[Gambas-devel] Event design choice

[tobi]

Hi,

embarrassing but I want to ask for advice: Regarding Window and Screen class meaning spheres (Screen
being a terminal screen on which several Windows reside) in gb.ncurses, I already moved some and am
going to move other symbols from the former to the latter - yippi, the component is experimental! ;)
(this is entirely to unwind the whole sources and ease the addition of controls)
Seriously, I'm stuck at one point: the Window class raises a Read event when data arrives at the
input queue. Since there can be more Windows on one Screen which all share the same input queue (one
per screen), there must be a Window that is _solely explicitly_ allowed to raise that Read event, in
order to prevent concurrently raised events which will then issue, e.g., a blocking read call on the
input queue because the multiple instances steal each other input... - it was like what I mentioned
before this horror scenario and works.
As now the Screen class develops, it could be better to unwind that mess and let only the Screen
class raise a Read event, since there is one input queue per Screen - the point: simplification.
On the other side, we can have multiple event names for the numerous Windows and set focus (the
focused Window will raise Read event) on that one, we are currently operating on (think of: a dialog
box), that means if I do DialogWindow.SetFocus(), the DialogBox_Read() event will be risen instead
of the former, e.g., MainWindow_Read() event. That procedure could equally ease program flow for the
cautious programmer as well as it will create spaghetti code for the unexperienced one. (The
aforementioned effect could be achieved by using flags, too, of course...)

That's my dilemma now. Has anyone remarks on either solution that may help me decide? I wonder if
there could be a way to niftily implement a ShowModal() method...

Regards,
Tobi