qimagewriter.cpp

Absolute File Name:

/home/qt/qt5_coco/qt5/qtbase/src/gui/image/qimagewriter.cpp

Source code

Switch to Preprocessed file

Line Source Count

1 /**************************************************************************** -

2 ** -

4 ** Contact: https://www.qt.io/licensing/ -

5 ** -

6 ** This file is part of the QtGui module of the Qt Toolkit. -

7 ** -

8 ** $QT_BEGIN_LICENSE:LGPL$ -

9 ** Commercial License Usage -

10 ** Licensees holding valid commercial Qt licenses may use this file in -

11 ** accordance with the commercial license agreement provided with the -

12 ** Software or, alternatively, in accordance with the terms contained in -

13 ** a written agreement between you and The Qt Company. For licensing terms -

14 ** and conditions see https://www.qt.io/terms-conditions. For further -

15 ** information use the contact form at https://www.qt.io/contact-us. -

16 ** -

17 ** GNU Lesser General Public License Usage -

18 ** Alternatively, this file may be used under the terms of the GNU Lesser -

19 ** General Public License version 3 as published by the Free Software -

20 ** Foundation and appearing in the file LICENSE.LGPL3 included in the -

21 ** packaging of this file. Please review the following information to -

22 ** ensure the GNU Lesser General Public License version 3 requirements -

23 ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. -

24 ** -

25 ** GNU General Public License Usage -

26 ** Alternatively, this file may be used under the terms of the GNU -

27 ** General Public License version 2.0 or (at your option) the GNU General -

28 ** Public license version 3 or any later version approved by the KDE Free -

29 ** Qt Foundation. The licenses are as published by the Free Software -

30 ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 -

31 ** included in the packaging of this file. Please review the following -

32 ** information to ensure the GNU General Public License requirements will -

33 ** be met: https://www.gnu.org/licenses/gpl-2.0.html and -

34 ** https://www.gnu.org/licenses/gpl-3.0.html. -

35 ** -

36 ** $QT_END_LICENSE$ -

37 ** -

38 ****************************************************************************/ -

