1QImageFormatType(3qt) QImageFormatType(3qt)
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6 QImageFormatType - Factory that makes QImageFormat objects
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9 #include <qasyncimageio.h>
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11 Public Members
12 virtual ~QImageFormatType ()
13 virtual QImageFormat * decoderFor ( const uchar * buffer, int length )
14 = 0
15 virtual const char * formatName () const = 0
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17 Protected Members
18 QImageFormatType ()
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21 The QImageFormatType class is a factory that makes QImageFormat
22 objects.
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24 Whereas the QImageIO class allows for complete loading of images,
25 QImageFormatType allows for incremental loading of images.
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27 New image file formats are installed by creating objects of derived
28 classes of QImageFormatType. They must implement decoderFor() and
29 formatName().
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31 QImageFormatType is a very simple class. Its only task is to recognize
32 image data in some format and make a new object, subclassed from
33 QImageFormat, which can decode that format.
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35 The factories for formats built into Qt are automatically defined
36 before any other factory is initialized. If two factories would
37 recognize an image format, the factory created last will override the
38 earlier one; you can thus override current and future built-in formats.
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40 See also Graphics Classes, Image Processing Classes, and Multimedia
41 Classes.
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45 Constructs a factory. It automatically registers itself with
46 QImageDecoder.
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49 Destroys a factory. It automatically unregisters itself from
50 QImageDecoder.
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53 ) [pure virtual]
54 Returns a decoder for decoding an image that starts with the bytes in
55 buffer. The length of the data is given in length. This function should
56 only return a decoder if it is certain that the decoder applies to data
57 with the given header. Returns 0 if there is insufficient data in the
58 header to make a positive identification or if the data is not
59 recognized.
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62 Returns the name of the format supported by decoders from this factory.
63 The string is statically allocated.
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67 http://doc.trolltech.com/qimageformattype.html
68 http://www.trolltech.com/faq/tech.html
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71 Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the
72 license file included in the distribution for a complete license
73 statement.
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76 Generated automatically from the source code.
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79 If you find a bug in Qt, please report it as described in
80 http://doc.trolltech.com/bughowto.html. Good bug reports help us to
81 help you. Thank you.
82
83 The definitive Qt documentation is provided in HTML format; it is
84 located at $QTDIR/doc/html and can be read using Qt Assistant or with a
85 web browser. This man page is provided as a convenience for those users
86 who prefer man pages, although this format is not officially supported
87 by Trolltech.
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89 If you find errors in this manual page, please report them to qt-
90 bugs@trolltech.com. Please include the name of the manual page
91 (qimageformattype.3qt) and the Qt version (3.3.8).
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95Trolltech AS 2 February 2007 QImageFormatType(3qt)