widget-window

The class of all windows that implement dialog-items (also known as widgets or controls). The subclasses of this class are os-widget-window (for widgets that are provided by the underlying window system or operating system) and lisp-widget-window (for widgets that are implemented from scratch within Lisp). This class is not instantiable.

To create a widget, an application calls make-instance on a dialog-item class. When the dialog-item is added to a parent window (with add-component or with the :dialog-items argument to make-window), then an instance of the associated widget-window class is automatically created to implement the visible window of the widget. Calling the function window on the dialog-item will then return its associated widget-window. A widget-device method tells the dialog-item class which widget-window class to instantiate.

In releases prior to 7.0, the symbol widget-window named the class which is now called os-widget-window.

A diagram of window and widget classes is shown in Widget and window classes in cgide.htm.

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Created 2010.1.21.