/src/qtbase/src/gui/image/qimagereader.cpp
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1 | | // Copyright (C) 2016 The Qt Company Ltd. |
2 | | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
3 | | // Qt-Security score:critical reason:data-parser |
4 | | |
5 | | //#define QIMAGEREADER_DEBUG |
6 | | |
7 | | /*! |
8 | | \class QImageReader |
9 | | \brief The QImageReader class provides a format independent interface |
10 | | for reading images from files or other devices. |
11 | | |
12 | | \inmodule QtGui |
13 | | \reentrant |
14 | | \ingroup painting |
15 | | |
16 | | The most common way to read images is through QImage and QPixmap's |
17 | | constructors, or by calling QImage::load() and |
18 | | QPixmap::load(). QImageReader is a specialized class which gives |
19 | | you more control when reading images. For example, you can read an |
20 | | image into a specific size by calling setScaledSize(), and you can |
21 | | select a clip rect, effectively loading only parts of an image, by |
22 | | calling setClipRect(). Depending on the underlying support in the |
23 | | image format, this can save memory and speed up loading of images. |
24 | | |
25 | | To read an image, you start by constructing a QImageReader object. |
26 | | Pass either a file name or a device pointer, and the image format |
27 | | to QImageReader's constructor. You can then set several options, |
28 | | such as the clip rect (by calling setClipRect()) and scaled size |
29 | | (by calling setScaledSize()). canRead() returns the image if the |
30 | | QImageReader can read the image (i.e., the image format is |
31 | | supported and the device is open for reading). Call read() to read |
32 | | the image. |
33 | | |
34 | | If any error occurs when reading the image, read() will return a |
35 | | null QImage. You can then call error() to find the type of error |
36 | | that occurred, or errorString() to get a human readable |
37 | | description of what went wrong. |
38 | | |
39 | | \note QImageReader assumes exclusive control over the file or |
40 | | device that is assigned. Any attempts to modify the assigned file |
41 | | or device during the lifetime of the QImageReader object will |
42 | | yield undefined results. |
43 | | |
44 | | \section1 Formats |
45 | | |
46 | | Call supportedImageFormats() for a list of formats that |
47 | | QImageReader can read. QImageReader supports all built-in image |
48 | | formats, in addition to any image format plugins that support |
49 | | reading. Call supportedMimeTypes() to obtain a list of supported MIME |
50 | | types, which for example can be passed to QFileDialog::setMimeTypeFilters(). |
51 | | |
52 | | QImageReader autodetects the image format by default, by looking at the |
53 | | provided (optional) format string, the file name suffix, and the data |
54 | | stream contents. You can enable or disable this feature, by calling |
55 | | setAutoDetectImageFormat(). |
56 | | |
57 | | \section1 High Resolution Versions of Images |
58 | | |
59 | | It is possible to provide high resolution versions of images should a scaling |
60 | | between \e{device pixels} and \e{device independent pixels} be in effect. |
61 | | |
62 | | The high resolution version is marked by the suffix \c @2x on the base name. |
63 | | The image read will have its \e{device pixel ratio} set to a value of 2. |
64 | | |
65 | | This can be disabled by setting the environment variable |
66 | | \c QT_HIGHDPI_DISABLE_2X_IMAGE_LOADING. |
67 | | |
68 | | \sa QImageWriter, QImageIOHandler, QImageIOPlugin, QMimeDatabase, QColorSpace |
69 | | \sa QImage::devicePixelRatio(), QPixmap::devicePixelRatio(), QIcon, QPainter::drawPixmap(), QPainter::drawImage() |
70 | | */ |
71 | | |
72 | | /*! |
73 | | \enum QImageReader::ImageReaderError |
74 | | |
75 | | This enum describes the different types of errors that can occur |
76 | | when reading images with QImageReader. |
77 | | |
78 | | \value FileNotFoundError QImageReader was used with a file name, |
79 | | but not file was found with that name. This can also happen if the |
80 | | file name contained no extension, and the file with the correct |
81 | | extension is not supported by Qt. |
82 | | |
83 | | \value DeviceError QImageReader encountered a device error when |
84 | | reading the image. You can consult your particular device for more |
85 | | details on what went wrong. |
86 | | |
87 | | \value UnsupportedFormatError Qt does not support the requested |
88 | | image format. |
89 | | |
90 | | \value InvalidDataError The image data was invalid, and |
91 | | QImageReader was unable to read an image from it. The can happen |
92 | | if the image file is damaged. |
93 | | |
94 | | \value UnknownError An unknown error occurred. If you get this |
95 | | value after calling read(), it is most likely caused by a bug in |
96 | | QImageReader. |
97 | | */ |
98 | | #include "qimagereader.h" |
99 | | |
100 | | #include <qbytearray.h> |
101 | | #ifdef QIMAGEREADER_DEBUG |
102 | | #include <qdebug.h> |
103 | | #endif |
104 | | #include <qfile.h> |
105 | | #include <qfileinfo.h> |
106 | | #include <qimage.h> |
107 | | #include <qimageiohandler.h> |
108 | | #include <qlist.h> |
109 | | #include <qrect.h> |
110 | | #include <qsize.h> |
111 | | #include <qcolor.h> |
112 | | #include <qvariant.h> |
113 | | |
114 | | // factory loader |
115 | | #include <qcoreapplication.h> |
116 | | #include <private/qfactoryloader_p.h> |
117 | | #include <QtCore/private/qlocking_p.h> |
118 | | |
119 | | // for qt_getImageText |
120 | | #include <private/qimage_p.h> |
121 | | |
122 | | // image handlers |
123 | | #include <private/qbmphandler_p.h> |
124 | | #include <private/qppmhandler_p.h> |
125 | | #include <private/qxbmhandler_p.h> |
126 | | #include <private/qxpmhandler_p.h> |
127 | | #ifndef QT_NO_IMAGEFORMAT_PNG |
128 | | #include <private/qpnghandler_p.h> |
129 | | #endif |
130 | | |
131 | | #include <private/qimagereaderwriterhelpers_p.h> |
132 | | #include <qtgui_tracepoints_p.h> |
133 | | |
134 | | #include <algorithm> |
135 | | |
136 | | QT_BEGIN_NAMESPACE |
137 | | |
138 | | using namespace QImageReaderWriterHelpers; |
139 | | using namespace Qt::StringLiterals; |
140 | | |
141 | | Q_TRACE_POINT(qtgui, QImageReader_read_before_reading, QImageReader *reader, const QString &filename); |
142 | | Q_TRACE_POINT(qtgui, QImageReader_read_after_reading, QImageReader *reader, bool result); |
143 | | |
144 | | static QImageIOHandler *createReadHandlerHelper(QIODevice *device, |
145 | | const QByteArray &format, |
146 | | bool autoDetectImageFormat, |
147 | | bool ignoresFormatAndExtension) |
148 | 13.4k | { |
149 | 13.4k | if (!autoDetectImageFormat && format.isEmpty()) |
150 | 0 | return nullptr; |
151 | | |
152 | 13.4k | QByteArray form = format.toLower(); |
153 | 13.4k | QImageIOHandler *handler = nullptr; |
154 | 13.4k | QByteArray suffix; |
155 | | |
156 | 13.4k | #if QT_CONFIG(imageformatplugin) |
157 | 13.4k | Q_CONSTINIT static QBasicMutex mutex; |
158 | 13.4k | const auto locker = qt_scoped_lock(mutex); |
159 | | |
160 | 13.4k | typedef QMultiMap<int, QString> PluginKeyMap; |
161 | | |
162 | | // check if we have plugins that support the image format |
163 | 13.4k | auto l = QImageReaderWriterHelpers::pluginLoader(); |
164 | 13.4k | const PluginKeyMap keyMap = l->keyMap(); |
165 | | |
166 | | #ifdef QIMAGEREADER_DEBUG |
167 | | qDebug() << "QImageReader::createReadHandler( device =" << (void *)device << ", format =" << format << ")," |
168 | | << keyMap.uniqueKeys().size() << "plugins available: " << keyMap; |
169 | | #endif |
170 | | |
171 | 13.4k | int testFormatPluginIndex = -1; |
172 | 13.4k | #endif // QT_CONFIG(imageformatplugin) |
173 | | |
174 | 13.4k | if (device && format.isEmpty() && autoDetectImageFormat && !ignoresFormatAndExtension) { |