39 -

40 /*! -

41 \class QImageWriter -

42 \brief The QImageWriter class provides a format independent interface -

43 for writing images to files or other devices. -

44 -

45 \inmodule QtGui -

46 \reentrant -

47 \ingroup painting -

48 \ingroup io -

49 -

50 QImageWriter supports setting format specific options, such as the -

51 gamma level, compression level and quality, prior to storing the -

52 image. If you do not need such options, you can use QImage::save() -

53 or QPixmap::save() instead. -

54 -

55 To store an image, you start by constructing a QImageWriter -

56 object. Pass either a file name or a device pointer, and the -

57 image format to QImageWriter's constructor. You can then set -

58 several options, such as the gamma level (by calling setGamma()) -

59 and quality (by calling setQuality()). canWrite() returns \c true if -

60 QImageWriter can write the image (i.e., the image format is -

61 supported and the device is open for writing). Call write() to -

62 write the image to the device. -

63 -

64 If any error occurs when writing the image, write() will return -

65 false. You can then call error() to find the type of error that -

66 occurred, or errorString() to get a human readable description of -

67 what went wrong. -

68 -

69 Call supportedImageFormats() for a list of formats that -

70 QImageWriter can write. QImageWriter supports all built-in image -

71 formats, in addition to any image format plugins that support -

72 writing. -

73 -

74 \sa QImageReader, QImageIOHandler, QImageIOPlugin -

75 */ -

76 -

77 /*! -

78 \enum QImageWriter::ImageWriterError -

79 -

80 This enum describes errors that can occur when writing images with -

81 QImageWriter. -

82 -

83 \value DeviceError QImageWriter encountered a device error when -

84 writing the image data. Consult your device for more details on -

85 what went wrong. -

86 -

87 \value UnsupportedFormatError Qt does not support the requested -

88 image format. -

89 -

90 \value UnknownError An unknown error occurred. If you get this -

91 value after calling write(), it is most likely caused by a bug in -

92 QImageWriter. -

93 */ -

94 -

95 #include "qimagewriter.h" -

96 -

97 #include <qbytearray.h> -

98 #include <qfile.h> -

99 #include <qfileinfo.h> -

100 #include <qimage.h> -

101 #include <qimageiohandler.h> -

102 #include <qjsonarray.h> -

103 #include <qset.h> -

104 #include <qvariant.h> -

105 -

106 // factory loader -

107 #include <qcoreapplication.h> -

108 #include <private/qfactoryloader_p.h> -

109 -

110 // image handlers -

111 #include <private/qbmphandler_p.h> -

112 #include <private/qppmhandler_p.h> -

113 #include <private/qxbmhandler_p.h> -

114 #include <private/qxpmhandler_p.h> -

115 #ifndef QT_NO_IMAGEFORMAT_PNG -

116 #include <private/qpnghandler_p.h> -

117 #endif -

118 #ifndef QT_NO_IMAGEFORMAT_JPEG -

119 #include <private/qjpeghandler_p.h> -

120 #endif -

121 #ifdef QT_BUILTIN_GIF_READER -

122 #include <private/qgifhandler_p.h> -

123 #endif -

124 -

125 #include <algorithm> -

126 -

127 QT_BEGIN_NAMESPACE -

128 -

129 #ifndef QT_NO_IMAGEFORMATPLUGIN -

130 Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, loader, -

131 (QImageIOHandlerFactoryInterface_iid, QLatin1String("/imageformats"))) -

132 #endif -

133 -

134 static QImageIOHandler *createWriteHandlerHelper(QIODevice *device, -

135 const QByteArray &format) -

136 { -

137 QByteArray form = format.toLower(); -

138 QByteArray suffix; -

139 QImageIOHandler *handler = 0; -

140 -

141 #ifndef QT_NO_IMAGEFORMATPLUGIN -

142 typedef QMultiMap<int, QString> PluginKeyMap; -

143 -

144 // check if any plugins can write the image -

145 QFactoryLoader *l = loader(); -

146 const PluginKeyMap keyMap = l->keyMap(); -

147 int suffixPluginIndex = -1; -

148 #endif -

149 -

150 if (device && format.isEmpty()) { -

151 // if there's no format, see if \a device is a file, and if so, find -

152 // the file suffix and find support for that format among our plugins. -

153 // this allows plugins to override our built-in handlers. -

154 if (QFile *file = qobject_cast<QFile *>(device)) { -

155 if (!(suffix = QFileInfo(file->fileName()).suffix().toLower().toLatin1()).isEmpty()) { -

156 #ifndef QT_NO_IMAGEFORMATPLUGIN -

157 const int index = keyMap.key(QString::fromLatin1(suffix), -1); -

158 if (index != -1) -

159 suffixPluginIndex = index; -

160 #endif -

161 } -

162 } -

163 } -

164 -

165 QByteArray testFormat = !form.isEmpty() ? form : suffix; -

166 -

167 #ifndef QT_NO_IMAGEFORMATPLUGIN -

168 if (suffixPluginIndex != -1) { -

169 // when format is missing, check if we can find a plugin for the -

170 // suffix. -

171 const int index = keyMap.key(QString::fromLatin1(suffix), -1); -

172 if (index != -1) { -

173 QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(l->instance(index)); -

174 if (plugin && (plugin->capabilities(device, suffix) & QImageIOPlugin::CanWrite)) -

175 handler = plugin->create(device, suffix); -

176 } -

177 } -

178 #endif // QT_NO_IMAGEFORMATPLUGIN -

179 -

180 // check if any built-in handlers can write the image -

181 if (!handler && !testFormat.isEmpty()) { -

182

if (false) {

dead code: { }

183

#ifndef QT_NO_IMAGEFORMAT_PNG

dead code: { }

184

} else if (testFormat == "png") {

dead code: { }

185 handler = new QPngHandler; -

186 #endif -

187 #ifndef QT_NO_IMAGEFORMAT_JPEG -

188 } else if (testFormat == "jpg" || testFormat == "jpeg") { -

189 handler = new QJpegHandler; -

190 #endif -

191 #ifdef QT_BUILTIN_GIF_READER -

192 } else if (testFormat == "gif") { -

193 handler = new QGifHandler; -

194 #endif -

195 #ifndef QT_NO_IMAGEFORMAT_BMP -

196 } else if (testFormat == "bmp") { -

197 handler = new QBmpHandler; -

198 } else if (testFormat == "dib") { -

199 handler = new QBmpHandler(QBmpHandler::DibFormat); -

200 #endif -

201 #ifndef QT_NO_IMAGEFORMAT_XPM -

202 } else if (testFormat == "xpm") { -

203 handler = new QXpmHandler; -

204 #endif -

205 #ifndef QT_NO_IMAGEFORMAT_XBM -

206 } else if (testFormat == "xbm") { -

207 handler = new QXbmHandler; -

208 handler->setOption(QImageIOHandler::SubType, testFormat); -

209 #endif -

210 #ifndef QT_NO_IMAGEFORMAT_PPM -

211 } else if (testFormat == "pbm" || testFormat == "pbmraw" || testFormat == "pgm" -

