From dd9c09de18fa8919f18466c61e6d0e28d6eb17ab Mon Sep 17 00:00:00 2001
From: Teun van den Brand <49372158+teunbrand@users.noreply.github.com>
Date: Thu, 23 Nov 2023 00:39:33 +0100
Subject: [PATCH 01/13] add double-dispatch for layers

---
 NAMESPACE             | 1 +
 R/plot-construction.R | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/NAMESPACE b/NAMESPACE
index c5f5a94219..ccd9f7a6b8 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -57,6 +57,7 @@ S3method(ggplot_add,Coord)
 S3method(ggplot_add,Facet)
 S3method(ggplot_add,Guides)
 S3method(ggplot_add,Layer)
+S3method(ggplot_add,Layer.default)
 S3method(ggplot_add,Scale)
 S3method(ggplot_add,by)
 S3method(ggplot_add,data.frame)
diff --git a/R/plot-construction.R b/R/plot-construction.R
index c4cafd2dc8..028282dc29 100644
--- a/R/plot-construction.R
+++ b/R/plot-construction.R
@@ -165,7 +165,13 @@ ggplot_add.by <- function(object, plot, object_name) {
 }
 
 #' @export
+#' @method ggplot_add Layer
 ggplot_add.Layer <- function(object, plot, object_name) {
+  UseMethod("ggplot_add.Layer", plot)
+}
+
+#' @export
+ggplot_add.Layer.default <- function(object, plot, object_name) {
   plot$layers <- append(plot$layers, object)
 
   # Add any new labels

From aaefb1eca29caa11405e51ba0c105f0bc55b714e Mon Sep 17 00:00:00 2001
From: Teun van den Brand <49372158+teunbrand@users.noreply.github.com>
Date: Sun, 26 Nov 2023 11:23:03 +0100
Subject: [PATCH 02/13] Convert `ggplot_add()` to S7 generic

---
 DESCRIPTION           |   1 +
 NAMESPACE             |  22 +++-----
 R/ggplot2-package.R   |   1 +
 R/plot-construction.R | 115 ++++++++++++++++++++++++++++--------------
 4 files changed, 86 insertions(+), 53 deletions(-)

