refreshing the GUI

James LewisMoss
29 Nov 2000 15:01:25 -0500

>>>>> On Wed, 29 Nov 2000 11:11:33 -0800, Dave Peticolas <> said:

 Dave> James LewisMoss writes:
 >> >>>>> On Wed, 29 Nov 2000 01:59:22 -0800, Dave Peticolas
 >> >>>>> <> sa
 >> id:
 Dave> Design ------
 Dave> The refresh mechanism will be designed in two parts, an engine
 Dave> component and a GUI component. The engine component will be a
 Dave> simple change callback mechanism, while the GUI component will
 Dave> be a GUI entity manager that includes refresh management, as
 Dave> well as other functionality.
 >> So a change to data occurs.  The engine has a registered listener
 >> in the GUI Component Manager that it calls to say something has
 >> changed.  What happens then?

 Dave> Refreshing is controlled by gnc_suspend_gui_refresh()
 Dave> gnc_resume_gui_refresh(), and gnc_gui_refresh_all().

 Dave> The first two are used as a pair:

 Dave> gnc_suspend_gui_refresh ()

 Dave> ... perform some changes, edit accounts, transactions, etc. ...
 Dave> ... no refresh callbacks occur during this period ...

 Dave> gnc_resume_gui_refresh () /* This causes the refresh callbacks
 Dave> to
 Dave>                              be invoked for all the registered
 Dave>                              components with the changes that
 Dave>                              ocurred above. */

Hash table of changes.  If gnc_suspend_gui_refresh isn't called the
refresh callbacks get called for each change?

 Dave> The last is used when doing very large amounts of changes, for
 Dave> which it would just be simpler to refresh everything:

 Dave> gnc_engine_suspend_change_callbacks () /* turn off engine
 Dave> callbacks */

 Dave> ... destroy all entities ...  ... load new ones from file ...

 Dave> gnc_engine_resume_change_callbaks ()

 Dave> gnc_gui_refresh_all () /* force all components to refresh
 Dave> unconditionally */

So the engine calls this in the CM?  Better to have another callback

 >> I'm trying to figure out what the close, find and iteration
 >> callbacks are meant to do and who registers with who.

 Dave> The close callback is for closing the gui component. The CM is
 Dave> meant to be more than just a refresh manager.

Is this the introduction of the CM?  What else will it do?  So when
the CM decides a component should close it calls the close callback on
the componont?  When the component closes it calls the close callback?

Are all components required to register with the CM?

 Dave> The find callback is so components can find related components
 Dave> in the same class (for example, if the user opens and already
 Dave> open account, the existing window should be raised instead of
 Dave> opening a new one).

Ah.  Hmm.  Seems you are including two things here.

1) Data update callbacks.
2) Component management.

That accurate?

 Dave> The iteration is to aid component management. Right now, it
 Dave> will mainly be used in conjunction with the close operation,
 Dave> but there could be additional uses in the future.

Still confused here.


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