[RQt-devel] a couple of minor things

[Michael Lawrence]

On Fri, Sep 17, 2010 at 6:15 AM, Michael Lawrence <michafla at gene.com> wrote:

>
>
> On Fri, Sep 17, 2010 at 4:39 AM, Deepayan Sarkar <
> deepayan.sarkar at gmail.com> wrote:
>
>> Hi,
>>
>> A couple of low-priority things that might be nice to have:
>>
>> (1) In dealing with images, Qt used unsigned int for colors.
>>
>> > qimg <- Qt$QImage(100, 100, Qt$QImage$Format_ARGB32_Premultiplied)
>> > qimg$fill(0L)
>> > qimg$pixel(40, 50)
>> [1] 0
>>
>> Is there an easy way to implement conversion to/from R colors? (Maybe
>> through R color <-> R integer <-> unsigned int.)
>>
>>
> For images, I was thinking we could have a converter between QImage and R
> images stored as matrices (as used by graphics devices in recent versions of
> R). Any pixel-wise manipulation of images from R would be too slow in
> general.
>
> Btw, there is already conversion between QColor and the output of
> col2rgb(), using qcol2rgb() and qcolor().
>
>  (2) QByteArrays are almost like strings, and used in various places. E.g.,
>>
>> > Qt$QImageReader$supportedImageFormats()
>> Error in qinvokeStatic(cl, name, ...) :
>>  Attempt to create SmokeObject with NULL class
>>
>
In latest svn:

> sapply(Qt$QImageReader$supportedImageFormats(), rawToChar)
 [1] "bmp"  "gif"  "ico"  "jpeg" "jpg"  "pbm"  "pgm"  "png"  "ppm"  "svg"
[11] "xbm"  "xpm"



> > Qt$QByteArray()
>> NULL
>>
>>
> Qt$QByteArray()
raw(0)



> Is there a risk in allowing the conversion?
>>
>
>
> The above looks like a bug. QByteArray is supposed to be converted to a raw
> vector (closest R equivalent in my opinion, as QByteArray has no notion of
> locale, etc), which is then easily converted to a string if necessary with
> rawToChar().
>
>
>> -Deepayan
>> _______________________________________________
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>> Qtinterfaces-devel at lists.r-forge.r-project.org
>>
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>>
>
>
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