Re: Event mechanisms for GUI's

["Lucretia" <lucretia9@lycos.co.uk>]

On Oct 19, 9:18 pm, "Jeffrey R. Carter"
<spam.not.jrcar...@acm.not.spam.org> wrote:
>>That seems overly complicated. Something like
>
> type Window_ID is ...;
>
> type Widget_ID is ...;
>
> type Event_ID is
>     (Close, Left_Click, Middle_Click, Right_Click, Double_Click, ...);
>
> type Event_List is array (Positive range <>) of Event_ID;
>
> type Event_Set is private;
>
> function Make (List : Event_List) return Event_Set;
>
> procedure Add (To : in Window_ID; Event : in Event_ID);
> procedure Remove (From : in Window_ID; Event : in Event_ID);
>
> procedure Add (To : in Window_ID; Set : in Event_Set);
> procedure Remove (From : in Window_ID; Set : in Event_Set);
>
> function Event_Pending (Window : Window_ID) return Boolean;
> procedure Get (Event : out Event_ID; Widget : out Widget_ID);

What exactly are you adding or removing from the window_id?

This also seems a bit more procedural, rather than using the more
natural OO way. Remember, in Ada you use what applies and is more
natural, a GUI is inherently OO.

Thanks,.
Luke.