175 | | // if there's no format, see if \a device is a file, and if so, find the file suffix |
176 | 0 | if (QFile *file = qobject_cast<QFile *>(device)) { |
177 | 0 | suffix = QFileInfo(file->fileName()).suffix().toLower().toLatin1(); |
178 | | #ifdef QIMAGEREADER_DEBUG |
179 | | qDebug() << "QImageReader::createReadHandler: device file suffix:" << suffix; |
180 | | #endif |
181 | 0 | } |
182 | 0 | } |
183 | | |
184 | 13.4k | QByteArray testFormat = !form.isEmpty() ? form : suffix; |
185 | 13.4k | if (ignoresFormatAndExtension) |
186 | 0 | testFormat = QByteArray(); |
187 | | |
188 | 13.4k | #if QT_CONFIG(imageformatplugin) |
189 | 13.4k | if (!testFormat.isEmpty()) { |
190 | | // Check first support for the given format name or suffix among our plugins' registered |
191 | | // formats. This allows plugins to override our built-in handlers. |
192 | 13.4k | const qint64 pos = device ? device->pos() : 0; |
193 | 13.4k | for (int testIndex : keyMap.keys(QLatin1StringView(testFormat))) { |
194 | 0 | QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(l->instance(testIndex)); |
195 | 0 | if (plugin && plugin->capabilities(device, testFormat) & QImageIOPlugin::CanRead) { |
196 | | #ifdef QIMAGEREADER_DEBUG |
197 | | qDebug() << "QImageReader::createReadHandler: format" << testFormat |
198 | | << "recognized, the" << keyMap.values(testIndex) << "plugin can read this format."; |
199 | | #endif |
200 | 0 | handler = plugin->create(device, testFormat); |
201 | 0 | testFormatPluginIndex = testIndex; |
202 | 0 | break; |
203 | 0 | } |
204 | 0 | } |
205 | 13.4k | if (device && !device->isSequential()) |
206 | 13.4k | device->seek(pos); // Should not have moved, but guard against buggy plugins |
207 | 13.4k | } |
208 | 13.4k | #endif // QT_CONFIG(imageformatplugin) |
209 | | |
210 | | // if we don't have a handler yet, check if we have built-in support for |
211 | | // the format |
212 | 13.4k | if (!handler && !testFormat.isEmpty()) { |
213 | 13.4k | if (false) { |
214 | 0 | #ifndef QT_NO_IMAGEFORMAT_PNG |
215 | 13.4k | } else if (testFormat == "png") { |
216 | 5.79k | handler = new QPngHandler; |
217 | 5.79k | #endif |
218 | 5.79k | #ifndef QT_NO_IMAGEFORMAT_BMP |
219 | 7.61k | } else if (testFormat == "bmp") { |
220 | 0 | handler = new QBmpHandler; |
221 | 7.61k | } else if (testFormat == "dib") { |
222 | 0 | handler = new QBmpHandler(QBmpHandler::DibFormat); |
223 | 0 | #endif |
224 | 0 | #ifndef QT_NO_IMAGEFORMAT_XPM |
225 | 7.61k | } else if (testFormat == "xpm") { |
226 | 0 | handler = new QXpmHandler; |
227 | 0 | #endif |
228 | 0 | #ifndef QT_NO_IMAGEFORMAT_XBM |
229 | 7.61k | } else if (testFormat == "xbm") { |
230 | 0 | handler = new QXbmHandler; |
231 | 0 | handler->setOption(QImageIOHandler::SubType, testFormat); |
232 | 0 | #endif |
233 | 0 | #ifndef QT_NO_IMAGEFORMAT_PPM |
234 | 7.61k | } else if (testFormat == "pbm" || testFormat == "pbmraw" || testFormat == "pgm" |
235 | 7.61k | || testFormat == "pgmraw" || testFormat == "ppm" || testFormat == "ppmraw") { |
236 | 0 | handler = new QPpmHandler; |
237 | 0 | handler->setOption(QImageIOHandler::SubType, testFormat); |
238 | 0 | #endif |
239 | 0 | } |
240 | | |
241 | | #ifdef QIMAGEREADER_DEBUG |
242 | | if (handler) |
243 | | qDebug() << "QImageReader::createReadHandler: using the built-in handler for" << testFormat; |
244 | | #endif |
245 | 13.4k | } |
246 | | |
247 | 13.4k | #if QT_CONFIG(imageformatplugin) |
248 | 13.4k | if (!handler && !testFormat.isEmpty() && autoDetectImageFormat) { |
249 | | // check if any other plugin supports the format name (they are not allowed to |
250 | | // read from the device yet). |
251 | 7.61k | const qint64 pos = device ? device->pos() : 0; |
252 | | |
253 | 7.61k | const int keyCount = keyMap.size(); |
254 | 7.61k | for (int i = 0; i < keyCount; ++i) { |
255 | 0 | if (i != testFormatPluginIndex) { |
256 | 0 | QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(l->instance(i)); |
257 | 0 | if (plugin && plugin->capabilities(device, testFormat) & QImageIOPlugin::CanRead) { |
258 | | #ifdef QIMAGEREADER_DEBUG |
259 | | qDebug() << "QImageReader::createReadHandler: the" << keyMap.values(i) << "plugin can read this format"; |
260 | | #endif |
261 | 0 | handler = plugin->create(device, testFormat); |
262 | 0 | break; |
263 | 0 | } |
264 | 0 | } |
265 | 0 | } |
266 | 7.61k | if (device && !device->isSequential()) |
267 | 7.61k | device->seek(pos); // Should not have moved, but guard against buggy plugins |
268 | 7.61k | } |
269 | 13.4k | #endif // QT_CONFIG(imageformatplugin) |
270 | | |
271 | 13.4k | if (handler && device && !suffix.isEmpty()) { |
272 | 0 | Q_ASSERT(qobject_cast<QFile *>(device)); |
273 | | // We have a file claiming to be of a recognized format. Now confirm that |
274 | | // the handler also recognizes the file contents. |
275 | 0 | const qint64 pos = device->pos(); |
276 | 0 | handler->setDevice(device); |
277 | 0 | if (!form.isEmpty()) |
278 | 0 | handler->setFormat(form); |
279 | 0 | bool canRead = handler->canRead(); |
280 | 0 | device->seek(pos); |
281 | 0 | if (canRead) { |
282 | | // ok, we're done. |
283 | 0 | return handler; |
284 | 0 | } |
285 | | #ifdef QIMAGEREADER_DEBUG |
286 | | qDebug() << "QImageReader::createReadHandler: the" << suffix << "handler can not read this file"; |
287 | | #endif |
288 | | // File may still be valid, just with wrong suffix, so fall back to |
289 | | // finding a handler based on contents, below. |
290 | 0 | delete handler; |
291 | 0 | handler = nullptr; |
292 | 0 | } |
293 | | |
294 | 13.4k | #if QT_CONFIG(imageformatplugin) |
295 | 13.4k | if (!handler && (autoDetectImageFormat || ignoresFormatAndExtension)) { |
296 | | // check if any of our plugins recognize the file from its contents. |
297 | 7.61k | const qint64 pos = device ? device->pos() : 0; |
298 | 7.61k | const int keyCount = keyMap.size(); |
299 | 7.61k | for (int i = 0; i < keyCount; ++i) { |
300 | 0 | if (i != testFormatPluginIndex) { |
301 | 0 | QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(l->instance(i)); |
302 | 0 | if (plugin && plugin->capabilities(device, QByteArray()) & QImageIOPlugin::CanRead) { |
303 | 0 | handler = plugin->create(device, testFormat); |
304 | | #ifdef QIMAGEREADER_DEBUG |
305 | | qDebug() << "QImageReader::createReadHandler: the" << keyMap.values(i) << "plugin can read this data"; |
306 | | #endif |
307 | 0 | break; |
308 | 0 | } |
309 | 0 | } |
310 | 0 | } |
311 | 7.61k | if (device && !device->isSequential()) |
312 | 7.61k | device->seek(pos); |
313 | 7.61k | } |
314 | 13.4k | #endif // QT_CONFIG(imageformatplugin) |
315 | | |
316 | 13.4k | if (!handler && (autoDetectImageFormat || ignoresFormatAndExtension)) { |
317 | | // check if any of our built-in handlers recognize the file from its |
318 | | // contents. |
319 | 7.61k | int currentFormat = 0; |
320 | 7.61k | if (!suffix.isEmpty()) { |
321 | | // If reading from a file with a suffix, start testing our |
322 | | // built-in handler for that suffix first. |
323 | 0 | for (int i = 0; i < _qt_NumFormats; ++i) { |
324 | 0 | if (_qt_BuiltInFormats[i].extension == suffix) { |
325 | 0 | currentFormat = i; |
326 | 0 | break; |
327 | 0 | } |
328 | 0 | } |
329 | 0 | } |
330 | | |
331 | 7.61k | QByteArray subType; |
332 | 7.61k | int numFormats = _qt_NumFormats; |
333 | 32.2k | while (device && numFormats >= 0) { |
334 | 31.4k | const qint64 pos = device->pos(); |
335 | 31.4k | switch (currentFormat) { |
336 | 0 | #ifndef QT_NO_IMAGEFORMAT_PNG |
337 | 8.46k | case _qt_PngFormat: |
338 | 8.46k | if (QPngHandler::canRead(device)) |
339 | 2.44k | handler = new QPngHandler; |
340 | 8.46k | break; |
341 | 0 | #endif |
342 | 0 | #ifndef QT_NO_IMAGEFORMAT_BMP |
343 | 5.17k | case _qt_BmpFormat: |