212 || testFormat == "pgmraw" || testFormat == "ppm" || testFormat == "ppmraw") { -

213 handler = new QPpmHandler; -

214 handler->setOption(QImageIOHandler::SubType, testFormat); -

215 #endif -

216 } -

217 } -

218 -

219 #ifndef QT_NO_IMAGEFORMATPLUGIN -

220 if (!testFormat.isEmpty()) { -

221 const int keyCount = keyMap.size(); -

222 for (int i = 0; i < keyCount; ++i) { -

223 QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(l->instance(i)); -

224 if (plugin && (plugin->capabilities(device, testFormat) & QImageIOPlugin::CanWrite)) { -

225 delete handler; -

226 handler = plugin->create(device, testFormat); -

227 break; -

228 } -

229 } -

230 } -

231 #endif // QT_NO_IMAGEFORMATPLUGIN -

232 -

233 if (!handler) -

234 return 0; -

235 -

236 handler->setDevice(device); -

237 if (!testFormat.isEmpty()) -

238 handler->setFormat(testFormat); -

239 return handler; -

240 } -

241 -

242 class QImageWriterPrivate -

243 { -

244 public: -

245 QImageWriterPrivate(QImageWriter *qq); -

246 -

247 bool canWriteHelper(); -

248 -

249 // device -

250 QByteArray format; -

251 QIODevice *device; -

252 bool deleteDevice; -

253 QImageIOHandler *handler; -

254 -

255 // image options -

256 int quality; -

257 int compression; -

258 float gamma; -

259 QString description; -

260 QString text; -

261 QByteArray subType; -

262 bool optimizedWrite; -

263 bool progressiveScanWrite; -

264 QImageIOHandler::Transformations transformation; -

265 -

266 // error -

267 QImageWriter::ImageWriterError imageWriterError; -

268 QString errorString; -

269 -

270 QImageWriter *q; -

271 }; -

272 -

273 /*! -

274 \internal -

275 */ -

276 QImageWriterPrivate::QImageWriterPrivate(QImageWriter *qq) -

277 { -

278 device = 0; -

279 deleteDevice = false; -

280 handler = 0; -

281 quality = -1; -

282 compression = 0; -

283 gamma = 0.0; -

284 optimizedWrite = false; -

285 progressiveScanWrite = false; -

286 imageWriterError = QImageWriter::UnknownError; -

287 errorString = QImageWriter::tr("Unknown error"); -

288 transformation = QImageIOHandler::TransformationNone; -

289 -

290 q = qq; -

291 } -

292 -

293 bool QImageWriterPrivate::canWriteHelper() -

294 { -

295 if (!device) { -

296 imageWriterError = QImageWriter::DeviceError; -

297 errorString = QImageWriter::tr("Device is not set"); -

298 return false; -

299 } -

300 if (!device->isOpen()) -

301 device->open(QIODevice::WriteOnly); -

302 if (!device->isWritable()) { -

303 imageWriterError = QImageWriter::DeviceError; -

304 errorString = QImageWriter::tr("Device not writable"); -

305 return false; -

306 } -

307 if (!handler && (handler = createWriteHandlerHelper(device, format)) == 0) { -