diff --git a/DESCRIPTION b/DESCRIPTION
index 77cb1ce98d..3d44dff8ec 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -40,6 +40,7 @@ Imports:
     MASS,
     mgcv,
     rlang (>= 1.1.0),
+    S7,
     scales (>= 1.2.0),
     stats,
     tibble,
diff --git a/NAMESPACE b/NAMESPACE
index ccd9f7a6b8..439ffdda8b 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -51,21 +51,6 @@ S3method(get_alt_text,ggplot_built)
 S3method(get_alt_text,gtable)
 S3method(ggplot,"function")
 S3method(ggplot,default)
-S3method(ggplot_add,"NULL")
-S3method(ggplot_add,"function")
-S3method(ggplot_add,Coord)
-S3method(ggplot_add,Facet)
-S3method(ggplot_add,Guides)
-S3method(ggplot_add,Layer)
-S3method(ggplot_add,Layer.default)
-S3method(ggplot_add,Scale)
-S3method(ggplot_add,by)
-S3method(ggplot_add,data.frame)
-S3method(ggplot_add,default)
-S3method(ggplot_add,labels)
-S3method(ggplot_add,list)
-S3method(ggplot_add,theme)
-S3method(ggplot_add,uneval)
 S3method(ggplot_build,ggplot)
 S3method(ggplot_gtable,ggplot_built)
 S3method(grid.draw,absoluteGrob)
@@ -701,6 +686,13 @@ import(gtable)
 import(rlang)
 import(scales)
 import(vctrs)
+importFrom(S7,"method<-")
+importFrom(S7,S7_dispatch)
+importFrom(S7,class_any)
+importFrom(S7,class_list)
+importFrom(S7,method)
+importFrom(S7,new_S3_class)
+importFrom(S7,new_generic)
 importFrom(glue,glue)
 importFrom(glue,glue_collapse)
 importFrom(lifecycle,deprecated)
diff --git a/R/ggplot2-package.R b/R/ggplot2-package.R
index 539f03db97..35e656b725 100644
--- a/R/ggplot2-package.R
+++ b/R/ggplot2-package.R
@@ -5,6 +5,7 @@
 #' @import scales grid gtable rlang vctrs
 #' @importFrom glue glue glue_collapse
 #' @importFrom lifecycle deprecated
+#' @importFrom S7 class_any class_list method method<- new_generic new_S3_class S7_dispatch
 #' @importFrom stats setNames
 #' @importFrom utils head tail
 ## usethis namespace: end
diff --git a/R/plot-construction.R b/R/plot-construction.R
index 028282dc29..49dc21c64d 100644
--- a/R/plot-construction.R
+++ b/R/plot-construction.R
@@ -87,49 +87,80 @@ add_ggplot <- function(p, object, objectname) {
 #'
 #' @keywords internal
 #' @export
-ggplot_add <- function(object, plot, object_name) {
-  UseMethod("ggplot_add")
-}
-#' @export
-ggplot_add.default <- function(object, plot, object_name) {
+ggplot_add <- new_generic(
+  "ggplot_add",
+  dispatch_args = c("object", "plot"),
+  fun = function(object, plot, object_name) S7_dispatch()
+)
+
+class_ggplot <- new_S3_class("ggplot")
+
+method(
+  ggplot_add,
+  list(object = class_any, plot = class_ggplot)
+) <- function(object, plot, object_name) {
   cli::cli_abort("Can't add {.var {object_name}} to a {.cls ggplot} object.")
 }
-#' @export
-ggplot_add.NULL <- function(object, plot, object_name) {
+
+method(
+  ggplot_add,
+  list(object = new_S3_class("NULL"), plot = class_ggplot)
+) <- function(object, plot, object_name) {
   plot
 }
-#' @export
-ggplot_add.data.frame <- function(object, plot, object_name) {
+
+method(
+  ggplot_add,
+  list(object = new_S3_class("data.frame"), plot = class_ggplot)
+) <- function(object, plot, object_name) {
   plot$data <- object
   plot
 }
-#' @export
-ggplot_add.function <- function(object, plot, object_name) {
+
+method(
+  ggplot_add,
+  list(object = new_S3_class("function"), plot = class_ggplot)
+) <- function(object, plot, object_name) {
   cli::cli_abort(c(
-          "Can't add {.var {object_name}} to a {.cls ggplot} object",
+    "Can't add {.var {object_name}} to a {.cls ggplot} object",
     "i" = "Did you forget to add parentheses, as in {.fn {object_name}}?"
   ))
 }
-#' @export
-ggplot_add.theme <- function(object, plot, object_name) {
+
+method(
+  ggplot_add,
+  list(object = new_S3_class("theme"), plot = class_ggplot)
+) <- function(object, plot, object_name) {
   plot$theme <- add_theme(plot$theme, object)
   plot
 }
-#' @export
-ggplot_add.Scale <- function(object, plot, object_name) {
+
+method(
+  ggplot_add,
+  list(object = new_S3_class("Scale"), plot = class_ggplot)
+) <- function(object, plot, object_name) {
   plot$scales$add(object)
   plot
 }
-#' @export
-ggplot_add.labels <- function(object, plot, object_name) {
+
+method(
+  ggplot_add,
+  list(object = new_S3_class("labels"), plot = class_ggplot)
+) <- function(object, plot, object_name) {
   update_labels(plot, object)
 }
-#' @export
-ggplot_add.Guides <- function(object, plot, object_name) {
+
+method(
+  ggplot_add,
+  list(object = new_S3_class("Guides"), plot = class_ggplot)
+) <- function(object, plot, object_name) {
   update_guides(plot, object)
 }
-#' @export
-ggplot_add.uneval <- function(object, plot, object_name) {
+
+method(
+  ggplot_add,
+  list(object = new_S3_class("uneval"), plot = class_ggplot)
+) <- function(object, plot, object_name) {
   plot$mapping <- defaults(object, plot$mapping)
   # defaults() doesn't copy class, so copy it.
   class(plot$mapping) <- class(object)
@@ -138,8 +169,11 @@ ggplot_add.uneval <- function(object, plot, object_name) {
   names(labels) <- names(object)
   update_labels(plot, labels)
 }
-#' @export
-ggplot_add.Coord <- function(object, plot, object_name) {
+
+method(
+  ggplot_add,
+  list(object = new_S3_class("Coord"), plot = class_ggplot)
+) <- function(object, plot, object_name) {
   if (!isTRUE(plot$coordinates$default)) {
     cli::cli_inform("Coordinate system already present. Adding new coordinate system, which will replace the existing one.")
   }
@@ -147,31 +181,36 @@ ggplot_add.Coord <- function(object, plot, object_name) {
   plot$coordinates <- object
   plot
 }
-#' @export
-ggplot_add.Facet <- function(object, plot, object_name) {
+
+method(
+  ggplot_add,
+  list(object = new_S3_class("Facet"), plot = class_ggplot)
+) <- function(object, plot, object_name) {
   plot$facet <- object
   plot
 }
-#' @export
-ggplot_add.list <- function(object, plot, object_name) {
+
+method(
+  ggplot_add,
+  list(object = class_list, plot = class_ggplot)
+) <- function(object, plot, object_name) {
   for (o in object) {
     plot <- plot %+% o
   }
   plot
 }
-#' @export
-ggplot_add.by <- function(object, plot, object_name) {
-  ggplot_add.list(object, plot, object_name)
-}
 
