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<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QImageDecoder Class Reference</h1>
<p>The QImageDecoder class is an incremental image decoder for all supported image formats.
<a href="#details">More...</a>
<p><tt>#include <<a href="qasyncimageio-h.html">qasyncimageio.h</a>></tt>
<p><a href="qimagedecoder-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li><div class=fn><a href="#QImageDecoder"><b>QImageDecoder</b></a> ( QImageConsumer * c )</div></li>
<li><div class=fn><a href="#~QImageDecoder"><b>~QImageDecoder</b></a> ()</div></li>
<li><div class=fn>const QImage & <a href="#image"><b>image</b></a> ()</div></li>
<li><div class=fn>int <a href="#decode"><b>decode</b></a> ( const uchar * buffer, int length )</div></li>
</ul>
<h2>Static Public Members</h2>
<ul>
<li><div class=fn>const char * <a href="#formatName"><b>formatName</b></a> ( const uchar * buffer, int length )</div></li>
<li><div class=fn>QImageFormatType * <a href="#format"><b>format</b></a> ( const char * name )</div></li>
<li><div class=fn>QStrList <a href="#inputFormats"><b>inputFormats</b></a> ()</div></li>
<li><div class=fn>void <a href="#registerDecoderFactory"><b>registerDecoderFactory</b></a> ( QImageFormatType * f )</div></li>
<li><div class=fn>void <a href="#unregisterDecoderFactory"><b>unregisterDecoderFactory</b></a> ( QImageFormatType * f )</div></li>
</ul>
<hr><a name="details"></a><h2>Detailed Description</h2>
The QImageDecoder class is an incremental image decoder for all supported image formats.
<p>
<p> New formats are installed by creating objects of class
<a href="qimageformattype.html">QImageFormatType</a>; the <a href="qmovie.html">QMovie</a> class can be used for
all installed incremental image formats. QImageDecoder is
useful only for creating new ways of feeding data to an <a href="qimageconsumer.html">QImageConsumer</a>.
<p> A QImageDecoder is a machine that decodes images. It takes encoded
image data via its <a href="#decode">decode</a>() method and expresses its decoding by
supplying information to a QImageConsumer. It implements its
decoding by using a <a href="qimageformat.html">QImageFormat</a> created by one of the
currently-existing QImageFormatType factory-objects.
<p> QImageFormatType and QImageFormat are the classes that you might
need to implement support for additional image formats.
<p>
<p> Qt supports GIF reading if it is configured that way during
installation (see qgif.h). If it is, we are required to state that
"The Graphics Interchange Format(c) is the Copyright property of
CompuServe Incorporated. GIF(sm) is a Service Mark property of
CompuServe Incorporated."
<p>See also <a href="graphics.html">Graphics Classes</a>, <a href="images.html">Image Processing Classes</a> and <a href="multimedia.html">Multimedia Classes</a>.
<hr><h2>Member Function Documentation</h2>
<h3 class=fn><a name="QImageDecoder"></a>QImageDecoder::QImageDecoder ( <a href="qimageconsumer.html">QImageConsumer</a> * c )
</h3>
Constructs a QImageDecoder that will send change information to
the <a href="qimageconsumer.html">QImageConsumer</a> <em>c</em>.
<h3 class=fn><a name="~QImageDecoder"></a>QImageDecoder::~QImageDecoder ()
</h3>
Destroys a QImageDecoder. The image it built is destroyed. The decoder
built by the factory for the file format is destroyed. The consumer
for which it decoded the image is <em>not</em> destroyed.
<h3 class=fn>int <a name="decode"></a>QImageDecoder::decode ( const uchar * buffer, int length )
</h3>
Call this function to decode some data into image changes. The data
in <em>buffer</em> will be decoded, sending change information to the
<a href="qimageconsumer.html">QImageConsumer</a> of this QImageDecoder until one of the change
functions of the consumer returns FALSE. The length of the data is
given in <em>length</em>.
<p> Returns the number of bytes consumed: 0 if consumption is complete,
and -1 if decoding fails due to invalid data.
<h3 class=fn><a href="qimageformattype.html">QImageFormatType</a> * <a name="format"></a>QImageDecoder::format ( const char * name )<tt> [static]</tt>
</h3> Returns a <a href="qimageformattype.html">QImageFormatType</a> by name. This might be used when the user
needs to force data to be interpreted as being in a certain format. <em>name</em> is one of the formats listed by <a href="#inputFormats">QImageDecoder::inputFormats</a>(). Note
that you will still need to supply decodable data to
result->decoderFor() before you can begin decoding the data.
<h3 class=fn>const char * <a name="formatName"></a>QImageDecoder::formatName ( const uchar * buffer, int length )<tt> [static]</tt>
</h3>
Call this function to find the name of the format of the given header.
The returned string is statically allocated. The function will look
at the first <em>length</em> characters in the <em>buffer</em>.
<p> Returns 0 if the format is not recognized.
<h3 class=fn>const <a href="qimage.html">QImage</a> & <a name="image"></a>QImageDecoder::image ()
</h3>
<p> Returns the image currently being decoded.
<h3 class=fn><a href="qstrlist.html">QStrList</a> <a name="inputFormats"></a>QImageDecoder::inputFormats ()<tt> [static]</tt>
</h3>
Returns a sorted list of formats for which asynchronous loading is supported.
<h3 class=fn>void <a name="registerDecoderFactory"></a>QImageDecoder::registerDecoderFactory ( <a href="qimageformattype.html">QImageFormatType</a> * f )<tt> [static]</tt>
</h3>
Registers the new <a href="qimageformattype.html">QImageFormatType</a> <em>f</em>. This is not needed in
application code because factories call this themselves.
<h3 class=fn>void <a name="unregisterDecoderFactory"></a>QImageDecoder::unregisterDecoderFactory ( <a href="qimageformattype.html">QImageFormatType</a> * f )<tt> [static]</tt>
</h3>
Unregisters the <a href="qimageformattype.html">QImageFormatType</a> <em>f</em>. This is not needed in
application code because factories call this themselves.
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