Restore legend.byrow (#5662)

* add `elements` to `arrange_layout`

* Fix `byrow`

* add test

Author: teunbrand

R/guide-.R

@@ -329,7 +329,7 @@ Guide <- ggproto(
 
     # Arrange and assemble grobs
     sizes  <- self$measure_grobs(grobs, params, elems)
-    layout <- self$arrange_layout(key, sizes, params)
+    layout <- self$arrange_layout(key, sizes, params, elems)
     self$assemble_drawing(grobs, layout, sizes, params, elems)
   },
 
@@ -340,7 +340,7 @@ Guide <- ggproto(
   },
 
   # Takes care of where grobs should be added to the output gtable.
-  arrange_layout = function(key, sizes, params) {
+  arrange_layout = function(key, sizes, params, elements) {
     return(invisible())
   },
 

R/guide-axis-theta.R

@@ -306,7 +306,7 @@ GuideAxisTheta <- ggproto(
     list(offset = max(height))
   },
 
-  arrange_layout = function(key, sizes, params) {
+  arrange_layout = function(key, sizes, params, elements) {
     NULL
   },
 

R/guide-axis.R

@@ -386,7 +386,7 @@ GuideAxis <- ggproto(
     sizes
   },
 
-  arrange_layout = function(key, sizes, params) {
+  arrange_layout = function(key, sizes, params, elements) {
 
     layout <- seq_along(sizes)
 

R/guide-legend.R

@@ -471,21 +471,16 @@ GuideLegend <- ggproto(
     )
     heights <- head(vec_interleave(!!!heights), -1)
 
-    list(
-      widths  = widths,
-      heights = heights,
-      padding = elements$padding,
-      label_position = elements$text_position
-    )
+    list(widths = widths, heights = heights)
   },
 
-  arrange_layout = function(key, sizes, params) {
+  arrange_layout = function(key, sizes, params, elements) {
 
     break_seq <- seq_len(params$n_breaks %||% 1L)
     dim <- c(params$nrow %||% 1L, params$ncol %||% 1L)
 
     # Find rows / columns of legend items
-    if (params$byrow %||% FALSE) {
+    if (elements$byrow %||% FALSE) {
       row <- ceiling(break_seq / dim[2L])
       col <- (break_seq - 1L) %% dim[2L] + 1L
     } else {
@@ -497,7 +492,7 @@ GuideLegend <- ggproto(
     key_col <- col * 2 - 1
 
     # Make gaps for key-label spacing depending on label position
-    position <- sizes$label_position
+    position <- elements$text_position
     key_row <- key_row + switch(position, top  = row, bottom = row - 1, 0)
     lab_row <- key_row + switch(position, top  = -1,  bottom = 1,       0)
     key_col <- key_col + switch(position, left = col, right  = col - 1, 0)

tests/testthat/_snaps/guides/legend-byrow-true.svg

@@ -1161,6 +1161,23 @@ test_that("guides() warns if unnamed guides are provided", {
   expect_null(guides())
 })
 
+test_that("legend.byrow works in `guide_legend()`", {
+
+  df <- data.frame(x = 1:6, f = LETTERS[1:6])
+
+  p <- ggplot(df, aes(x, x, colour = f)) +
+    geom_point() +
+    scale_colour_discrete(
+      guide = guide_legend(
+        ncol = 3,
+        theme = theme(legend.byrow = TRUE)
+      )
+    )
+
+  expect_doppelganger("legend.byrow = TRUE", p)
+
+})
+
 test_that("old S3 guides can be implemented", {
 
   my_env <- env()