-#' @export
-#' @method ggplot_add Layer
-ggplot_add.Layer <- function(object, plot, object_name) {
-  UseMethod("ggplot_add.Layer", plot)
+method(
+  ggplot_add,
+  list(object = new_S3_class("by"), plot = class_ggplot)
+) <- function(object, plot, object_name) {
+  ggplot_add.list(object, plot, object_name)
 }
 
-#' @export
-ggplot_add.Layer.default <- function(object, plot, object_name) {
+method(
+  ggplot_add,
+  list(object = new_S3_class("Layer"), plot = class_ggplot)
+) <- function(object, plot, object_name) {
   plot$layers <- append(plot$layers, object)
 
   # Add any new labels

From cd7cc4ed54510e17701dc8a3df5574e2257ed38e Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Mon, 27 Nov 2023 11:02:03 +0100
Subject: [PATCH 03/13] Declare classes beforehand

---
 R/plot-construction.R | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/R/plot-construction.R b/R/plot-construction.R
index 49dc21c64d..4d40f2f174 100644
--- a/R/plot-construction.R
+++ b/R/plot-construction.R
@@ -102,6 +102,19 @@ method(
   cli::cli_abort("Can't add {.var {object_name}} to a {.cls ggplot} object.")
 }
 
+# Class declarations for S7 dispatch. If S7 gets implemented more broadly,
+# consider moving these to a new file.
+class_ggplot <- S7::new_S3_class("ggplot")
+class_theme  <- S7::new_S3_class("theme")
+class_scale  <- S7::new_S3_class("Scale")
+class_labels <- S7::new_S3_class("labels")
+class_guides <- S7::new_S3_class("Guides")
+class_aes    <- S7::new_S3_class("uneval")
+class_coord  <- S7::new_S3_class("Coord")
+class_facet  <- S7::new_S3_class("Facet")
+class_by     <- S7::new_S3_class("by")
+class_layer  <- S7::new_S3_class("Layer")
+
 method(
   ggplot_add,
   list(object = new_S3_class("NULL"), plot = class_ggplot)

From a4e4c35b2d26b2d861b6603d5dbfb6de2d7f6c67 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Mon, 27 Nov 2023 11:02:41 +0100
Subject: [PATCH 04/13] Follow Hadley's advice

---
 NAMESPACE             |   7 --
 R/ggplot2-package.R   |   1 -
 R/plot-construction.R | 222 ++++++++++++++++++------------------------
 3 files changed, 96 insertions(+), 134 deletions(-)

diff --git a/NAMESPACE b/NAMESPACE
index 439ffdda8b..b24d627889 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -686,13 +686,6 @@ import(gtable)
 import(rlang)
 import(scales)
 import(vctrs)
-importFrom(S7,"method<-")
-importFrom(S7,S7_dispatch)
-importFrom(S7,class_any)
-importFrom(S7,class_list)
-importFrom(S7,method)
-importFrom(S7,new_S3_class)
-importFrom(S7,new_generic)
 importFrom(glue,glue)
 importFrom(glue,glue_collapse)
 importFrom(lifecycle,deprecated)
diff --git a/R/ggplot2-package.R b/R/ggplot2-package.R
index 35e656b725..539f03db97 100644
--- a/R/ggplot2-package.R
+++ b/R/ggplot2-package.R
@@ -5,7 +5,6 @@
 #' @import scales grid gtable rlang vctrs
 #' @importFrom glue glue glue_collapse
 #' @importFrom lifecycle deprecated
-#' @importFrom S7 class_any class_list method method<- new_generic new_S3_class S7_dispatch
 #' @importFrom stats setNames
 #' @importFrom utils head tail
 ## usethis namespace: end
diff --git a/R/plot-construction.R b/R/plot-construction.R
index 4d40f2f174..785820488d 100644
--- a/R/plot-construction.R
+++ b/R/plot-construction.R
@@ -70,7 +70,7 @@ add_ggplot <- function(p, object, objectname) {
   if (is.null(object)) return(p)
 
