qundostack.cpp

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39 -

40 #include <QtCore/qdebug.h> -

41 #include "qundostack.h" -

42 #include "qundogroup.h" -

43 #include "qundostack_p.h" -

44 -

45 #ifndef QT_NO_UNDOCOMMAND -

46 -

47 QT_BEGIN_NAMESPACE -

48 -

49 /*! -

50 \class QUndoCommand -

51 \brief The QUndoCommand class is the base class of all commands stored on a QUndoStack. -

52 \since 4.2 -

53 -

54 \inmodule QtWidgets -

55 -

56 For an overview of Qt's Undo Framework, see the -

57 \l{Overview of Qt's Undo Framework}{overview document}. -

58 -

59 A QUndoCommand represents a single editing action on a document; for example, -

60 inserting or deleting a block of text in a text editor. QUndoCommand can apply -

61 a change to the document with redo() and undo the change with undo(). The -

62 implementations for these functions must be provided in a derived class. -

63 -

64 \snippet code/src_gui_util_qundostack.cpp 0 -

65 -

66 A QUndoCommand has an associated text(). This is a short string -

67 describing what the command does. It is used to update the text -

68 properties of the stack's undo and redo actions; see -

69 QUndoStack::createUndoAction() and QUndoStack::createRedoAction(). -

70 -

71 QUndoCommand objects are owned by the stack they were pushed on. -

72 QUndoStack deletes a command if it has been undone and a new command is pushed. For example: -

73 -

74 \snippet code/src_gui_util_qundostack.cpp 1 -

75 -

76 In effect, when a command is pushed, it becomes the top-most command -

77 on the stack. -

78 -

79 To support command compression, QUndoCommand has an id() and the virtual function -

80 mergeWith(). These functions are used by QUndoStack::push(). -

81 -

82 To support command macros, a QUndoCommand object can have any number of child -

83 commands. Undoing or redoing the parent command will cause the child -

84 commands to be undone or redone. A command can be assigned -

85 to a parent explicitly in the constructor. In this case, the command -

86 will be owned by the parent. -

87 -

88 The parent in this case is usually an empty command, in that it doesn't -

89 provide its own implementation of undo() and redo(). Instead, it uses -

90 the base implementations of these functions, which simply call undo() or -

91 redo() on all its children. The parent should, however, have a meaningful -

92 text(). -

93 -

94 \snippet code/src_gui_util_qundostack.cpp 2 -

95 -

96 Another way to create macros is to use the convenience functions -

97 QUndoStack::beginMacro() and QUndoStack::endMacro(). -

98 -

99 \sa QUndoStack -

100 */ -

101 -

102 /*! -

103 Constructs a QUndoCommand object with the given \a parent and \a text. -

104 -

105 If \a parent is not 0, this command is appended to parent's child list. -

106 The parent command then owns this command and will delete it in its -

107 destructor. -

108 -

109 \sa ~QUndoCommand() -

110 */ -

111 -

112 QUndoCommand::QUndoCommand(const QString &text, QUndoCommand *parent) -

113 { -

114 d = new QUndoCommandPrivate; -

115 if (parent != 0) -

116 parent->d->child_list.append(this); -

117 setText(text); -

118 } -

119 -

120 /*! -

121 Constructs a QUndoCommand object with parent \a parent. -

122 -

123 If \a parent is not 0, this command is appended to parent's child list. -

124 The parent command then owns this command and will delete it in its -

125 destructor. -

126 -

127 \sa ~QUndoCommand() -

128 */ -

129 -

130 QUndoCommand::QUndoCommand(QUndoCommand *parent) -

131 { -

132 d = new QUndoCommandPrivate; -

133 if (parent != 0) -

134 parent->d->child_list.append(this); -

135 } -

136 -

137 /*! -

138 Destroys the QUndoCommand object and all child commands. -

139 -

140 \sa QUndoCommand() -

141 */ -

142 -

143 QUndoCommand::~QUndoCommand() -

144 { -

145 qDeleteAll(d->child_list); -

146 delete d; -

147 } -

148 -

149 /*! -

150 Returns the ID of this command. -

151 -

152 A command ID is used in command compression. It must be an integer unique to -

153 this command's class, or -1 if the command doesn't support compression. -

154 -

155 If the command supports compression this function must be overridden in the -

156 derived class to return the correct ID. The base implementation returns -1. -

157 -

158 QUndoStack::push() will only try to merge two commands if they have the -

159 same ID, and the ID is not -1. -

160 -

161 \sa mergeWith(), QUndoStack::push() -

162 */ -

163 -

164 int QUndoCommand::id() const -

165 { -

166 return -1; -

167 } -

168 -

169 /*! -

170 Attempts to merge this command with \a command. Returns \c true on -

171 success; otherwise returns \c false. -

172 -

173 If this function returns \c true, calling this command's redo() must have the same -

174 effect as redoing both this command and \a command. -

175 Similarly, calling this command's undo() must have the same effect as undoing -

176 \a command and this command. -

177 -

178 QUndoStack will only try to merge two commands if they have the same id, and -

179 the id is not -1. -

180 -

181 The default implementation returns \c false. -

182 -

183 \snippet code/src_gui_util_qundostack.cpp 3 -

184 -

185 \sa id(), QUndoStack::push() -

186 */ -

187 -

188 bool QUndoCommand::mergeWith(const QUndoCommand *command) -

189 { -

190 Q_UNUSED(command); -

191 return false; -

192 } -

193 -

194 /*! -

195 Applies a change to the document. This function must be implemented in -

196 the derived class. Calling QUndoStack::push(), -

197 QUndoStack::undo() or QUndoStack::redo() from this function leads to -

198 undefined beahavior. -

199 -

200 The default implementation calls redo() on all child commands. -

201 -

202 \sa undo() -

203 */ -

204 -

205 void QUndoCommand::redo() -

206 { -

207 for (int i = 0; i < d->child_list.size(); ++i) -

208 d->child_list.at(i)->redo(); -

209 } -

210 -

211 /*! -

212 Reverts a change to the document. After undo() is called, the state of -

213 the document should be the same as before redo() was called. This function must -

