Fix coord_map to allow switching axis position (#3069)

* Fix scale position for coord_map()

* Add news bullet

* Add visual test for top/right scale positions in coord_map()

* Better defaults for arrange when x.arrange is NULL

* Fix test

Author: karawoo

NEWS.md

@@ -6,6 +6,8 @@
   text from running out of the strip and borders from looking thicker than for
   other strips (@karawoo, #2772 and #3061).
 
+* `coord_map()` now can have axes on the top and right (@karawoo, #3042).
+
 * `geom_rug()` now works with `coord_flip()` (@has2k1, #2987).
 
 * Layers now have a new member function `setup_layer()` which is called at the

R/coord-map.r

@@ -189,7 +189,8 @@ CoordMap <- ggproto("CoordMap", Coord,
       x.range = ret$x$range, y.range = ret$y$range,
       x.proj = ret$x$proj, y.proj = ret$y$proj,
       x.major = ret$x$major, x.minor = ret$x$minor, x.labels = ret$x$labels,
-      y.major = ret$y$major, y.minor = ret$y$minor, y.labels = ret$y$labels
+      y.major = ret$y$major, y.minor = ret$y$minor, y.labels = ret$y$labels,
+      x.arrange = scale_x$axis_order(), y.arrange = scale_y$axis_order()
     )
     details
   },
@@ -243,7 +244,7 @@ CoordMap <- ggproto("CoordMap", Coord,
   },
 
   render_axis_h = function(self, panel_params, theme) {
-    arrange <- panel_params$x.arrange %||% c("primary", "secondary")
+    arrange <- panel_params$x.arrange %||% c("secondary", "primary")
 
     if (is.null(panel_params$x.major)) {
       return(list(
@@ -259,8 +260,8 @@ CoordMap <- ggproto("CoordMap", Coord,
     pos <- self$transform(x_intercept, panel_params)
 
     axes <- list(
-      bottom = guide_axis(pos$x, panel_params$x.labels, "bottom", theme),
-      top = guide_axis(pos$x, panel_params$x.labels, "top", theme)
+      top = guide_axis(pos$x, panel_params$x.labels, "top", theme),
+      bottom = guide_axis(pos$x, panel_params$x.labels, "bottom", theme)
     )
     axes[[which(arrange == "secondary")]] <- zeroGrob()
     axes

tests/figs/coord-map/coord-map-switched-scale-position.svg

@@ -1,9 +1,9 @@
 context("coord_map")
 
-test_that("USA state map drawn", {
-  us_map <- map_data("usa")
-  p_us <- ggplot(us_map, aes(x = long, y = lat, group = group))
+us_map <- map_data("usa")
+p_us <- ggplot(us_map, aes(x = long, y = lat, group = group))
 
+test_that("USA state map drawn", {
   expect_doppelganger(
     "USA mercator",
     p_us +
@@ -12,6 +12,17 @@ test_that("USA state map drawn", {
   )
 })
 
+test_that("coord_map scale position can be switched", {
+  expect_doppelganger(
+    "coord_map switched scale position",
+    p_us +
+      geom_polygon(fill = NA, colour = "grey50") +
+      coord_map("mercator") +
+      scale_y_continuous(position = "right") +
+      scale_x_continuous(position = "top")
+  )
+})
+
 test_that("Inf is squished to range", {
   d <- cdata(
     ggplot(data_frame(x = 0, y = 0)) +