui.text.SmartBackspaceManager.UndoSpec;
  20 import net.sourceforge.phpdt.ui.PreferenceConstants;
  21 import net.sourceforge.phpeclipse.PHPeclipsePlugin;
  22 import net.sourceforge.phpeclipse.phpeditor.PHPUnitEditor;
  23
  24 import org.eclipse.jface.preference.IPreferenceStore;
  25 import org.eclipse.jface.text.BadLocationException;
  26 import org.eclipse.jface.text.DocumentCommand;
  27 import org.eclipse.jface.text.IAutoEditStrategy;
  28 import org.eclipse.jface.text.IDocument;
  29 import org.eclipse.jface.text.IRegion;
  30 import org.eclipse.jface.text.ITextSelection;
  31 import org.eclipse.jface.text.ITypedRegion;
  32 import org.eclipse.jface.text.Region;
  33 import org.eclipse.jface.text.TextSelection;
  34 import org.eclipse.jface.text.TextUtilities;
  35 import org.eclipse.text.edits.DeleteEdit;
  36 import org.eclipse.text.edits.MalformedTreeException;
  37 import org.eclipse.text.edits.ReplaceEdit;
  38 import org.eclipse.text.edits.TextEdit;
  39 import org.eclipse.ui.IEditorPart;
  40 import org.eclipse.ui.IWorkbenchPage;
  41 import org.eclipse.ui.texteditor.ITextEditorExtension2;
  42 import org.eclipse.ui.texteditor.ITextEditorExtension3;
  43
  44 /**
  45  * Modifies <code>DocumentCommand</code>s inserting semicolons and opening
  46  * braces to place them smartly, i.e. moving them to the end of a line if that
  47  * is what the user expects.
  48  *
  49  * <p>
  50  * In practice, semicolons and braces (and the caret) are moved to the end of
  51  * the line if they are typed anywhere except for semicolons in a
  52  * <code>for</code> statements definition. If the line contains a semicolon or
  53  * brace after the current caret position, the cursor is moved after it.
  54  * </p>
  55  *
  56  * @see org.eclipse.jface.text.DocumentCommand
  57  * @since 3.0
  58  */
  59 public class SmartSemicolonAutoEditStrategy implements IAutoEditStrategy {
  60
  61         /** String representation of a semicolon. */
  62         private static final String SEMICOLON = ";"; //$NON-NLS-1$
  63
  64         /** Char representation of a semicolon. */
  65         private static final char SEMICHAR = ';';
  66
  67         /** String representation of a opening brace. */
  68         private static final String BRACE = "{"; //$NON-NLS-1$
  69
  70         /** Char representation of a opening brace */
  71         private static final char BRACECHAR = '{';
  72
  73         private char fCharacter;
  74
  75         private String fPartitioning;
  76
  77         /**
  78          * Creates a new SmartSemicolonAutoEditStrategy.
  79          *
  80          * @param partitioning
  81          *            the document partitioning
  82          */
  83         public SmartSemicolonAutoEditStrategy(String partitioning) {
  84                 fPartitioning = partitioning;
  85         }
  86
  87         /*
  88          * @see org.eclipse.jface.text.IAutoEditStrategy#customizeDocumentCommand(org.eclipse.jface.text.IDocument,
  89          *      org.eclipse.jface.text.DocumentCommand)
  90          */
  91         public void customizeDocumentCommand(IDocument document,
  92                         DocumentCommand command) {
  93                 // 0: early pruning
  94                 // also customize if <code>doit</code> is false (so it works in code
  95                 // completion situations)
  96                 // if (!command.doit)
  97                 // return;
  98
  99                 if (command.text == null)
 100                         return;
 101
 102                 if (command.text.equals(SEMICOLON))
 103                         fCharacter = SEMICHAR;
 104                 else if (command.text.equals(BRACE))
 105                         fCharacter = BRACECHAR;
 106                 else
 107                         return;
 108
 109                 IPreferenceStore store = PHPeclipsePlugin.getDefault()
 110                                 .getPreferenceStore();
 111                 if (fCharacter == SEMICHAR
 112                                 && !store
 113                                                 .getBoolean(PreferenceConstants.EDITOR_SMART_SEMICOLON))
 114                         return;
 115                 if (fCharacter == BRACECHAR
 116                                 && !store
 117                                                 .getBoolean(PreferenceConstants.EDITOR_SMART_OPENING_BRACE))
 118                         return;
 119
 120                 IWorkbenchPage page = PHPeclipsePlugin.getActivePage();
 121                 if (page == null)
 122                         return;
 123                 IEditorPart part = page.getActiveEditor();
 124                 if (!(part instanceof PHPUnitEditor))
 125                         return;
 126                 PHPUnitEditor editor = (PHPUnitEditor) part;
 127                 if (editor.getInsertMode() != ITextEditorExtension3.SMART_INSERT
 128                                 || !editor.isEditable())
 129                         return;
 130                 ITextEditorExtension2 extension = (ITextEditorExtension2) editor
 131                                 .getAdapter(ITextEditorExtension2.class);
 132                 if (extension != null && !extension.validateEditorInputState())
 133                         return;
 134                 if (isMultilineSelection(document, command))
 135                         return;
 136
 137                 // 1: find concerned line / position in java code, location in statement
 138                 int pos = command.offset;
 139                 ITextSelection line;
 140                 try {
 141                         IRegion l = document.getLineInformationOfOffset(pos);
 142                         line = new TextSelection(document, l.getOffset(), l.getLength());
 143                 } catch (BadLocationException e) {
 144                         return;
 145                 }
 146
 147                 // 2: choose action based on findings (is for-Statement?)
 148                 // for now: compute the best position to insert the new character
 149                 int positionInLine = computeCharacterPosition(document, line, pos
 150                                 - line.getOffset(), fCharacter, fPartitioning);
 151                 int position = positionInLine + line.getOffset();
 152
 153                 // never position before the current position!
