Arguments: dialog-item
Performs what might be called "MS subclassing" on the window of dialog-item. This has nothing to do with CLOS classes, but rather causes lisp to intercept all low-level messages that are sent to widget windows and are normally handled within the Windows operating system where these widgets are implemented. All low-level Windows events for dialog-item will be passed to the pc:control-procedure generic function. In addition, the keypress and mouse-click events will call an event method for the dialog-item's window and that event.
You need to call subclass-widget only if you want to handle these
low-level Windows events that are usually handled by MS-Windows
internally. For example, when a user types a new value into an
(single-line) editable-text widget, you normally know
only what the new string and the old string are; if you want to know
what actual key was pressed, then you will need to call
subclass-widget and then write an event method on the window to handle
the keypress event. Or you may want to intercept a mouse click on a
widget even when its value is not changed by the click.
If subclass-window is called on a window that is already subclassed,
no action is taken and nil is returned,
otherwise t is returned.
Common Graphics and IDE documentation is described in About Common Graphics and IDE documentation in cgide.htm.
The documentation is described in introduction.htm and the index is in index.htm.
Copyright (c) 1998-2000, Franz Inc. Berkeley, CA., USA. All rights reserved.
Created 2000.10.5.