344 | 5.17k | if (QBmpHandler::canRead(device)) |
345 | 1.07k | handler = new QBmpHandler; |
346 | 5.17k | break; |
347 | 0 | #endif |
348 | 0 | #ifndef QT_NO_IMAGEFORMAT_XPM |
349 | 3.36k | case _qt_XpmFormat: |
350 | 3.36k | if (QXpmHandler::canRead(device)) |
351 | 2.51k | handler = new QXpmHandler; |
352 | 3.36k | break; |
353 | 0 | #endif |
354 | 0 | #ifndef QT_NO_IMAGEFORMAT_PPM |
355 | 3.44k | case _qt_PbmFormat: |
356 | 6.89k | case _qt_PgmFormat: |
357 | 10.9k | case _qt_PpmFormat: |
358 | 10.9k | if (QPpmHandler::canRead(device, &subType)) { |
359 | 653 | handler = new QPpmHandler; |
360 | 653 | handler->setOption(QImageIOHandler::SubType, subType); |
361 | 653 | } |
362 | 10.9k | break; |
363 | 0 | #endif |
364 | 0 | #ifndef QT_NO_IMAGEFORMAT_XBM |
365 | 3.44k | case _qt_XbmFormat: |
366 | 3.44k | if (QXbmHandler::canRead(device)) |
367 | 85 | handler = new QXbmHandler; |
368 | 3.44k | break; |
369 | 0 | #endif |
370 | 0 | default: |
371 | 0 | break; |
372 | 31.4k | } |
373 | 31.4k | if (!device->isSequential()) |
374 | 31.4k | device->seek(pos); |
375 | | |
376 | 31.4k | if (handler) { |
377 | | #ifdef QIMAGEREADER_DEBUG |
378 | | qDebug("QImageReader::createReadHandler: the %s built-in handler can read this data", |
379 | | _qt_BuiltInFormats[currentFormat].extension); |
380 | | #endif |
381 | 6.77k | break; |
382 | 6.77k | } |
383 | | |
384 | 24.6k | --numFormats; |
385 | 24.6k | ++currentFormat; |
386 | 24.6k | if (currentFormat >= _qt_NumFormats) |
387 | 845 | currentFormat = 0; |
388 | 24.6k | } |
389 | 7.61k | } |
390 | | |
391 | 13.4k | if (!handler) { |
392 | | #ifdef QIMAGEREADER_DEBUG |
393 | | qDebug("QImageReader::createReadHandler: no handlers found. giving up."); |
394 | | #endif |
395 | | // no handler: give up. |
396 | 845 | return nullptr; |
397 | 845 | } |
398 | | |
399 | 12.5k | handler->setDevice(device); |
400 | 12.5k | if (!form.isEmpty()) |
401 | 12.5k | handler->setFormat(form); |
402 | 12.5k | return handler; |
403 | 13.4k | } |
404 | | |
405 | | class QImageReaderPrivate |
406 | | { |
407 | | public: |
408 | | QImageReaderPrivate(QImageReader *qq); |
409 | | ~QImageReaderPrivate(); |
410 | | |
411 | | // device |
412 | | QByteArray format; |
413 | | bool autoDetectImageFormat; |
414 | | bool ignoresFormatAndExtension; |
415 | | QIODevice *device; |
416 | | bool deleteDevice; |
417 | | QImageIOHandler *handler; |
418 | | bool initHandler(); |
419 | | |
420 | | // image options |
421 | | QRect clipRect; |
422 | | QSize scaledSize; |
423 | | QRect scaledClipRect; |
424 | | int quality; |
425 | | QMap<QString, QString> text; |
426 | | void getText(); |
427 | | enum { |
428 | | UsePluginDefault, |
429 | | ApplyTransform, |
430 | | DoNotApplyTransform |
431 | | } autoTransform; |
432 | | |
433 | | // error |
434 | | QImageReader::ImageReaderError imageReaderError; |
435 | | QString errorString; |
436 | | |
437 | | QImageReader *q; |
438 | | |
439 | | static int maxAlloc; |
440 | | }; |
441 | | |
442 | | int QImageReaderPrivate::maxAlloc = 256; // 256 MB is enough for an 8K 64bpp image |
443 | | |
444 | | /*! |
445 | | \internal |
446 | | */ |
447 | | QImageReaderPrivate::QImageReaderPrivate(QImageReader *qq) |
448 | 13.4k | : autoDetectImageFormat(true), ignoresFormatAndExtension(false) |
449 | 13.4k | { |
450 | 13.4k | device = nullptr; |
451 | 13.4k | deleteDevice = false; |
452 | 13.4k | handler = nullptr; |
453 | 13.4k | quality = -1; |
454 | 13.4k | imageReaderError = QImageReader::UnknownError; |
455 | 13.4k | autoTransform = UsePluginDefault; |
456 | | |
457 | 13.4k | q = qq; |
458 | 13.4k | } |
459 | | |
460 | | /*! |
461 | | \internal |
462 | | */ |
463 | | QImageReaderPrivate::~QImageReaderPrivate() |
464 | 13.4k | { |
465 | 13.4k | delete handler; |
466 | 13.4k | if (deleteDevice) |
467 | 0 | delete device; |
468 | 13.4k | } |
469 | | |
470 | | /*! |
471 | | \internal |
472 | | */ |
473 | | bool QImageReaderPrivate::initHandler() |
474 | 63.6k | { |
475 | 63.6k | if (handler) |
476 | 50.2k | return true; |
477 | | |
478 | | // check some preconditions |
479 | 13.4k | if (!device || (!deleteDevice && !device->isOpen() && !device->open(QIODevice::ReadOnly))) { |
480 | 0 | imageReaderError = QImageReader::DeviceError; |
481 | 0 | errorString = QImageReader::tr("Invalid device"); |
482 | 0 | return false; |
483 | 0 | } |
484 | | |
485 | | // probe the file extension |
486 | 13.4k | if (deleteDevice && !device->isOpen() && !device->open(QIODevice::ReadOnly) && autoDetectImageFormat) { |
487 | 0 | Q_ASSERT(qobject_cast<QFile*>(device) != nullptr); // future-proofing; for now this should always be the case, so... |
488 | 0 | QFile *file = static_cast<QFile *>(device); |
489 | |
|
490 | 0 | if (file->error() == QFileDevice::ResourceError) { |
491 | | // this is bad. we should abort the open attempt and note the failure. |
492 | 0 | imageReaderError = QImageReader::DeviceError; |
493 | 0 | errorString = file->errorString(); |
494 | 0 | return false; |
495 | 0 | } |
496 | | |
497 | 0 | QList<QByteArray> extensions = QImageReader::supportedImageFormats(); |
498 | 0 | if (!format.isEmpty()) { |
499 | | // Try the most probable extension first |
500 | 0 | int currentFormatIndex = extensions.indexOf(format.toLower()); |
501 | 0 | if (currentFormatIndex > 0) |
502 | 0 | extensions.swapItemsAt(0, currentFormatIndex); |
503 | 0 | } |
504 | |
|
505 | 0 | int currentExtension = 0; |
506 | |
|
507 | 0 | QString fileName = file->fileName(); |
508 | 0 | bool fileIsOpen; |
509 | |
|
510 | 0 | do { |
511 | 0 | file->setFileName(fileName + u'.' |
512 | 0 | + QLatin1StringView(extensions.at(currentExtension++).constData())); |
513 | 0 | fileIsOpen = file->open(QIODevice::ReadOnly); |
514 | 0 | } while (!fileIsOpen && currentExtension < extensions.size()); |
515 | |
|
516 | 0 | if (!fileIsOpen) { |
517 | 0 | imageReaderError = QImageReader::FileNotFoundError; |
518 | 0 | errorString = QImageReader::tr("File not found"); |
519 | 0 | file->setFileName(fileName); // restore the old file name |
520 | 0 | return false; |
521 | 0 | } |
522 | 0 | } |
523 | | |
524 | | // assign a handler |
525 | 13.4k | if ((handler = createReadHandlerHelper(device, format, autoDetectImageFormat, ignoresFormatAndExtension)) == nullptr) { |
526 | 845 | imageReaderError = QImageReader::UnsupportedFormatError; |
527 | 845 | errorString = QImageReader::tr("Unsupported image format"); |
528 | 845 | return false; |
529 | 845 | } |
530 | 12.5k | return true; |
531 | 13.4k | } |
532 | | |
533 | | /*! |
534 | | \internal |
535 | | */ |
536 | | void QImageReaderPrivate::getText() |
537 | 0 | { |
538 | 0 | if (text.isEmpty() && q->supportsOption(QImageIOHandler::Description)) |
539 | 0 | text = qt_getImageTextFromDescription(handler->option(QImageIOHandler::Description).toString()); |
540 | 0 | } |
541 | | |
542 | | /*! |
543 | | Constructs an empty QImageReader object. Before reading an image, |
544 | | call setDevice() or setFileName(). |
545 | | */ |
546 | | QImageReader::QImageReader() |
547 | 0 | : d(new QImageReaderPrivate(this)) |
548 | 0 | { |
549 | 0 | } |
550 | | |
551 | | /*! |
552 | | Constructs a QImageReader object with the device \a device and the |
553 | | image format \a format. |
554 | | */ |
555 | | QImageReader::QImageReader(QIODevice *device, const QByteArray &format) |
556 | 13.4k | : d(new QImageReaderPrivate(this)) |
557 | 13.4k | { |
558 | 13.4k | d->device = device; |
559 | 13.4k | d->format = format; |
560 | 13.4k | } |
561 | | |
562 | | /*! |
563 | | Constructs a QImageReader object with the file name \a fileName |
564 | | and the image format \a format. |
565 | | |
566 | | \sa setFileName() |
567 | | */ |
568 | | QImageReader::QImageReader(const QString &fileName, const QByteArray &format) |
