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QImageDecoder Class Reference

The QImageDecoder class is an incremental image decoder for all supported image formats. More...

#include <qasyncimageio.h>

List of all member functions.

Public Members

Static Public Members


Detailed Description

The QImageDecoder class is an incremental image decoder for all supported image formats.

New formats are installed by creating objects of class QImageFormatType; the QMovie class can be used for all installed incremental image formats. QImageDecoder is useful only for creating new ways of feeding data to an QImageConsumer.

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."


Member Function Documentation

QImageDecoder::QImageDecoder ( QImageConsumer * c )

Constructs a QImageDecoder that will send change information to a given QImageConsumer.

QImageDecoder::~QImageDecoder ()

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 not destroyed.

int QImageDecoder::decode ( const uchar * buffer, int length )

Call this function to decode some data into image changes. The data will be decoded, sending change information to the QImageConsumer of this QImageDecoder until one of the change functions of the consumer returns FALSE.

Returns the number of bytes consumed: 0 if consumption is complete, and -1 if decoding fails due to invalid data.

QImageFormatType * QImageDecoder::format ( const char * name ) [static]

Returns a QImageFormatType by name. This might be used when the user needs to force data to be interpreted as being in a certain format. name is one of the formats listed by QImageDecoder::inputFormats(). Note that you will still need to supply decodable data to result->decoderFor() before you can begin decoding the data.

const char * QImageDecoder::formatName ( const uchar * buffer, int length ) [static]

Call this function to find the name of the format of the given header. The returned string is statically allocated.

Returns 0 if the format is not recognized.

const QImage & QImageDecoder::image ()

Returns the image currently being decoded.

QStrList QImageDecoder::inputFormats () [static]

Returns a sorted list of formats for which asynchronous loading is supported.

void QImageDecoder::registerDecoderFactory ( QImageFormatType * f ) [static]

Registers a new QImageFormatType. This is not needed in application code because factories call this themselves.

void QImageDecoder::unregisterDecoderFactory ( QImageFormatType * f ) [static]

Unregisters a new QImageFormatType. This is not needed in application code because factories call this themselves.

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