Martin Friebe schrieb:

> - The public/shareable model would have to be ref-counted. Or explicit 
> ownership would need to be assigned and the owner would need to keep 
> track of all Shareholders.

The latter. The model must know about all views, to be notified of 
changes. This suggests a viewer chain, as used e.g. for Windows 
clipboard viewers.


> - The Model can be serialized. Special classes would to this work. 
> Therefore a model can be saved to one file, or to a set of files

A separation in multiple classes is dangerous, because changes to the 
model (number or type of values) had to be reflected in all related 
classes, in every project using that model.


> The it would only need an appropriate serialize class to save all of them.

Or an accordingly overwritten virtual method.


> The Model could also carry callback lists, so the anybody who needs to 
> know that it was loaded or saved could register a callback
>   Model.AddOnSerailizedCallback( AMethod )

The beforementioned list of view(er)s. When actions shall be monitored, 
then an implementation in the controller seems to make more sense to me.

DoDi

_______________________________________________
Lazarus mailing list
[email protected]
http://www.lazarus.freepascal.org/mailman/listinfo/lazarus

Reply via email to