569 | 0 | : QImageReader(new QFile(fileName), format) |
570 | 0 | { |
571 | 0 | d->deleteDevice = true; |
572 | 0 | } |
573 | | |
574 | | /*! |
575 | | Destructs the QImageReader object. |
576 | | */ |
577 | | QImageReader::~QImageReader() |
578 | 13.4k | { |
579 | 13.4k | delete d; |
580 | 13.4k | } |
581 | | |
582 | | /*! |
583 | | Sets the format QImageReader will use when reading images, to \a |
584 | | format. \a format is a case insensitive text string. Example: |
585 | | |
586 | | \snippet code/src_gui_image_qimagereader.cpp 0 |
587 | | |
588 | | You can call supportedImageFormats() for the full list of formats |
589 | | QImageReader supports. |
590 | | |
591 | | \sa format() |
592 | | */ |
593 | | void QImageReader::setFormat(const QByteArray &format) |
594 | 0 | { |
595 | 0 | d->format = format; |
596 | 0 | } |
597 | | |
598 | | /*! |
599 | | Returns the format QImageReader uses for reading images. |
600 | | |
601 | | You can call this function after assigning a device to the |
602 | | reader to determine the format of the device. For example: |
603 | | |
604 | | \snippet code/src_gui_image_qimagereader.cpp 1 |
605 | | |
606 | | If the reader cannot read any image from the device (e.g., there is no |
607 | | image there, or the image has already been read), or if the format is |
608 | | unsupported, this function returns an empty QByteArray(). |
609 | | |
610 | | \sa setFormat(), supportedImageFormats() |
611 | | */ |
612 | | QByteArray QImageReader::format() const |
613 | 0 | { |
614 | 0 | if (d->format.isEmpty()) { |
615 | 0 | if (!d->initHandler()) |
616 | 0 | return QByteArray(); |
617 | 0 | return d->handler->canRead() ? d->handler->format() : QByteArray(); |
618 | 0 | } |
619 | | |
620 | 0 | return d->format; |
621 | 0 | } |
622 | | |
623 | | /*! |
624 | | If \a enabled is true, image format autodetection is enabled; otherwise, |
625 | | it is disabled. By default, autodetection is enabled. |
626 | | |
627 | | QImageReader uses an extensive approach to detecting the image format; |
628 | | firstly, if you pass a file name to QImageReader, it will attempt to |
629 | | detect the file extension if the given file name does not point to an |
630 | | existing file, by appending supported default extensions to the given file |
631 | | name, one at a time. It then uses the following approach to detect the |
632 | | image format: |
633 | | |
634 | | \list |
635 | | |
636 | | \li Image plugins are queried first, based on either the optional format |
637 | | string, or the file name suffix (if the source device is a file). No |
638 | | content detection is done at this stage. QImageReader will choose the |
639 | | first plugin that supports reading for this format. |
640 | | |
641 | | \li If no plugin supports the image format, Qt's built-in handlers are |
642 | | checked based on either the optional format string, or the file name |
643 | | suffix. |
644 | | |
645 | | \li If no capable plugins or built-in handlers are found, each plugin is |
646 | | tested by inspecting the content of the data stream. |
647 | | |
648 | | \li If no plugins could detect the image format based on data contents, |
649 | | each built-in image handler is tested by inspecting the contents. |
650 | | |
651 | | \li Finally, if all above approaches fail, QImageReader will report failure |
652 | | when trying to read the image. |
653 | | |
654 | | \endlist |
655 | | |
656 | | By disabling image format autodetection, QImageReader will only query the |
657 | | plugins and built-in handlers based on the format string (i.e., no file |
658 | | name extensions are tested). |
659 | | |
660 | | \sa QImageIOHandler::canRead(), QImageIOPlugin::capabilities() |
661 | | */ |
662 | | void QImageReader::setAutoDetectImageFormat(bool enabled) |
663 | 0 | { |
664 | 0 | d->autoDetectImageFormat = enabled; |
665 | 0 | } |
666 | | |
667 | | /*! |
668 | | Returns \c true if image format autodetection is enabled on this image |
669 | | reader; otherwise returns \c false. By default, autodetection is enabled. |
670 | | |
671 | | \sa setAutoDetectImageFormat() |
672 | | */ |
673 | | bool QImageReader::autoDetectImageFormat() const |
674 | 0 | { |
675 | 0 | return d->autoDetectImageFormat; |
676 | 0 | } |
677 | | |
678 | | |
679 | | /*! |
680 | | If \a ignored is set to true, then the image reader will ignore |
681 | | specified formats or file extensions and decide which plugin to |
682 | | use only based on the contents in the datastream. |
683 | | |
684 | | Setting this flag means that all image plugins gets loaded. Each |
685 | | plugin will read the first bytes in the image data and decide if |
686 | | the plugin is compatible or not. |
687 | | |
688 | | This also disables auto detecting the image format. |
689 | | |
690 | | \sa decideFormatFromContent() |
691 | | */ |
692 | | |
693 | | void QImageReader::setDecideFormatFromContent(bool ignored) |
694 | 0 | { |
695 | 0 | d->ignoresFormatAndExtension = ignored; |
696 | 0 | } |
697 | | |
698 | | |
699 | | /*! |
700 | | Returns whether the image reader should decide which plugin to use |
701 | | only based on the contents of the datastream rather than on the file |
702 | | extension. |
703 | | |
704 | | \sa setDecideFormatFromContent() |
705 | | */ |
706 | | |
707 | | bool QImageReader::decideFormatFromContent() const |
708 | 0 | { |
709 | 0 | return d->ignoresFormatAndExtension; |
710 | 0 | } |
711 | | |
712 | | |
713 | | /*! |
714 | | Sets QImageReader's device to \a device. If a device has already |
715 | | been set, the old device is removed from QImageReader and is |
716 | | otherwise left unchanged. |
717 | | |
718 | | If the device is not already open, QImageReader will attempt to |
719 | | open the device in \l {QIODeviceBase::}{ReadOnly} mode by calling |
720 | | open(). Note that this does not work for certain devices, such as |
721 | | QProcess, QTcpSocket and QUdpSocket, where more logic is required |
722 | | to open the device. |
723 | | |
724 | | \sa device(), setFileName() |
725 | | */ |
726 | | void QImageReader::setDevice(QIODevice *device) |
727 | 0 | { |
728 | 0 | delete d->handler; |
729 | 0 | d->handler = nullptr; |
730 | 0 | if (d->device && d->deleteDevice) |
731 | 0 | delete d->device; |
732 | 0 | d->device = device; |
733 | 0 | d->deleteDevice = false; |
734 | 0 | d->text.clear(); |
735 | 0 | } |
736 | | |
737 | | /*! |
738 | | Returns the device currently assigned to QImageReader, or \nullptr |
739 | | if no device has been assigned. |
740 | | */ |
741 | | QIODevice *QImageReader::device() const |
742 | 0 | { |
743 | 0 | return d->device; |
744 | 0 | } |
745 | | |
746 | | /*! |
747 | | Sets the file name of QImageReader to \a fileName. Internally, |
748 | | QImageReader will create a QFile object and open it in \l |
749 | | {QIODeviceBase::}{ReadOnly} mode, and use this when reading images. |
750 | | |
751 | | If \a fileName does not include a file extension (e.g., .png or .bmp), |
752 | | QImageReader will cycle through all supported extensions until it finds |
753 | | a matching file. |
754 | | |
755 | | \sa fileName(), setDevice(), supportedImageFormats() |
756 | | */ |
757 | | void QImageReader::setFileName(const QString &fileName) |
758 | 0 | { |
759 | 0 | setDevice(new QFile(fileName)); |
760 | 0 | d->deleteDevice = true; |
761 | 0 | } |
762 | | |
763 | | /*! |
764 | | If the currently assigned device is a QFile, or if setFileName() |
765 | | has been called, this function returns the name of the file |
766 | | QImageReader reads from. Otherwise (i.e., if no device has been |
767 | | assigned or the device is not a QFile), an empty QString is |
768 | | returned. |
769 | | |
770 | | \sa setFileName(), setDevice() |
771 | | */ |
772 | | QString QImageReader::fileName() const |
