The QStyle class is an abstract base class that encapsulates the look and feel of a GUI.| doc.qt.io
The QSize class defines the size of a two-dimensional object using integer point precision.| doc.qt.io
The QRect class defines a rectangle in the plane using integer precision.| doc.qt.io
The QPaintEvent class contains event parameters for paint events.| doc.qt.io
The QMargins class defines the four margins of a rectangle.| doc.qt.io
The QWidget class is the base class of all user interface objects.| doc.qt.io
The QObject class is the base class of all Qt objects.| doc.qt.io
The Qt namespace contains miscellaneous identifiers used throughout the Qt library.| doc.qt.io
The QPainter class performs low-level painting on widgets and other paint devices.| doc.qt.io
The QLayout class is the base class of geometry managers.| doc.qt.io