214 be implemented in the derived class. Calling QUndoStack::push(), -

215 QUndoStack::undo() or QUndoStack::redo() from this function leads to -

216 undefined beahavior. -

217 -

218 The default implementation calls undo() on all child commands in reverse order. -

219 -

220 \sa redo() -

221 */ -

222 -

223 void QUndoCommand::undo() -

224 { -

225 for (int i = d->child_list.size() - 1; i >= 0; --i) -

226 d->child_list.at(i)->undo(); -

227 } -

228 -

229 /*! -

230 Returns a short text string describing what this command does; for example, -

231 "insert text". -

232 -

233 The text is used for names of items in QUndoView. -

234 -

235 \sa actionText(), setText(), QUndoStack::createUndoAction(), QUndoStack::createRedoAction() -

236 */ -

237 -

238 QString QUndoCommand::text() const -

239 { -

240 return d->text; -

241 } -

242 -

243 /*! -

244 \since 4.8 -

245 -

246 Returns a short text string describing what this command does; for example, -

247 "insert text". -

248 -

249 The text is used when the text properties of the stack's undo and redo -

250 actions are updated. -

251 -

252 \sa text(), setText(), QUndoStack::createUndoAction(), QUndoStack::createRedoAction() -

253 */ -

254 -

255 QString QUndoCommand::actionText() const -

256 { -

257 return d->actionText; -

258 } -

259 -

260 /*! -

261 Sets the command's text to be the \a text specified. -

262 -

263 The specified text should be a short user-readable string describing what this -

264 command does. -

265 -

266 If you need to have two different strings for text() and actionText(), separate -

267 them with "\\n" and pass into this function. Even if you do not use this feature -

268 for English strings during development, you can still let translators use two -

269 different strings in order to match specific languages' needs. -

270 The described feature and the function actionText() are available since Qt 4.8. -

271 -

272 \sa text(), actionText(), QUndoStack::createUndoAction(), QUndoStack::createRedoAction() -

273 */ -

274 -

275 void QUndoCommand::setText(const QString &text) -

276 { -

277 int cdpos = text.indexOf(QLatin1Char('\n')); -

278 if (cdpos > 0) { -

279 d->text = text.left(cdpos); -

280 d->actionText = text.mid(cdpos + 1); -

281 } else { -

282 d->text = text; -

283 d->actionText = text; -

284 } -

285 } -

286 -

287 /*! -

288 \since 4.4 -

289 -

290 Returns the number of child commands in this command. -

291 -

292 \sa child() -

293 */ -

294 -

295 int QUndoCommand::childCount() const -

296 { -

297 return d->child_list.count(); -

298 } -

299 -

300 /*! -

301 \since 4.4 -

302 -

303 Returns the child command at \a index. -

304 -

305 \sa childCount(), QUndoStack::command() -

306 */ -

307 -

308 const QUndoCommand *QUndoCommand::child(int index) const -

309 { -

310 if (index < 0 || index >= d->child_list.count()) -

311 return 0; -

312 return d->child_list.at(index); -

313 } -

314 -

315 #endif // QT_NO_UNDOCOMMAND -

316 -

317 #ifndef QT_NO_UNDOSTACK -

318 -

319 /*! -

320 \class QUndoStack -

321 \brief The QUndoStack class is a stack of QUndoCommand objects. -

322 \since 4.2 -

323 -

324 \inmodule QtWidgets -

325 -

326 For an overview of Qt's Undo Framework, see the -

327 \l{Overview of Qt's Undo Framework}{overview document}. -

328 -

329 An undo stack maintains a stack of commands that have been applied to a -

330 document. -

331 -

332 New commands are pushed on the stack using push(). Commands can be -

333 undone and redone using undo() and redo(), or by triggering the -

334 actions returned by createUndoAction() and createRedoAction(). -

335 -

336 QUndoStack keeps track of the \a current command. This is the command -

337 which will be executed by the next call to redo(). The index of this -

338 command is returned by index(). The state of the edited object can be -

339 rolled forward or back using setIndex(). If the top-most command on the -

340 stack has already been redone, index() is equal to count(). -

341 -

342 QUndoStack provides support for undo and redo actions, command -

343 compression, command macros, and supports the concept of a -

344 \e{clean state}. -

345 -

346 \section1 Undo and Redo Actions -

347 -

348 QUndoStack provides convenient undo and redo QAction objects, which -

349 can be inserted into a menu or a toolbar. When commands are undone or -

350 redone, QUndoStack updates the text properties of these actions -

351 to reflect what change they will trigger. The actions are also disabled -

352 when no command is available for undo or redo. These actions -

353 are returned by QUndoStack::createUndoAction() and QUndoStack::createRedoAction(). -

