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.
| QAbstractEventDispatcher | Manages Qt's event queue, excluding GUI-related events |
| QAction | Abstract user interface action that can be inserted into widgets with QWidget::addAction() |
| QActionGroup | Groups actions together |
| QApplication | Manages the GUI application's control flow and main settings |
| QCoreApplication | Event loop for Qt applications |
| QDockWindow | Widget that can be docked inside a QMainWindow or floated as a top-level window on the desktop |
| QMainWindow | Main application window |
| QMenu | Menu widget for use in menu bars, context menus, and other popup menus |
| QMenuBar | Horizontal menu bar |
| 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 that contains a set of controls |