net.sourceforge.phpeclipse.ui/src/net/sourceforge/phpdt/internal/ui/text/link/LinkedPositionManager.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2003 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
  12 package net.sourceforge.phpdt.internal.ui.text.link;
  13
  14 import java.util.Arrays;
  15 import java.util.Comparator;
  16 import java.util.HashMap;
  17 import java.util.Map;
  18
  19 //import net.sourceforge.phpeclipse.PHPeclipsePlugin;
  20
  21 import net.sourceforge.phpeclipse.ui.WebUI;
  22
  23 //incastrix
  24 //import org.eclipse.jface.text.Assert;
  25 import org.eclipse.core.runtime.Assert;
  26 import org.eclipse.jface.text.BadLocationException;
  27 import org.eclipse.jface.text.BadPositionCategoryException;
  28 import org.eclipse.jface.text.DocumentCommand;
  29 import org.eclipse.jface.text.DocumentEvent;
  30 import org.eclipse.jface.text.IAutoEditStrategy;
  31 import org.eclipse.jface.text.IDocument;
  32 import org.eclipse.jface.text.IDocumentExtension;
  33 import org.eclipse.jface.text.IDocumentListener;
  34 import org.eclipse.jface.text.IPositionUpdater;
  35 import org.eclipse.jface.text.Position;
  36 import org.eclipse.jface.text.TypedPosition;
  37 //import org.eclipse.jface.text.contentassist.ICompletionProposal;
  38
  39 /**
  40  * This class manages linked positions in a document. Positions are linked by
  41  * type names. If positions have the same type name, they are considered as
  42  * <em>linked</em>.
  43  *
  44  * The manager remains active on a document until any of the following actions
  45  * occurs:
  46  *
  47  * <ul>
  48  * <li>A document change is performed which would invalidate any of the above
  49  * constraints.</li>
  50  *
  51  * <li>The method <code>uninstall()</code> is called.</li>
  52  *
  53  * <li>Another instance of <code>LinkedPositionManager</code> tries to gain
  54  * control of the same document.
  55  * </ul>
  56  */
  57 public class LinkedPositionManager implements IDocumentListener,
  58                 IPositionUpdater, IAutoEditStrategy {
  59
  60         // This class still exists to properly handle code assist.
  61         // This is due to the fact that it cannot be distinguished betweeen document
  62         // changes which are
  63         // issued by code assist and document changes which origin from another text
  64         // viewer.
  65         // There is a conflict in interest since in the latter case the linked mode
  66         // should be left, but in the former case
  67         // the linked mode should remain.
  68         // To support content assist, document changes have to be propagated to
  69         // connected positions
  70         // by registering replace commands using IDocumentExtension.
  71         // if it wasn't for the support of content assist, the documentChanged()
  72         // method could be reduced to
  73         // a simple call to leave(true)
  74         private class Replace implements IDocumentExtension.IReplace {
  75
  76                 private Position fReplacePosition;
  77
  78                 private int fReplaceDeltaOffset;
  79
  80                 private int fReplaceLength;
  81
  82                 private String fReplaceText;
  83
  84                 public Replace(Position position, int deltaOffset, int length,
  85                                 String text) {
  86                         fReplacePosition = position;
  87                         fReplaceDeltaOffset = deltaOffset;
  88                         fReplaceLength = length;
  89                         fReplaceText = text;
  90                 }
  91
  92                 public void perform(IDocument document, IDocumentListener owner) {
  93                         document.removeDocumentListener(owner);
  94                         try {
  95                                 document.replace(fReplacePosition.getOffset()
  96                                                 + fReplaceDeltaOffset, fReplaceLength, fReplaceText);
  97                         } catch (BadLocationException e) {
  98                                 WebUI.log(e);
  99                                 // TBD
 100                         }
 101                         document.addDocumentListener(owner);
 102                 }
 103         }
 104
 105         private static class PositionComparator implements Comparator {
 106                 /*
 107                  * @see Comparator#compare(Object, Object)
 108                  */
 109                 public int compare(Object object0, Object object1) {
 110                         Position position0 = (Position) object0;
 111                         Position position1 = (Position) object1;
 112
 113                         return position0.getOffset() - position1.getOffset();
 114                 }
 115         }
 116
 117         private static final String LINKED_POSITION_PREFIX = "LinkedPositionManager.linked.position"; //$NON-NLS-1$
 118
 119         private static final Comparator fgPositionComparator = new PositionComparator();
 120
 121         private static final Map fgActiveManagers = new HashMap();
 122
 123         private static int fgCounter = 0;
 124
 125         private IDocument fDocument;
 126
 127         private ILinkedPositionListener fListener;
 128
 129         private String fPositionCategoryName;
 130
 131         private boolean fMustLeave;
 132
 133         /**
 134          * Flag that records the state of this manager. As there are many different
 135          * entities that may call leave or exit, these cannot always be sure whether
 136          * the linked position infrastructure is still active. This is especially
 137          * true for multithreaded situations.