354 -

355 \section1 Command Compression and Macros -

356 -

357 Command compression is useful when several commands can be compressed -

358 into a single command that can be undone and redone in a single operation. -

359 For example, when a user types a character in a text editor, a new command -

360 is created. This command inserts the character into the document at the -

361 cursor position. However, it is more convenient for the user to be able -

362 to undo or redo typing of whole words, sentences, or paragraphs. -

363 Command compression allows these single-character commands to be merged -

364 into a single command which inserts or deletes sections of text. -

365 For more information, see QUndoCommand::mergeWith() and push(). -

366 -

367 A command macro is a sequence of commands, all of which are undone and -

368 redone in one go. Command macros are created by giving a command a list -

369 of child commands. -

370 Undoing or redoing the parent command will cause the child commands to -

371 be undone or redone. Command macros may be created explicitly -

372 by specifying a parent in the QUndoCommand constructor, or by using the -

373 convenience functions beginMacro() and endMacro(). -

374 -

375 Although command compression and macros appear to have the same effect to the -

376 user, they often have different uses in an application. Commands that -

377 perform small changes to a document may be usefully compressed if there is -

378 no need to individually record them, and if only larger changes are relevant -

379 to the user. -

380 However, for commands that need to be recorded individually, or those that -

381 cannot be compressed, it is useful to use macros to provide a more convenient -

382 user experience while maintaining a record of each command. -

383 -

384 \section1 Clean State -

385 -

386 QUndoStack supports the concept of a clean state. When the -

387 document is saved to disk, the stack can be marked as clean using -

388 setClean(). Whenever the stack returns to this state through undoing and -

389 redoing commands, it emits the signal cleanChanged(). This signal -

390 is also emitted when the stack leaves the clean state. This signal is -

391 usually used to enable and disable the save actions in the application, -

392 and to update the document's title to reflect that it contains unsaved -

393 changes. -

394 -

395 \sa QUndoCommand, QUndoView -

396 */ -

397 -

398 #ifndef QT_NO_ACTION -

399 -

400 QUndoAction::QUndoAction(const QString &prefix, QObject *parent) -

401 : QAction(parent) -

402 { -

403 m_prefix = prefix; -

404 } -

405 -

406 void QUndoAction::setPrefixedText(const QString &text) -

407 { -

408 if (m_defaultText.isEmpty()) { -

409 QString s = m_prefix; -

410 if (!m_prefix.isEmpty() && !text.isEmpty()) -

411 s.append(QLatin1Char(' ')); -

412 s.append(text); -

413 setText(s); -

414 } else { -

415 if (text.isEmpty()) -

416 setText(m_defaultText); -

417 else -

418 setText(m_prefix.arg(text)); -

419 } -

420 } -

421 -

422 void QUndoAction::setTextFormat(const QString &textFormat, const QString &defaultText) -

423 { -

424 m_prefix = textFormat; -

425 m_defaultText = defaultText; -

426 } -

427 -

428 #endif // QT_NO_ACTION -

429 -

430 /*! \internal -

431 Sets the current index to \a idx, emitting appropriate signals. If \a clean is true, -

432 makes \a idx the clean index as well. -

433 */ -

434 -

435 void QUndoStackPrivate::setIndex(int idx, bool clean) -

436 { -

437 Q_Q(QUndoStack); -

438 -

439 bool was_clean = index == clean_index; -

440 -

441 if (idx != index) { -

442 index = idx; -

443 emit q->indexChanged(index); -

444 emit q->canUndoChanged(q->canUndo()); -

445 emit q->undoTextChanged(q->undoText()); -

446 emit q->canRedoChanged(q->canRedo()); -

447 emit q->redoTextChanged(q->redoText()); -

448 } -

449 -

450 if (clean) -

451 clean_index = index; -

452 -

453 bool is_clean = index == clean_index; -

454 if (is_clean != was_clean) -

455 emit q->cleanChanged(is_clean); -

456 } -

457 -

458 /*! \internal -

459 If the number of commands on the stack exceedes the undo limit, deletes commands from -

460 the bottom of the stack. -

461 -

462 Returns \c true if commands were deleted. -

463 */ -

464 -

465 bool QUndoStackPrivate::checkUndoLimit() -

466 { -

467 if (undo_limit <= 0 || !macro_stack.isEmpty() || undo_limit >= command_list.count()) -

468 return false; -

469 -

470 int del_count = command_list.count() - undo_limit; -

471 -

472 for (int i = 0; i < del_count; ++i) -

473 delete command_list.takeFirst(); -

474 -

475 index -= del_count; -

476 if (clean_index != -1) { -

477 if (clean_index < del_count) -

478 clean_index = -1; // we've deleted the clean command -

479 else -

480 clean_index -= del_count; -

481 } -

482 -

483 return true; -

484 } -

485 -

486 /*! -

487 Constructs an empty undo stack with the parent \a parent. The -

488 stack will initially be in the clean state. If \a parent is a -

489 QUndoGroup object, the stack is automatically added to the group. -

490 -

491 \sa push() -

492 */ -

493 -

494 QUndoStack::QUndoStack(QObject *parent) -

495 : QObject(*(new QUndoStackPrivate), parent) -

496 { -

497 #ifndef QT_NO_UNDOGROUP -

498 if (QUndoGroup *group = qobject_cast<QUndoGroup*>(parent)) -

499 group->addStack(this); -

500 #endif -

501 } -

502 -

503 /*! -

504 Destroys the undo stack, deleting any commands that are on it. If the -

505 stack is in a QUndoGroup, the stack is automatically removed from the group. -

