Added Use as Numeric and Display as Factor checkboxes to Graphics dialog

[MeSophie]

Fixes #8428
@rdstern , @N-thony I added Use as Numeric and Display as Factor checkbox on Graphics dialog. Please check it.

[rdstern]

@MeSophie I think this change is easier than the code we started with. I need to check with @lilyclements, but suggest you keep the first checkbox and call it Group (or Group X - I am not sure. The second checkbox and code is deleted.
Then I show the code you had, and my change, which I prefer - found it on stack overflow of course!
Adding the group parameter does all we need!

# Dialog: Graphics

survey <- data_book$get_data_frame(data_name="survey")
##last_graph <- ggplot2::ggplot(data=survey, mapping=ggplot2::aes(x=as.numeric(variety), y=yield)) + ggplot2::geom_line() + theme_grey()
last_graph <- ggplot2::ggplot(data=survey, mapping=ggplot2::aes(x=variety,group=1, y=yield)) + ggplot2::geom_line() + theme_grey()
data_book$add_object(data_name="survey", object_name="last_graph", object_type_label="graph", object_format="image", object=check_graph(graph_object=last_graph))
data_book$get_object_data(data_name="survey", object_name="last_graph", as_file=TRUE)
rm(list=c("last_graph", "survey"))

I have also made a new issue, on further possible improvements for this dialog, and suggest we now close this one, once this small change is merged.

[MeSophie]

I think this change is easier than the code we started with. I need to check with @lilyclements, but suggest you keep the first checkbox and call it Group (or Group X - I am not sure. The second checkbox and code is deleted.
Then I show the code you had, and my change, which I prefer - found it on stack overflow of course!
Adding the group parameter does all we need!

@rdstern I notice also that on your code you added geom_line. Will this geom_line function be added at the same time as the group parameter when the box is ticked?

[MeSophie]

@rdstern Please can you check the new change.

[rdstern]

@MeSophie this works, but the group=1 is added at the wrong time. If I do group before chooseing the geom, then it doesn't add group=1 into the code. If I untick, after getting the geom, and then tick again, it is fine. The action of ticking should add the code group=1 whatevwer the geom.

[MeSophie]

@rdstern I think it is okay now.

[rdstern]

@MeSophie this looks fine now. @lloyddewit there is more to improve on this dialog, but I would be happy to see this merged first. And the corresponding issue can then be closed.

[lloyddewit]

@MeSophie looks good, just a couple of small suggestions

[lloyddewit]

@rdstern if you can retest/approve, then we can merge, thanks

[rdstern]

@lloyddewit this still looks fine