 138          */
 139         private boolean fIsActive = false;
 140
 141         /**
 142          * Creates a <code>LinkedPositionManager</code> for a
 143          * <code>IDocument</code>.
 144          *
 145          * @param document
 146          *            the document to use with linked positions.
 147          * @param canCoexist
 148          *            <code>true</code> if this manager can coexist with an
 149          *            already existing one
 150          */
 151         public LinkedPositionManager(IDocument document, boolean canCoexist) {
 152                 Assert.isNotNull(document);
 153                 fDocument = document;
 154                 fPositionCategoryName = LINKED_POSITION_PREFIX + (fgCounter++);
 155                 install(canCoexist);
 156         }
 157
 158         /**
 159          * Creates a <code>LinkedPositionManager</code> for a
 160          * <code>IDocument</code>.
 161          *
 162          * @param document
 163          *            the document to use with linked positions.
 164          */
 165         public LinkedPositionManager(IDocument document) {
 166                 this(document, false);
 167         }
 168
 169         /**
 170          * Sets a listener to notify changes of current linked position.
 171          */
 172         public void setLinkedPositionListener(ILinkedPositionListener listener) {
 173                 fListener = listener;
 174         }
 175
 176         /**
 177          * Adds a linked position to the manager with the type being the content of
 178          * the document at the specified range. There are the following constraints
 179          * for linked positions:
 180          *
 181          * <ul>
 182          * <li>Any two positions have spacing of at least one character. This
 183          * implies that two positions must not overlap.</li>
 184          *
 185          * <li>The string at any position must not contain line delimiters.</li>
 186          * </ul>
 187          *
 188          * @param offset
 189          *            the offset of the position.
 190          * @param length
 191          *            the length of the position.
 192          */
 193         public void addPosition(int offset, int length) throws BadLocationException {
 194                 String type = fDocument.get(offset, length);
 195                 addPosition(offset, length, type);
 196         }
 197
 198         /**
 199          * Adds a linked position of the specified position type to the manager.
 200          * There are the following constraints for linked positions:
 201          *
 202          * <ul>
 203          * <li>Any two positions have spacing of at least one character. This
 204          * implies that two positions must not overlap.</li>
 205          *
 206          * <li>The string at any position must not contain line delimiters.</li>
 207          * </ul>
 208          *
 209          * @param offset
 210          *            the offset of the position.
 211          * @param length
 212          *            the length of the position.
 213          * @param type
 214          *            the position type name - any positions with the same type are
 215          *            linked.
 216          */
 217         public void addPosition(int offset, int length, String type)
 218                         throws BadLocationException {
 219                 Position[] positions = getPositions(fDocument);
 220
 221                 if (positions != null) {
 222                         for (int i = 0; i < positions.length; i++)
 223                                 if (collides(positions[i], offset, length))
 224                                         throw new BadLocationException(
 225                                                         LinkedPositionMessages
 226                                                                         .getString(("LinkedPositionManager.error.position.collision"))); //$NON-NLS-1$
 227                 }
 228
 229                 String content = fDocument.get(offset, length);
 230
 231                 if (containsLineDelimiters(content))
 232                         throw new BadLocationException(
 233                                         LinkedPositionMessages
 234                                                         .getString(("LinkedPositionManager.error.contains.line.delimiters"))); //$NON-NLS-1$
 235
 236                 try {
 237                         fDocument.addPosition(fPositionCategoryName, new TypedPosition(
 238                                         offset, length, type));
 239                 } catch (BadPositionCategoryException e) {
 240                         WebUI.log(e);
 241                         Assert.isTrue(false);
 242                 }
 243         }
 244
 245         /**
 246          * Adds a linked position to the manager. The current document content at
 247          * the specified range is taken as the position type.
