don't rely on element$prop

Author: teunbrand

R/save.R

@@ -103,7 +103,9 @@ ggsave <- function(filename, plot = get_last_plot(),
     limitsize = limitsize, dpi = dpi)
 
   if (is_null(bg)) {
-    bg <- calc_element("plot.background", plot_theme(plot))$fill %||% "transparent"
+    bg <- calc_element("plot.background", plot_theme(plot))
+    bg <- if (S7::prop_exists(bg, "fill")) bg@fill else NULL
+    bg <- bg %||% "transparent"
   }
   old_dev <- grDevices::dev.cur()
   dev(filename = filename, width = dim[1], height = dim[2], bg = bg, ...)

R/theme.R

@@ -779,15 +779,22 @@ calc_element <- function(element, theme, verbose = FALSE, skip_blank = FALSE,
 
   # Calculate the parent objects' inheritance
   if (verbose) cli::cli_inform("{pnames}")
+
+  # once we've started skipping blanks, we continue doing so until the end of the
+  # recursion; we initiate skipping blanks if we encounter an element that
+  # doesn't inherit blank.
+  skip_blank <- skip_blank ||
+    (!is.null(el_out) &&
+       !isTRUE(S7::S7_inherits(el_out) &&
+               S7::prop_exists(el_out, "inherit.blank") &&
+               el_out@inherit.blank))
+
   parents <- lapply(
     pnames,
     calc_element,
     theme,
     verbose = verbose,
-    # once we've started skipping blanks, we continue doing so until the end of the
-    # recursion; we initiate skipping blanks if we encounter an element that
-    # doesn't inherit blank.
-    skip_blank = skip_blank || (!is.null(el_out) && !isTRUE(el_out$inherit.blank)),
+    skip_blank = skip_blank,
     call = call
   )
 

tests/testthat/test-theme.R

@@ -346,7 +346,7 @@ test_that("all elements in complete themes have inherit.blank=TRUE", {
   inherit_blanks <- function(theme) {
     all(vapply(theme, function(el) {
       if (inherits(el, "element") && !S7::S7_inherits(el, element_blank)) {
-        el$inherit.blank
+        el@inherit.blank
       } else {
         TRUE
       }