QImageConsumer(3qt)QImageConsumer(3qt)NAMEQImageConsumer - Abstraction used by QImageDecoder
SYNOPSIS
#include <qasyncimageio.h>
Public Members
virtual void end () = 0
virtual void changed ( const QRect & ) = 0
virtual void frameDone () = 0
virtual void frameDone ( const QPoint & offset, const QRect & rect ) =
0
virtual void setLooping ( int n ) = 0
virtual void setFramePeriod ( int milliseconds ) = 0
virtual void setSize ( int, int ) = 0
DESCRIPTION
The QImageConsumer class is an abstraction used by QImageDecoder.
The QMovie class, or QLabel::setMovie(), are easy to use and for most
situations do what you want with regards animated images.
A QImageConsumer consumes information about changes to the QImage
maintained by a QImageDecoder. Think of the QImage as the model or
source of the image data, with the QImageConsumer as a view of that
data and the QImageDecoder being the controller that orchestrates the
relationship between the model and the view.
You'd use the QImageConsumer class, for example, if you were
implementing a web browser with your own image loaders.
See also QImageDecoder, Graphics Classes, Image Processing Classes, and
Multimedia Classes.
MEMBER FUNCTION DOCUMENTATIONvoid QImageConsumer::changed ( const QRect & ) [pure virtual]
Called when the given area of the image has changed.
void QImageConsumer::end () [pure virtual]
Called when all the data from all the frames has been decoded and
revealed as changed().
void QImageConsumer::frameDone () [pure virtual]
One of the two frameDone() functions will be called when a frame of an
animated image has ended and been revealed as changed().
When this function is called, the current image should be displayed.
The decoder will not make any further changes to the image until the
next call to QImageFormat::decode().
void QImageConsumer::frameDone ( const QPoint & offset, const QRect & rect )
[pure virtual]
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
One of the two frameDone() functions will be called when a frame of an
animated image has ended and been revealed as changed().
When this function is called, the area rect in the current image should
be moved by offset and displayed.
The decoder will not make any further changes to the image until the
next call to QImageFormat::decode().
void QImageConsumer::setFramePeriod ( int milliseconds ) [pure virtual]
Notes that the frame about to be decoded should not be displayed until
the given number of milliseconds after the time that this function is
called. Of course, the image may not have been decoded by then, in
which case the frame should not be displayed until it is complete. A
value of -1 (the assumed default) indicates that the image should be
displayed even while it is only partially loaded.
void QImageConsumer::setLooping ( int n ) [pure virtual]
Called to indicate that the sequence of frames in the image should be
repeated n times, including the sequence during decoding.
0 = Forever
1 = Only display frames the first time through
2 = Repeat once after first pass through images
etc.
To make the QImageDecoder do this, just delete it and pass the
information to it again for decoding (setLooping() will be called
again, of course, but that can be ignored), or keep copies of the
changed areas at the ends of frames.
void QImageConsumer::setSize ( int, int ) [pure virtual]
This function is called as soon as the size of the image has been
determined.
SEE ALSO
http://doc.trolltech.com/qimageconsumer.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the
license file included in the distribution for a complete license
statement.
AUTHOR
Generated automatically from the source code.
BUGS
If you find a bug in Qt, please report it as described in
http://doc.trolltech.com/bughowto.html. Good bug reports help us to
help you. Thank you.
The definitive Qt documentation is provided in HTML format; it is
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If you find errors in this manual page, please report them to qt-
bugs@trolltech.com. Please include the name of the manual page
(qimageconsumer.3qt) and the Qt version (3.3.8).
Trolltech AS 2 February 2007 QImageConsumer(3qt)