506 -

507 \sa QUndoStack() -

508 */ -

509 -

510 QUndoStack::~QUndoStack() -

511 { -

512 #ifndef QT_NO_UNDOGROUP -

513 Q_D(QUndoStack); -

514 if (d->group != 0) -

515 d->group->removeStack(this); -

516 #endif -

517 clear(); -

518 } -

519 -

520 /*! -

521 Clears the command stack by deleting all commands on it, and returns the stack -

522 to the clean state. -

523 -

524 Commands are not undone or redone; the state of the edited object remains -

525 unchanged. -

526 -

527 This function is usually used when the contents of the document are -

528 abandoned. -

529 -

530 \sa QUndoStack() -

531 */ -

532 -

533 void QUndoStack::clear() -

534 { -

535 Q_D(QUndoStack); -

536 -

537 if (d->command_list.isEmpty()) -

538 return; -

539 -

540 bool was_clean = isClean(); -

541 -

542 d->macro_stack.clear(); -

543 qDeleteAll(d->command_list); -

544 d->command_list.clear(); -

545 -

546 d->index = 0; -

547 d->clean_index = 0; -

548 -

549 emit indexChanged(0); -

550 emit canUndoChanged(false); -

551 emit undoTextChanged(QString()); -

552 emit canRedoChanged(false); -

553 emit redoTextChanged(QString()); -

554 -

555 if (!was_clean) -

556 emit cleanChanged(true); -

557 } -

558 -

559 /*! -

560 Pushes \a cmd on the stack or merges it with the most recently executed command. -

561 In either case, executes \a cmd by calling its redo() function. -

562 -

563 If \a cmd's id is not -1, and if the id is the same as that of the -

564 most recently executed command, QUndoStack will attempt to merge the two -

565 commands by calling QUndoCommand::mergeWith() on the most recently executed -

566 command. If QUndoCommand::mergeWith() returns \c true, \a cmd is deleted. -

567 -

568 In all other cases \a cmd is simply pushed on the stack. -

569 -

570 If commands were undone before \a cmd was pushed, the current command and -

571 all commands above it are deleted. Hence \a cmd always ends up being the -

572 top-most on the stack. -

573 -

574 Once a command is pushed, the stack takes ownership of it. There -

575 are no getters to return the command, since modifying it after it has -

576 been executed will almost always lead to corruption of the document's -

577 state. -

578 -

579 \sa QUndoCommand::id(), QUndoCommand::mergeWith() -

580 */ -

581 -

582 void QUndoStack::push(QUndoCommand *cmd) -

583 { -

584 Q_D(QUndoStack); -

585 cmd->redo(); -

586 -

587 bool macro = !d->macro_stack.isEmpty(); -

588 -

589 QUndoCommand *cur = 0; -

590

if (macro) {

macro	Description
TRUE	never evaluated
FALSE	never evaluated

591 QUndoCommand *macro_cmd = d->macro_stack.lastconstLast(); -

592

if (!macro_cmd->d->child_list.isEmpty())

!macro_cmd->d-...list.isEmpty()	Description
TRUE	never evaluated
FALSE	never evaluated

593

cur = macro_cmd->d->child_list.lastconstLast();

never executed: cur = macro_cmd->d->child_list.constLast();

594

} else {

never executed: end of block

595

if (d->index > 0)

d->index > 0	Description
TRUE	never evaluated
FALSE	never evaluated

596

cur = d->command_list.at(d->index - 1);

never executed: cur = d->command_list.at(d->index - 1);

597

while (d->index < d->command_list.size())

d->index < d->...nd_list.size()	Description
TRUE	never evaluated
FALSE	never evaluated

598

delete d->command_list.takeLast();

never executed: delete d->command_list.takeLast();

599

if (d->clean_index > d->index)

d->clean_index > d->index	Description
TRUE	never evaluated
FALSE	never evaluated

600

d->clean_index = -1; // we've deleted the clean state

never executed: d->clean_index = -1;

601

}

never executed: end of block

602 -

603

bool try_merge = cur != 0

cur != 0	Description
TRUE	never evaluated
FALSE	never evaluated

604

&& cur->id() != -1

cur->id() != -1	Description
TRUE	never evaluated
FALSE	never evaluated

605

&& cur->id() == cmd->id()

cur->id() == cmd->id()	Description
TRUE	never evaluated
FALSE	never evaluated

606

&& (macro || d->index != d->clean_index);

macro	Description
TRUE	never evaluated
FALSE	never evaluated

d->index != d->clean_index	Description
TRUE	never evaluated
FALSE	never evaluated