 154                 if (position < pos)
 155                         return;
 156
 157                 // never double already existing content
 158                 if (alreadyPresent(document, fCharacter, position))
 159                         return;
 160
 161                 // don't do special processing if what we do is actually the normal
 162                 // behaviour
 163                 String insertion = adjustSpacing(document, position, fCharacter);
 164                 if (command.offset == position && insertion.equals(command.text))
 165                         return;
 166
 167                 try {
 168
 169                         final SmartBackspaceManager manager = (SmartBackspaceManager) editor
 170                                         .getAdapter(SmartBackspaceManager.class);
 171                         if (manager != null
 172                                         && PHPeclipsePlugin.getDefault().getPreferenceStore()
 173                                                         .getBoolean(
 174                                                                         PreferenceConstants.EDITOR_SMART_BACKSPACE)) {
 175                                 TextEdit e1 = new ReplaceEdit(command.offset, command.text
 176                                                 .length(), document.get(command.offset, command.length));
 177                                 UndoSpec s1 = new UndoSpec(command.offset
 178                                                 + command.text.length(), new Region(command.offset, 0),
 179                                                 new TextEdit[] { e1 }, 0, null);
 180
 181                                 DeleteEdit smart = new DeleteEdit(position, insertion.length());
 182                                 ReplaceEdit raw = new ReplaceEdit(command.offset,
 183                                                 command.length, command.text);
 184                                 UndoSpec s2 = new UndoSpec(position + insertion.length(),
 185                                                 new Region(command.offset + command.text.length(), 0),
 186                                                 new TextEdit[] { smart, raw }, 2, s1);
 187                                 manager.register(s2);
 188                         }
 189
 190                         // 3: modify command
 191                         command.offset = position;
 192                         command.length = 0;
 193                         command.caretOffset = position;
 194                         command.text = insertion;
 195                         command.doit = true;
 196                         command.owner = null;
 197                 } catch (MalformedTreeException e) {
 198                         PHPeclipsePlugin.log(e);
 199                 } catch (BadLocationException e) {
 200                         PHPeclipsePlugin.log(e);
 201                 }
 202
 203         }
 204
 205         /**
 206          * Returns <code>true</code> if the document command is applied on a multi
 207          * line selection, <code>false</code> otherwise.
 208          *
 209          * @param document
 210          *            the document
 211          * @param command
 212          *            the command
 213          * @return <code>true</code> if <code>command</code> is a multiline
 214          *         command
 215          */
 216         private boolean isMultilineSelection(IDocument document,
 217                         DocumentCommand command) {
 218                 try {
 219                         return document.getNumberOfLines(command.offset, command.length) > 1;
 220                 } catch (BadLocationException e) {
 221                         // ignore
 222                         return false;
 223                 }
 224         }
 225
 226         /**
 227          * Adds a space before a brace if it is inserted after a parenthesis, equal
 228          * sign, or one of the keywords <code>try, else, do</code>.
 229          *
 230          * @param document
 231          *            the document we are working on
 232          * @param position
 233          *            the insert position of <code>character</code>
 234          * @param character
 235          *            the character to be inserted
 236          * @return a <code>String</code> consisting of <code>character</code>
 237          *         plus any additional spacing
 238          */
 239         private String adjustSpacing(IDocument doc, int position, char character) {
 240                 if (character == BRACECHAR) {
 241                         if (position > 0 && position <= doc.getLength()) {
 242                                 int pos = position - 1;
 243                                 if (looksLike(doc, pos, ")") //$NON-NLS-1$
 244                                                 || looksLike(doc, pos, "=") //$NON-NLS-1$
 245                                                 || looksLike(doc, pos, "]") //$NON-NLS-1$
 246                                                 || looksLike(doc, pos, "try") //$NON-NLS-1$
 247                                                 || looksLike(doc, pos, "else") //$NON-NLS-1$
 248                                                 || looksLike(doc, pos, "synchronized") //$NON-NLS-1$
 249                                                 || looksLike(doc, pos, "static") //$NON-NLS-1$
 250                                                 || looksLike(doc, pos, "finally") //$NON-NLS-1$
 251                                                 || looksLike(doc, pos, "do")) //$NON-NLS-1$
 252                                         return new String(new char[] { ' ', character });
 253                         }
 254                 }
 255
 256                 return new String(new char[] { character });
 257         }
 258
 259         /**
 260          * Checks whether a character to be inserted is already present at the
 261          * insert location (perhaps separated by some whitespace from
 262          * <code>position</code>.
 263          *
 264          * @param document
 265          *            the document we are working on
 266          * @param position
 267          *            the insert position of <code>ch</code>
 268          * @param character
 269          *            the character to be inserted
 270          * @return <code>true</code> if <code>ch</code> is already present at
 271          *         <code>location</code>, <code>false</code> otherwise
 272          */
 273         private boolean alreadyPresent(IDocument document, char ch, int position) {
 274                 int pos = firstNonWhitespaceForward(document, position, fPartitioning,
 275                                 document.getLength());
 276                 try {
 277                         if (pos != -1 && document.getChar(pos) == ch)
 278                                 return true;
 279                 } catch (BadLocationException e) {
 280                 }
 281
 282                 return false;
 283         }
 284
 285         /**
 286          * Computes the next insert position of the given character in the current
 287          * line.
 288          *
 289          * @param document
 290          *            the document we are working on
 291          * @param line
 292          *            the line where the change is being made
 293          * @param offset
 294          *            the position of the caret in the line when
 295          *            <code>character</code> was typed
 296          * @param character
 297          *            the character to look for
 298          * @param partitioning
 299          *            the document partitioning
 300          * @return the position where <code>character</code> should be inserted /
 301          *         replaced
 302          */
 303         protected static int computeCharacterPosition(IDocument document,
 304                         ITextSelection line, int offset, char character, String partitioning) {
 305                 String text = line.getText();
 306                 if (text == null)
 307                         return 0;
 308
 309                 int insertPos;
 310                 if (character == BRACECHAR) {
 311
 312                         insertPos = computeArrayInitializationPos(document, line, offset,
 313                                         partitioning);
 314
 315                         if (insertPos == -1) {
 316                                 insertPos = computeAfterTryDoElse(document, line, offset);
 317                         }
 318
 319                         if (insertPos == -1) {
 320                                 insertPos = computeAfterParenthesis(document, line, offset,
 321                                                 partitioning);
 322                         }
 323
 324                 } else if (character == SEMICHAR) {
 325
 326                         if (isForStatement(text, offset)) {
 327                                 insertPos = -1; // don't do anything in for statements, as semis
 328                                                                 // are vital part of these
 329                         } else {
 330                                 int nextPartitionPos = nextPartitionOrLineEnd(document, line,
 331                                                 offset, partitioning);
 332                                 insertPos = startOfWhitespaceBeforeOffset(text,
 333                                                 nextPartitionPos);
 334                                 // if there is a semi present, return its location as
 335                                 // alreadyPresent() will take it out this way.