773 | 12.5k | { |
774 | 12.5k | QFile *file = qobject_cast<QFile *>(d->device); |
775 | 12.5k | return file ? file->fileName() : QString(); |
776 | 12.5k | } |
777 | | |
778 | | /*! |
779 | | Sets the quality setting of the image format to \a quality. |
780 | | |
781 | | Some image formats, in particular lossy ones, entail a tradeoff between a) |
782 | | visual quality of the resulting image, and b) decoding execution time. |
783 | | This function sets the level of that tradeoff for image formats that |
784 | | support it. |
785 | | |
786 | | In case of scaled image reading, the quality setting may also influence the |
787 | | tradeoff level between visual quality and execution speed of the scaling |
788 | | algorithm. |
789 | | |
790 | | The value range of \a quality depends on the image format. For example, |
791 | | the "jpeg" format supports a quality range from 0 (low visual quality) to |
792 | | 100 (high visual quality). |
793 | | |
794 | | \sa quality() setScaledSize() |
795 | | */ |
796 | | void QImageReader::setQuality(int quality) |
797 | 0 | { |
798 | 0 | d->quality = quality; |
799 | 0 | } |
800 | | |
801 | | /*! |
802 | | Returns the quality setting of the image format. |
803 | | |
804 | | \sa setQuality() |
805 | | */ |
806 | | int QImageReader::quality() const |
807 | 0 | { |
808 | 0 | return d->quality; |
809 | 0 | } |
810 | | |
811 | | |
812 | | /*! |
813 | | Returns the size of the image, without actually reading the image |
814 | | contents. |
815 | | |
816 | | If the image format does not support this feature, this function returns |
817 | | an invalid size. Qt's built-in image handlers all support this feature, |
818 | | but custom image format plugins are not required to do so. |
819 | | |
820 | | \sa QImageIOHandler::ImageOption, QImageIOHandler::option(), QImageIOHandler::supportsOption() |
821 | | */ |
822 | | QSize QImageReader::size() const |
823 | 0 | { |
824 | 0 | if (supportsOption(QImageIOHandler::Size)) |
825 | 0 | return d->handler->option(QImageIOHandler::Size).toSize(); |
826 | | |
827 | 0 | return QSize(); |
828 | 0 | } |
829 | | |
830 | | /*! |
831 | | Returns the format of the image, without actually reading the image |
832 | | contents. The format describes the image format \l QImageReader::read() |
833 | | returns, not the format of the actual image. |
834 | | |
835 | | If the image format does not support this feature, this function returns |
836 | | an invalid format. |
837 | | |
838 | | \sa QImageIOHandler::ImageOption, QImageIOHandler::option(), QImageIOHandler::supportsOption() |
839 | | */ |
840 | | QImage::Format QImageReader::imageFormat() const |
841 | 0 | { |
842 | 0 | if (supportsOption(QImageIOHandler::ImageFormat)) |
843 | 0 | return (QImage::Format)d->handler->option(QImageIOHandler::ImageFormat).toInt(); |
844 | | |
845 | 0 | return QImage::Format_Invalid; |
846 | 0 | } |
847 | | |
848 | | /*! |
849 | | Returns the text keys for this image. You can use |
850 | | these keys with text() to list the image text for |
851 | | a certain key. |
852 | | |
853 | | Support for this option is implemented through |
854 | | QImageIOHandler::Description. |
855 | | |
856 | | \sa text(), QImageWriter::setText(), QImage::textKeys() |
857 | | */ |
858 | | QStringList QImageReader::textKeys() const |
859 | 0 | { |
860 | 0 | d->getText(); |
861 | 0 | return d->text.keys(); |
862 | 0 | } |
863 | | |
864 | | /*! |
865 | | Returns the image text associated with \a key. |
866 | | |
867 | | Support for this option is implemented through |
868 | | QImageIOHandler::Description. |
869 | | |
870 | | \sa textKeys(), QImageWriter::setText() |
871 | | */ |
872 | | QString QImageReader::text(const QString &key) const |
873 | 0 | { |
874 | 0 | d->getText(); |
875 | 0 | return d->text.value(key); |
876 | 0 | } |
877 | | |
878 | | /*! |
879 | | Sets the image clip rect (also known as the ROI, or Region Of |
880 | | Interest) to \a rect. The coordinates of \a rect are relative to |
881 | | the untransformed image size, as returned by size(). |
882 | | |
883 | | \sa clipRect(), setScaledSize(), setScaledClipRect() |
884 | | */ |
885 | | void QImageReader::setClipRect(const QRect &rect) |
886 | 0 | { |
887 | 0 | d->clipRect = rect; |
888 | 0 | } |
889 | | |
890 | | /*! |
891 | | Returns the clip rect (also known as the ROI, or Region Of |
892 | | Interest) of the image. If no clip rect has been set, an invalid |
893 | | QRect is returned. |
894 | | |
895 | | \sa setClipRect() |
896 | | */ |
897 | | QRect QImageReader::clipRect() const |
898 | 0 | { |
899 | 0 | return d->clipRect; |
900 | 0 | } |
901 | | |
902 | | /*! |
903 | | Sets the scaled size of the image to \a size. The scaling is |
904 | | performed after the initial clip rect, but before the scaled clip |
905 | | rect is applied. The algorithm used for scaling depends on the |
906 | | image format. By default (i.e., if the image format does not |
907 | | support scaling), QImageReader will use QImage::scale() with |
908 | | Qt::SmoothScaling. |
909 | | |
910 | | If only one dimension is set in \a size, the other one will be |
911 | | computed from the image's \l {size()} {natural size} so as to |
912 | | maintain the aspect ratio. |
913 | | |
914 | | \sa scaledSize(), setClipRect(), setScaledClipRect() |
915 | | */ |
916 | | void QImageReader::setScaledSize(const QSize &size) |
917 | 0 | { |
918 | 0 | d->scaledSize = size; |
919 | 0 | } |
920 | | |
921 | | /*! |
922 | | Returns the scaled size of the image. |
923 | | |
924 | | \sa setScaledSize() |
925 | | */ |
926 | | QSize QImageReader::scaledSize() const |
927 | 0 | { |
928 | 0 | return d->scaledSize; |
929 | 0 | } |
930 | | |
931 | | /*! |
932 | | Sets the scaled clip rect to \a rect. The scaled clip rect is the |
933 | | clip rect (also known as ROI, or Region Of Interest) that is |
934 | | applied after the image has been scaled. |
935 | | |
936 | | \sa scaledClipRect(), setScaledSize() |
937 | | */ |
938 | | void QImageReader::setScaledClipRect(const QRect &rect) |
939 | 0 | { |
940 | 0 | d->scaledClipRect = rect; |
941 | 0 | } |
942 | | |
943 | | /*! |
944 | | Returns the scaled clip rect of the image. |
945 | | |
946 | | \sa setScaledClipRect() |
947 | | */ |
948 | | QRect QImageReader::scaledClipRect() const |
949 | 0 | { |
950 | 0 | return d->scaledClipRect; |
951 | 0 | } |
952 | | |
953 | | /*! |
954 | | Sets the background color to \a color. |
955 | | Image formats that support this operation are expected to |
956 | | initialize the background to \a color before reading an image. |
957 | | |
958 | | \sa backgroundColor(), read() |
959 | | */ |
960 | | void QImageReader::setBackgroundColor(const QColor &color) |
961 | 0 | { |
962 | 0 | if (supportsOption(QImageIOHandler::BackgroundColor)) |
963 | 0 | d->handler->setOption(QImageIOHandler::BackgroundColor, color); |
964 | 0 | } |
965 | | |
966 | | /*! |
967 | | Returns the background color that's used when reading an image. |
968 | | If the image format does not support setting the background color |
969 | | an invalid color is returned. |
970 | | |
971 | | \sa setBackgroundColor(), read() |
972 | | */ |
973 | | QColor QImageReader::backgroundColor() const |
974 | 0 | { |
975 | 0 | if (supportsOption(QImageIOHandler::BackgroundColor)) |
976 | 0 | return qvariant_cast<QColor>(d->handler->option(QImageIOHandler::BackgroundColor)); |
977 | 0 | return QColor(); |
978 | 0 | } |
979 | | |
980 | | /*! |
981 | | Returns \c true if the image format supports animation; |
982 | | otherwise, false is returned. |
983 | | |
984 | | \sa QMovie::supportedFormats() |
985 | | */ |
986 | | bool QImageReader::supportsAnimation() const |
987 | 0 | { |
988 | 0 | if (supportsOption(QImageIOHandler::Animation)) |
