5.3 DUIM-Sheets Module
handle-event
Generic function
Summary
Implements any defined policies of the specified sheet with respect to the specified event.
Signature
handle-event sheet event => ()
Arguments
Values
None
Library
duim-sheets
Module
duim-sheets
Description
Implements any defined policies of sheet with respect to event. Methods defined on this generic are called by DUIM to do the handling.
For example, to highlight a sheet in response to an event that informs the sheet when the pointer has entered the region it occupies, there should be a method to carry out the policy that specializes the appropriate sheet and event classes.
DUIM itself implements no semantically meaningful handle-event methods; It is the responsibility of any application to implement all of its own handle-event methods. It is also the responsibility of the application to decide the protocol and relationship between all of these methods.
Take care when adding next-method() calls in any handle-event methods that you write. Because DUIM itself supplies no built-in methods, you must ensure that you have supplied a valid method yourself. For each event class you are handling, you should decide whether a call to next-method is actually required.