 248          * <p>
 249          * There are the following constraints for linked positions:
 250          *
 251          * <ul>
 252          * <li>Any two positions have spacing of at least one character. This
 253          * implies that two positions must not overlap.</li>
 254          *
 255          * <li>The string at any position must not contain line delimiters.</li>
 256          * </ul>
 257          *
 258          * It is usually best to set the first item in
 259          * <code>additionalChoices</code> to be equal with the text inserted at
 260          * the current position.
 261          * </p>
 262          *
 263          * @param offset
 264          *            the offset of the position.
 265          * @param length
 266          *            the length of the position.
 267          * @param additionalChoices
 268          *            a number of additional choices to be displayed when selecting
 269          *            a position of this <code>type</code>.
 270          */
 271 //      public void addPosition(int offset, int length,
 272 //                      ICompletionProposal[] additionalChoices)
 273 //                      throws BadLocationException {
 274 //              String type = fDocument.get(offset, length);
 275 //              addPosition(offset, length, type, additionalChoices);
 276 //      }
 277
 278         /**
 279          * Adds a linked position of the specified position type to the manager.
 280          * There are the following constraints for linked positions:
 281          *
 282          * <ul>
 283          * <li>Any two positions have spacing of at least one character. This
 284          * implies that two positions must not overlap.</li>
 285          *
 286          * <li>The string at any position must not contain line delimiters.</li>
 287          * </ul>
 288          *
 289          * It is usually best to set the first item in
 290          * <code>additionalChoices</code> to be equal with the text inserted at
 291          * the current position.
 292          *
 293          * @param offset
 294          *            the offset of the position.
 295          * @param length
 296          *            the length of the position.
 297          * @param type
 298          *            the position type name - any positions with the same type are
 299          *            linked.
 300          * @param additionalChoices
 301          *            a number of additional choices to be displayed when selecting
 302          *            a position of this <code>type</code>.
 303          */
 304 //      public void addPosition(int offset, int length, String type,
 305 //                      ICompletionProposal[] additionalChoices)
 306 //                      throws BadLocationException {
 307 //              Position[] positions = getPositions(fDocument);
 308 //
 309 //              if (positions != null) {
 310 //                      for (int i = 0; i < positions.length; i++)
 311 //                              if (collides(positions[i], offset, length))
 312 //                                      throw new BadLocationException(
 313 //                                                      LinkedPositionMessages
 314 //                                                                      .getString(("LinkedPositionManager.error.position.collision"))); //$NON-NLS-1$
 315 //              }
 316 //
 317 //              String content = fDocument.get(offset, length);
 318 //
 319 //              if (containsLineDelimiters(content))
 320 //                      throw new BadLocationException(
 321 //                                      LinkedPositionMessages
 322 //                                                      .getString(("LinkedPositionManager.error.contains.line.delimiters"))); //$NON-NLS-1$
 323 //
 324 //              try {
 325 //                      fDocument.addPosition(fPositionCategoryName, new ProposalPosition(
 326 //                                      offset, length, type, additionalChoices));
 327 //              } catch (BadPositionCategoryException e) {
 328 //                      WebUI.log(e);
 329 //                      Assert.isTrue(false);
 330 //              }
 331 //      }
 332
 333         /**
 334          * Tests if a manager is already active for a document.
