Question

These classes provide everything you need for a typical modern main application window, like the main window itself, menu and tool bars, a statusbar, etc.

QAction	Abstract user interface action that can appear both in menus and tool bars
QActionGroup	Groups actions together
QApplication	Manages the GUI application's control flow and main settings
QDockArea	Manages and lays out QDockWindows
QDockWindow	Widget which can be docked inside a QDockArea or floated as a top level window on the desktop
QMainWindow	Main application window, with a menu bar, dock windows (e.g. for toolbars), and a status bar
QMenuBar	Horizontal menu bar
QPopupMenu	Popup menu widget
QSessionManager	Access to the session manager
QSizeGrip	Corner-grip for resizing a top-level window
QStatusBar	Horizontal bar suitable for presenting status information
QToolBar	Movable panel containing widgets such as tool buttons
QWorkspace	Workspace window that can contain decorated windows, e.g. for MDI