 336                                 if (insertPos > 0 && text.charAt(insertPos - 1) == character)
 337                                         insertPos = insertPos - 1;
 338                         }
 339
 340                 } else {
 341                         Assert.isTrue(false);
 342                         return -1;
 343                 }
 344
 345                 return insertPos;
 346         }
 347
 348         /**
 349          * Computes an insert position for an opening brace if <code>offset</code>
 350          * maps to a position in <code>document</code> that looks like being the
 351          * RHS of an assignment or like an array definition.
 352          *
 353          * @param document
 354          *            the document being modified
 355          * @param line
 356          *            the current line under investigation
 357          * @param offset
 358          *            the offset of the caret position, relative to the line start.
 359          * @param partitioning
 360          *            the document partitioning
 361          * @return an insert position relative to the line start if
 362          *         <code>line</code> looks like being an array initialization at
 363          *         <code>offset</code>, -1 otherwise
 364          */
 365         private static int computeArrayInitializationPos(IDocument document,
 366                         ITextSelection line, int offset, String partitioning) {
 367                 // search backward while WS, find = (not != <= >= ==) in default
 368                 // partition
 369                 int pos = offset + line.getOffset();
 370
 371                 if (pos == 0)
 372                         return -1;
 373
 374                 int p = firstNonWhitespaceBackward(document, pos - 1, partitioning, -1);
 375
 376                 if (p == -1)
 377                         return -1;
 378
 379                 try {
 380
 381                         char ch = document.getChar(p);
 382                         if (ch != '=' && ch != ']')
 383                                 return -1;
 384
 385                         if (p == 0)
 386                                 return offset;
 387
 388                         p = firstNonWhitespaceBackward(document, p - 1, partitioning, -1);
 389                         if (p == -1)
 390                                 return -1;
 391
 392                         ch = document.getChar(p);
 393                         if (Scanner.isPHPIdentifierPart(ch) || ch == ']' || ch == '[')
 394                                 return offset;
 395
 396                 } catch (BadLocationException e) {
 397                 }
 398                 return -1;
 399         }
 400
 401         /**
 402          * Computes an insert position for an opening brace if <code>offset</code>
 403          * maps to a position in <code>document</code> involving a keyword taking
 404          * a block after it. These are: <code>try</code>, <code>do</code>,
 405          * <code>synchronized</code>, <code>static</code>,
 406          * <code>finally</code>, or <code>else</code>.
 407          *
 408          * @param document
 409          *            the document being modified
 410          * @param line
 411          *            the current line under investigation
 412          * @param offset
 413          *            the offset of the caret position, relative to the line start.
 414          * @return an insert position relative to the line start if
 415          *         <code>line</code> contains one of the above keywords at or
 416          *         before <code>offset</code>, -1 otherwise
 417          */
 418         private static int computeAfterTryDoElse(IDocument doc,
 419                         ITextSelection line, int offset) {
 420                 // search backward while WS, find 'try', 'do', 'else' in default
 421                 // partition
 422                 int p = offset + line.getOffset();
 423                 p = firstWhitespaceToRight(doc, p);
 424                 if (p == -1)
 425                         return -1;
 426                 p--;
 427
 428                 if (looksLike(doc, p, "try") //$NON-NLS-1$
 429                                 || looksLike(doc, p, "do") //$NON-NLS-1$
 430                                 || looksLike(doc, p, "synchronized") //$NON-NLS-1$
 431                                 || looksLike(doc, p, "static") //$NON-NLS-1$
 432                                 || looksLike(doc, p, "finally") //$NON-NLS-1$
 433                                 || looksLike(doc, p, "else")) //$NON-NLS-1$
 434                         return p + 1 - line.getOffset();
 435
 436                 return -1;
 437         }
 438
 439         /**
 440          * Computes an insert position for an opening brace if <code>offset</code>
 441          * maps to a position in <code>document</code> with a expression in
 442          * parenthesis that will take a block after the closing parenthesis.
 443          *
 444          * @param document
 445          *            the document being modified
 446          * @param line
 447          *            the current line under investigation
 448          * @param offset
 449          *            the offset of the caret position, relative to the line start.