308 imageWriterError = QImageWriter::UnsupportedFormatError; -

309 errorString = QImageWriter::tr("Unsupported image format"); -

310 return false; -

311 } -

312 return true; -

313 } -

314 -

315 /*! -

316 Constructs an empty QImageWriter object. Before writing, you must -

317 call setFormat() to set an image format, then setDevice() or -

318 setFileName(). -

319 */ -

320 QImageWriter::QImageWriter() -

321 : d(new QImageWriterPrivate(this)) -

322 { -

323 } -

324 -

325 /*! -

326 Constructs a QImageWriter object using the device \a device and -

327 image format \a format. -

328 */ -

329 QImageWriter::QImageWriter(QIODevice *device, const QByteArray &format) -

330 : d(new QImageWriterPrivate(this)) -

331 { -

332 d->device = device; -

333 d->format = format; -

334 } -

335 -

336 /*! -

337 Constructs a QImageWriter objects that will write to a file with -

338 the name \a fileName, using the image format \a format. If \a -

339 format is not provided, QImageWriter will detect the image format -

340 by inspecting the extension of \a fileName. -

341 */ -

342 QImageWriter::QImageWriter(const QString &fileName, const QByteArray &format) -

343 : d(new QImageWriterPrivate(this)) -

344 { -

345 QFile *file = new QFile(fileName); -

346 d->device = file; -

347 d->deleteDevice = true; -

348 d->format = format; -

349 } -

350 -

351 /*! -

352 Destructs the QImageWriter object. -

353 */ -

354 QImageWriter::~QImageWriter() -

355 { -

356 if (d->deleteDevice) -

357 delete d->device; -

358 delete d->handler; -

359 delete d; -

360 } -

361 -

362 /*! -

363 Sets the format QImageWriter will use when writing images, to \a -

364 format. \a format is a case insensitive text string. Example: -

365 -

366 \snippet code/src_gui_image_qimagewriter.cpp 0 -

367 -

368 You can call supportedImageFormats() for the full list of formats -

369 QImageWriter supports. -

370 -

371 \sa format() -

372 */ -

373 void QImageWriter::setFormat(const QByteArray &format) -

374 { -

375 d->format = format; -

376 } -

377 -

378 /*! -

379 Returns the format QImageWriter uses for writing images. -

380 -

381 \sa setFormat() -

382 */ -

383 QByteArray QImageWriter::format() const -

384 { -

385 return d->format; -

386 } -

387 -

388 /*! -

389 Sets QImageWriter's device to \a device. If a device has already -

390 been set, the old device is removed from QImageWriter and is -

391 otherwise left unchanged. -

392 -

393 If the device is not already open, QImageWriter will attempt to -

394 open the device in \l QIODevice::WriteOnly mode by calling -

395 open(). Note that this does not work for certain devices, such as -

396 QProcess, QTcpSocket and QUdpSocket, where more logic is required -

397 to open the device. -

398 -

399 \sa device(), setFileName() -

400 */ -

401 void QImageWriter::setDevice(QIODevice *device) -

402 { -

403 if (d->device && d->deleteDevice) -

404 delete d->device; -

405 -

406 d->device = device; -

407 d->deleteDevice = false; -

408 delete d->handler; -

409 d->handler = 0; -

410 } -

411 -

412 /*! -

413 Returns the device currently assigned to QImageWriter, or 0 if no -

414 device has been assigned. -

415 */ -

416 QIODevice *QImageWriter::device() const -

417 { -

418 return d->device; -

419 } -

420 -

421 /*! -

422 Sets the file name of QImageWriter to \a fileName. Internally, -

423 QImageWriter will create a QFile and open it in \l -

424 QIODevice::WriteOnly mode, and use this file when writing images. -

425 -

426 \sa fileName(), setDevice() -

427 */ -

428 void QImageWriter::setFileName(const QString &fileName) -

429 { -

430 setDevice(new QFile(fileName)); -

431 d->deleteDevice = true; -

432 } -

433 -

434 /*! -

435 If the currently assigned device is a QFile, or if setFileName() -

436 has been called, this function returns the name of the file -

437 QImageWriter writes to. Otherwise (i.e., if no device has been -

438 assigned or the device is not a QFile), an empty QString is -

439 returned. -

440 -

441 \sa setFileName(), setDevice() -

442 */ -

443 QString QImageWriter::fileName() const -

444 { -

445 QFile *file = qobject_cast<QFile *>(d->device); -

446 return file ? file->fileName() : QString(); -

447 } -

448 -

449 /*! -

450 Sets the quality setting of the image format to \a quality. -

451 -

452 Some image formats, in particular lossy ones, entail a tradeoff between a) -

453 visual quality of the resulting image, and b) encoding execution time and -

454 compression level. This function sets the level of that tradeoff for image -

455 formats that support it. For other formats, this value is ignored. -

456 -

457 The value range of \a quality depends on the image format. For example, -

458 the "jpeg" format supports a quality range from 0 (low visual quality, high -