989 | 0 | return d->handler->option(QImageIOHandler::Animation).toBool(); |
990 | 0 | return false; |
991 | 0 | } |
992 | | |
993 | | /*! |
994 | | \since 5.4 |
995 | | |
996 | | Returns the subtype of the image. |
997 | | */ |
998 | | QByteArray QImageReader::subType() const |
999 | 0 | { |
1000 | 0 | if (supportsOption(QImageIOHandler::SubType)) |
1001 | 0 | return d->handler->option(QImageIOHandler::SubType).toByteArray(); |
1002 | 0 | return QByteArray(); |
1003 | 0 | } |
1004 | | |
1005 | | /*! |
1006 | | \since 5.4 |
1007 | | |
1008 | | Returns the list of subtypes supported by an image. |
1009 | | */ |
1010 | | QList<QByteArray> QImageReader::supportedSubTypes() const |
1011 | 0 | { |
1012 | 0 | if (supportsOption(QImageIOHandler::SupportedSubTypes)) |
1013 | 0 | return qvariant_cast<QList<QByteArray> >(d->handler->option(QImageIOHandler::SupportedSubTypes)); |
1014 | 0 | return QList<QByteArray>(); |
1015 | 0 | } |
1016 | | |
1017 | | /*! |
1018 | | \since 5.5 |
1019 | | |
1020 | | Returns the transformation metadata of the image, including image orientation. If the format |
1021 | | does not support transformation metadata, QImageIOHandler::TransformationNone is returned. |
1022 | | |
1023 | | \sa setAutoTransform(), autoTransform() |
1024 | | */ |
1025 | | QImageIOHandler::Transformations QImageReader::transformation() const |
1026 | 0 | { |
1027 | 0 | int option = QImageIOHandler::TransformationNone; |
1028 | 0 | if (supportsOption(QImageIOHandler::ImageTransformation)) |
1029 | 0 | option = d->handler->option(QImageIOHandler::ImageTransformation).toInt(); |
1030 | 0 | return QImageIOHandler::Transformations(option); |
1031 | 0 | } |
1032 | | |
1033 | | /*! |
1034 | | \since 5.5 |
1035 | | |
1036 | | Determines that images returned by read() should have transformation metadata automatically |
1037 | | applied if \a enabled is \c true. |
1038 | | |
1039 | | \sa autoTransform(), transformation(), read() |
1040 | | */ |
1041 | | void QImageReader::setAutoTransform(bool enabled) |
1042 | 0 | { |
1043 | 0 | d->autoTransform = enabled ? QImageReaderPrivate::ApplyTransform |
1044 | 0 | : QImageReaderPrivate::DoNotApplyTransform; |
1045 | 0 | } |
1046 | | |
1047 | | /*! |
1048 | | \since 5.5 |
1049 | | |
1050 | | Returns \c true if the image handler will apply transformation metadata on read(). |
1051 | | |
1052 | | \sa setAutoTransform(), transformation(), read() |
1053 | | */ |
1054 | | bool QImageReader::autoTransform() const |
1055 | 830 | { |
1056 | 830 | switch (d->autoTransform) { |
1057 | 0 | case QImageReaderPrivate::ApplyTransform: |
1058 | 0 | return true; |
1059 | 0 | case QImageReaderPrivate::DoNotApplyTransform: |
1060 | 0 | return false; |
1061 | 830 | case QImageReaderPrivate::UsePluginDefault: |
1062 | 830 | Q_FALLTHROUGH(); |
1063 | 830 | default: |
1064 | 830 | break; |
1065 | 830 | } |
1066 | 830 | return false; |
1067 | 830 | } |
1068 | | |
1069 | | /*! |
1070 | | Returns \c true if an image can be read for the device (i.e., the |
1071 | | image format is supported, and the device seems to contain valid |
1072 | | data); otherwise returns \c false. |
1073 | | |
1074 | | canRead() is a lightweight function that only does a quick test to |
1075 | | see if the image data is valid. read() may still return false |
1076 | | after canRead() returns \c true, if the image data is corrupt. |
1077 | | |
1078 | | \note A QMimeDatabase lookup is normally a better approach than this |
1079 | | function for identifying potentially non-image files or data. |
1080 | | |
1081 | | For images that support animation, canRead() returns \c false when |
1082 | | all frames have been read. |
1083 | | |
1084 | | \sa read(), supportedImageFormats(), QMimeDatabase |
1085 | | */ |
1086 | | bool QImageReader::canRead() const |
1087 | 0 | { |
1088 | 0 | if (!d->initHandler()) |
1089 | 0 | return false; |
1090 | | |
1091 | 0 | return d->handler->canRead(); |
1092 | 0 | } |
1093 | | |
1094 | | /*! |
1095 | | Reads an image from the device. On success, the image that was |
1096 | | read is returned; otherwise, a null QImage is returned. You can |
1097 | | then call error() to find the type of error that occurred, or |
1098 | | errorString() to get a human readable description of the error. |
1099 | | |
1100 | | For image formats that support animation, calling read() |
1101 | | repeatedly will return the next frame. When all frames have been |
1102 | | read, a null image will be returned. |
1103 | | |
1104 | | \sa canRead(), supportedImageFormats(), supportsAnimation(), QMovie |
1105 | | */ |
1106 | | QImage QImageReader::read() |
1107 | 13.4k | { |
1108 | | // Because failed image reading might have side effects, we explicitly |
1109 | | // return a null image instead of the image we've just created. |
1110 | 13.4k | QImage image; |
1111 | 13.4k | return read(&image) ? image : QImage(); |
1112 | 13.4k | } |
1113 | | |
1114 | | extern void qt_imageTransform(QImage &src, QImageIOHandler::Transformations orient); |
1115 | | |
1116 | | /*! |
1117 | | \overload |
1118 | | |
1119 | | Reads an image from the device into \a image, which must point to a |
1120 | | QImage. Returns \c true on success; otherwise, returns \c false. |
1121 | | |
1122 | | If \a image has same format and size as the image data that is about to be |
1123 | | read, this function may not need to allocate a new image before |
1124 | | reading. Because of this, it can be faster than the other read() overload, |
1125 | | which always constructs a new image; especially when reading several |
1126 | | images with the same format and size. |
1127 | | |
1128 | | \snippet code/src_gui_image_qimagereader.cpp 2 |
1129 | | |
1130 | | For image formats that support animation, calling read() repeatedly will |
1131 | | return the next frame. When all frames have been read, a null image will |
1132 | | be returned. |
1133 | | |
1134 | | \sa canRead(), supportedImageFormats(), supportsAnimation(), QMovie |
1135 | | */ |
1136 | | bool QImageReader::read(QImage *image) |
1137 | 13.4k | { |
1138 | 13.4k | if (!image) { |
1139 | 0 | qWarning("QImageReader::read: cannot read into null pointer"); |
1140 | 0 | return false; |
1141 | 0 | } |
1142 | | |
1143 | 13.4k | if (!d->initHandler()) |
1144 | 845 | return false; |
1145 | | |
1146 | 12.5k | QSize scaledSize = d->scaledSize; |
1147 | 12.5k | if ((scaledSize.width() <= 0 && scaledSize.height() > 0) || |
1148 | 12.5k | (scaledSize.height() <= 0 && scaledSize.width() > 0)) { |
1149 | | // if only one dimension is given, let's try to calculate the second one |
1150 | | // based on the original image size and maintaining the aspect ratio |
1151 | 0 | if (const QSize originalSize = size(); !originalSize.isEmpty()) { |
1152 | 0 | if (scaledSize.width() <= 0) { |
1153 | 0 | const auto ratio = qreal(scaledSize.height()) / originalSize.height(); |
1154 | 0 | scaledSize.setWidth(qRound(originalSize.width() * ratio)); |
1155 | 0 | } else { |
1156 | 0 | const auto ratio = qreal(scaledSize.width()) / originalSize.width(); |
1157 | 0 | scaledSize.setHeight(qRound(originalSize.height() * ratio)); |
1158 | 0 | } |
1159 | 0 | } |
1160 | 0 | } |
1161 | | |
1162 | 12.5k | const bool supportScaledSize = supportsOption(QImageIOHandler::ScaledSize) && scaledSize.isValid(); |
1163 | 12.5k | const bool supportClipRect = supportsOption(QImageIOHandler::ClipRect) && !d->clipRect.isNull(); |
1164 | 12.5k | const bool supportScaledClipRect = supportsOption(QImageIOHandler::ScaledClipRect) && !d->scaledClipRect.isNull(); |
1165 | | |
1166 | | // set the handler specific options. |
1167 | 12.5k | if (supportScaledSize) { |
1168 | 0 | if (supportClipRect || d->clipRect.isNull()) { |
1169 | | // Only enable the ScaledSize option if there is no clip rect, or |
1170 | | // if the handler also supports ClipRect. |
