QBitmap(3qt)QBitmap(3qt)NAME
QBitmap - Monochrome (1-bit depth) pixmaps
SYNOPSIS
#include <qbitmap.h>
Inherits QPixmap.
Public Members
QBitmap ()
QBitmap ( int w, int h, bool clear = FALSE, QPixmap::Optimization
optimization = QPixmap::DefaultOptim )
QBitmap ( const QSize & size, bool clear = FALSE, QPixmap::Optimization
optimization = QPixmap::DefaultOptim )
QBitmap ( int w, int h, const uchar * bits, bool isXbitmap = FALSE )
QBitmap ( const QSize & size, const uchar * bits, bool isXbitmap =
FALSE )
QBitmap ( const QBitmap & bitmap )
QBitmap ( const QString & fileName, const char * format = 0 )
QBitmap & operator= ( const QBitmap & bitmap )
QBitmap & operator= ( const QPixmap & pixmap )
QBitmap & operator= ( const QImage & image )
QBitmap xForm ( const QWMatrix & matrix ) const
DESCRIPTION
The QBitmap class provides monochrome (1-bit depth) pixmaps.
The QBitmap class is a monochrome off-screen paint device used mainly
for creating custom QCursor and QBrush objects, in QPixmap::setMask()
and for QRegion.
A QBitmap is a QPixmap with a depth of 1. If a pixmap with a depth
greater than 1 is assigned to a bitmap, the bitmap will be dithered
automatically. A QBitmap is guaranteed to always have the depth 1,
unless it is QPixmap::isNull() which has depth 0.
When drawing in a QBitmap (or QPixmap with depth 1), we recommend using
the QColor objects Qt::color0 and Qt::color1. Painting with color0 sets
the bitmap bits to 0, and painting with color1 sets the bits to 1. For
a bitmap, 0-bits indicate background (or transparent) and 1-bits
indicate foreground (or opaque). Using the black and white QColor
objects make no sense because the QColor::pixel() value is not
necessarily 0 for black and 1 for white.
The QBitmap can be transformed (translated, scaled, sheared or rotated)
using xForm().
Just like the QPixmap class, QBitmap is optimized by the use of
implicit sharing, so it is very efficient to pass QBitmap objects as
arguments.
See also QPixmap, QPainter::drawPixmap(), bitBlt(), Shared Classes,
Graphics Classes, Image Processing Classes, and Implicitly and
Explicitly Shared Classes.
MEMBER FUNCTION DOCUMENTATIONQBitmap::QBitmap ()
Constructs a null bitmap.
See also QPixmap::isNull().
QBitmap::QBitmap ( int w, int h, bool clear = FALSE, QPixmap::Optimization
optimization = QPixmap::DefaultOptim )
Constructs a bitmap with width w and height h.
The contents of the bitmap is uninitialized if clear is FALSE;
otherwise it is filled with pixel value 0 (the QColor Qt::color0).
The optional optimization argument specifies the optimization setting
for the bitmap. The default optimization should be used in most cases.
Games and other pixmap-intensive applications may benefit from setting
this argument; see QPixmap::Optimization.
See also QPixmap::setOptimization() and
QPixmap::setDefaultOptimization().
QBitmap::QBitmap ( const QSize & size, bool clear = FALSE,
QPixmap::Optimization optimization = QPixmap::DefaultOptim )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Constructs a bitmap with the size size.
The contents of the bitmap is uninitialized if clear is FALSE;
otherwise it is filled with pixel value 0 (the QColor Qt::color0).
The optional optimization argument specifies the optimization setting
for the bitmap. The default optimization should be used in most cases.
Games and other pixmap-intensive applications may benefit from setting
this argument; see QPixmap::Optimization.
QBitmap::QBitmap ( int w, int h, const uchar * bits, bool isXbitmap = FALSE )
Constructs a bitmap with width w and height h and sets the contents to
bits.
The isXbitmap flag should be TRUE if bits was generated by the X11
bitmap program. The X bitmap bit order is little endian. The QImage
documentation discusses bit order of monochrome images.
Example (creates an arrow bitmap):
uchar arrow_bits[] = { 0x3f, 0x1f, 0x0f, 0x1f, 0x3b, 0x71, 0xe0, 0xc0 };
QBitmap bm( 8, 8, arrow_bits, TRUE );
QBitmap::QBitmap ( const QSize & size, const uchar * bits, bool isXbitmap =
FALSE )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Constructs a bitmap with the size size and sets the contents to bits.
The isXbitmap flag should be TRUE if bits was generated by the X11
bitmap program. The X bitmap bit order is little endian. The QImage
documentation discusses bit order of monochrome images.
QBitmap::QBitmap ( const QBitmap & bitmap )
Constructs a bitmap that is a copy of bitmap.
QBitmap::QBitmap ( const QString & fileName, const char * format = 0 )
Constructs a bitmap from the file fileName. If the file does not exist
or is of an unknown format, the bitmap becomes a null bitmap.
The parameters fileName and format are passed on to QPixmap::load().
Dithering will be performed if the file format uses more than 1 bit per
pixel.
See also QPixmap::isNull(), QPixmap::load(), QPixmap::loadFromData(),
QPixmap::save(), and QPixmap::imageFormat().
QBitmap & QBitmap::operator= ( const QBitmap & bitmap )
Assigns the bitmap bitmap to this bitmap and returns a reference to
this bitmap.
QBitmap & QBitmap::operator= ( const QPixmap & pixmap )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Assigns the pixmap pixmap to this bitmap and returns a reference to
this bitmap.
Dithering will be performed if the pixmap has a QPixmap::depth()
greater than 1.
QBitmap & QBitmap::operator= ( const QImage & image )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Converts the image image to a bitmap and assigns the result to this
bitmap. Returns a reference to the bitmap.
Dithering will be performed if the image has a QImage::depth() greater
than 1.
QBitmap QBitmap::xForm ( const QWMatrix & matrix ) const
Returns a transformed copy of this bitmap by using matrix.
This function does exactly the same as QPixmap::xForm(), except that it
returns a QBitmap instead of a QPixmap.
See also QPixmap::xForm().
SEE ALSO
http://doc.trolltech.com/qbitmap.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
located at $QTDIR/doc/html and can be read using Qt Assistant or with a
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who prefer man pages, although this format is not officially supported
by Trolltech.
If you find errors in this manual page, please report them to qt-
bugs@trolltech.com. Please include the name of the manual page
(qbitmap.3qt) and the Qt version (3.3.8).
Trolltech AS 2 February 2007 QBitmap(3qt)