459 compression) to 100 (high visual quality, low compression). -

460 -

461 \sa quality() -

462 */ -

463 void QImageWriter::setQuality(int quality) -

464 { -

465 d->quality = quality; -

466 } -

467 -

468 /*! -

469 Returns the quality setting of the image format. -

470 -

471 \sa setQuality() -

472 */ -

473 int QImageWriter::quality() const -

474 { -

475 return d->quality; -

476 } -

477 -

478 /*! -

479 This is an image format specific function that set the compression -

480 of an image. For image formats that do not support setting the -

481 compression, this value is ignored. -

482 -

483 The value range of \a compression depends on the image format. For -

484 example, the "tiff" format supports two values, 0(no compression) and -

485 1(LZW-compression). -

486 -

487 \sa compression() -

488 */ -

489 void QImageWriter::setCompression(int compression) -

490 { -

491 d->compression = compression; -

492 } -

493 -

494 /*! -

495 Returns the compression of the image. -

496 -

497 \sa setCompression() -

498 */ -

499 int QImageWriter::compression() const -

500 { -

501 return d->compression; -

502 } -

503 -

504 /*! -

505 This is an image format specific function that sets the gamma -

506 level of the image to \a gamma. For image formats that do not -

507 support setting the gamma level, this value is ignored. -

508 -

509 The value range of \a gamma depends on the image format. For -

510 example, the "png" format supports a gamma range from 0.0 to 1.0. -

511 -

512 \sa quality() -

513 */ -

514 void QImageWriter::setGamma(float gamma) -

515 { -

516 d->gamma = gamma; -

517 } -

518 -

519 /*! -

520 Returns the gamma level of the image. -

521 -

522 \sa setGamma() -

523 */ -

524 float QImageWriter::gamma() const -

525 { -

526 return d->gamma; -

527 } -

528 -

529 /*! -

530 \since 5.4 -

531 -

532 This is an image format specific function that sets the -

533 subtype of the image to \a type. Subtype can be used by -

534 a handler to determine which format it should use while -

535 saving the image. -

536 -

537 For example, saving an image in DDS format with A8R8G8R8 subtype: -

538 -

539 \snippet code/src_gui_image_qimagewriter.cpp 3 -

540 */ -

541 void QImageWriter::setSubType(const QByteArray &type) -

542 { -

543 d->subType = type; -

544 } -

545 -

546 /*! -

547 \since 5.4 -

548 -

549 Returns the subtype of the image. -

550 -

551 \sa setSubType() -

552 */ -

553 QByteArray QImageWriter::subType() const -

554 { -

555 return d->subType; -

556 } -

557 -

558 /*! -

559 \since 5.4 -

560 -

561 Returns the list of subtypes supported by an image. -

562 */ -

563 QList<QByteArray> QImageWriter::supportedSubTypes() const -

564 { -

565 if (!supportsOption(QImageIOHandler::SupportedSubTypes)) -

566 return QList<QByteArray>(); -

567 return d->handler->option(QImageIOHandler::SupportedSubTypes).value< QList<QByteArray> >(); -

568 } -

569 -

570 /*! -

571 \since 5.5 -

572 -

573 This is an image format-specific function which sets the \a optimize flags when -

574 writing images. For image formats that do not support setting an \a optimize flag, -

575 this value is ignored. -

576 -

577 The default is false. -

578 -

579 \sa optimizedWrite() -

580 */ -

581 void QImageWriter::setOptimizedWrite(bool optimize) -

582 { -

583 d->optimizedWrite = optimize; -

584 } -

585 -

586 /*! -

587 \since 5.5 -

588 -

589 Returns whether optimization has been turned on for writing the image. -

590 -

591 \sa setOptimizedWrite() -

592 */ -

593 bool QImageWriter::optimizedWrite() const -

594 { -

595 return d->optimizedWrite; -

596 } -

597 -

598 /*! -

599 \since 5.5 -

600 -

601 This is an image format-specific function which turns on \a progressive scanning -

602 when writing images. For image formats that do not support setting a \a progressive -

603 scan flag, this value is ignored. -

604 -

605 The default is false. -

606 -

607 \sa progressiveScanWrite() -

608 */ -

609 -

610 void QImageWriter::setProgressiveScanWrite(bool progressive) -

611 { -

612 d->progressiveScanWrite = progressive; -

613 } -

614 -

615 /*! -

616 \since 5.5 -

617 -

618 Returns whether the image should be written as a progressive image. -

619 -

620 \sa setProgressiveScanWrite() -

621 */ -

622 bool QImageWriter::progressiveScanWrite() const -

623 { -

624 return d->progressiveScanWrite; -

625 } -

626 -

627 /*! -

628 \since 5.5 -

629 -

630 Sets the image transformations metadata including orientation to \a transform. -

631 -

632 If transformation metadata is not supported by the image format, -

633 the transform is applied before writing. -

634 -

635 \sa transformation(), write() -

636 */ -

637 void QImageWriter::setTransformation(QImageIOHandler::Transformations transform) -