1171 | 0 | d->handler->setOption(QImageIOHandler::ScaledSize, scaledSize); |
1172 | 0 | } |
1173 | 0 | } |
1174 | 12.5k | if (supportClipRect) |
1175 | 0 | d->handler->setOption(QImageIOHandler::ClipRect, d->clipRect); |
1176 | 12.5k | if (supportScaledClipRect) |
1177 | 0 | d->handler->setOption(QImageIOHandler::ScaledClipRect, d->scaledClipRect); |
1178 | 12.5k | if (supportsOption(QImageIOHandler::Quality)) |
1179 | 8.23k | d->handler->setOption(QImageIOHandler::Quality, d->quality); |
1180 | | |
1181 | | // read the image |
1182 | 12.5k | QString filename = fileName(); |
1183 | 12.5k | if (Q_TRACE_ENABLED(QImageReader_read_before_reading)) { |
1184 | 0 | Q_TRACE(QImageReader_read_before_reading, this, filename.isEmpty() ? u"unknown"_s : filename); |
1185 | 0 | } |
1186 | | |
1187 | 12.5k | const bool result = d->handler->read(image); |
1188 | | |
1189 | 12.5k | Q_TRACE(QImageReader_read_after_reading, this, result); |
1190 | | |
1191 | 12.5k | if (!result) { |
1192 | 11.7k | d->imageReaderError = InvalidDataError; |
1193 | 11.7k | d->errorString = QImageReader::tr("Unable to read image data"); |
1194 | 11.7k | return false; |
1195 | 11.7k | } |
1196 | | |
1197 | | // provide default implementations for any unsupported image |
1198 | | // options |
1199 | 830 | if (supportClipRect) { |
1200 | 0 | if (supportScaledSize) { |
1201 | 0 | if (supportScaledClipRect) { |
1202 | | // all features are supported by the handler; nothing to do. |
1203 | 0 | } else { |
1204 | | // the image is already scaled, so apply scaled clipping. |
1205 | 0 | if (!d->scaledClipRect.isNull()) |
1206 | 0 | *image = image->copy(d->scaledClipRect); |
1207 | 0 | } |
1208 | 0 | } else { |
1209 | 0 | if (supportScaledClipRect) { |
1210 | | // supports scaled clipping but not scaling, most |
1211 | | // likely a broken handler. |
1212 | 0 | } else { |
1213 | 0 | if (scaledSize.isValid()) { |
1214 | 0 | *image = image->scaled(scaledSize, Qt::IgnoreAspectRatio, Qt::SmoothTransformation); |
1215 | 0 | } |
1216 | 0 | if (d->scaledClipRect.isValid()) { |
1217 | 0 | *image = image->copy(d->scaledClipRect); |
1218 | 0 | } |
1219 | 0 | } |
1220 | 0 | } |
1221 | 830 | } else { |
1222 | 830 | if (supportScaledSize && d->clipRect.isNull()) { |
1223 | 0 | if (supportScaledClipRect) { |
1224 | | // nothing to do (ClipRect is ignored!) |
1225 | 0 | } else { |
1226 | | // provide all workarounds. |
1227 | 0 | if (d->scaledClipRect.isValid()) { |
1228 | 0 | *image = image->copy(d->scaledClipRect); |
1229 | 0 | } |
1230 | 0 | } |
1231 | 830 | } else { |
1232 | 830 | if (supportScaledClipRect) { |
1233 | | // this makes no sense; a handler that supports |
1234 | | // ScaledClipRect but not ScaledSize is broken, and we |
1235 | | // can't work around it. |
1236 | 830 | } else { |
1237 | | // provide all workarounds. |
1238 | 830 | if (d->clipRect.isValid()) |
1239 | 0 | *image = image->copy(d->clipRect); |
1240 | 830 | if (scaledSize.isValid()) |
1241 | 0 | *image = image->scaled(scaledSize, Qt::IgnoreAspectRatio, Qt::SmoothTransformation); |
1242 | 830 | if (d->scaledClipRect.isValid()) |
1243 | 0 | *image = image->copy(d->scaledClipRect); |
1244 | 830 | } |
1245 | 830 | } |
1246 | 830 | } |
1247 | | |
1248 | | // successful read; check for "@Nx" file name suffix and set device pixel ratio. |
1249 | 830 | static bool disableNxImageLoading = !qEnvironmentVariableIsEmpty("QT_HIGHDPI_DISABLE_2X_IMAGE_LOADING"); |
1250 | 830 | if (!disableNxImageLoading) { |
1251 | 830 | const QByteArray suffix = QFileInfo(filename).baseName().right(3).toLatin1(); |
1252 | 830 | if (suffix.size() == 3 && suffix[0] == '@' && suffix[1] >= '2' && suffix[1] <= '9' && suffix[2] == 'x') |
1253 | 0 | image->setDevicePixelRatio(suffix[1] - '0'); |
1254 | 830 | } |
1255 | 830 | if (autoTransform()) |
1256 | 0 | qt_imageTransform(*image, transformation()); |
1257 | | |
1258 | 830 | return true; |
1259 | 12.5k | } |
1260 | | |
1261 | | /*! |
1262 | | For image formats that support animation, this function steps over the |
1263 | | current image, returning true if successful or false if there is no |
1264 | | following image in the animation. |
1265 | | |
1266 | | The default implementation calls read(), then discards the resulting |
1267 | | image, but the image handler may have a more efficient way of implementing |
1268 | | this operation. |
1269 | | |
1270 | | \sa jumpToImage(), QImageIOHandler::jumpToNextImage() |
1271 | | */ |
1272 | | bool QImageReader::jumpToNextImage() |
1273 | 0 | { |
1274 | 0 | if (!d->initHandler()) |
1275 | 0 | return false; |
1276 | 0 | return d->handler->jumpToNextImage(); |
1277 | 0 | } |
1278 | | |
1279 | | /*! |
1280 | | For image formats that support animation, this function skips to the image |
1281 | | whose sequence number is \a imageNumber, returning true if successful |
1282 | | or false if the corresponding image cannot be found. |
1283 | | |
1284 | | The next call to read() will attempt to read this image. |
1285 | | |
1286 | | \sa jumpToNextImage(), QImageIOHandler::jumpToImage() |
1287 | | */ |
1288 | | bool QImageReader::jumpToImage(int imageNumber) |
1289 | 0 | { |
1290 | 0 | if (!d->initHandler()) |
1291 | 0 | return false; |
1292 | 0 | return d->handler->jumpToImage(imageNumber); |
1293 | 0 | } |
1294 | | |
1295 | | /*! |
1296 | | For image formats that support animation, this function returns the number |
1297 | | of times the animation should loop. If this function returns -1, it can |
1298 | | either mean the animation should loop forever, or that an error occurred. |
1299 | | If an error occurred, canRead() will return false. |
1300 | | |
1301 | | \sa supportsAnimation(), QImageIOHandler::loopCount(), canRead() |
1302 | | */ |
1303 | | int QImageReader::loopCount() const |
1304 | 0 | { |
1305 | 0 | if (!d->initHandler()) |
1306 | 0 | return -1; |
1307 | 0 | return d->handler->loopCount(); |
1308 | 0 | } |
1309 | | |
1310 | | /*! |
1311 | | For image formats that support animation, this function returns the total |
1312 | | number of images in the animation. If the format does not support |
1313 | | animation, 0 is returned. |
1314 | | |
1315 | | This function returns -1 if an error occurred. |
1316 | | |
1317 | | \sa supportsAnimation(), QImageIOHandler::imageCount(), canRead() |
1318 | | */ |
1319 | | int QImageReader::imageCount() const |
1320 | 0 | { |
1321 | 0 | if (!d->initHandler()) |
1322 | 0 | return -1; |
1323 | 0 | return d->handler->imageCount(); |
1324 | 0 | } |
1325 | | |
1326 | | /*! |
1327 | | For image formats that support animation, this function returns the number |
1328 | | of milliseconds to wait until displaying the next frame in the animation. |
1329 | | If the image format doesn't support animation, 0 is returned. |
1330 | | |
1331 | | This function returns -1 if an error occurred. |
1332 | | |
1333 | | \sa supportsAnimation(), QImageIOHandler::nextImageDelay(), canRead() |
1334 | | */ |
1335 | | int QImageReader::nextImageDelay() const |
1336 | 0 | { |
1337 | 0 | if (!d->initHandler()) |
1338 | 0 | return -1; |
1339 | 0 | return d->handler->nextImageDelay(); |
1340 | 0 | } |
1341 | | |
1342 | | /*! |
1343 | | For image formats that support animation, this function returns the |
1344 | | sequence number of the current frame. If the image format doesn't support |
1345 | | animation, 0 is returned. |
1346 | | |
1347 | | This function returns -1 if an error occurred. |
1348 | | |
1349 | | \sa supportsAnimation(), QImageIOHandler::currentImageNumber(), canRead() |
1350 | | */ |
1351 | | int QImageReader::currentImageNumber() const |
1352 | 0 | { |
1353 | 0 | if (!d->initHandler()) |
1354 | 0 | return -1; |
1355 | 0 | return d->handler->currentImageNumber(); |
1356 | 0 | } |
1357 | | |
1358 | | /*! |
