[RQt-devel] Question about Qt$QComboBox in qtbase

[John Verzani]

Thanks Michael. WIll check it out. Yes, I definitely miss rGtkDataFrame for
qtbase. My gWidgetsQt versions that use the table widget are really slow
even for moderately sized data sets. --John

On Wed, Apr 14, 2010 at 1:11 PM, Michael Lawrence <lawrence.michael at gene.com
> wrote:

> Alright, I think it's fixed in svn. Was deleting the QStandardItem, even
> though Qt owned it (in the model). Unfortunately, Qt has fairly ad-hoc
> memory ownership policies compared to GTK+.
>
> Also, in this simple case, you might find cb$insertItem(i-1, letters[i]) to
> be easier than explicitly creating the QStandardItem.
>
> At some point we will need vectorized functions for populating data models
> like rGtkDataFrame.
>
> Michael
>
>
> On Wed, Apr 14, 2010 at 9:48 AM, Michael Lawrence <michafla at gene.com>wrote:
>
>>
>>
>> On Wed, Apr 14, 2010 at 7:41 AM, John Verzani <verzani at math.csi.cuny.edu>wrote:
>>
>>> I am having trouble consistently getting a combobox to behave properly.
>>> In particular, with this test case I rarely get past 40 before the process
>>> dies. Am I setting up the combobox completely wrong? (I've tried  using
>>> setItemText but that failed as well and I don't think my issue is having so
>>> many widgets open.)
>>>
>>>
>>> library(qtbase)
>>>
>>> testit <- function(i) {
>>>   cb <- Qt$QComboBox()
>>>   mod <- cb$model()
>>>
>>>   ## set values
>>>   sapply(seq_along(letters), function(i) {
>>>     item <- Qt$QStandardItem(letters[i])
>>>     mod$setItem(i-1, item)
>>>   })
>>>
>>>   cb$setCurrentIndex(2)
>>>   cat(i, cb$model()$item(2)$text(), "\n")
>>> }
>>>
>>>
>>> ##
>>> for(i in 1:1000) {
>>>   out <- try(testit(i), silent=TRUE)
>>>   if(inherits(out, "try-error")) {
>>>     print(i)
>>>     stop(i)
>>>   }
>>> }
>>>
>>> ## eventually dies but not consistently, e.g:
>>> ...
>>> 8 c
>>> [1] 9
>>> Error in eval.with.vis(expr, envir, enclos) :
>>>   Error in cat(i, cb$model()$item(2)$text(), "\n") :
>>>   attempt to apply non-function
>>>
>>> (Basically what happens is all items in the model are set to NULL, so the
>>> call to the text method fails.)
>>>
>>>
>> Yea it looks like corruption somewhere. No idea where though, will have to
>> look into it.
>>
>> Thanks,
>> Michael
>>
>>
>>>
>>> > sessionInfo()
>>> R version 2.10.1 (2009-12-14)
>>> i486-pc-linux-gnu
>>>
>>> locale:
>>> [1] en_US.UTF-8
>>>
>>> attached base packages:
>>> [1] stats     graphics  grDevices utils     datasets  methods   base
>>>
>>> other attached packages:
>>> [1] qtbase_0.6-2
>>>
>>> --
>>> John Verzani
>>> Chair, Department of Mathematics
>>> College of Staten Island, CUNY
>>> verzani at math.csi.cuny.edu
>>>
>>> _______________________________________________
>>> Qtinterfaces-devel mailing list
>>> Qtinterfaces-devel at lists.r-forge.r-project.org
>>>
>>> https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/qtinterfaces-devel
>>>
>>>
>>
>


-- 
John Verzani
Chair, Department of Mathematics
College of Staten Island, CUNY
verzani at math.csi.cuny.edu
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