 335          */
 336 //      public static boolean hasActiveManager(IDocument document) {
 337 //              return fgActiveManagers.get(document) != null;
 338 //      }
 339
 340         private void install(boolean canCoexist) {
 341
 342                 if (fIsActive)
 343                         ;// JavaPlugin.log(new Status(IStatus.WARNING,
 344                                 // JavaPlugin.getPluginId(), IStatus.OK, "LinkedPositionManager
 345                                 // is already active: "+fPositionCategoryName, new
 346                                 // IllegalStateException())); //$NON-NLS-1$
 347                 else {
 348                         fIsActive = true;
 349                         // JavaPlugin.log(new Status(IStatus.INFO, JavaPlugin.getPluginId(),
 350                         // IStatus.OK, "LinkedPositionManager activated:
 351                         // "+fPositionCategoryName, new Exception())); //$NON-NLS-1$
 352                 }
 353
 354                 if (!canCoexist) {
 355                         LinkedPositionManager manager = (LinkedPositionManager) fgActiveManagers
 356                                         .get(fDocument);
 357                         if (manager != null)
 358                                 manager.leave(true);
 359                 }
 360
 361                 fgActiveManagers.put(fDocument, this);
 362                 fDocument.addPositionCategory(fPositionCategoryName);
 363                 fDocument.addPositionUpdater(this);
 364                 fDocument.addDocumentListener(this);
 365
 366                 fMustLeave = false;
 367         }
 368
 369         /**
 370          * Leaves the linked mode. If unsuccessful, the linked positions are
 371          * restored to the values at the time they were added.
 372          */
 373         public void uninstall(boolean success) {
 374
 375                 if (!fIsActive)
 376                         // we migth also just return
 377                         ;// JavaPlugin(new Status(IStatus.WARNING,
 378                                 // JavaPlugin.getPluginId(), IStatus.OK, "LinkedPositionManager
 379                                 // activated: "+fPositionCategoryName, new
 380                                 // IllegalStateException())); //$NON-NLS-1$
 381                 else {
 382                         fDocument.removeDocumentListener(this);
 383
 384                         try {
 385                                 Position[] positions = getPositions(fDocument);
 386                                 if ((!success) && (positions != null)) {
 387                                         // restore
 388                                         for (int i = 0; i != positions.length; i++) {
 389                                                 TypedPosition position = (TypedPosition) positions[i];
 390                                                 fDocument.replace(position.getOffset(), position
 391                                                                 .getLength(), position.getType());
 392                                         }
 393                                 }
 394
 395                                 fDocument.removePositionCategory(fPositionCategoryName);
 396
 397                                 fIsActive = false;
 398                                 // JavaPlugin.log(new Status(IStatus.INFO,
 399                                 // JavaPlugin.getPluginId(), IStatus.OK, "LinkedPositionManager
 400                                 // deactivated: "+fPositionCategoryName, new Exception()));
 401                                 // //$NON-NLS-1$
 402
 403                         } catch (BadLocationException e) {
 404                                 WebUI.log(e);
 405                                 Assert.isTrue(false);
 406
 407                         } catch (BadPositionCategoryException e) {
 408                                 WebUI.log(e);
 409                                 Assert.isTrue(false);
 410
 411                         } finally {
 412                                 fDocument.removePositionUpdater(this);
 413                                 fgActiveManagers.remove(fDocument);
 414                         }
 415                 }
 416
 417         }
 418
 419         /**
 420          * Returns the position at the given offset, <code>null</code> if there is
 421          * no position.
 422          *
 423          * @since 2.1
 424          */
 425         public Position getPosition(int offset) {
 426                 Position[] positions = getPositions(fDocument);
 427                 if (positions == null)
 428                         return null;
 429
 430                 for (int i = positions.length - 1; i >= 0; i--) {
 431                         Position position = positions[i];
 432                         if (offset >= position.getOffset()
 433                                         && offset <= position.getOffset() + position.getLength())
 434                                 return positions[i];
 435                 }
 436
 437                 return null;
 438         }
 439
 440         /**
 441          * Returns the first linked position.
 442          *
 443          * @return returns <code>null</code> if no linked position exist.
 444          */
 445         public Position getFirstPosition() {
 446                 return getNextPosition(-1);
 447         }
 448
 449         public Position getLastPosition() {
 450                 Position[] positions = getPositions(fDocument);
 451                 for (int i = positions.length - 1; i >= 0; i--) {
 452                         String type = ((TypedPosition) positions[i]).getType();
 453                         int j;
 454                         for (j = 0; j != i; j++)
 455                                 if (((TypedPosition) positions[j]).getType().equals(type))
 456                                         break;
 457
 458                         if (j == i)
 459                                 return positions[i];
 460                 }
 461
 462                 return null;
 463         }
 464
 465         /**
 466          * Returns the next linked position with an offset greater than
 467          * <code>offset</code>. If another position with the same type and offset
 468          * lower than <code>offset</code> exists, the position is skipped.