1359 | | For image formats that support animation, this function returns |
1360 | | the rect for the current frame. Otherwise, a null rect is returned. |
1361 | | |
1362 | | \sa supportsAnimation(), QImageIOHandler::currentImageRect() |
1363 | | */ |
1364 | | QRect QImageReader::currentImageRect() const |
1365 | 0 | { |
1366 | 0 | if (!d->initHandler()) |
1367 | 0 | return QRect(); |
1368 | 0 | return d->handler->currentImageRect(); |
1369 | 0 | } |
1370 | | |
1371 | | /*! |
1372 | | Returns the type of error that occurred last. |
1373 | | |
1374 | | \sa ImageReaderError, errorString() |
1375 | | */ |
1376 | | QImageReader::ImageReaderError QImageReader::error() const |
1377 | 0 | { |
1378 | 0 | return d->imageReaderError; |
1379 | 0 | } |
1380 | | |
1381 | | /*! |
1382 | | Returns a human readable description of the last error that |
1383 | | occurred. |
1384 | | |
1385 | | \sa error() |
1386 | | */ |
1387 | | QString QImageReader::errorString() const |
1388 | 0 | { |
1389 | 0 | if (d->errorString.isEmpty()) |
1390 | 0 | return QImageReader::tr("Unknown error"); |
1391 | 0 | return d->errorString; |
1392 | 0 | } |
1393 | | |
1394 | | /*! |
1395 | | Returns \c true if the reader supports \a option; otherwise returns |
1396 | | false. |
1397 | | |
1398 | | Different image formats support different options. Call this function to |
1399 | | determine whether a certain option is supported by the current format. For |
1400 | | example, the PNG format allows you to embed text into the image's metadata |
1401 | | (see text()), and the BMP format allows you to determine the image's size |
1402 | | without loading the whole image into memory (see size()). |
1403 | | |
1404 | | \snippet code/src_gui_image_qimagereader.cpp 3 |
1405 | | |
1406 | | \sa QImageWriter::supportsOption() |
1407 | | */ |
1408 | | bool QImageReader::supportsOption(QImageIOHandler::ImageOption option) const |
1409 | 50.2k | { |
1410 | 50.2k | if (!d->initHandler()) |
1411 | 0 | return false; |
1412 | 50.2k | return d->handler->supportsOption(option); |
1413 | 50.2k | } |
1414 | | |
1415 | | /*! |
1416 | | If supported, this function returns the image format of the file |
1417 | | \a fileName. Otherwise, an empty string is returned. |
1418 | | */ |
1419 | | QByteArray QImageReader::imageFormat(const QString &fileName) |
1420 | 0 | { |
1421 | 0 | QFile file(fileName); |
1422 | 0 | if (!file.open(QFile::ReadOnly)) |
1423 | 0 | return QByteArray(); |
1424 | | |
1425 | 0 | return imageFormat(&file); |
1426 | 0 | } |
1427 | | |
1428 | | /*! |
1429 | | If supported, this function returns the image format of the device |
1430 | | \a device. Otherwise, an empty string is returned. |
1431 | | |
1432 | | \sa QImageReader::autoDetectImageFormat() |
1433 | | */ |
1434 | | QByteArray QImageReader::imageFormat(QIODevice *device) |
1435 | 0 | { |
1436 | 0 | QByteArray format; |
1437 | 0 | QImageIOHandler *handler = createReadHandlerHelper(device, format, /* autoDetectImageFormat = */ true, false); |
1438 | 0 | if (handler) { |
1439 | 0 | if (handler->canRead()) |
1440 | 0 | format = handler->format(); |
1441 | 0 | delete handler; |
1442 | 0 | } |
1443 | 0 | return format; |
1444 | 0 | } |
1445 | | |
1446 | | /*! |
1447 | | Returns the list of image formats supported by QImageReader. |
1448 | | |
1449 | | By default, Qt can read the following formats: |
1450 | | |
1451 | | \table |
1452 | | \header \li Format \li MIME type \li Description |
1453 | | \row \li BMP \li image/bmp \li Windows Bitmap |
1454 | | \row \li GIF \li image/gif \li Graphic Interchange Format (optional) |
1455 | | \row \li JPG \li image/jpeg \li Joint Photographic Experts Group |
1456 | | \row \li PNG \li image/png \li Portable Network Graphics |
1457 | | \row \li PBM \li image/x-portable-bitmap \li Portable Bitmap |
1458 | | \row \li PGM \li image/x-portable-graymap \li Portable Graymap |
1459 | | \row \li PPM \li image/x-portable-pixmap \li Portable Pixmap |
1460 | | \row \li XBM \li image/x-xbitmap \li X11 Bitmap |
1461 | | \row \li XPM \li image/x-xpixmap \li X11 Pixmap |
1462 | | \row \li SVG \li image/svg+xml \li Scalable Vector Graphics |
1463 | | \endtable |
1464 | | |
1465 | | Reading and writing SVG files is supported through the \l{Qt SVG} module. |
1466 | | The \l{Qt Image Formats} module provides support for additional image formats. |
1467 | | |
1468 | | Note that the QCoreApplication instance must be created before this function is |
1469 | | called. |
1470 | | |
1471 | | \sa setFormat(), QImageWriter::supportedImageFormats(), QImageIOPlugin |
1472 | | */ |
1473 | | |
1474 | | QList<QByteArray> QImageReader::supportedImageFormats() |
1475 | 0 | { |
1476 | 0 | return QImageReaderWriterHelpers::supportedImageFormats(QImageReaderWriterHelpers::CanRead); |
1477 | 0 | } |
1478 | | |
1479 | | /*! |
1480 | | Returns the list of MIME types supported by QImageReader. |
1481 | | |
1482 | | Note that the QApplication instance must be created before this function is |
1483 | | called. |
1484 | | |
1485 | | \sa supportedImageFormats(), QImageWriter::supportedMimeTypes() |
1486 | | */ |
1487 | | |
1488 | | QList<QByteArray> QImageReader::supportedMimeTypes() |
1489 | 0 | { |
1490 | 0 | return QImageReaderWriterHelpers::supportedMimeTypes(QImageReaderWriterHelpers::CanRead); |
1491 | 0 | } |
1492 | | |
1493 | | /*! |
1494 | | \since 5.12 |
1495 | | |
1496 | | Returns the list of image formats corresponding to \a mimeType. |
1497 | | |
1498 | | Note that the QGuiApplication instance must be created before this function is |
1499 | | called. |
1500 | | |
1501 | | \sa supportedImageFormats(), supportedMimeTypes() |
1502 | | */ |
1503 | | |
1504 | | QList<QByteArray> QImageReader::imageFormatsForMimeType(const QByteArray &mimeType) |
1505 | 0 | { |
1506 | 0 | return QImageReaderWriterHelpers::imageFormatsForMimeType(mimeType, |
1507 | 0 | QImageReaderWriterHelpers::CanRead); |
1508 | 0 | } |
1509 | | |
1510 | | /*! |
1511 | | \since 6.0 |
1512 | | |
1513 | | Returns the current allocation limit, in megabytes. |
1514 | | |
1515 | | \sa setAllocationLimit() |
1516 | | */ |
1517 | | int QImageReader::allocationLimit() |
1518 | 81.5k | { |
1519 | 81.5k | static int envLimit = []() { |
1520 | 24 | bool ok = false; |
1521 | 24 | int res = qEnvironmentVariableIntValue("QT_IMAGEIO_MAXALLOC", &ok); |
1522 | 24 | return ok ? res : -1; |
1523 | 24 | }(); |
1524 | | |
1525 | 81.5k | return envLimit >= 0 ? envLimit : QImageReaderPrivate::maxAlloc; |
1526 | 81.5k | } |
1527 | | |
1528 | | /*! |
1529 | | \since 6.0 |
1530 | | |
1531 | | Sets the allocation limit to \a mbLimit megabytes. Images that would |
1532 | | require a QImage memory allocation above this limit will be rejected. |
1533 | | If \a mbLimit is 0, the allocation size check will be disabled. |
1534 | | |
1535 | | This limit helps applications avoid unexpectedly large memory usage from |
1536 | | loading corrupt image files. It is normally not needed to change it. The |
1537 | | default limit is large enough for all commonly used image sizes. |
1538 | | |
1539 | | At runtime, this value may be overridden by the environment variable \c QT_IMAGEIO_MAXALLOC. |
1540 | | |
1541 | | \note The memory requirements are calculated for a minimum of 32 bits per pixel, since Qt will |
1542 | | typically convert an image to that depth when it is used in GUI. This means that the effective |
1543 | | allocation limit is significantly smaller than \a mbLimit when reading 1 bpp and 8 bpp images. |
1544 | | |
1545 | | \sa allocationLimit() |
1546 | | */ |
1547 | | void QImageReader::setAllocationLimit(int mbLimit) |
1548 | 0 | { |
1549 | 0 | if (mbLimit >= 0) |
1550 | 0 | QImageReaderPrivate::maxAlloc = mbLimit; |
1551 | 0 | } |
1552 | | |
1553 | | QT_END_NAMESPACE |