Playing with {ggtext} and {epoxy}

tryout_epoxy

library(epoxy)
library(ggplot2)
library(ggtext)

# Creating an epoxy theme element
element_epoxy <- function(...) {
  el <- ggtext::element_markdown(...)
  class(el) <- union("element_epoxy", class(el))
  el
}

# Rendering the epoxy element is simply pulling the label through the epoxy
# function and forwarding it to element_markdown's element_grob method.
element_grob.element_epoxy <- function(element, label = "", ...) {
  label <- vapply(label, epoxy, character(1))
  NextMethod()
}

# Basic plot with epoxied x-axis
p <- ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  theme(axis.title.x.bottom = element_epoxy())

# Test plot
p + labs(x = "{.italic 'Engine Displacement'}")

# Helper function for setting span styles
span_style <- function(style) {
  force(style)
  function(x) paste0("<span style = '", style, "'>", x, "</span>")
}

# Set new transformers
epoxy_transform_set(
  .red     = span_style("color:red"),
  .blue    = span_style("color:blue"),
  .serif   = span_style("font-family:serif"),
  .papyrus = span_style("font-family:Papyrus")
)

# Using new transformers
p + labs(x = "{.red .serif 'Engine Displacement'}")
p + labs(x = "{.papyrus .blue 'Engine Displacement'}")

Rendered as a reprex with ragg device:

library(epoxy)
library(ggplot2)
library(ggtext)

# Creating an epoxy theme element
element_epoxy <- function(...) {
  el <- ggtext::element_markdown(...)
  class(el) <- union("element_epoxy", class(el))
  el
}

# Rendering the epoxy element is simply pulling the label through the epoxy
# function and forwarding it to element_markdown's element_grob method.
element_grob.element_epoxy <- function(element, label = "", ...) {
  label <- vapply(label, epoxy, character(1))
  NextMethod()
}

# Basic plot with epoxied x-axis
p <- ggplot(mpg, aes(displ, hwy)) +
  geom_point() +
  theme(axis.title.x.bottom = element_epoxy())

# Test plot
p + labs(x = "{.italic 'Engine Displacement'}")

# Helper function for setting span styles
span_style <- function(style) {
  force(style)
  function(x) paste0("<span style = '", style, "'>", x, "</span>")
}

# Set new transformers
epoxy_transform_set(
  .red     = span_style("color:red"),
  .blue    = span_style("color:blue"),
  .serif   = span_style("font-family:serif"),
  .papyrus = span_style("font-family:Papyrus")
)

# Using new transformers
p + labs(x = "{.red .serif 'Engine Displacement'}")

p + labs(x = "{.papyrus .blue 'Engine Displacement'}")

^{Created on 2023-10-06 with reprex v2.0.2}