Theme element: draw labels as icons

A theme element parallel to ggplot2::element_text(), for use in axis.text, strip.text, legend.text, and similar theme settings. Any label matching a name in icons is drawn as that icon; every other label falls back to plain element_text() drawing.

Usage

element_icon(
  icons = NULL,
  ...,
  size = NULL,
  colour = NULL,
  inherit.blank = FALSE
)

Arguments

icons

A named list() of icon objects (see Details), or NULL (the default) to disable icon substitution.

...

Other arguments passed on to ggplot2::element_text().

size

Point size for text, and the point width/height for icons.

colour

Colour for text, and the fill colour for icons.

inherit.blank

See ggplot2::element_text().

Value

An element_icon object: a subclass of element_text (itself a ggplot2 theme element), for use in ggplot2::theme().

Details

icons is a named list() of individual, length-1 icons, one entry per label to replace:

element_icon(icons = list(
  low = icons::fontawesome$solid$`battery-quarter`,
  high = icons::fontawesome$solid$`battery-full`
))

See also

geom_icon()

Examples

library(ggplot2)

# bundled placeholder shapes; a real pack (e.g. icons::fontawesome) works the same
shapes <- icons::icon_set(system.file("icons", package = "ggicons"))
cyl_icons <- list(
  `4` = shapes$circle,
  `6` = shapes$square,
  `8` = shapes$triangle
)

ggplot(mtcars, aes(factor(cyl), mpg)) +
  geom_boxplot() +
  theme(axis.text.x = element_icon(icons = cyl_icons, size = 14))
#> Error in loadNamespace(x): there is no package called ‘grImport2’

# a real icon pack (here, Font Awesome) works the same way
battery <- list(
  `4` = icons::fontawesome$solid$`battery-quarter`,
  `6` = icons::fontawesome$solid$`battery-half`,
  `8` = icons::fontawesome$solid$`battery-full`
)

ggplot(mtcars, aes(factor(cyl), mpg)) +
  geom_boxplot() +
  theme(axis.text.x = element_icon(icons = battery, size = 14))
#> Error in loadNamespace(x): there is no package called ‘grImport2’