607 -

608

if (try_merge && cur->mergeWith(cmd)) {

try_merge	Description
TRUE	never evaluated
FALSE	never evaluated

cur->mergeWith(cmd)	Description
TRUE	never evaluated
FALSE	never evaluated

609 delete cmd; -

610

if (!macro) {

!macro	Description
TRUE	never evaluated
FALSE	never evaluated

611 emit indexChanged(d->index); -

612 emit canUndoChanged(canUndo()); -

613 emit undoTextChanged(undoText()); -

614 emit canRedoChanged(canRedo()); -

615 emit redoTextChanged(redoText()); -

616

}

never executed: end of block

617

} else {

never executed: end of block

618

if (macro) {

macro	Description
TRUE	never evaluated
FALSE	never evaluated

619 d->macro_stack.lastconstLast()->d->child_list.append(cmd); -

620

} else {

never executed: end of block

621 d->command_list.append(cmd); -

622 d->checkUndoLimit(); -

623 d->setIndex(d->index + 1, false); -

624

}

never executed: end of block

625 } -

626 } -

627 -

628 /*! -

629 Marks the stack as clean and emits cleanChanged() if the stack was -

630 not already clean. -

631 -

632 This is typically called when a document is saved, for example. -

633 -

634 Whenever the stack returns to this state through the use of undo/redo -

635 commands, it emits the signal cleanChanged(). This signal is also -

636 emitted when the stack leaves the clean state. -

637 -

638 \sa isClean(), cleanIndex() -

639 */ -

640 -

641 void QUndoStack::setClean() -

642 { -

643 Q_D(QUndoStack); -

644

if (Q_UNLIKELY(!d->macro_stack.isEmpty())())) {

__builtin_expe...pty()), false)	Description
TRUE	never evaluated
FALSE	never evaluated

645 qWarning("QUndoStack::setClean(): cannot set clean in the middle of a macro"); -

646

return;

never executed: return;

647 } -

648 -

649 d->setIndex(d->index, true); -

650

}

never executed: end of block

651 -

652 /*! -

653 If the stack is in the clean state, returns \c true; otherwise returns \c false. -

654 -

655 \sa setClean(), cleanIndex() -

656 */ -

657 -

658 bool QUndoStack::isClean() const -

659 { -

660 Q_D(const QUndoStack); -

661 if (!d->macro_stack.isEmpty()) -

662 return false; -

663 return d->clean_index == d->index; -

664 } -

665 -

666 /*! -

667 Returns the clean index. This is the index at which setClean() was called. -

668 -

669 A stack may not have a clean index. This happens if a document is saved, -

670 some commands are undone, then a new command is pushed. Since -

671 push() deletes all the undone commands before pushing the new command, the stack -

672 can't return to the clean state again. In this case, this function returns -1. -

673 -

674 \sa isClean(), setClean() -

675 */ -

676 -

677 int QUndoStack::cleanIndex() const -

678 { -

679 Q_D(const QUndoStack); -

680 return d->clean_index; -

681 } -

682 -

683 /*! -

684 Undoes the command below the current command by calling QUndoCommand::undo(). -

685 Decrements the current command index. -

686 -

687 If the stack is empty, or if the bottom command on the stack has already been -

688 undone, this function does nothing. -

689 -

690 \sa redo(), index() -

691 */ -

692 -

693 void QUndoStack::undo() -

694 { -

695 Q_D(QUndoStack); -

696

if (d->index == 0)

d->index == 0	Description
TRUE	never evaluated
FALSE	never evaluated

697

return;

never executed: return;

698 -

699

if (Q_UNLIKELY(!d->macro_stack.isEmpty())())) {

__builtin_expe...pty()), false)	Description
TRUE	never evaluated
FALSE	never evaluated

700 qWarning("QUndoStack::undo(): cannot undo in the middle of a macro"); -

701

return;

never executed: return;

702 } -

703 -

704 int idx = d->index - 1; -

705 d->command_list.at(idx)->undo(); -

706 d->setIndex(idx, false); -

707

}

never executed: end of block

708 -

709 /*! -

710 Redoes the current command by calling QUndoCommand::redo(). Increments the current -

711 command index. -

712 -

713 If the stack is empty, or if the top command on the stack has already been -

714 redone, this function does nothing. -

715 -

716 \sa undo(), index() -

717 */ -

718 -

719 void QUndoStack::redo() -

720 { -

721 Q_D(QUndoStack); -

722

if (d->index == d->command_list.size())

d->index == d-...nd_list.size()	Description
TRUE	never evaluated
FALSE	never evaluated

723

return;

never executed: return;

724 -

725

if (Q_UNLIKELY(!d->macro_stack.isEmpty())())) {

__builtin_expe...pty()), false)	Description
TRUE	never evaluated
FALSE	never evaluated

726 qWarning("QUndoStack::redo(): cannot redo in the middle of a macro"); -

727

return;

never executed: return;

728 } -

729 -

730 d->command_list.at(d->index)->redo(); -

731 d->setIndex(d->index + 1, false); -

732

}

never executed: end of block

733 -

734 /*! -

735 Returns the number of commands on the stack. Macro commands are counted as -

736 one command. -

737 -

738 \sa index(), setIndex(), command() -

739 */ -

740 -

741 int QUndoStack::count() const -

742 { -

743 Q_D(const QUndoStack); -

744 return d->command_list.size(); -

745 } -

746 -

747 /*! -

748 Returns the index of the current command. This is the command that will be -

749 executed on the next call to redo(). It is not always the top-most command -

750 on the stack, since a number of commands may have been undone. -

751 -

752 \sa undo(), redo(), count() -

753 */ -

754 -

755 int QUndoStack::index() const -

756 { -

757 Q_D(const QUndoStack); -

758 return d->index; -

759 } -

760 -

761 /*! -

762 Repeatedly calls undo() or redo() until the current command index reaches -

763 \a idx. This function can be used to roll the state of the document forwards -

764 of backwards. indexChanged() is emitted only once. -

765 -

766 \sa index(), count(), undo(), redo() -

767 */ -

768 -

769 void QUndoStack::setIndex(int idx) -

770 { -

771 Q_D(QUndoStack); -

772

if (Q_UNLIKELY(!d->macro_stack.isEmpty())())) {

__builtin_expe...pty()), false)	Description
TRUE	never evaluated
FALSE	never evaluated

773 qWarning("QUndoStack::setIndex(): cannot set index in the middle of a macro"); -