   p <- plot_clone(p)
-  p <- ggplot_add(object, p, objectname)
+  p <- ggplot_add(object, p, object_name = objectname)
   set_last_plot(p)
   p
 }
@@ -87,20 +87,7 @@ add_ggplot <- function(p, object, objectname) {
 #'
 #' @keywords internal
 #' @export
-ggplot_add <- new_generic(
-  "ggplot_add",
-  dispatch_args = c("object", "plot"),
-  fun = function(object, plot, object_name) S7_dispatch()
-)
-
-class_ggplot <- new_S3_class("ggplot")
-
-method(
-  ggplot_add,
-  list(object = class_any, plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  cli::cli_abort("Can't add {.var {object_name}} to a {.cls ggplot} object.")
-}
+ggplot_add <- S7::new_generic("ggplot_add", c("object", "plot"))
 
 # Class declarations for S7 dispatch. If S7 gets implemented more broadly,
 # consider moving these to a new file.
@@ -115,129 +102,112 @@ class_facet  <- S7::new_S3_class("Facet")
 class_by     <- S7::new_S3_class("by")
 class_layer  <- S7::new_S3_class("Layer")
 
-method(
-  ggplot_add,
-  list(object = new_S3_class("NULL"), plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  plot
-}
+S7::method(ggplot_add, list(S7::class_any, class_ggplot)) <-
+  function(object, plot, object_name) {
+    cli::cli_abort("Can't add {.var {object_name}} to a {.cls ggplot} object.")
+  }
 
-method(
-  ggplot_add,
-  list(object = new_S3_class("data.frame"), plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  plot$data <- object
-  plot
-}
+# Cannot currently double dispatch on NULL directly
+# replace `S7::new_S3_class("NULL")` with `NULL` when S7 version > 0.1.1
+S7::method(ggplot_add, list(S7::new_S3_class("NULL"), class_ggplot)) <-
+  function(object, plot, object_name) {
+    plot
+  }
 
-method(
-  ggplot_add,
-  list(object = new_S3_class("function"), plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  cli::cli_abort(c(
-    "Can't add {.var {object_name}} to a {.cls ggplot} object",
-    "i" = "Did you forget to add parentheses, as in {.fn {object_name}}?"
-  ))
-}
+S7::method(ggplot_add, list(S7::class_data.frame, class_ggplot)) <-
+  function(object, plot, object_name) {
+    plot$data <- object
+    plot
+  }
 
-method(
-  ggplot_add,
-  list(object = new_S3_class("theme"), plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  plot$theme <- add_theme(plot$theme, object)
-  plot
-}
+S7::method(ggplot_add, list(S7::class_function, class_ggplot)) <-
+  function(object, plot, object_name) {
+    cli::cli_abort(c(
+      "Can't add {.var {object_name}} to a {.cls ggplot} object",
+      "i" = "Did you forget to add parentheses, as in {.fn {object_name}}?"
+    ))
+  }
 
-method(
-  ggplot_add,
-  list(object = new_S3_class("Scale"), plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  plot$scales$add(object)
-  plot
-}
+S7::method(ggplot_add, list(class_theme, class_ggplot)) <-
+  function(object, plot, object_name) {
+    plot$theme <- add_theme(plot$theme, object)
+    plot
+  }
 
-method(
-  ggplot_add,
-  list(object = new_S3_class("labels"), plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  update_labels(plot, object)
-}
+S7::method(ggplot_add, list(class_scale, class_ggplot)) <-
+  function(object, plot, object_name) {
+    plot$scales$add(object)
+    plot
+  }
 