638 { -

639 d->transformation = transform; -

640 } -

641 -

642 /*! -

643 \since 5.5 -

644 -

645 Returns the transformation and orientation the image has been set to written with. -

646 -

647 \sa setTransformation() -

648 */ -

649 QImageIOHandler::Transformations QImageWriter::transformation() const -

650 { -

651 return d->transformation; -

652 } -

653 -

654 /*! -

655 \obsolete -

656 -

657 Use setText() instead. -

658 -

659 This is an image format specific function that sets the -

660 description of the image to \a description. For image formats that -

661 do not support setting the description, this value is ignored. -

662 -

663 The contents of \a description depends on the image format. -

664 -

665 \sa description() -

666 */ -

667 void QImageWriter::setDescription(const QString &description) -

668 { -

669 d->description = description; -

670 } -

671 -

672 /*! -

673 \obsolete -

674 -

675 Use QImageReader::text() instead. -

676 -

677 Returns the description of the image. -

678 -

679 \sa setDescription() -

680 */ -

681 QString QImageWriter::description() const -

682 { -

683 return d->description; -

684 } -

685 -

686 /*! -

687 \since 4.1 -

688 -

689 Sets the image text associated with the key \a key to -

690 \a text. This is useful for storing copyright information -

691 or other information about the image. Example: -

692 -

693 \snippet code/src_gui_image_qimagewriter.cpp 1 -

694 -

695 If you want to store a single block of data -

696 (e.g., a comment), you can pass an empty key, or use -

697 a generic key like "Description". -

698 -

699 The key and text will be embedded into the -

700 image data after calling write(). -

701 -

702 Support for this option is implemented through -

703 QImageIOHandler::Description. -

704 -

705 \sa QImage::setText(), QImageReader::text() -

706 */ -

707 void QImageWriter::setText(const QString &key, const QString &text) -

708 { -

709 if (!d->description.isEmpty()) -

710 d->description += QLatin1String("\n\n"); -

711 d->description += key.simplified() + QLatin1String(": ") + text.simplified(); -

712 } -

713 -

714 /*! -

715 Returns \c true if QImageWriter can write the image; i.e., the image -

716 format is supported and the assigned device is open for reading. -

717 -

718 \sa write(), setDevice(), setFormat() -

719 */ -

720 bool QImageWriter::canWrite() const -

721 { -

722 if (QFile *file = qobject_cast<QFile *>(d->device)) { -

723 const bool remove = !file->isOpen() && !file->exists(); -

724 const bool result = d->canWriteHelper(); -

725 if (!result && remove) -

726 file->remove(); -

727 return result; -

728 } -

729 -

730 return d->canWriteHelper(); -

731 } -

732 -

733 extern void qt_imageTransform(QImage &src, QImageIOHandler::Transformations orient); -

734 -

735 /*! -

736 Writes the image \a image to the assigned device or file -

737 name. Returns \c true on success; otherwise returns \c false. If the -

738 operation fails, you can call error() to find the type of error -

739 that occurred, or errorString() to get a human readable -

740 description of the error. -

741 -

742 \sa canWrite(), error(), errorString() -

743 */ -

744 bool QImageWriter::write(const QImage &image) -

745 { -

746 if (!canWrite()) -

747 return false; -

748 -

749 QImage img = image; -

750 if (d->handler->supportsOption(QImageIOHandler::Quality)) -

751 d->handler->setOption(QImageIOHandler::Quality, d->quality); -

752 if (d->handler->supportsOption(QImageIOHandler::CompressionRatio)) -

753 d->handler->setOption(QImageIOHandler::CompressionRatio, d->compression); -

754 if (d->handler->supportsOption(QImageIOHandler::Gamma)) -

755 d->handler->setOption(QImageIOHandler::Gamma, d->gamma); -

756 if (!d->description.isEmpty() && d->handler->supportsOption(QImageIOHandler::Description)) -

757 d->handler->setOption(QImageIOHandler::Description, d->description); -

758 if (!d->subType.isEmpty() && d->handler->supportsOption(QImageIOHandler::SubType)) -

759 d->handler->setOption(QImageIOHandler::SubType, d->subType); -

760 if (d->handler->supportsOption(QImageIOHandler::OptimizedWrite)) -

761 d->handler->setOption(QImageIOHandler::OptimizedWrite, d->optimizedWrite); -

762 if (d->handler->supportsOption(QImageIOHandler::ProgressiveScanWrite)) -

763 d->handler->setOption(QImageIOHandler::ProgressiveScanWrite, d->progressiveScanWrite); -

764 if (d->handler->supportsOption(QImageIOHandler::ImageTransformation)) -

765 d->handler->setOption(QImageIOHandler::ImageTransformation, int(d->transformation)); -