774

return;

never executed: return;

775 } -

776 -

777

if (idx < 0)

idx < 0	Description
TRUE	never evaluated
FALSE	never evaluated

778

idx = 0;

never executed: idx = 0;

779

else if (idx > d->command_list.size())

idx > d->command_list.size()	Description
TRUE	never evaluated
FALSE	never evaluated

780

idx = d->command_list.size();

never executed: idx = d->command_list.size();

781 -

782 int i = d->index; -

783

while (i < idx)

i < idx	Description
TRUE	never evaluated
FALSE	never evaluated

784

d->command_list.at(i++)->redo();

never executed: d->command_list.at(i++)->redo();

785

while (i > idx)

i > idx	Description
TRUE	never evaluated
FALSE	never evaluated

786

d->command_list.at(--i)->undo();

never executed: d->command_list.at(--i)->undo();

787 -

788 d->setIndex(idx, false); -

789

}

never executed: end of block

790 -

791 /*! -

792 Returns \c true if there is a command available for undo; otherwise returns \c false. -

793 -

794 This function returns \c false if the stack is empty, or if the bottom command -

795 on the stack has already been undone. -

796 -

797 Synonymous with index() == 0. -

798 -

799 \sa index(), canRedo() -

800 */ -

801 -

802 bool QUndoStack::canUndo() const -

803 { -

804 Q_D(const QUndoStack); -

805 if (!d->macro_stack.isEmpty()) -

806 return false; -

807 return d->index > 0; -

808 } -

809 -

810 /*! -

811 Returns \c true if there is a command available for redo; otherwise returns \c false. -

812 -

813 This function returns \c false if the stack is empty or if the top command -

814 on the stack has already been redone. -

815 -

816 Synonymous with index() == count(). -

817 -

818 \sa index(), canUndo() -

819 */ -

820 -

821 bool QUndoStack::canRedo() const -

822 { -

823 Q_D(const QUndoStack); -

824 if (!d->macro_stack.isEmpty()) -

825 return false; -

826 return d->index < d->command_list.size(); -

827 } -

828 -

829 /*! -

830 Returns the text of the command which will be undone in the next call to undo(). -

831 -

832 \sa QUndoCommand::actionText(), redoText() -

833 */ -

834 -

835 QString QUndoStack::undoText() const -

836 { -

837 Q_D(const QUndoStack); -

838 if (!d->macro_stack.isEmpty()) -

839 return QString(); -

840 if (d->index > 0) -

841 return d->command_list.at(d->index - 1)->actionText(); -

842 return QString(); -

843 } -

844 -

845 /*! -

846 Returns the text of the command which will be redone in the next call to redo(). -

847 -

848 \sa QUndoCommand::actionText(), undoText() -

849 */ -

850 -

851 QString QUndoStack::redoText() const -

852 { -

853 Q_D(const QUndoStack); -

854 if (!d->macro_stack.isEmpty()) -

855 return QString(); -

856 if (d->index < d->command_list.size()) -

857 return d->command_list.at(d->index)->actionText(); -

858 return QString(); -

859 } -

860 -

861 #ifndef QT_NO_ACTION -

862 -

863 /*! -

864 Creates an undo QAction object with the given \a parent. -

865 -

866 Triggering this action will cause a call to undo(). The text of this action -

867 is the text of the command which will be undone in the next call to undo(), -

868 prefixed by the specified \a prefix. If there is no command available for undo, -

869 this action will be disabled. -

870 -

871 If \a prefix is empty, the default template "Undo %1" is used instead of prefix. -

872 Before Qt 4.8, the prefix "Undo" was used by default. -

873 -

874 \sa createRedoAction(), canUndo(), QUndoCommand::text() -

875 */ -

876 -

877 QAction *QUndoStack::createUndoAction(QObject *parent, const QString &prefix) const -

878 { -

879 QUndoAction *result = new QUndoAction(prefix, parent); -

880 if (prefix.isEmpty()) -

881 result->setTextFormat(tr("Undo %1"), tr("Undo", "Default text for undo action")); -

882 -

883 result->setEnabled(canUndo()); -

884 result->setPrefixedText(undoText()); -

885 connect(this, SIGNAL(canUndoChanged(bool)), -

886 result, SLOT(setEnabled(bool))); -

887 connect(this, SIGNAL(undoTextChanged(QString)), -

888 result, SLOT(setPrefixedText(QString))); -

889 connect(result, SIGNAL(triggered()), this, SLOT(undo())); -

890 return result; -

891 } -

892 -

893 /*! -

894 Creates an redo QAction object with the given \a parent. -

895 -

896 Triggering this action will cause a call to redo(). The text of this action -

897 is the text of the command which will be redone in the next call to redo(), -

898 prefixed by the specified \a prefix. If there is no command available for redo, -

899 this action will be disabled. -

900 -

901 If \a prefix is empty, the default template "Redo %1" is used instead of prefix. -

902 Before Qt 4.8, the prefix "Redo" was used by default. -

903 -

904 \sa createUndoAction(), canRedo(), QUndoCommand::text() -

905 */ -

906 -

907 QAction *QUndoStack::createRedoAction(QObject *parent, const QString &prefix) const -

908 { -

909 QUndoAction *result = new QUndoAction(prefix, parent); -

910 if (prefix.isEmpty()) -

911 result->setTextFormat(tr("Redo %1"), tr("Redo", "Default text for redo action")); -