 450          * @param partitioning
 451          *            the document partitioning
 452          * @return an insert position relative to the line start if
 453          *         <code>line</code> contains a parenthesized expression that can
 454          *         be followed by a block, -1 otherwise
 455          */
 456         private static int computeAfterParenthesis(IDocument document,
 457                         ITextSelection line, int offset, String partitioning) {
 458                 // find the opening parenthesis for every closing parenthesis on the
 459                 // current line after offset
 460                 // return the position behind the closing parenthesis if it looks like a
 461                 // method declaration
 462                 // or an expression for an if, while, for, catch statement
 463                 int pos = offset + line.getOffset();
 464                 int length = line.getOffset() + line.getLength();
 465                 int scanTo = scanForward(document, pos, partitioning, length, '}');
 466                 if (scanTo == -1)
 467                         scanTo = length;
 468
 469                 int closingParen = findClosingParenToLeft(document, pos, partitioning) - 1;
 470
 471                 while (true) {
 472                         int startScan = closingParen + 1;
 473                         closingParen = scanForward(document, startScan, partitioning,
 474                                         scanTo, ')');
 475                         if (closingParen == -1)
 476                                 break;
 477
 478                         int openingParen = findOpeningParenMatch(document, closingParen,
 479                                         partitioning);
 480
 481                         // no way an expression at the beginning of the document can mean
 482                         // anything
 483                         if (openingParen < 1)
 484                                 break;
 485
 486                         // only select insert positions for parenthesis currently embracing
 487                         // the caret
 488                         if (openingParen > pos)
 489                                 continue;
 490
 491                         if (looksLikeAnonymousClassDef(document, openingParen - 1,
 492                                         partitioning))
 493                                 return closingParen + 1 - line.getOffset();
 494
 495                         if (looksLikeIfWhileForCatch(document, openingParen - 1,
 496                                         partitioning))
 497                                 return closingParen + 1 - line.getOffset();
 498
 499                         if (looksLikeMethodDecl(document, openingParen - 1, partitioning))
 500                                 return closingParen + 1 - line.getOffset();
 501
 502                 }
 503
 504                 return -1;
 505         }
 506
 507         /**
 508          * Finds a closing parenthesis to the left of <code>position</code> in
 509          * document, where that parenthesis is only separated by whitespace from
 510          * <code>position</code>. If no such parenthesis can be found,
 511          * <code>position</code> is returned.
 512          *
 513          * @param document
 514          *            the document being modified
 515          * @param position
 516          *            the first character position in <code>document</code> to be
 517          *            considered
 518          * @param partitioning
 519          *            the document partitioning
 520          * @return the position of a closing parenthesis left to
 521          *         <code>position</code> separated only by whitespace, or
 522          *         <code>position</code> if no parenthesis can be found
 523          */
 524         private static int findClosingParenToLeft(IDocument document, int position,
 525                         String partitioning) {
 526                 final char CLOSING_PAREN = ')';
 527                 try {
 528                         if (position < 1)
 529                                 return position;
 530
 531                         int nonWS = firstNonWhitespaceBackward(document, position - 1,
 532                                         partitioning, -1);
 533                         if (nonWS != -1 && document.getChar(nonWS) == CLOSING_PAREN)
 534                                 return nonWS;
 535                 } catch (BadLocationException e1) {
 536                 }
 537                 return position;
 538         }
 539
 540         /**
 541          * Finds the first whitespace character position to the right of (and
 542          * including) <code>position</code>.
 543          *
 544          * @param document
 545          *            the document being modified
 546          * @param position
 547          *            the first character position in <code>document</code> to be
 548          *            considered
 549          * @return the position of a whitespace character greater or equal than
 550          *         <code>position</code> separated only by whitespace, or -1 if
 551          *         none found
 552          */
 553         private static int firstWhitespaceToRight(IDocument document, int position) {
 554                 int length = document.getLength();
 555                 Assert.isTrue(position >= 0);
 556                 Assert.isTrue(position <= length);
 557
 558                 try {
 559                         while (position < length) {
 560                                 char ch = document.getChar(position);
 561                                 if (Character.isWhitespace(ch))
 562                                         return position;
 563                                 position++;
 564                         }
 565                         return position;
 566                 } catch (BadLocationException e) {
 567                 }
 568                 return -1;
 569         }
 570
 571         /**
 572          * Finds the highest position in <code>document</code> such that the
 573          * position is &lt;= <code>position</code> and &gt; <code>bound</code>
 574          * and <code>Character.isWhitespace(document.getChar(pos))</code>
 575          * evaluates to <code>false</code> and the position is in the default
 576          * partition.
 577          *
 578          * @param document
 579          *            the document being modified
 580          * @param position
 581          *            the first character position in <code>document</code> to be
 582          *            considered
 583          * @param partitioning
 584          *            the document partitioning
 585          * @param bound
 586          *            the first position in <code>document</code> to not consider
 587          *            any more, with <code>bound</code> &gt; <code>position</code>
 588          * @return the highest position of one element in <code>chars</code> in [<code>position</code>,
 589          *         <code>scanTo</code>) that resides in a Java partition, or
 590          *         <code>-1</code> if none can be found
 591          */
 592         private static int firstNonWhitespaceBackward(IDocument document,
 593                         int position, String partitioning, int bound) {
 594                 Assert.isTrue(position < document.getLength());
 595                 Assert.isTrue(bound >= -1);
 596
 597                 try {
 598                         while (position > bound) {
 599                                 char ch = document.getChar(position);
 600                                 if (!Character.isWhitespace(ch)
 601                                                 && isDefaultPartition(document, position, partitioning))
 602                                         return position;
 603                                 position--;
 604                         }
 605                 } catch (BadLocationException e) {
 606                 }
 607                 return -1;
 608         }
 609
 610         /**
 611          * Finds the smallest position in <code>document</code> such that the
 612          * position is &gt;= <code>position</code> and &lt; <code>bound</code>
 613          * and <code>Character.isWhitespace(document.getChar(pos))</code>
 614          * evaluates to <code>false</code> and the position is in the default
 615          * partition.
 616          *
 617          * @param document
 618          *            the document being modified
 619          * @param position
 620          *            the first character position in <code>document</code> to be
 621          *            considered
 622          * @param partitioning
 623          *            the document partitioning
 624          * @param bound
 625          *            the first position in <code>document</code> to not consider
 626          *            any more, with <code>bound</code> &gt; <code>position</code>
 627          * @return the smallest position of one element in <code>chars</code> in [<code>position</code>,
 628          *         <code>scanTo</code>) that resides in a Java partition, or
 629          *         <code>-1</code> if none can be found
 630          */
 631         private static int firstNonWhitespaceForward(IDocument document,
 632                         int position, String partitioning, int bound) {
 633                 Assert.isTrue(position >= 0);
 634                 Assert.isTrue(bound <= document.getLength());
 635
 636                 try {
 637                         while (position < bound) {
 638                                 char ch = document.getChar(position);
 639                                 if (!Character.isWhitespace(ch)
 640                                                 && isDefaultPartition(document, position, partitioning))
 641                                         return position;
 642                                 position++;
 643                         }
 644                 } catch (BadLocationException e) {
 645                 }
 646                 return -1;
 647         }
 648
 649         /**
 650          * Finds the highest position in <code>document</code> such that the
 651          * position is &lt;= <code>position</code> and &gt; <code>bound</code>
 652          * and <code>document.getChar(position) == ch</code> evaluates to
 653          * <code>true</code> for at least one ch in <code>chars</code> and the
 654          * position is in the default partition.
