Support autoformatting of ggrepel functions

[py9mrg]

Hello,

I was wondering how much hassle it would be to include support for the ggrepel functions? Obviously we can manually do this with something like:

  update_geom_defaults("text_repel",
                       list(family = "desired font", color = "desired color"))

and similar for label_repel. But if theme_xaringan() could do it for us that would be nice. I guess it shouldn't be too tricky to add a ggrepel = TRUE argument into theme_xaringan(), and whack in an if statement - but if it could automatically pick up any geoms that are text or label and then set those accordingly, that might be quite a convenient solution (for the user). Assuming there's no extension packages around that have those in their geom names - which could make this more hassle than it's worth! Here's an MWE of what I mean:

---
title: "Example"
output: html_document
---

knitr::opts_chunk$set(echo = TRUE)

library(ggplot2)
library(tidyverse)
library(xaringanthemer)
style_mono_accent(
  base_color = "#DC322F",               # bright red
  inverse_background_color = "#002B36", # dark dark blue
  inverse_header_color = "#31b09e",     # light aqua green
  inverse_text_color = "#FFFFFF",       # white
  title_slide_background_color = "var(--base)",
  text_font_google = google_font("Kelly Slab"),
  header_font_google = google_font("Oleo Script")
)

data <- tibble( 
  label = LETTERS[1:5],
  x = 1:5,
  y = (1:5)^2
)

p_text <- data %>%
  ggplot(aes(x = x, y = y, label = label)) +
  geom_text() +
  theme_xaringan()
p_text

library(ggrepel)

p_repel <- data %>%
  ggplot(aes(x = x, y = y, label = label)) +
  geom_text_repel() +
  theme_xaringan()
p_repel

[gadenbuie]

This seems reasonable. I think we could condition on testing if ggrepel is installed before setting the defaults. Thanks for the reprex!