QPictureIO Class Reference
[QtGui module]

void QPictureIO::defineIOHandler ( const char * format, const char * header, const char * flags, picture_io_handler readPicture, picture_io_handler writePicture )   [static]

Defines a picture I/O handler for the picture format called format, which is recognized using the regular expression defined in header, read using readPicture and written using writePicture.

flags is a string of single-character flags for this format. The only flag defined currently is T (upper case), so the only legal value for flags are "T" and the empty string. The "T" flag means that the picture file is a text file, and Qt should treat all newline conventions as equivalent. (XPM files and some PPM files are text files for example.)

format is used to select a handler to write a QPicture; header is used to select a handler to read an picture file.

If readPicture is a null pointer, the QPictureIO will not be able to read pictures in format. If writePicture is a null pointer, the QPictureIO will not be able to write pictures in format. If both are null, the QPictureIO object is valid but useless.

Example:

 void readSVG(QPictureIO *picture)
 {
     // read the picture using the picture->ioDevice()
 }

 void writeSVG(QPictureIO *picture)
 {
     // write the picture using the picture->ioDevice()
 }

     // add the SVG picture handler
     // ...

Before the regular expression test, all the 0 bytes in the file header are converted to 1 bytes. This is done because when Qt was ASCII-based, QRegExp could not handle 0 bytes in strings.

The regexp is only applied on the first 14 bytes of the file.

(Note that if one handlerIO supports writing a format and another supports reading it, Qt supports both reading and writing. If two handlers support the same operation, Qt chooses one arbitrarily.)

         QPictureIO iio;
         QPixmap  pixmap;
         iio.setFileName("vegeburger.pic");
         if (iio.read()) {        // OK
             QPicture picture = iio.picture();
             QPainter painter(&pixmap);
             painter.drawPicture(0, 0, picture);
         }

         QPictureIO iio;
         QPicture   picture;
         QPainter painter(&picture);
         painter.drawPixmap(0, 0, pixmap);
         iio.setPicture(picture);
         iio.setFileName("vegeburger.pic");
         iio.setFormat("PIC");
         if (iio.write())
             return true; // returned true if written successfully