912 -

913 result->setEnabled(canRedo()); -

914 result->setPrefixedText(redoText()); -

915 connect(this, SIGNAL(canRedoChanged(bool)), -

916 result, SLOT(setEnabled(bool))); -

917 connect(this, SIGNAL(redoTextChanged(QString)), -

918 result, SLOT(setPrefixedText(QString))); -

919 connect(result, SIGNAL(triggered()), this, SLOT(redo())); -

920 return result; -

921 } -

922 -

923 #endif // QT_NO_ACTION -

924 -

925 /*! -

926 Begins composition of a macro command with the given \a text description. -

927 -

928 An empty command described by the specified \a text is pushed on the stack. -

929 Any subsequent commands pushed on the stack will be appended to the empty -

930 command's children until endMacro() is called. -

931 -

932 Calls to beginMacro() and endMacro() may be nested, but every call to -

933 beginMacro() must have a matching call to endMacro(). -

934 -

935 While a macro is being composed, the stack is disabled. This means that: -

936 \list -

937 \li indexChanged() and cleanChanged() are not emitted, -

938 \li canUndo() and canRedo() return false, -

939 \li calling undo() or redo() has no effect, -

940 \li the undo/redo actions are disabled. -

941 \endlist -

942 -

943 The stack becomes enabled and appropriate signals are emitted when endMacro() -

944 is called for the outermost macro. -

945 -

946 \snippet code/src_gui_util_qundostack.cpp 4 -

947 -

948 This code is equivalent to: -

949 -

950 \snippet code/src_gui_util_qundostack.cpp 5 -

951 -

952 \sa endMacro() -

953 */ -

954 -

955 void QUndoStack::beginMacro(const QString &text) -

956 { -

957 Q_D(QUndoStack); -

958 QUndoCommand *cmd = new QUndoCommand(); -

959 cmd->setText(text); -

960 -

961

if (d->macro_stack.isEmpty()) {

d->macro_stack.isEmpty()	Description
TRUE	never evaluated
FALSE	never evaluated

962

while (d->index < d->command_list.size())

d->index < d->...nd_list.size()	Description
TRUE	never evaluated
FALSE	never evaluated

963

delete d->command_list.takeLast();

never executed: delete d->command_list.takeLast();

964

if (d->clean_index > d->index)

d->clean_index > d->index	Description
TRUE	never evaluated
FALSE	never evaluated

965

d->clean_index = -1; // we've deleted the clean state

never executed: d->clean_index = -1;

966 d->command_list.append(cmd); -

967

} else {

never executed: end of block

968 d->macro_stack.lastconstLast()->d->child_list.append(cmd); -

969

}

never executed: end of block

970 d->macro_stack.append(cmd); -

971 -

972

if (d->macro_stack.count() == 1) {

d->macro_stack.count() == 1	Description
TRUE	never evaluated
FALSE	never evaluated

973 emit canUndoChanged(false); -

974 emit undoTextChanged(QString()); -

975 emit canRedoChanged(false); -

976 emit redoTextChanged(QString()); -

977

}

never executed: end of block

978

}

never executed: end of block

979 -

980 /*! -

981 Ends composition of a macro command. -

982 -

983 If this is the outermost macro in a set nested macros, this function emits -

984 indexChanged() once for the entire macro command. -

985 -

986 \sa beginMacro() -

987 */ -

988 -

989 void QUndoStack::endMacro() -

990 { -

991 Q_D(QUndoStack); -

992

if (Q_UNLIKELY(d->macro_stack.isEmpty())())) {

__builtin_expe...pty()), false)	Description
TRUE	never evaluated
FALSE	never evaluated

993 qWarning("QUndoStack::endMacro(): no matching beginMacro()"); -

994

return;

never executed: return;

995 } -

996 -

997 d->macro_stack.removeLast(); -

998 -

999

if (d->macro_stack.isEmpty()) {

d->macro_stack.isEmpty()	Description
TRUE	never evaluated
FALSE	never evaluated

1000 d->checkUndoLimit(); -

1001 d->setIndex(d->index + 1, false); -

1002

}

never executed: end of block

1003

}

never executed: end of block

1004 -

1005 /*! -

1006 \since 4.4 -

1007 -

1008 Returns a const pointer to the command at \a index. -

1009 -

1010 This function returns a const pointer, because modifying a command, -

1011 once it has been pushed onto the stack and executed, almost always -

1012 causes corruption of the state of the document, if the command is -

1013 later undone or redone. -

1014 -

1015 \sa QUndoCommand::child() -

1016 */ -

1017 const QUndoCommand *QUndoStack::command(int index) const -

1018 { -

1019 Q_D(const QUndoStack); -

1020 -

1021 if (index < 0 || index >= d->command_list.count()) -

1022 return 0; -

1023 return d->command_list.at(index); -

1024 } -

1025 -

1026 /*! -

1027 Returns the text of the command at index \a idx. -

1028 -

1029 \sa beginMacro() -

1030 */ -

1031 -

1032 QString QUndoStack::text(int idx) const -

1033 { -

1034 Q_D(const QUndoStack); -

1035 -

1036 if (idx < 0 || idx >= d->command_list.size()) -

1037 return QString(); -

1038 return d->command_list.at(idx)->text(); -

1039 } -

1040 -

1041 /*! -

1042 \property QUndoStack::undoLimit -

1043 \brief the maximum number of commands on this stack. -

1044 \since 4.3 -

1045 -

1046 When the number of commands on a stack exceedes the stack's undoLimit, commands are -

1047 deleted from the bottom of the stack. Macro commands (commands with child commands) -

