--- Krasimir Angelov
The "on" function in the GIO doesn't mean write-only attribute. The "on" function converts Event to Attr
on :: Event w a -> Attr w a
The returned attribute is read/write. The following example explains this:
oldhanlder <- get button (on click) set button [on click =: f >> oldhandler]
or
set button [on click ~: \oldhandler -> f >> oldhandler]
I forget to note that the Events in the lates GIO version are optimised and in addition we have "off" function: off :: Event w a -> Prop w The following example unregister handler to the "click" event: set button [off click] This is equivalent to: set button [on click =: return ()] but under X and events like "mouse" and "keyboard" is more effective because the "off" function unregisters handlers in the X. Krasimir __________________________________________________ Do you Yahoo!? Yahoo! Tax Center - File online, calculators, forms, and more http://platinum.yahoo.com