Fix calculation of theme defaults

NEWS.md

@@ -135,6 +135,8 @@
 
 * `position_jitter()` gains a `seed` argument that allows specifying a random seed for reproducible jittering (#1996, @krlmlr).
 
+* Fixed bug where a new complete `theme` may fail to override all elements of the default `theme`.
+  (@has2k1, #2058, #2079)
 
 ### sf
 

R/labeller.r

@@ -509,7 +509,9 @@ build_strip <- function(label_df, labeller, theme, horizontal) {
     grobs_right <- apply(grobs_right, 1, function(strips) {
       gtable_matrix("strip", matrix(strips, nrow = 1), widths, unit(1, "null"), clip = "on")
     })
-    theme$strip.text.y$angle <- adjust_angle(theme$strip.text.y$angle)
+    if (inherits(theme$strip.text.y, "element_text")) {
+      theme$strip.text.y$angle <- adjust_angle(theme$strip.text.y$angle)
+    }
     grobs_left <- apply(labels, c(1, 2), ggstrip, theme = theme,
       horizontal = horizontal)
     widths <- unit(apply(grobs_left, 2, max_width), "cm")

R/theme-defaults.r

@@ -375,6 +375,7 @@ theme_classic <- function(base_size = 11, base_family = "",
 theme_void <- function(base_size = 11, base_family = "",
                        base_line_size = base_size / 22,
                        base_rect_size = base_size / 22) {
+  half_line <- base_size / 2
   theme(
     # Use only inherited elements and make almost everything blank
     # Only keep indispensable text
@@ -388,10 +389,29 @@ theme_void <- function(base_size = 11, base_family = "",
                          ),
     axis.text =        element_blank(),
     axis.title =       element_blank(),
+    axis.ticks.length =  unit(0, "pt"),
+    legend.key.size =    unit(1.2, "lines"),
+    legend.position =    "right",
     legend.text =        element_text(size = rel(0.8)),
     legend.title =       element_text(hjust = 0),
     strip.text =         element_text(size = rel(0.8)),
+    strip.switch.pad.grid = unit(0.1, "cm"),
+    strip.switch.pad.wrap = unit(0.1, "cm"),
+    panel.ontop =        FALSE,
+    panel.spacing =      unit(half_line, "pt"),
     plot.margin =        unit(c(0, 0, 0, 0), "lines"),
+    plot.title =         element_text(
+                           size = rel(1.2),
+                           hjust = 0, vjust = 1,
+                           margin = margin(t = half_line * 1.2)),
+    plot.subtitle =      element_text(
+                           size = rel(0.9),
+                           hjust = 0, vjust = 1,
+                           margin = margin(t = half_line * 0.9)),
+    plot.caption =       element_text(
+                           size = rel(0.9),
+                           hjust = 1, vjust = 1,
+                           margin = margin(t = half_line * 0.9)),
 
     complete = TRUE
   )

R/theme.r

@@ -415,8 +415,15 @@ theme <- function(line,
 
 
 # Combine plot defaults with current theme to get complete theme for a plot
-plot_theme <- function(x) {
-  defaults(x$theme, theme_get())
+plot_theme <- function(x, default_theme=theme_get()) {
+  complete <- attr(x$theme, "complete")
+  if (is.null(complete)) {
+    default_theme
+  } else if (complete) {
+    x$theme
+  } else {
+    defaults(x$theme, default_theme)
+  }
 }
 
 #' Modify properties of an element in a theme object

tests/testthat/test-theme.r

@@ -163,6 +163,7 @@ test_that("Complete and non-complete themes interact correctly with ggplot objec
   expect_false(attr(p$plot$theme, "complete"))
   expect_equal(p$plot$theme$text$colour, "red")
   expect_equal(p$plot$theme$text$face, "italic")
+
 })
 
 test_that("theme(validate=FALSE) means do not validate_element", {
@@ -224,6 +225,19 @@ test_that("Elements can be merged", {
   )
 })
 
+test_that("Final calculated plot theme should not blend a complete theme with the default theme", {
+  default_theme <- theme_gray() + theme(axis.text.x = element_text(colour = "red"))
+
+  ptheme <- plot_theme(qplot(1:3, 1:3) + theme_void(), default_theme)
+  expect_null(ptheme$axis.text.x)
+
+  ptheme <- plot_theme(qplot(1:3, 1:3) + theme_gray(), default_theme)
+  expect_true(is.null(ptheme$axis.text.x$colour) || ptheme$axis.text.x$colour != "red")
+
+  ptheme <- plot_theme(qplot(1:3, 1:3) + theme(axis.text.y = element_text(colour = "blue")), default_theme)
+  expect_equal(ptheme$axis.text.x$colour, "red")
+  expect_equal(ptheme$axis.text.y$colour, "blue")
+})
 
 # Visual tests ------------------------------------------------------------