766 else -

767 qt_imageTransform(img, d->transformation); -

768 -

769 if (!d->handler->write(img)) -

770 return false; -

771 if (QFile *file = qobject_cast<QFile *>(d->device)) -

772 file->flush(); -

773 return true; -

774 } -

775 -

776 /*! -

777 Returns the type of error that last occurred. -

778 -

779 \sa ImageWriterError, errorString() -

780 */ -

781 QImageWriter::ImageWriterError QImageWriter::error() const -

782 { -

783 return d->imageWriterError; -

784 } -

785 -

786 /*! -

787 Returns a human readable description of the last error that occurred. -

788 -

789 \sa error() -

790 */ -

791 QString QImageWriter::errorString() const -

792 { -

793 return d->errorString; -

794 } -

795 -

796 /*! -

797 \since 4.2 -

798 -

799 Returns \c true if the writer supports \a option; otherwise returns -

800 false. -

801 -

802 Different image formats support different options. Call this function to -

803 determine whether a certain option is supported by the current format. For -

804 example, the PNG format allows you to embed text into the image's metadata -

805 (see text()). -

806 -

807 \snippet code/src_gui_image_qimagewriter.cpp 2 -

808 -

809 Options can be tested after the writer has been associated with a format. -

810 -

811 \sa QImageReader::supportsOption(), setFormat() -

812 */ -

813 bool QImageWriter::supportsOption(QImageIOHandler::ImageOption option) const -

814 { -

815 if (!d->handler && (d->handler = createWriteHandlerHelper(d->device, d->format)) == 0) { -

816 d->imageWriterError = QImageWriter::UnsupportedFormatError; -

817 d->errorString = QImageWriter::tr("Unsupported image format"); -

818 return false; -

819 } -

820 -

821 return d->handler->supportsOption(option); -

822 } -

823 -

824 -

825 #ifndef QT_NO_IMAGEFORMATPLUGIN -

826 void supportedImageHandlerFormats(QFactoryLoader *loader, -

827 QImageIOPlugin::Capability cap, -

828 QList<QByteArray> *result) -

829 { -

830 typedef QMultiMap<int, QString> PluginKeyMap; -

831 typedef PluginKeyMap::const_iterator PluginKeyMapConstIterator; -

832 -

833 const PluginKeyMap keyMap = loader->keyMap(); -

834 const PluginKeyMapConstIterator cend = keyMap.constEnd(); -

835 int i = -1; -

836 QImageIOPlugin *plugin = 0; -

837 result->reserve(result->size() + keyMap.size()); -

838 for (PluginKeyMapConstIterator it = keyMap.constBegin(); it != cend; ++it) { -

839 if (it.key() != i) { -

840 i = it.key(); -

841 plugin = qobject_cast<QImageIOPlugin *>(loader->instance(i)); -

842 } -

843 const QByteArray key = it.value().toLatin1(); -

844 if (plugin && (plugin->capabilities(0, key) & cap) != 0) -

845 result->append(key); -

846 } -

847 } -

848 -

849 void supportedImageHandlerMimeTypes(QFactoryLoader *loader, -

850 QImageIOPlugin::Capability cap, -

851 QList<QByteArray> *result) -

852 { -

853 QList<QJsonObject> metaDataList = loader->metaData(); -

854 -

855 const int pluginCount = metaDataList.size(); -

856

for (int i = 0; i < pluginCount; ++i) {

i < pluginCount	Description
TRUE	never evaluated
FALSE	never evaluated

857 const QJsonObject metaData = metaDataList.at(i).value(QStringLiteralQLatin1String("MetaData")).toObject(); -

858 const QJsonArray keys = metaData.value(QStringLiteralQLatin1String("Keys")).toArray(); -

859 const QJsonArray mimeTypes = metaData.value(QStringLiteralQLatin1String("MimeTypes")).toArray(); -

860 QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(loader->instance(i)); -

861 const int keyCount = keys.size(); -

862

for (int k = 0; k < keyCount; ++k) {

k < keyCount	Description
TRUE	never evaluated
FALSE	never evaluated

863

if (plugin && (plugin->capabilities(0, keys.at(k).toString().toLatin1()) & cap) != 0)

plugin	Description
TRUE	never evaluated
FALSE	never evaluated

(plugin->capab...)) & cap) != 0	Description
TRUE	never evaluated
FALSE	never evaluated

864

result->append(mimeTypes.at(k).toString().toLatin1());

never executed: result->append(mimeTypes.at(k).toString().toLatin1());