-method(
-  ggplot_add,
-  list(object = new_S3_class("Guides"), plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  update_guides(plot, object)
-}
+S7::method(ggplot_add, list(class_labels, class_ggplot)) <-
+  function(object, plot, object_name) {
+    update_labels(plot, object)
+  }
 
-method(
-  ggplot_add,
-  list(object = new_S3_class("uneval"), plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  plot$mapping <- defaults(object, plot$mapping)
-  # defaults() doesn't copy class, so copy it.
-  class(plot$mapping) <- class(object)
-
-  labels <- make_labels(object)
-  names(labels) <- names(object)
-  update_labels(plot, labels)
-}
+S7::method(ggplot_add, list(class_guides, class_ggplot)) <-
+  function(object, plot, object_name) {
+    update_guides(plot, object)
+  }
 
-method(
-  ggplot_add,
-  list(object = new_S3_class("Coord"), plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  if (!isTRUE(plot$coordinates$default)) {
-    cli::cli_inform("Coordinate system already present. Adding new coordinate system, which will replace the existing one.")
+S7::method(ggplot_add, list(class_aes, class_ggplot)) <-
+  function(object, plot, object_name) {
+    plot$mapping <- defaults(object, plot$mapping)
+    # defaults() doesn't copy class, so copy it.
+    class(plot$mapping) <- class(object)
+
+    labels <- make_labels(object)
+    names(labels) <- names(object)
+    update_labels(plot, labels)
   }
 
-  plot$coordinates <- object
-  plot
-}
+S7::method(ggplot_add, list(class_coord, class_ggplot)) <-
+  function(object, plot, object_name) {
+    if (!isTRUE(plot$coordinates$default)) {
+      cli::cli_inform("Coordinate system already present. Adding new coordinate system, which will replace the existing one.")
+    }
 
-method(
-  ggplot_add,
-  list(object = new_S3_class("Facet"), plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  plot$facet <- object
-  plot
-}
+    plot$coordinates <- object
+    plot
+  }
 
-method(
-  ggplot_add,
-  list(object = class_list, plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  for (o in object) {
-    plot <- plot %+% o
+S7::method(ggplot_add, list(class_facet, class_ggplot)) <-
+  function(object, plot, object_name) {
+    plot$facet <- object
+    plot
   }
-  plot
-}
 
-method(
-  ggplot_add,
-  list(object = new_S3_class("by"), plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  ggplot_add.list(object, plot, object_name)
-}
+S7::method(ggplot_add, list(S7::class_list, class_ggplot)) <-
+  function(object, plot, object_name) {
+    for (o in object) {
+      plot <- plot %+% o
+    }
+    plot
+  }
 
-method(
-  ggplot_add,
-  list(object = new_S3_class("Layer"), plot = class_ggplot)
-) <- function(object, plot, object_name) {
-  plot$layers <- append(plot$layers, object)
-
-  # Add any new labels
-  mapping <- make_labels(object$mapping)
-  default <- lapply(make_labels(object$stat$default_aes), function(l) {
-    attr(l, "fallback") <- TRUE
-    l
-  })
-  new_labels <- defaults(mapping, default)
-  current_labels <- plot$labels
-  current_fallbacks <- vapply(current_labels, function(l) isTRUE(attr(l, "fallback")), logical(1))
-  plot$labels <- defaults(current_labels[!current_fallbacks], new_labels)
-  if (any(current_fallbacks)) {
-    plot$labels <- defaults(plot$labels, current_labels)
-  }
-  plot
-}
+S7::method(ggplot_add, list(class_by, class_ggplot)) <-
+  function(object, plot, object_name) {
+    S7::method(ggplot_add, list(class_list, class_ggplot))(
+      object, plot, object_name
+    )
+  }
+
+S7::method(ggplot_add, list(class_layer, class_ggplot)) <-
+  function(object, plot, object_name) {
+    plot$layers <- append(plot$layers, object)
+
+    # Add any new labels
+    mapping <- make_labels(object$mapping)
+    default <- lapply(make_labels(object$stat$default_aes), function(l) {
+      attr(l, "fallback") <- TRUE
+      l
+    })
+    new_labels <- defaults(mapping, default)
+    current_labels <- plot$labels
+    current_fallbacks <- vapply(current_labels, function(l) isTRUE(attr(l, "fallback")), logical(1))
+    plot$labels <- defaults(current_labels[!current_fallbacks], new_labels)
+    if (any(current_fallbacks)) {
+      plot$labels <- defaults(plot$labels, current_labels)
+    }
+    plot
+  }

