From: David Vallner <david@...>
Date: 2006-02-10T05:26:16+09:00
Subject: Re: How to improve this kind of API?

Dňa Štvrtok 09 Február 2006 20:42 Lyle Johnson napísal:
> I'm looking to make an API change for some methods in FXRuby and would
> appreciate some suggestions about how to improve them. The pattern shows up
> in several places in the code, but it always boils down to some widget
> attribute that can have a combination of bit-flags. For example, the 4-way
> splitter window can be configured to expand only its top-left pane:
>
> splitter1.expanded = TOP_LEFT
>
> or to expand both the top left and top right panes:
>
> splitter2.expanded = TOP_LEFT | TOP_RIGHT
>
> And to check whether, say, the BOTTOM_LEFT pane is expanded:
>
> (splitter3.expanded & BOTTOM_LEFT) != 0
>
> Now, what I'm thinking of doing is replacing the symbolic constants with
> Ruby symbols, and doing something like this instead:
>
> splitter1.expand(:top_left)
> splitter2.expand(:top_left, :top_right)
>
> and then having checks like:
>
> splitter3.expanded? :bottom_left
>
> I think that in order to "turn off" one of those bits, I'm probably also
> going to need to add something like:
>
> splitter4.unexpand(:bottom_right)
>
> Now, the question is, is there some existing pattern in Ruby that this
> reminds you of? In other words, what is the Ruby Way to handle this kind of
> setting?
>
> Thanks in advance for your suggestions!
>
> Lyle

Looks fine to me. Personally I wish more GUI toolkits provided 
functions/methods like set_flag() and clear_flag() (or the even rarer 
explicit getters and setters for all applicable flags) that take flags that 
are to be changed instead having to futz around with unintuitive catch-all 
style flag fields and doing bitwise fandango all the time. Keep up the food 
work.

David Vallner