11.5. Graphical UI Toolkits
While the SDL API is easier to use than the framebuffer interface, it is not, in itself, a convenient library for developing a GUI. SDL supports event handling and graphics, but the two are only loosely coupled. When building a GUI, we use objects for which the display and the input mechanism are inherently connected. Examples include scroll bars, drop-down menus, and text-entry forms. GUI toolkits support GUI development by providing a collection of these objects (widgets). Figure 11-9 illustrates the relationships between a widget, a user, and the underlying application.