 655          *
 656          * @param document
 657          *            the document being modified
 658          * @param position
 659          *            the first character position in <code>document</code> to be
 660          *            considered
 661          * @param partitioning
 662          *            the document partitioning
 663          * @param bound
 664          *            the first position in <code>document</code> to not consider
 665          *            any more, with <code>scanTo</code> &gt;
 666          *            <code>position</code>
 667          * @param chars
 668          *            an array of <code>char</code> to search for
 669          * @return the highest position of one element in <code>chars</code> in (<code>bound</code>,
 670          *         <code>position</code>] that resides in a Java partition, or
 671          *         <code>-1</code> if none can be found
 672          */
 673         private static int scanBackward(IDocument document, int position,
 674                         String partitioning, int bound, char[] chars) {
 675                 Assert.isTrue(bound >= -1);
 676                 Assert.isTrue(position < document.getLength());
 677
 678                 Arrays.sort(chars);
 679
 680                 try {
 681                         while (position > bound) {
 682
 683                                 if (Arrays.binarySearch(chars, document.getChar(position)) >= 0
 684                                                 && isDefaultPartition(document, position, partitioning))
 685                                         return position;
 686
 687                                 position--;
 688                         }
 689                 } catch (BadLocationException e) {
 690                 }
 691                 return -1;
 692         }
 693
 694         // /**
 695         // * Finds the highest position in <code>document</code> such that the
 696         // position is &lt;= <code>position</code>
 697         // * and &gt; <code>bound</code> and <code>document.getChar(position) ==
 698         // ch</code> evaluates to <code>true</code>
 699         // * and the position is in the default partition.
 700         // *
 701         // * @param document the document being modified
 702         // * @param position the first character position in <code>document</code>
 703         // to be considered
 704         // * @param bound the first position in <code>document</code> to not
 705         // consider any more, with <code>scanTo</code> &gt; <code>position</code>
 706         // * @param chars an array of <code>char</code> to search for
 707         // * @return the highest position of one element in <code>chars</code> in
 708         // [<code>position</code>, <code>scanTo</code>) that resides in a Java
 709         // partition, or <code>-1</code> if none can be found
 710         // */
 711         // private static int scanBackward(IDocument document, int position, int
 712         // bound, char ch) {
 713         // return scanBackward(document, position, bound, new char[] {ch});
 714         // }
 715         //
 716         /**
 717          * Finds the lowest position in <code>document</code> such that the
 718          * position is &gt;= <code>position</code> and &lt; <code>bound</code>
 719          * and <code>document.getChar(position) == ch</code> evaluates to
 720          * <code>true</code> for at least one ch in <code>chars</code> and the
 721          * position is in the default partition.
 722          *
 723          * @param document
 724          *            the document being modified
 725          * @param position
 726          *            the first character position in <code>document</code> to be
 727          *            considered
 728          * @param partitioning
 729          *            the document partitioning
 730          * @param bound
 731          *            the first position in <code>document</code> to not consider
 732          *            any more, with <code>scanTo</code> &gt;
 733          *            <code>position</code>
 734          * @param chars
 735          *            an array of <code>char</code> to search for
 736          * @return the lowest position of one element in <code>chars</code> in [<code>position</code>,
 737          *         <code>bound</code>) that resides in a Java partition, or
 738          *         <code>-1</code> if none can be found
 739          */
 740         private static int scanForward(IDocument document, int position,
 741                         String partitioning, int bound, char[] chars) {
 742                 Assert.isTrue(position >= 0);
 743                 Assert.isTrue(bound <= document.getLength());
 744
 745                 Arrays.sort(chars);
 746
 747                 try {
 748                         while (position < bound) {
 749
 750                                 if (Arrays.binarySearch(chars, document.getChar(position)) >= 0
 751                                                 && isDefaultPartition(document, position, partitioning))
 752                                         return position;
 753
 754                                 position++;
 755                         }
 756                 } catch (BadLocationException e) {
 757                 }
 758                 return -1;
 759         }
 760
 761         /**
 762          * Finds the lowest position in <code>document</code> such that the
 763          * position is &gt;= <code>position</code> and &lt; <code>bound</code>
 764          * and <code>document.getChar(position) == ch</code> evaluates to
 765          * <code>true</code> and the position is in the default partition.
 766          *
 767          * @param document
 768          *            the document being modified
 769          * @param position
 770          *            the first character position in <code>document</code> to be
 771          *            considered
 772          * @param partitioning
 773          *            the document partitioning
 774          * @param bound
 775          *            the first position in <code>document</code> to not consider
 776          *            any more, with <code>scanTo</code> &gt;
 777          *            <code>position</code>
 778          * @param chars
 779          *            an array of <code>char</code> to search for
 780          * @return the lowest position of one element in <code>chars</code> in [<code>position</code>,
 781          *         <code>bound</code>) that resides in a Java partition, or
 782          *         <code>-1</code> if none can be found
 783          */
 784         private static int scanForward(IDocument document, int position,
 785                         String partitioning, int bound, char ch) {
 786                 return scanForward(document, position, partitioning, bound,
 787                                 new char[] { ch });
 788         }
 789
 790         /**
 791          * Checks whether the content of <code>document</code> in the range (<code>offset</code>,
 792          * <code>length</code>) contains the <code>new</code> keyword.
 793          *
 794          * @param document
 795          *            the document being modified
 796          * @param offset
 797          *            the first character position in <code>document</code> to be
 798          *            considered
 799          * @param length
 800          *            the length of the character range to be considered
 801          * @param partitioning
 802          *            the document partitioning
 803          * @return <code>true</code> if the specified character range contains a
 804          *         <code>new</code> keyword, <code>false</code> otherwise.
