The QIODevice class is the base interface class of all I/O devices in Qt.| doc.qt.io
The QPicture class is a paint device that records and replays QPainter commands.| doc.qt.io
The QRect class defines a rectangle in the plane using integer precision.| doc.qt.io
The header file includes Qt fundamental type declarations.| doc.qt.io
The QPainter class performs low-level painting on widgets and other paint devices.| doc.qt.io
Reference counting for fast copying.| doc.qt.io
The QString class provides a Unicode character string.| doc.qt.io