Consider linewidth in legend key sizes (#5346)

* Key size accounts for linewidth

* Add test

* Add bullet

NEWS.md

@@ -75,6 +75,8 @@
  * `guide_coloursteps()` and `guide_bins()` sort breaks (#5152).
  * `guide_axis()` gains a `cap` argument that can be used to trim the
  axis line to extreme breaks (#4907).
+ * Fixed regression in `guide_legend()` where the `linewidth` key size
+ wasn't adapted to the width of the lines (#5160).
 
 * `geom_label()` now uses the `angle` aesthetic (@teunbrand, #2785)
 * 'lines' units in `geom_label()`, often used in the `label.padding` argument, 

R/guide-legend.R

@@ -329,10 +329,6 @@ GuideLegend <- ggproto(
 
  data <- modify_list(data, params$override.aes)
 
- if (!is.null(data$size)) {
- data$size[is.na(data$size)] <- 0
- }
-
  list(
  draw_key = layer$geom$draw_key,
  data = data,
@@ -728,15 +724,17 @@ measure_legend_keys <- function(decor, n, dim, byrow = FALSE,
  zeroes <- rep(0, prod(dim) - n)
 
  # For every layer, extract the size in cm
- size <- lapply(decor, function(g) g$data$size / 10) # mm to cm
+ size <- lapply(decor, function(g) {
+ lwd <- g$data$linewidth %||% 0
+ lwd[is.na(lwd)] <- 0
+ size <- g$data$size %||% 0
+ size[is.na(size)] <- 0
+ vec_recycle((size + lwd) / 10, size = nrow(g$data))
+ })
  size <- inject(cbind(!!!size))
 
- # Guard against layers with no size aesthetic
- if (any(dim(size) == 0)) {
- size <- matrix(0, ncol = 1, nrow = n)
- } else {
- size <- size[seq_len(n), , drop = FALSE]
- }
+ # Binned legends may have `n + 1` breaks, but we need to display `n` keys.
+ size <- vec_slice(size, seq_len(n))
 
  # For every key, find maximum across all layers
  size <- apply(size, 1, max)

tests/testthat/test-guides.R

@@ -627,6 +627,17 @@ test_that("guides title and text are positioned correctly", {
  expect_doppelganger("rotated guide titles and labels", p )
 })
 
+test_that("size and linewidth affect key size", {
+ df <- data_frame(x = c(0, 1, 2))
+ p <- ggplot(df, aes(x, x)) +
+ geom_point(aes(size = x)) +
+ geom_line(aes(linewidth = 2 - x)) +
+ scale_size_continuous(range = c(1, 12)) +
+ scale_linewidth_continuous(range = c(1, 20))
+
+ expect_doppelganger("enlarged guides", p)
+})
+
 test_that("colorbar can be styled", {
  df <- data_frame(x = c(0, 1, 2))
  p <- ggplot(df, aes(x, x, color = x)) + geom_point()