 805          */
 806         private static boolean isNewMatch(IDocument document, int offset,
 807                         int length, String partitioning) {
 808                 Assert.isTrue(length >= 0);
 809                 Assert.isTrue(offset >= 0);
 810                 Assert.isTrue(offset + length < document.getLength() + 1);
 811
 812                 try {
 813                         String text = document.get(offset, length);
 814                         int pos = text.indexOf("new"); //$NON-NLS-1$
 815
 816                         while (pos != -1
 817                                         && !isDefaultPartition(document, pos + offset, partitioning))
 818                                 pos = text.indexOf("new", pos + 2); //$NON-NLS-1$
 819
 820                         if (pos < 0)
 821                                 return false;
 822
 823                         if (pos != 0 && Scanner.isPHPIdentifierPart(text.charAt(pos - 1)))
 824                                 return false;
 825
 826                         if (pos + 3 < length
 827                                         && Scanner.isPHPIdentifierPart(text.charAt(pos + 3)))
 828                                 return false;
 829
 830                         return true;
 831
 832                 } catch (BadLocationException e) {
 833                 }
 834                 return false;
 835         }
 836
 837         /**
 838          * Checks whether the content of <code>document</code> at
 839          * <code>position</code> looks like an anonymous class definition.
 840          * <code>position</code> must be to the left of the opening parenthesis of
 841          * the definition's parameter list.
 842          *
 843          * @param document
 844          *            the document being modified
 845          * @param position
 846          *            the first character position in <code>document</code> to be
 847          *            considered
 848          * @param partitioning
 849          *            the document partitioning
 850          * @return <code>true</code> if the content of <code>document</code>
 851          *         looks like an anonymous class definition, <code>false</code>
 852          *         otherwise
 853          */
 854         private static boolean looksLikeAnonymousClassDef(IDocument document,
 855                         int position, String partitioning) {
 856                 int previousCommaOrParen = scanBackward(document, position - 1,
 857                                 partitioning, -1, new char[] { ',', '(' });
 858                 if (previousCommaOrParen == -1 || position < previousCommaOrParen + 5) // 2
 859                                                                                                                                                                 // for
 860                                                                                                                                                                 // borders,
 861                                                                                                                                                                 // 3
 862                                                                                                                                                                 // for
 863                                                                                                                                                                 // "new"
 864                         return false;
 865
 866                 if (isNewMatch(document, previousCommaOrParen + 1, position
 867                                 - previousCommaOrParen - 2, partitioning))
 868                         return true;
 869
 870                 return false;
 871         }
 872
 873         /**
 874          * Checks whether <code>position</code> resides in a default (Java)
 875          * partition of <code>document</code>.
 876          *
 877          * @param document
 878          *            the document being modified
 879          * @param position
 880          *            the position to be checked
 881          * @param partitioning
 882          *            the document partitioning
 883          * @return <code>true</code> if <code>position</code> is in the default
 884          *         partition of <code>document</code>, <code>false</code>
 885          *         otherwise
 886          */
 887         private static boolean isDefaultPartition(IDocument document, int position,
 888                         String partitioning) {
 889                 Assert.isTrue(position >= 0);
 890                 Assert.isTrue(position <= document.getLength());
 891
 892                 try {
 893                         // don't use getPartition2 since we're interested in the scanned
 894                         // character's partition
 895                         ITypedRegion region = TextUtilities.getPartition(document,
 896                                         partitioning, position, false);
 897                         return region.getType().equals(IDocument.DEFAULT_CONTENT_TYPE);
 898
 899                 } catch (BadLocationException e) {
 900                 }
 901
 902                 return false;
 903         }
 904
 905         /**
 906          * Finds the position of the parenthesis matching the closing parenthesis at
 907          * <code>position</code>.
 908          *
 909          * @param document
 910          *            the document being modified
 911          * @param position
 912          *            the position in <code>document</code> of a closing
 913          *            parenthesis
 914          * @param partitioning
 915          *            the document partitioning
 916          * @return the position in <code>document</code> of the matching
 917          *         parenthesis, or -1 if none can be found
 918          */
 919         private static int findOpeningParenMatch(IDocument document, int position,
 920                         String partitioning) {
 921                 final char CLOSING_PAREN = ')';
 922                 final char OPENING_PAREN = '(';
 923
 924                 Assert.isTrue(position < document.getLength());
 925                 Assert.isTrue(position >= 0);
 926                 Assert.isTrue(isDefaultPartition(document, position, partitioning));
 927
 928                 try {
 929
 930                         Assert.isTrue(document.getChar(position) == CLOSING_PAREN);
 931
 932                         int depth = 1;
 933                         while (true) {
 934                                 position = scanBackward(document, position - 1, partitioning,
 935                                                 -1, new char[] { CLOSING_PAREN, OPENING_PAREN });
 936                                 if (position == -1)
 937                                         return -1;
 938
 939                                 if (document.getChar(position) == CLOSING_PAREN)
 940                                         depth++;
 941                                 else
 942                                         depth--;
 943
 944                                 if (depth == 0)
 945                                         return position;
 946                         }
 947
 948                 } catch (BadLocationException e) {
 949                         return -1;
 950                 }
 951         }
 952
 953         /**
 954          * Checks whether, to the left of <code>position</code> and separated only
 955          * by whitespace, <code>document</code> contains a keyword taking a
 956          * parameter list and a block after it. These are: <code>if</code>,
 957          * <code>while</code>, <code>catch</code>, <code>for</code>,
 958          * <code>synchronized</code>, <code>switch</code>.
