[GUI] GUIs and events (was: Re: Concurrency)

Nick Name nick.name@inwind.it
Wed, 12 Mar 2003 19:21:24 +0100


On Wed, 12 Mar 2003 19:05:51 +0100
Wolfgang Thaller <wolfgang.thaller@gmx.net> wrote:

> 1a) Event loops may be nested, i.e. a callback, or (if proposal 2 is 
>  also accepted), any other IO action, may call a CGA function that
>  runs another event loop, e.g. for handling an application-modal
>  dialog (the main event loop won't handle events during that time).

I am sorry to make you repeat yourself, but I wish to understand it
well. Event loops may be nested, but: there will be a way to avoid that.
Is this what you are saying? There needs to be a way to make both a
callback and its parent window handle events simultaneously, even in
non-preemptive environments, without forkIO.

I hate when a dialog hangs a program (sometimes it happens to be popped
up in a wm layer lower than the application, guess what happens then),
seriously, so I need a way to code a program and be sure that, on any
implementation, callbacks will be handled properly even when there are
dialogs popped up.

I am sure that you are previewing this case and handling gracefully,
just want to understand how you would do it in a non preemptive
environment.

Vincenzo