On Sat, Jan 29, 2011 at 1:44 AM, Philippe Lhoste <[email protected]> wrote:
> On 29/01/2011 10:26, calathus wrote:
>
>> When we write GUI application in Java, the most important part is GUI
>> application logic (description of user interaction), not layout.
>> So we don't want to bother with layout in Java code level, also some GUI
>> object should be determined by the data type used in the application.
>> For instance, if type is boolean, we may want to map to check box etc.
>> And if we want to change these data type, we should not have to modify
>> the layout(most of case) file.
>>
>
> I agree with most, but not all. I think all GUI should be described in
> separate files, indeed, with no logic in it (or, at best/worst, only code
> pertaining to GUI logic).
> But the leafs must be part of this description: if the type is boolean, the
> GUI designer can choose to implement it with radio buttons, combo box or
> even a list, if they need/want it. It is not a concern of the code.
>
I think some missing ingredient here was the systematic default
specification mechanism like CSS in HTML.
If we start modifying layout for customized GUI object, the layout files are
going to depend on data type.
for instance, if the GUI object is specified as check box, and later the
data type is changed to String or enumerated type, such GUI object is no
longer appropriate. Or we may need to go through all layout files to change
to appropriate GUI object.
Also many cases, systematic use or default for bold or color is important to
have nice look and feel. if it has css like another file shared among
several layout files, we can achieve this easily. Definitely BXML can
introduce such idea also(we may calll it BCSS).
More concretely, CSS like pattern matching and some grouping by name('class'
in CSS, but confusing in programming language), identification with id can
be used here as well as the structure based pattern if we map the structure
in XML(but may not be so important).
For instance if some <bxml:ref =abc /> is mapped to list from checkbox, it
can overwrite the mapping by:
abc => checkbox
groupA => checkbox
Most of case, these mapping will be done based on associated data type, but
it cab be overridden by BCSS file.
Basically, this will achieve the goal to eliminate data related information
from layout, and layout related information from application logic(Java).
>
> I agree fully with the concept of separating code and GUI, and there are
> several approaches for that. Martin Fowler made a series of articles
> covering pros and cons of such approaches: some designs are better suited to
> low level machinery (control design), others are better for higher level GUI
> design, with one or the other allowing better testing (replacing with mock
> objects), and so on.
>
> I wonder if Visage could be used for designing GUIs for Pivot. I haven't
> looked at its design recently, if it needs a library bigger than Pivot, it
> might not be worth the effort... ;-)
>
>
> --
> Philippe Lhoste
> -- (near) Paris -- France
> -- http://Phi.Lho.free.fr
> -- -- -- -- -- -- -- -- -- -- -- -- -- --
>
--
Cheers,
calathus
