Missing Scale$get_transformation() (#5607)

* Use `Scale$get_transformation()` more

* Only inverse transform is there is an actual transform

Author: teunbrand

R/axis-secondary.R

@@ -179,7 +179,7 @@ AxisSecondary <- ggproto("AxisSecondary", NULL,
     }
     if (is.derived(self$name) && !is.waive(scale$name)) self$name <- scale$name
     if (is.derived(self$breaks)) self$breaks <- scale$breaks
-    if (is.waive(self$breaks)) self$breaks <- scale$transformation$breaks
+    if (is.waive(self$breaks)) self$breaks <- scale$get_transformation()$breaks
     if (is.derived(self$labels)) self$labels <- scale$labels
     if (is.derived(self$guide)) self$guide <- scale$guide
   },

R/guide-axis-logticks.R

@@ -149,7 +149,7 @@ GuideAxisLogticks <- ggproto(
 
     # Reconstruct a transformation if user has prescaled data
     if (!is.null(params$prescale_base)) {
-      trans_name <- scale$scale$transformation$name
+      trans_name <- scale$get_transformation()$name
       if (trans_name != "identity") {
         cli::cli_warn(paste0(
           "The {.arg prescale_base} argument will override the scale's ",

R/scale-.R

@@ -609,7 +609,7 @@ check_breaks_labels <- function(breaks, labels, call = NULL) {
 default_transform <- function(self, x) {
   transformation <- self$get_transformation()
   new_x <- transformation$transform(x)
-  check_transformation(x, new_x, self$transformation$name, call = self$call)
+  check_transformation(x, new_x, transformation$name, call = self$call)
   new_x
 }
 

R/scales-.R

@@ -89,8 +89,9 @@ ScalesList <- ggproto("ScalesList", NULL,
     # If the scale contains to trans or trans is identity, there is no need
     # to transform anything
     idx_skip <- vapply(self$scales, function(x) {
+      transformation <- x$get_transformation()
       has_default_transform(x) &&
-        (is.null(x$transformation) || identical(x$transformation$transform, identity))
+        (is.null(transformation) || identical(transformation$transform, identity))
     }, logical(1L))
     scales <- self$scales[!idx_skip]
 
@@ -113,8 +114,9 @@ ScalesList <- ggproto("ScalesList", NULL,
     # If the scale contains to trans or trans is identity, there is no need
     # to transform anything
     idx_skip <- vapply(self$scales, function(x) {
+      transformation <- x$get_transformation()
       has_default_transform(x) &&
-        (is.null(x$transformation) || identical(x$transformation$transform, identity))
+        (is.null(transformation) || identical(transformation$transform, identity))
     }, logical(1))
     scales <- self$scales[!idx_skip]
 
@@ -129,7 +131,11 @@ ScalesList <- ggproto("ScalesList", NULL,
         if (length(aesthetics) == 0) {
           return()
         }
-        lapply(df[aesthetics], scale$transformation$inverse)
+        inverse <- scale$get_transformation()$inverse
+        if (is.null(inverse)) {
+          return()
+        }
+        lapply(df[aesthetics], inverse)
       }
     ), recursive = FALSE)
 

R/stat-function.R

@@ -66,7 +66,7 @@ StatFunction <- ggproto("StatFunction", Stat,
       } else {
         # For continuous scales, need to back transform from transformed range
         # to original values
-        x_trans <- scales$x$transformation$inverse(xseq)
+        x_trans <- scales$x$get_transformation()$inverse(xseq)
       }
     }
 
@@ -75,7 +75,7 @@ StatFunction <- ggproto("StatFunction", Stat,
     y_out <- inject(fun(x_trans, !!!args))
     if (!is.null(scales$y) && !scales$y$is_discrete()) {
       # For continuous scales, need to apply transform
-      y_out <- scales$y$transformation$transform(y_out)
+      y_out <- scales$y$get_transformation()$transform(y_out)
     }
 
     data_frame0(x = xseq, y = y_out)