From 1b00a60affbe162aa0acb3b21d076e51085ad173 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Mon, 27 Nov 2023 11:08:22 +0100
Subject: [PATCH 05/13] redocument

---
 R/plot-construction.R | 4 +++-
 man/ggplot_add.Rd     | 6 ++++--
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/R/plot-construction.R b/R/plot-construction.R
index 785820488d..6b05af01c2 100644
--- a/R/plot-construction.R
+++ b/R/plot-construction.R
@@ -81,7 +81,9 @@ add_ggplot <- function(p, object, objectname) {
 #'
 #' @param object An object to add to the plot
 #' @param plot The ggplot object to add `object` to
-#' @param object_name The name of the object to add
+#' @param ... Additional arguments to pass to the methods. Typically, an
+#'   `object_name` argument that gives a display name for `object` to use
+#'   in error messages.
 #'
 #' @return A modified ggplot object
 #'
diff --git a/man/ggplot_add.Rd b/man/ggplot_add.Rd
index 0bd2e2a698..3986ef2962 100644
--- a/man/ggplot_add.Rd
+++ b/man/ggplot_add.Rd
@@ -4,14 +4,16 @@
 \alias{ggplot_add}
 \title{Add custom objects to ggplot}
 \usage{
-ggplot_add(object, plot, object_name)
+ggplot_add(object, plot, ...)
 }
 \arguments{
 \item{object}{An object to add to the plot}
 
 \item{plot}{The ggplot object to add \code{object} to}
 
-\item{object_name}{The name of the object to add}
+\item{...}{Additional arguments to pass to the methods. Typically, an
+\code{object_name} argument that gives a display name for \code{object} to use
+in error messages.}
 }
 \value{
 A modified ggplot object

From d8bf5e3b1099aa81064ca5a597a60bd8829a55de Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Mon, 27 Nov 2023 16:48:54 +0100
Subject: [PATCH 06/13] class declaration to front

---
 R/all-classes.R       | 11 +++++++++++
 R/plot-construction.R | 13 -------------
 2 files changed, 11 insertions(+), 13 deletions(-)
 create mode 100644 R/all-classes.R

diff --git a/R/all-classes.R b/R/all-classes.R
new file mode 100644
index 0000000000..e92f68b185
--- /dev/null
+++ b/R/all-classes.R
@@ -0,0 +1,11 @@
+# Class declarations for S7 dispatch.
+class_theme  <- S7::new_S3_class("theme")
+class_scale  <- S7::new_S3_class("Scale")
+class_labels <- S7::new_S3_class("labels")
+class_guides <- S7::new_S3_class("Guides")
+class_aes    <- S7::new_S3_class("uneval")
+class_coord  <- S7::new_S3_class("Coord")
+class_facet  <- S7::new_S3_class("Facet")
+class_by     <- S7::new_S3_class("by")
+class_layer  <- S7::new_S3_class("Layer")
+class_scales_list <- S7::new_S3_class("ScalesList")
diff --git a/R/plot-construction.R b/R/plot-construction.R
index 6b05af01c2..ec8060d88f 100644
--- a/R/plot-construction.R
+++ b/R/plot-construction.R
@@ -91,19 +91,6 @@ add_ggplot <- function(p, object, objectname) {
 #' @export
 ggplot_add <- S7::new_generic("ggplot_add", c("object", "plot"))
 
-# Class declarations for S7 dispatch. If S7 gets implemented more broadly,
-# consider moving these to a new file.
-class_ggplot <- S7::new_S3_class("ggplot")
-class_theme  <- S7::new_S3_class("theme")
-class_scale  <- S7::new_S3_class("Scale")
-class_labels <- S7::new_S3_class("labels")
-class_guides <- S7::new_S3_class("Guides")
-class_aes    <- S7::new_S3_class("uneval")
-class_coord  <- S7::new_S3_class("Coord")
-class_facet  <- S7::new_S3_class("Facet")
-class_by     <- S7::new_S3_class("by")
-class_layer  <- S7::new_S3_class("Layer")
-
 S7::method(ggplot_add, list(S7::class_any, class_ggplot)) <-
   function(object, plot, object_name) {
     cli::cli_abort("Can't add {.var {object_name}} to a {.cls ggplot} object.")