 469          *
 470          * @return returns <code>null</code> if no linked position exist.
 471          */
 472         public Position getNextPosition(int offset) {
 473                 Position[] positions = getPositions(fDocument);
 474                 return findNextPosition(positions, offset);
 475         }
 476
 477         private static Position findNextPosition(Position[] positions, int offset) {
 478                 // skip already visited types
 479                 for (int i = 0; i != positions.length; i++) {
 480                         if (positions[i].getOffset() > offset) {
 481                                 String type = ((TypedPosition) positions[i]).getType();
 482                                 int j;
 483                                 for (j = 0; j != i; j++)
 484                                         if (((TypedPosition) positions[j]).getType().equals(type))
 485                                                 break;
 486
 487                                 if (j == i)
 488                                         return positions[i];
 489                         }
 490                 }
 491
 492                 return null;
 493         }
 494
 495         /**
 496          * Returns the position with the greatest offset smaller than
 497          * <code>offset</code>.
 498          *
 499          * @return returns <code>null</code> if no linked position exist.
 500          */
 501         public Position getPreviousPosition(int offset) {
 502                 Position[] positions = getPositions(fDocument);
 503                 if (positions == null)
 504                         return null;
 505
 506                 TypedPosition currentPosition = (TypedPosition) findCurrentPosition(
 507                                 positions, offset);
 508                 String currentType = currentPosition == null ? null : currentPosition
 509                                 .getType();
 510
 511                 Position lastPosition = null;
 512                 Position position = getFirstPosition();
 513
 514                 while (position != null && position.getOffset() < offset) {
 515                         if (!((TypedPosition) position).getType().equals(currentType))
 516                                 lastPosition = position;
 517                         position = findNextPosition(positions, position.getOffset());
 518                 }
 519
 520                 return lastPosition;
 521         }
 522
 523         private Position[] getPositions(IDocument document) {
 524
 525                 if (!fIsActive)
 526                         // we migth also just return an empty array
 527                         ;// JavaPlugin(new Status(IStatus.WARNING,
 528                                 // JavaPlugin.getPluginId(), IStatus.OK, "LinkedPositionManager
 529                                 // is not active: "+fPositionCategoryName, new
 530                                 // IllegalStateException())); //$NON-NLS-1$
 531
 532                 try {
 533                         Position[] positions = document.getPositions(fPositionCategoryName);
 534                         Arrays.sort(positions, fgPositionComparator);
 535                         return positions;
 536
 537                 } catch (BadPositionCategoryException e) {
 538                         WebUI.log(e);
 539                         Assert.isTrue(false);
 540                 }
 541
 542                 return null;
 543         }
 544
 545         public static boolean includes(Position position, int offset, int length) {
 546                 return (offset >= position.getOffset())
 547                                 && (offset + length <= position.getOffset()
 548                                                 + position.getLength());
 549         }
 550
 551 //      public static boolean excludes(Position position, int offset, int length) {
 552 //              return (offset + length <= position.getOffset())
 553 //                              || (position.getOffset() + position.getLength() <= offset);
 554 //      }
 555
 556         /*
 557          * Collides if spacing if positions intersect each other or are adjacent.