 959          *
 960          * @param document
 961          *            the document being modified
 962          * @param position
 963          *            the first character position in <code>document</code> to be
 964          *            considered
 965          * @param partitioning
 966          *            the document partitioning
 967          * @return <code>true</code> if <code>document</code> contains any of
 968          *         the above keywords to the left of <code>position</code>,
 969          *         <code>false</code> otherwise
 970          */
 971         private static boolean looksLikeIfWhileForCatch(IDocument document,
 972                         int position, String partitioning) {
 973                 position = firstNonWhitespaceBackward(document, position, partitioning,
 974                                 -1);
 975                 if (position == -1)
 976                         return false;
 977
 978                 return looksLike(document, position, "if") //$NON-NLS-1$
 979                                 || looksLike(document, position, "while") //$NON-NLS-1$
 980                                 || looksLike(document, position, "catch") //$NON-NLS-1$
 981                                 || looksLike(document, position, "synchronized") //$NON-NLS-1$
 982                                 || looksLike(document, position, "switch") //$NON-NLS-1$
 983                                 || looksLike(document, position, "for"); //$NON-NLS-1$
 984         }
 985
 986         /**
 987          * Checks whether code>document</code> contains the <code>String</code> <code>like</code>
 988          * such that its last character is at <code>position</code>. If <code>like</code>
 989          * starts with a identifier part (as determined by
 990          * {@link Scanner#isPHPIdentifierPart(char)}), it is also made sure that
 991          * <code>like</code> is preceded by some non-identifier character or
 992          * stands at the document start.
 993          *
 994          * @param document
 995          *            the document being modified
 996          * @param position
 997          *            the first character position in <code>document</code> to be
 998          *            considered
 999          * @param like
1000          *            the <code>String</code> to look for.
1001          * @return <code>true</code> if <code>document</code> contains <code>like</code>
1002          *         such that it ends at <code>position</code>, <code>false</code>
1003          *         otherwise
1004          */
1005         private static boolean looksLike(IDocument document, int position,
1006                         String like) {
1007                 int length = like.length();
1008                 if (position < length - 1)
1009                         return false;
1010
1011                 try {
1012                         if (!like.equals(document.get(position - length + 1, length)))
1013                                 return false;
1014
1015                         if (position >= length
1016                                         && Scanner.isPHPIdentifierPart(like.charAt(0))
1017                                         && Scanner.isPHPIdentifierPart(document.getChar(position
1018                                                         - length)))
1019                                 return false;
1020
1021                 } catch (BadLocationException e) {
1022                         return false;
1023                 }
1024
1025                 return true;
1026         }
1027
1028         /**
1029          * Checks whether the content of <code>document</code> at
1030          * <code>position</code> looks like a method declaration header (i.e. only
1031          * the return type and method name). <code>position</code> must be just
1032          * left of the opening parenthesis of the parameter list.
1033          *
1034          * @param document
1035          *            the document being modified
1036          * @param position
1037          *            the first character position in <code>document</code> to be
1038          *            considered
1039          * @param partitioning
1040          *            the document partitioning
1041          * @return <code>true</code> if the content of <code>document</code>
1042          *         looks like a method definition, <code>false</code> otherwise
1043          */
1044         private static boolean looksLikeMethodDecl(IDocument document,
1045                         int position, String partitioning) {
1046
1047                 // method name
1048                 position = eatIdentToLeft(document, position, partitioning);
1049                 if (position < 1)
1050                         return false;
1051
1052                 position = eatBrackets(document, position - 1, partitioning);
1053                 if (position < 1)
1054                         return false;
1055
1056                 position = eatIdentToLeft(document, position - 1, partitioning);
1057
1058                 return position != -1;
1059         }
1060
1061         /**
1062          * From <code>position</code> to the left, eats any whitespace and then a
1063          * pair of brackets as used to declare an array return type like
1064          *
1065          * <pre>
1066          * String [ ]
1067          * </pre>. The return value is either the position of the opening bracket
1068          * or <code>position</code> if no pair of brackets can be parsed.
1069          *
1070          * @param document
1071          *            the document being modified
1072          * @param position
1073          *            the first character position in <code>document</code> to be
1074          *            considered
1075          * @param partitioning
1076          *            the document partitioning
1077          * @return the smallest character position of bracket pair or
1078          *         <code>position</code>
1079          */
1080         private static int eatBrackets(IDocument document, int position,
1081                         String partitioning) {
1082                 // accept array return type
1083                 int pos = firstNonWhitespaceBackward(document, position, partitioning,
1084                                 -1);
1085                 try {
1086                         if (pos > 1 && document.getChar(pos) == ']') {
1087                                 pos = firstNonWhitespaceBackward(document, pos - 1,
1088                                                 partitioning, -1);
1089                                 if (pos > 0 && document.getChar(pos) == '[')
1090                                         return pos;
1091                         }
1092                 } catch (BadLocationException e) {
1093                         // won't happen
1094                 }
1095                 return position;
1096         }
1097
1098         /**
1099          * From <code>position</code> to the left, eats any whitespace and the
1100          * first identifier, returning the position of the first identifier
1101          * character (in normal read order).
1102          * <p>
1103          * When called on a document with content <code>" some string  "</code> and
1104          * positionition 13, the return value will be 6 (the first letter in
1105          * <code>string</code>).
1106          * </p>
1107          *
1108          * @param document
1109          *            the document being modified
1110          * @param position
1111          *            the first character position in <code>document</code> to be
1112          *            considered
1113          * @param partitioning
1114          *            the document partitioning
1115          * @return the smallest character position of an identifier or -1 if none
1116          *         can be found; always &lt;= <code>position</code>
1117          */
1118         private static int eatIdentToLeft(IDocument document, int position,
1119                         String partitioning) {
1120                 if (position < 0)
1121                         return -1;
1122                 Assert.isTrue(position < document.getLength());
1123
1124                 int p = firstNonWhitespaceBackward(document, position, partitioning, -1);
1125                 if (p == -1)
1126                         return -1;
1127
1128                 try {
1129                         while (p >= 0) {
1130
1131                                 char ch = document.getChar(p);
1132                                 if (Scanner.isPHPIdentifierPart(ch)) {
1133                                         p--;
1134                                         continue;
1135                                 }
1136
1137                                 // length must be > 0
1138                                 if (Character.isWhitespace(ch) && p != position)
1139                                         return p + 1;
1140                                 else
1141                                         return -1;
1142
1143                         }
1144
1145                         // start of document reached
1146                         return 0;
1147
1148                 } catch (BadLocationException e) {
1149                 }
1150                 return -1;
1151         }
1152
1153         /**
1154          * Returns a position in the first java partition after the last non-empty
1155          * and non-comment partition. There is no non-whitespace from the returned
1156          * position to the end of the partition it is contained in.
