qimageconsumer(3qt)

1QImageConsumer(3qt)                                        QImageConsumer(3qt)
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NAME

6       QImageConsumer - Abstraction used by QImageDecoder
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SYNOPSIS

9       #include <qasyncimageio.h>
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11   Public Members
12       virtual void end () = 0
13       virtual void changed ( const QRect & ) = 0
14       virtual void frameDone () = 0
15       virtual void frameDone ( const QPoint & offset, const QRect & rect ) =
16           0
17       virtual void setLooping ( int n ) = 0
18       virtual void setFramePeriod ( int milliseconds ) = 0
19       virtual void setSize ( int, int ) = 0
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DESCRIPTION

22       The QImageConsumer class is an abstraction used by QImageDecoder.
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24       The QMovie class, or QLabel::setMovie(), are easy to use and for most
25       situations do what you want with regards animated images.
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27       A QImageConsumer consumes information about changes to the QImage
28       maintained by a QImageDecoder. Think of the QImage as the model or
29       source of the image data, with the QImageConsumer as a view of that
30       data and the QImageDecoder being the controller that orchestrates the
31       relationship between the model and the view.
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33       You'd use the QImageConsumer class, for example, if you were
34       implementing a web browser with your own image loaders.
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36       See also QImageDecoder, Graphics Classes, Image Processing Classes, and
37       Multimedia Classes.
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MEMBER FUNCTION DOCUMENTATION

void QImageConsumer::changed ( const QRect & ) [pure virtual]

41       Called when the given area of the image has changed.
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void QImageConsumer::end () [pure virtual]

44       Called when all the data from all the frames has been decoded and
45       revealed as changed().
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void QImageConsumer::frameDone () [pure virtual]

48       One of the two frameDone() functions will be called when a frame of an
49       animated image has ended and been revealed as changed().
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51       When this function is called, the current image should be displayed.
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53       The decoder will not make any further changes to the image until the
54       next call to QImageFormat::decode().
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void QImageConsumer::frameDone ( const QPoint & offset, const QRect & rect )

57       [pure virtual]
58       This is an overloaded member function, provided for convenience. It
59       behaves essentially like the above function.
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61       One of the two frameDone() functions will be called when a frame of an
62       animated image has ended and been revealed as changed().
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64       When this function is called, the area rect in the current image should
65       be moved by offset and displayed.
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67       The decoder will not make any further changes to the image until the
68       next call to QImageFormat::decode().
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void QImageConsumer::setFramePeriod ( int milliseconds ) [pure virtual]

71       Notes that the frame about to be decoded should not be displayed until
72       the given number of milliseconds after the time that this function is
73       called. Of course, the image may not have been decoded by then, in
74       which case the frame should not be displayed until it is complete. A
75       value of -1 (the assumed default) indicates that the image should be
76       displayed even while it is only partially loaded.
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void QImageConsumer::setLooping ( int n ) [pure virtual]

79       Called to indicate that the sequence of frames in the image should be
80       repeated n times, including the sequence during decoding.
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82       0 = Forever
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84       1 = Only display frames the first time through
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86       2 = Repeat once after first pass through images
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88       etc.
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90       To make the QImageDecoder do this, just delete it and pass the
91       information to it again for decoding (setLooping() will be called
92       again, of course, but that can be ignored), or keep copies of the
93       changed areas at the ends of frames.
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void QImageConsumer::setSize ( int, int ) [pure virtual]

96       This function is called as soon as the size of the image has been
97       determined.
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COPYRIGHT

105       Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com.  See the
106       license file included in the distribution for a complete license
107       statement.
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AUTHOR

110       Generated automatically from the source code.
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BUGS

113       If you find a bug in Qt, please report it as described in
114       http://doc.trolltech.com/bughowto.html.  Good bug reports help us to
115       help you. Thank you.
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117       The definitive Qt documentation is provided in HTML format; it is
118       located at $QTDIR/doc/html and can be read using Qt Assistant or with a
119       web browser. This man page is provided as a convenience for those users
120       who prefer man pages, although this format is not officially supported
121       by Trolltech.
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123       If you find errors in this manual page, please report them to qt-
124       bugs@trolltech.com.  Please include the name of the manual page
125       (qimageconsumer.3qt) and the Qt version (3.3.8).
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129Trolltech AS                    2 February 2007            QImageConsumer(3qt)