[R-gui] Automatic Widget Creation and Callbacks in RGtk

[Neil E. Klepeis]

Thanks Michael,

I'd switch to RGtk2 except I recall the dependency is Gtk 2.8.0.

Even though the Gtk 1.2 API states that gtkObjectSetData/GetData are 
available, I can't get them to work with Scale widgets in RGtk, e.g. 
with w$SetData("key", value).   Are these only available with RGtk2?

Anyway, I guess I'll stick with looping over all the widgets until I can 
upgrade to RGtk2.    You're right that it probably won't be too bad.

Thanks for RGtk2!

Neil


Michael Lawrence wrote:
> 
> 
>> I can't seem to find any way to send a character string of the 
>> appropriate arbitrary widget name to the callback function so that I 
>> can put the widget value into the parameter list.   I've tried setting 
>> an attribute of the widget with its associated parameter name when I 
>> create the callback, but the attribute seems to disappear when the 
>> callback is called.
>>
>>   
> 
> How about passing the parameter name as the "user data" to the callback.
> Like:
> 
> gSignalConnect(widget, "value-changed", fun, parameter_name)
> 
> Then that string is passed as the last parameter to 'fun'.
> Then you can update your global data structure.
> 
> Note: the code above is for RGtk2, but it looks like you're using the 
> old RGtk for GTK+ 1.2.
> Why not upgrade? http://www.ggobi.org/rgtk2
> 
> You could also use gObjectSetData() like widget$setData("param-name", 
> param_name)
> Then widget$getData("param-name") to get it back out.
> 
>> I can get around all this whole problem by simply looping through all 
>> of the widgets at once by name:
>>
>> for (i in widget.names) params[[i]] <- get(i)$GetValue()
>>
>> but this approach is inefficient when only one parameter is changed at 
>> a time.
>>

> 
> Are you sure this is that inefficient? How many widgets do you have per 
> GUI? This would be the simplest way to do it.
> 
> Michael