1157          *
1158          * @param document
1159          *            the document being modified
1160          * @param line
1161          *            the line under investigation
1162          * @param offset
1163          *            the caret offset into <code>line</code>
1164          * @param partitioning
1165          *            the document partitioning
1166          * @return the position of the next Java partition, or the end of
1167          *         <code>line</code>
1168          */
1169         private static int nextPartitionOrLineEnd(IDocument document,
1170                         ITextSelection line, int offset, String partitioning) {
1171                 // run relative to document
1172                 final int docOffset = offset + line.getOffset();
1173                 final int eol = line.getOffset() + line.getLength();
1174                 int nextPartitionPos = eol; // init with line end
1175                 int validPosition = docOffset;
1176
1177                 try {
1178                         ITypedRegion partition = TextUtilities.getPartition(document,
1179                                         partitioning, nextPartitionPos, true);
1180                         validPosition = getValidPositionForPartition(document, partition,
1181                                         eol);
1182                         while (validPosition == -1) {
1183                                 nextPartitionPos = partition.getOffset() - 1;
1184                                 if (nextPartitionPos < docOffset) {
1185                                         validPosition = docOffset;
1186                                         break;
1187                                 }
1188                                 partition = TextUtilities.getPartition(document, partitioning,
1189                                                 nextPartitionPos, false);
1190                                 validPosition = getValidPositionForPartition(document,
1191                                                 partition, eol);
1192                         }
1193                 } catch (BadLocationException e) {
1194                 }
1195
1196                 validPosition = Math.max(validPosition, docOffset);
1197                 // make relative to line
1198                 validPosition -= line.getOffset();
1199                 return validPosition;
1200         }
1201
1202         /**
1203          * Returns a valid insert location (except for whitespace) in
1204          * <code>partition</code> or -1 if there is no valid insert location. An
1205          * valid insert location is right after any java string or character
1206          * partition, or at the end of a java default partition, but never behind
1207          * <code>maxOffset</code>. Comment partitions or empty java partitions do
1208          * never yield valid insert positions.
1209          *
1210          * @param doc
1211          *            the document being modified
1212          * @param partition
1213          *            the current partition
1214          * @param maxOffset
1215          *            the maximum offset to consider
1216          * @return a valid insert location in <code>partition</code>, or -1 if
1217          *         there is no valid insert location
1218          */
1219         private static int getValidPositionForPartition(IDocument doc,
1220                         ITypedRegion partition, int maxOffset) {
1221                 final int INVALID = -1;
1222
1223                 if (IPHPPartitions.PHP_PHPDOC_COMMENT.equals(partition.getType()))
1224                         return INVALID;
1225                 if (IPHPPartitions.PHP_MULTILINE_COMMENT.equals(partition.getType()))
1226                         return INVALID;
1227                 if (IPHPPartitions.PHP_SINGLELINE_COMMENT.equals(partition.getType()))
1228                         return INVALID;
1229
1230                 int endOffset = Math.min(maxOffset, partition.getOffset()
1231                                 + partition.getLength());
1232
1233                 // if (IPHPPartitions.JAVA_CHARACTER.equals(partition.getType()))
1234                 // return endOffset;
1235                 if (IPHPPartitions.PHP_STRING_DQ.equals(partition.getType()))
1236                         return endOffset;
1237                 if (IPHPPartitions.PHP_STRING_SQ.equals(partition.getType()))
1238                         return endOffset;
1239                 if (IPHPPartitions.PHP_STRING_HEREDOC.equals(partition.getType()))
1240                         return endOffset;
1241                 if (IDocument.DEFAULT_CONTENT_TYPE.equals(partition.getType())) {
1242                         try {
1243                                 if (doc.get(partition.getOffset(),
1244                                                 endOffset - partition.getOffset()).trim().length() == 0)
1245                                         return INVALID;
1246                                 else
1247                                         return endOffset;
1248                         } catch (BadLocationException e) {
1249                                 return INVALID;
1250                         }
1251                 }
1252                 // default: we don't know anything about the partition - assume valid
1253                 return endOffset;
1254         }
1255
1256         /**
1257          * Determines whether the current line contains a for statement. Algorithm:
1258          * any "for" word in the line is a positive, "for" contained in a string
1259          * literal will produce a false positive.
1260          *
1261          * @param line
1262          *            the line where the change is being made
1263          * @param offset
1264          *            the position of the caret
1265          * @return <code>true</code> if <code>line</code> contains
1266          *         <code>for</code>, <code>false</code> otherwise
1267          */
1268         private static boolean isForStatement(String line, int offset) {
1269                 /* searching for (^|\s)for(\s|$) */
1270                 int forPos = line.indexOf("for"); //$NON-NLS-1$
1271                 if (forPos != -1) {
1272                         if ((forPos == 0 || !Scanner.isPHPIdentifierPart(line
1273                                         .charAt(forPos - 1)))
1274                                         && (line.length() == forPos + 3 || !Scanner
1275                                                         .isPHPIdentifierPart(line.charAt(forPos + 3))))
1276                                 return true;
1277                 }
1278                 return false;
1279         }
1280
1281         /**
1282          * Returns the position in <code>text</code> after which there comes only
1283          * whitespace, up to <code>offset</code>.
1284          *
1285          * @param text
1286          *            the text being searched
1287          * @param offset
1288          *            the maximum offset to search for
1289          * @return the smallest value <code>v</code> such that
1290          *         <code>text.substring(v, offset).trim() == 0</code>
1291          */
1292         private static int startOfWhitespaceBeforeOffset(String text, int offset) {
1293                 int i = Math.min(offset, text.length());
1294                 for (; i >= 1; i--) {
1295                         if (!Character.isWhitespace(text.charAt(i - 1)))
1296                                 break;
1297                 }
1298                 return i;
1299         }
1300 }