1048 are treated as one command. The default value is 0, which means that there is no -

1049 limit. -

1050 -

1051 This property may only be set when the undo stack is empty, since setting it on a -

1052 non-empty stack might delete the command at the current index. Calling setUndoLimit() -

1053 on a non-empty stack prints a warning and does nothing. -

1054 */ -

1055 -

1056 void QUndoStack::setUndoLimit(int limit) -

1057 { -

1058 Q_D(QUndoStack); -

1059 -

1060

if (Q_UNLIKELY(!d->command_list.isEmpty())())) {

__builtin_expe...pty()), false)	Description
TRUE	never evaluated
FALSE	never evaluated

1061 qWarning("QUndoStack::setUndoLimit(): an undo limit can only be set when the stack is empty"); -

1062

return;

never executed: return;

1063 } -

1064 -

1065

if (limit == d->undo_limit)

limit == d->undo_limit	Description
TRUE	never evaluated
FALSE	never evaluated

1066

return;

never executed: return;

1067 d->undo_limit = limit; -

1068 d->checkUndoLimit(); -

1069

}

never executed: end of block

1070 -

1071 int QUndoStack::undoLimit() const -

1072 { -

1073 Q_D(const QUndoStack); -

1074 -

1075 return d->undo_limit; -

1076 } -

1077 -

1078 /*! -

1079 \property QUndoStack::active -

1080 \brief the active status of this stack. -

1081 -

1082 An application often has multiple undo stacks, one for each opened document. The active -

1083 stack is the one associated with the currently active document. If the stack belongs -

1084 to a QUndoGroup, calls to QUndoGroup::undo() or QUndoGroup::redo() will be forwarded -

1085 to this stack when it is active. If the QUndoGroup is watched by a QUndoView, the view -

1086 will display the contents of this stack when it is active. If the stack does not belong to -

1087 a QUndoGroup, making it active has no effect. -

1088 -

1089 It is the programmer's responsibility to specify which stack is active by -

1090 calling setActive(), usually when the associated document window receives focus. -

1091 -

1092 \sa QUndoGroup -

1093 */ -

1094 -

1095 void QUndoStack::setActive(bool active) -

1096 { -

1097 #ifdef QT_NO_UNDOGROUP -

1098 Q_UNUSED(active); -

1099 #else -

1100 Q_D(QUndoStack); -

1101 -

1102 if (d->group != 0) { -

1103 if (active) -

1104 d->group->setActiveStack(this); -

1105 else if (d->group->activeStack() == this) -

1106 d->group->setActiveStack(0); -

1107 } -

1108 #endif -

1109 } -

1110 -

1111 bool QUndoStack::isActive() const -

1112 { -

1113 #ifdef QT_NO_UNDOGROUP -

1114 return true; -

1115 #else -

1116 Q_D(const QUndoStack); -

1117 return d->group == 0 || d->group->activeStack() == this; -

1118 #endif -

1119 } -

1120 -

1121 /*! -

1122 \fn void QUndoStack::indexChanged(int idx) -

1123 -

1124 This signal is emitted whenever a command modifies the state of the document. -

1125 This happens when a command is undone or redone. When a macro -

1126 command is undone or redone, or setIndex() is called, this signal -

1127 is emitted only once. -

1128 -

1129 \a idx specifies the index of the current command, ie. the command which will be -

1130 executed on the next call to redo(). -

1131 -

1132 \sa index(), setIndex() -

1133 */ -

1134 -

1135 /*! -

1136 \fn void QUndoStack::cleanChanged(bool clean) -

1137 -

1138 This signal is emitted whenever the stack enters or leaves the clean state. -

1139 If \a clean is true, the stack is in a clean state; otherwise this signal -

1140 indicates that it has left the clean state. -

1141 -

1142 \sa isClean(), setClean() -

1143 */ -

1144 -

1145 /*! -

1146 \fn void QUndoStack::undoTextChanged(const QString &undoText) -

1147 -

1148 This signal is emitted whenever the value of undoText() changes. It is -

1149 used to update the text property of the undo action returned by createUndoAction(). -

1150 \a undoText specifies the new text. -

1151 */ -

1152 -

1153 /*! -

1154 \fn void QUndoStack::canUndoChanged(bool canUndo) -

1155 -

1156 This signal is emitted whenever the value of canUndo() changes. It is -

1157 used to enable or disable the undo action returned by createUndoAction(). -

1158 \a canUndo specifies the new value. -

1159 */ -

1160 -

1161 /*! -

1162 \fn void QUndoStack::redoTextChanged(const QString &redoText) -

1163 -

1164 This signal is emitted whenever the value of redoText() changes. It is -

1165 used to update the text property of the redo action returned by createRedoAction(). -

1166 \a redoText specifies the new text. -

1167 */ -

1168 -

1169 /*! -

1170 \fn void QUndoStack::canRedoChanged(bool canRedo) -

1171 -

1172 This signal is emitted whenever the value of canRedo() changes. It is -

1173 used to enable or disable the redo action returned by createRedoAction(). -

1174 \a canRedo specifies the new value. -

1175 */ -

1176 -

1177 QT_END_NAMESPACE -

1178 -

1179 #include "moc_qundostack.cpp" -

1180 #include "moc_qundostack_p.cpp" -

1181 -

1182 #endif // QT_NO_UNDOSTACK -

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