transparent theme

NAMESPACE

@@ -683,6 +683,7 @@ export(theme_minimal)
 export(theme_replace)
 export(theme_set)
 export(theme_test)
+export(theme_transparent)
 export(theme_update)
 export(theme_void)
 export(transform_position)

NEWS.md

@@ -155,6 +155,8 @@ precedence between `bins` and `binwidth`. (@eliocamp, #4651)
 
 * Updated documentation for `geom_smooth()` to more clearly describe effects of the 
   `fullrange` parameter (@thoolihan, #4399).
+
+* Added `theme_transparent()` with transparent backgrounds. 
 
 # ggplot2 3.3.6
 This is a very small release only applying an internal change to comply with 

R/theme-defaults.r

@@ -671,3 +671,34 @@ theme_all_null <- function() {
   args <- c(elements, list(complete = TRUE))
   inject(theme(!!!args))
 }
+
+#' @export
+#' @rdname ggtheme
+theme_transparent <- function(base_size = 11, base_family = "",
+                              base_line_size = base_size / 22,
+                              base_rect_size = base_size / 22) {
+  # Based on theme_bw
+  theme_grey(
+    base_size = base_size,
+    base_family = base_family,
+    base_line_size = base_line_size,
+    base_rect_size = base_rect_size
+  ) %+replace%
+    theme(
+      panel.background  = element_blank(),
+      plot.background   = element_blank(),
+      legend.background = element_blank(),
+      legend.key        = element_blank(),
+      # theme_bw specifications
+      panel.border      = element_rect(fill = NA, colour = "grey20"),
+      # make gridlines dark, same contrast with white as in theme_grey
+      panel.grid        = element_line(colour = "grey92"),
+      panel.grid.minor  = element_line(linewidth = rel(0.5)),
+      # contour strips to match panel contour
+      strip.background  = element_rect(fill = "grey85", colour = "grey20"),
+
+      complete = TRUE
+    )
+}
+
+

tests/testthat/test-theme.r

@@ -328,6 +328,7 @@ test_that("all elements in complete themes have inherit.blank=TRUE", {
   expect_true(inherit_blanks(theme_linedraw()))
   expect_true(inherit_blanks(theme_minimal()))
   expect_true(inherit_blanks(theme_void()))
+  expect_true(inherit_blanks(theme_transparent()))
 })
 
 test_that("elements can be merged", {
@@ -477,6 +478,9 @@ test_that("provided themes explicitly define all elements", {
 
   t <- theme_test()
   expect_true(all(names(t) %in% elements))
+
+  t <- theme_transparent()
+  expect_true(all(names(t) %in% elements))
 })
 
 test_that("Theme elements are checked during build", {
@@ -538,6 +542,7 @@ test_that("themes don't change without acknowledgement", {
   expect_doppelganger("theme_light", plot + theme_light())
   expect_doppelganger("theme_void", plot + theme_void())
   expect_doppelganger("theme_linedraw", plot + theme_linedraw())
+  expect_doppelganger("theme_transparent", plot + theme_transparent())
 })
 
 test_that("themes look decent at larger base sizes", {
@@ -554,6 +559,7 @@ test_that("themes look decent at larger base sizes", {
   expect_doppelganger("theme_light_large", plot + theme_light(base_size = 33))
   expect_doppelganger("theme_void_large", plot + theme_void(base_size = 33))
   expect_doppelganger("theme_linedraw_large", plot + theme_linedraw(base_size = 33))
+  expect_doppelganger("theme_transparent", plot + theme_transparent(base_size = 33))
 })
 
 test_that("axes can be styled independently", {