Consistently use element_grob() or element_render() instead of textGrob()

[clauswilke]

There are a few cases where we call textGrob() directly instead of element_grob() or element_render(). Ideally, we should eliminate all of them. Here is a list of cases I'm currently aware of. There may be more. Reprexes will follow below.

• Axis text for non-standard axis position (e.g., x axis on top)
• Facet labels when using facet_wrap()
• Facet labels when using facet_grid()

(Checkmark means the issue has been addressed.)

[clauswilke]

Axis text for non-standard axis position was first reported here: wilkelab/ggtext#5 But now that I'm thinking about it, I think it works fine, so I'll check it off as Ok.

[clauswilke]

Facet labels when using facet_wrap(). First reported here: wilkelab/ggtext#2

library(tidyverse)
library(ggtext)
library(glue)
#> 
#> Attaching package: 'glue'
#> The following object is masked from 'package:dplyr':
#> 
#>     collapse

count(mtcars, cyl, carb) %>% 
  mutate(cyl_lab = as.character(
    glue("Cylinders {cyl} <span style='color:red'>(n={n})</span>")
  )) %>% 
  ggplot(aes(carb, n)) +
  geom_col() +
  facet_wrap(~cyl_lab) +
  theme(
    strip.text = element_markdown(),
    strip.text.x = element_markdown(),
    strip.text.y = element_markdown()
  )

^{Created on 2019-10-07 by the reprex package (v0.3.0)}

@hrbrmstr Anything you'd like to add?

[clauswilke]

The same problem exists in facet_grid().

library(tidyverse)
library(ggtext)
library(glue)
#> 
#> Attaching package: 'glue'
#> The following object is masked from 'package:dplyr':
#> 
#>     collapse

count(mtcars, cyl, carb) %>% 
  mutate(cyl_lab = as.character(
    glue("Cylinders {cyl} <span style='color:red'>(n={n})</span>")
  )) %>% 
  ggplot(aes(carb, n)) +
  geom_col() +
  facet_grid(~cyl_lab) +
  theme(
    strip.text = element_markdown(),
    strip.text.x = element_markdown(),
    strip.text.y = element_markdown()
  )

^{Created on 2019-10-07 by the reprex package (v0.3.0)}

[clauswilke]

Tagging this for the 3.3.0 milestone, with the understanding that it may not be possible to complete by then.

[z3tt]

For me rendered facet labels work, boxes could be checked. Thanks once again for this wonderful package!