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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><html><head><meta name="robots" content="noindex,noarchive">
<title>Qt Toolkit - QImageFormat Class</title><style type="text/css"><!--
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<h1 align=center>QImageFormat Class Reference</h1><br clear="all">
<p>
Incremental image decoder for a specific image format.
<a href="#details">More...</a>
<p>
<code>#include <<a href="qasyncimageio-h.html">qasyncimageio.h</a>></code>
<p><a href="qimageformat-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li><span class="fn">virtual<a href="qimageformat.html#a0"><strong>~QImageFormat</strong></a>()</span>
<li><span class="fn">virtualint<a href="qimageformat.html#a1"><strong>decode</strong></a>(QImage&img, QImageConsumer*consumer, constuchar*buffer, intlength)</span>
</ul>
<hr><h2><a name="details"></a>Detailed Description</h2>
Incremental image decoder for a specific image format.
<p>
By making a derived classes of <a href="qimageformattype.html">QImageFormatType</a> which in turn
creates objects that are a subclass of QImageFormat, you can add
support for more incremental image formats, allowing such formats to
be sources for a <a href="qmovie.html">QMovie</a>, or for the first frame of the image stream
to be loaded as a <a href="qimage.html">QImage</a> or <a href="qpixmap.html">QPixmap</a>.
<p>Your new subclass must override the <a href="qimageformat.html#a1">decode</a>() function in order to
process your new format.
<p>New QImageFormat objects are generated by new QImageFormatType factories.
<hr><h2>Member Function Documentation</h2>
<h3 class="fn"><a name="a0"></a>QImageFormat::~QImageFormat() <code>[virtual]</code></h3>
<p>Destructs the object.
<h3 class="fn">int<a name="a1"></a>QImageFormat::decode(<a href="qimage.html">QImage</a>&img, <a href="qimageconsumer.html">QImageConsumer</a>*consumer, constuchar*buffer, intlength) <code>[virtual]</code></h3>
<p>New subclasses must override this method.
<p>It should decode some or all of the bytes from <em>buffer</em> into
<em>img,</em> calling the methods of <em>consumer</em> as the decoding proceeds to
inform that consumer of changes to the image.
The consumer may be 0, in which case the function should just process
the data into <em>img</em> without telling any consumer about the changes.
Note that the decoder must store enough state
to be able to continue in subsequent calls to this method - this is
the essence of the incremental image loading.
<p>The function should return without processing all the data if it
reaches the end of a frame in the input.
<p>The function must return the number of bytes it has processed.
<hr><p>
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It was generated from the following files:
<ul>
<li>qasyncimageio.h: 1999/02/12
<li>qasyncimageio.cpp: 1999/02/13
</ul>
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<td>Copyright 1999 Troll Tech<td><a href="trademarks.html">Trademarks</a>
<td align="right"><div align="right">Qt version 1.45</div>
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