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QBitmap Class Reference
[com.trolltech.qt.gui module]

The QBitmap class provides monochrome (1-bit depth) pixmaps. More...

Inherits QPixmap.


Detailed 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, constructing QRegion objects, and for setting masks for pixmaps and widgets.

QBitmap is a QPixmap subclass ensuring a depth of 1, except for null objects which have a depth of 0. If a pixmap with a depth greater than 1 is assigned to a bitmap, the bitmap will be dithered automatically.

Use the QColor objects Qt::color0 and Qt::color1 when drawing on a QBitmap object (or a QPixmap object with depth 1).

Painting with Qt::color0 sets the bitmap bits to 0, and painting with Qt::color1 sets the bits to 1. For a bitmap, 0-bits indicate background (or transparent pixels) and 1-bits indicate foreground (or opaque pixels). Use the clear function to set all the bits to Qt::color0. Note that using the Qt::black and Qt::white colors make no sense because the QColor::pixel() value is not necessarily 0 for black and 1 for white.

The QBitmap class provides the transformed function returning a transformed copy of the bitmap; use the QMatrix argument to translate, scale, shear, and rotate the bitmap. In addition, QBitmap provides the static fromData() function which returns a bitmap constructed from the given uchar data, and the static fromImage function returning a converted copy of a QImage object.

Just like the QPixmap class, QBitmap is optimized by the use of implicit data sharing. For more information, see the {Implicit Data Sharing} documentation.

See also QPixmap, QImage, QImageReader, and QImageWriter.


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Qt Jambi 4.3.4_01