 558          */
 559         private static boolean collides(Position position, int offset, int length) {
 560                 return (offset <= position.getOffset() + position.getLength())
 561                                 && (position.getOffset() <= offset + length);
 562         }
 563
 564         private void leave(boolean success) {
 565                 try {
 566                         uninstall(success);
 567
 568                         if (fListener != null)
 569                                 fListener.exit((success ? LinkedPositionUI.COMMIT : 0)
 570                                                 | LinkedPositionUI.UPDATE_CARET);
 571                 } finally {
 572                         fMustLeave = false;
 573                 }
 574         }
 575
 576         private void abort() {
 577                 uninstall(true); // don't revert anything
 578
 579                 if (fListener != null)
 580                         fListener.exit(LinkedPositionUI.COMMIT); // don't let the UI
 581                                                                                                                 // restore anything
 582
 583                 // don't set fMustLeave, as we will get re-registered by a document
 584                 // event
 585         }
 586
 587         /*
 588          * @see IDocumentListener#documentAboutToBeChanged(DocumentEvent)
 589          */
 590         public void documentAboutToBeChanged(DocumentEvent event) {
 591
 592                 if (fMustLeave) {
 593                         event.getDocument().removeDocumentListener(this);
 594                         return;
 595                 }
 596
 597                 IDocument document = event.getDocument();
 598
 599                 Position[] positions = getPositions(document);
 600                 Position position = findCurrentPosition(positions, event.getOffset());
 601
 602                 // modification outside editable position
 603                 if (position == null) {
 604                         // check for destruction of constraints (spacing of at least 1)
 605                         if ((event.getText() == null || event.getText().length() == 0)
 606                                         && (findCurrentPosition(positions, event.getOffset()) != null)
 607                                         && // will never become true, see condition above
 608                                         (findCurrentPosition(positions, event.getOffset()
 609                                                         + event.getLength()) != null)) {
 610                                 leave(true);
 611                         }
 612
 613                         // modification intersects editable position
 614                 } else {
 615                         // modificaction inside editable position
 616                         if (includes(position, event.getOffset(), event.getLength())) {
 617                                 if (containsLineDelimiters(event.getText()))
 618                                         leave(true);
 619
 620                                 // modificaction exceeds editable position
 621                         } else {
 622                                 leave(true);
 623                         }
 624                 }
 625         }
 626
 627         /*
 628          * @see IDocumentListener#documentChanged(DocumentEvent)
 629          */
 630         public void documentChanged(DocumentEvent event) {
 631
 632                 // have to handle code assist, so can't just leave the linked mode
 633                 // leave(true);
 634
 635                 IDocument document = event.getDocument();
 636
 637                 Position[] positions = getPositions(document);
 638                 TypedPosition currentPosition = (TypedPosition) findCurrentPosition(
 639                                 positions, event.getOffset());
 640
 641                 // ignore document changes (assume it won't invalidate constraints)
 642                 if (currentPosition == null)
 643                         return;
 644
 645                 int deltaOffset = event.getOffset() - currentPosition.getOffset();
 646
 647                 if (fListener != null) {
 648                         int length = event.getText() == null ? 0 : event.getText().length();
 649                         fListener.setCurrentPosition(currentPosition, deltaOffset + length);
 650                 }
 651
 652                 for (int i = 0; i != positions.length; i++) {
 653                         TypedPosition p = (TypedPosition) positions[i];
 654
 655                         if (p.getType().equals(currentPosition.getType())
 656                                         && !p.equals(currentPosition)) {
 657                                 Replace replace = new Replace(p, deltaOffset,
 658                                                 event.getLength(), event.getText());
 659                                 ((IDocumentExtension) document)
 660                                                 .registerPostNotificationReplace(this, replace);
 661                         }
 662                 }
 663         }
 664
 665         /*
 666          * @see IPositionUpdater#update(DocumentEvent)
 667          */
 668         public void update(DocumentEvent event) {
 669
 670                 int eventOffset = event.getOffset();
 671                 int eventOldLength = event.getLength();
 672                 int eventNewLength = event.getText() == null ? 0 : event.getText()
 673                                 .length();
 674                 int deltaLength = eventNewLength - eventOldLength;
 675
 676                 Position[] positions = getPositions(event.getDocument());
 677
 678                 for (int i = 0; i != positions.length; i++) {
 679
 680                         Position position = positions[i];
 681
 682                         if (position.isDeleted())
 683                                 continue;
 684
 685                         int offset = position.getOffset();
 686                         int length = position.getLength();
 687                         int end = offset + length;
 688
 689                         if (offset > eventOffset + eventOldLength) // position comes way
 690                                                                                                                 // after change - shift
 691                                 position.setOffset(offset + deltaLength);
 692                         else if (end < eventOffset) // position comes way before change -
