[fpc-devel] Threads and alot of crap continued

[Michael Van Canneyt]

On Thu, 9 Nov 2006, Daniël Mantione wrote:

> 
> 
> Op Thu, 9 Nov 2006, schreef Florian Klaempfl:
> 
> > Michael Schnell schrieb:
> > > BTW.:
> > > 
> > > TPC comes with Free Vision.
> > > 
> > > The FPC IDE based on Free Vision seems to work fine.
> > > 
> > > The Free Vision "Non-GUI" seems to be event driven and thus needs to
> > > implement a kind of event scheduler.
> > 
> > It's an event handling loop using queues for input events. Very primitive :)
> 
> Hmmm... Actually I think event handling mechanism in FV is quite advanced. 
> 
> I.e. compare TV with VCL. In the VCL you define an event property 
> (i.e. key pressed) which gets magically called, and can modify the 
> methods in the object.
> 
> A first difference is that the event doesn't magically arrive at a 
> control, but is distributed by the event handler logic, which is 
> through overides completely under control of the programmer.
> 
> But I'm most impressed what happens when the event arrives at the right 
> view. In general, you don't start to modify fields directly, but a new 
> event is generated: a command. In effect, unlike the VCL, the program 
> logic is steered by commands, and not by direct events like mouse clicks.
> 
> Add to this the enable/disable system of commands. I.e. disable cmCut and all menu 
> bars, status bars, buttons, context menu's and whatever thing 
> that can generate a cmCut turns grey.
> 
> IMO it is still even today one of the best designed event systems and I 
> have to see a system that does it better...

At least the same exists in Delphi/lazarus. Just use actions.

Michael.