A GUI displays text as well as small images (called icons) that represent objects such as folders, files of different types, command buttons, and drop-down menus. In addition to entering text at the keyboard, the user of a GUI can select some of these icons with a pointing device, such as a mouse, and move them around on the display. Commands can be activated by pressing the enter key or control keys, by pressing a command button, by selecting a drop-down menu item, or by double-clicking on some icons with the mouse. Put more simply, a GUI displays all information, including text, graphically to its users and allows them to manipulate this information directly with a pointing device
It provide basic functionality for any window, such as the command buttons in the title bar.
| Term | Definition |
|---|---|
| Widget | A graphical element such as a button, textbox, or label that users can interact with. Widgets are the building blocks of GUI applications. |
| Window | A graphical container that holds one or more widgets. It provides a visual interface for the user to interact with the application. |
| Event | A signal generated by user actions such as clicking a button, typing in a textbox, or moving the mouse. GUI applications respond to these events by executing predefined actions or functions. |
| Layout Manager | Responsible for arranging widgets within a window. It determines the position and size of each widget to achieve a desired layout. |
| Callback Function | A function that is executed in response to an event. It is typically associated with a specific widget and is triggered when the widget generates a particular event. |
| Main Loop | The fundamental concept in GUI programming. It continuously listens for events and dispatches them to the appropriate event handlers, ensuring that the GUI remains responsive to user input. |