 693                                                                                 // leave alone
 694                                 ;
 695                         else if (offset <= eventOffset
 696                                         && end >= eventOffset + eventOldLength) {
 697                                 // event completely internal to the position - adjust length
 698                                 position.setLength(length + deltaLength);
 699                         } else if (offset < eventOffset) {
 700                                 // event extends over end of position - adjust length
 701                                 int newEnd = eventOffset + eventNewLength;
 702                                 position.setLength(newEnd - offset);
 703                         } else if (end > eventOffset + eventOldLength) {
 704                                 // event extends from before position into it - adjust offset
 705                                 // and length
 706                                 // offset becomes end of event, length ajusted acordingly
 707                                 // we want to recycle the overlapping part
 708                                 int newOffset = eventOffset + eventNewLength;
 709                                 position.setOffset(newOffset);
 710                                 position.setLength(length + deltaLength);
 711                         } else {
 712                                 // event consumes the position - delete it
 713                                 position.delete();
 714                                 // JavaPlugin.log(new Status(IStatus.INFO,
 715                                 // JavaPlugin.getPluginId(), IStatus.OK, "linked position
 716                                 // deleted -> must leave: "+fPositionCategoryName, null));
 717                                 // //$NON-NLS-1$
 718                                 fMustLeave = true;
 719                         }
 720                 }
 721
 722                 if (fMustLeave)
 723                         abort();
 724         }
 725
 726         private static Position findCurrentPosition(Position[] positions, int offset) {
 727                 for (int i = 0; i != positions.length; i++)
 728                         if (includes(positions[i], offset, 0))
 729                                 return positions[i];
 730
 731                 return null;
 732         }
 733
 734         private boolean containsLineDelimiters(String string) {
 735
 736                 if (string == null)
 737                         return false;
 738
 739                 String[] delimiters = fDocument.getLegalLineDelimiters();
 740
 741                 for (int i = 0; i != delimiters.length; i++)
 742                         if (string.indexOf(delimiters[i]) != -1)
 743                                 return true;
 744
 745                 return false;
 746         }
 747
 748         /**
 749          * Test if ok to modify through UI.
 750          */
 751         public boolean anyPositionIncludes(int offset, int length) {
 752                 Position[] positions = getPositions(fDocument);
 753
 754                 Position position = findCurrentPosition(positions, offset);
 755                 if (position == null)
 756                         return false;
 757
 758                 return includes(position, offset, length);
 759         }
 760
 761         /**
 762          * Returns the position that includes the given range.
 763          *
 764          * @param offset
 765          * @param length
 766          * @return position that includes the given range
 767          */
 768         public Position getEmbracingPosition(int offset, int length) {
 769                 Position[] positions = getPositions(fDocument);
 770
 771                 Position position = findCurrentPosition(positions, offset);
 772                 if (position != null && includes(position, offset, length))
 773                         return position;
 774
 775                 return null;
 776         }
 777
 778         /*
 779          * @see org.eclipse.jface.text.IAutoIndentStrategy#customizeDocumentCommand(org.eclipse.jface.text.IDocument,
 780          *      org.eclipse.jface.text.DocumentCommand)
 781          */
 782         public void customizeDocumentCommand(IDocument document,
 783                         DocumentCommand command) {
 784
 785                 if (fMustLeave) {
 786                         leave(true);
 787                         return;
 788                 }
 789
 790                 // don't interfere with preceding auto edit strategies
 791                 if (command.getCommandCount() != 1) {
 792                         leave(true);
 793                         return;
 794                 }
 795
 796                 Position[] positions = getPositions(document);
 797                 TypedPosition currentPosition = (TypedPosition) findCurrentPosition(
 798                                 positions, command.offset);
 799
 800                 // handle edits outside of a position
 801                 if (currentPosition == null) {
 802                         leave(true);
 803                         return;
 804                 }
 805
 806                 if (!command.doit)
 807                         return;
 808
 809                 command.doit = false;
 810                 command.owner = this;
 811                 command.caretOffset = command.offset + command.length;
 812
 813                 int deltaOffset = command.offset - currentPosition.getOffset();
 814
 815                 if (fListener != null)
 816                         fListener.setCurrentPosition(currentPosition, deltaOffset
 817                                         + command.text.length());
 818
 819                 for (int i = 0; i != positions.length; i++) {
 820                         TypedPosition position = (TypedPosition) positions[i];
 821
 822                         try {
 823                                 if (position.getType().equals(currentPosition.getType())
 824                                                 && !position.equals(currentPosition))
 825                                         command.addCommand(position.getOffset() + deltaOffset,
 826                                                         command.length, command.text, this);
 827                         } catch (BadLocationException e) {
 828                                 WebUI.log(e);
 829                         }
 830                 }
 831         }
 832
 833 }