865

}

never executed: end of block

866

}

never executed: end of block

867

}

never executed: end of block

868 #endif // QT_NO_IMAGEFORMATPLUGIN -

869 -

870 /*! -

871 Returns the list of image formats supported by QImageWriter. -

872 -

873 By default, Qt can write the following formats: -

874 -

875 \table -

876 \header \li Format \li MIME type \li Description -

877 \row \li BMP \li image/bmp \li Windows Bitmap -

878 \row \li JPG \li image/jpeg \li Joint Photographic Experts Group -

879 \row \li PNG \li image/png \li Portable Network Graphics -

880 \row \li PBM \li image/x-portable-bitmap \li Portable Bitmap -

881 \row \li PGM \li image/x-portable-graymap \li Portable Graymap -

882 \row \li PPM \li image/x-portable-pixmap \li Portable Pixmap -

883 \row \li XBM \li image/x-xbitmap \li X11 Bitmap -

884 \row \li XPM \li image/x-xpixmap \li X11 Pixmap -

885 \endtable -

886 -

887 Reading and writing SVG files is supported through the \l{Qt SVG} module. -

888 The \l{Qt Image Formats} module provides support for additional image formats. -

889 -

890 Note that the QApplication instance must be created before this function is -

891 called. -

892 -

893 \sa setFormat(), QImageReader::supportedImageFormats(), QImageIOPlugin -

894 */ -

895 QList<QByteArray> QImageWriter::supportedImageFormats() -

896 { -

897 QList<QByteArray> formats; -

898 #ifndef QT_NO_IMAGEFORMAT_BMP -

899 formats << "bmp"; -

900 #endif -

901 #ifndef QT_NO_IMAGEFORMAT_PPM -

902 formats << "pbm" << "pgm" << "ppm"; -

903 #endif -

904 #ifndef QT_NO_IMAGEFORMAT_XBM -

905 formats << "xbm"; -

906 #endif -

907 #ifndef QT_NO_IMAGEFORMAT_XPM -

908 formats << "xpm"; -

909 #endif -

910 #ifndef QT_NO_IMAGEFORMAT_PNG -

911 formats << "png"; -

912 #endif -

913 #ifndef QT_NO_IMAGEFORMAT_JPEG -

914 formats << "jpg" << "jpeg"; -

915 #endif -

916 -

917 #ifndef QT_NO_IMAGEFORMATPLUGIN -

918 supportedImageHandlerFormats(loader(), QImageIOPlugin::CanWrite, &formats); -

919 #endif // QT_NO_IMAGEFORMATPLUGIN -

920 -

921 std::sort(formats.begin(), formats.end()); -

922 formats.erase(std::unique(formats.begin(), formats.end()), formats.end()); -

923 return formats; -

924 } -

925 -

926 /*! -

927 Returns the list of MIME types supported by QImageWriter. -

928 -

929 Note that the QApplication instance must be created before this function is -

930 called. -

931 -

932 \sa supportedImageFormats(), QImageReader::supportedMimeTypes() -

933 */ -

934 QList<QByteArray> QImageWriter::supportedMimeTypes() -

935 { -

936 QList<QByteArray> mimeTypes; -

937 #ifndef QT_NO_IMAGEFORMAT_BMP -

938 mimeTypes << "image/bmp"; -

939 #endif -

940 #ifndef QT_NO_IMAGEFORMAT_PPM -

941 mimeTypes << "image/x-portable-bitmap"; -

942 mimeTypes << "image/x-portable-graymap"; -

943 mimeTypes << "image/x-portable-pixmap"; -

944 #endif -

945 #ifndef QT_NO_IMAGEFORMAT_XBM -

946 mimeTypes << "image/x-xbitmap"; -

947 #endif -

948 #ifndef QT_NO_IMAGEFORMAT_XPM -

949 mimeTypes << "image/x-xpixmap"; -

950 #endif -

951 #ifndef QT_NO_IMAGEFORMAT_PNG -

952 mimeTypes << "image/png"; -

953 #endif -

954 #ifndef QT_NO_IMAGEFORMAT_JPEG -

955 mimeTypes << "image/jpeg"; -

956 #endif -

957 -

958 #ifndef QT_NO_IMAGEFORMATPLUGIN -

959 supportedImageHandlerMimeTypes(loader(), QImageIOPlugin::CanWrite, &mimeTypes); -

960 #endif // QT_NO_IMAGEFORMATPLUGIN -

961 -

962 std::sort(mimeTypes.begin(), mimeTypes.end()); -

963 mimeTypes.erase(std::unique(mimeTypes.begin(), mimeTypes.end()), mimeTypes.end()); -

964 return mimeTypes; -

965 } -

966 -

967 QT_END_NAMESPACE -

Source code

Switch to Preprocessed file

Generated by Squish Coco Non-Commercial 4.3.0-BETA-master-30-08-2018-4cb69e9