From ffc347edd2c43b0e85f2c90a281ebca86c5ff809 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Mon, 27 Nov 2023 16:49:38 +0100
Subject: [PATCH 07/13] ggplot as S7 class

---
 R/plot.R | 86 ++++++++++++++++++++++++++++++++------------------------
 1 file changed, 50 insertions(+), 36 deletions(-)

diff --git a/R/plot.R b/R/plot.R
index 4494b774bc..794dc49eb4 100644
--- a/R/plot.R
+++ b/R/plot.R
@@ -1,3 +1,6 @@
+
+gg <- S7::new_class("gg", abstract = TRUE)
+
 #' Create a new ggplot
 #'
 #' `ggplot()` initializes a ggplot object. It can be used to
@@ -101,49 +104,60 @@
 #'     mapping = aes(x = group, y = group_mean), data = group_means_df,
 #'     colour = 'red', size = 3
 #'   )
-ggplot <- function(data = NULL, mapping = aes(), ...,
-                   environment = parent.frame()) {
-  UseMethod("ggplot")
-}
+ggplot <- S7::new_class(
+  name = "ggplot", parent = gg,
+  properties = list(
+    data        = S7::class_any,
+    layers      = S7::class_list,
+    scales      = class_scales_list,
+    guides      = class_guides,
+    mapping     = class_aes,
+    theme       = class_theme,
+    coordinates = class_coord,
+    facet       = class_facet,
+    labels      = S7::class_list,
+    plot_env    = S7::class_environment
+  ),
+  constructor = function(data = NULL, mapping = aes(), ...,
+                         environment = parent.frame()) {
 
-#' @export
-ggplot.default <- function(data = NULL, mapping = aes(), ...,
-                           environment = parent.frame()) {
-  if (!missing(mapping) && !inherits(mapping, "uneval")) {
-    cli::cli_abort(c(
-      "{.arg mapping} should be created with {.fn aes}.",
-      "x" = "You've supplied a {.cls {class(mapping)[1]}} object"
-    ))
-  }
+    if (!missing(mapping) && !inherits(mapping, "uneval")) {
+      cli::cli_abort(c(
+        "{.arg mapping} should be created with {.fn aes}.",
+        "x" = "You've supplied a {.cls {class(mapping)[1]}} object."
+      ))
+    }
 
-  data <- fortify(data, ...)
+    if (is.function(data)) {
+      cli::cli_abort(c(
+        "{.arg data} cannot be a function.",
+        "i" = "Have you misspelled the {.arg data} argument in {.fn ggplot}?"
+      ))
+    }
 
-  p <- structure(list(
-    data = data,
-    layers = list(),
-    scales = scales_list(),
-    guides = guides_list(),
-    mapping = mapping,
-    theme = list(),
-    coordinates = coord_cartesian(default = TRUE),
-    facet = facet_null(),
-    plot_env = environment
-  ), class = c("gg", "ggplot"))
+    data <- fortify(data, ...)
 
-  p$labels <- make_labels(mapping)
+    obj <- S7::new_object(
+      S7::S7_object(),
+      data    = data,
+      layers  = list(),
+      scales  = scales_list(),
+      guides  = guides_list(),
+      mapping = mapping,
+      theme   = theme(),
+      coordinates = coord_cartesian(default = TRUE),
+      facet   = facet_null(),
+      labels  = make_labels(mapping),
+      plot_env = environment
+    )
+
+    set_last_plot(obj)
+    obj
+  }
+)
 
-  set_last_plot(p)
-  p
 }
 
-#' @export
-ggplot.function <- function(data = NULL, mapping = aes(), ...,
-                            environment = parent.frame()) {
-  # Added to avoid functions end in ggplot.default
-  cli::cli_abort(c(
-    "{.arg data} cannot be a function.",
-    "i" = "Have you misspelled the {.arg data} argument in {.fn ggplot}"
-  ))
 }
 
 plot_clone <- function(plot) {

From 92f1e000f56ee10cfbf3f7c68c53966595f75a91 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Mon, 27 Nov 2023 16:50:19 +0100
Subject: [PATCH 08/13] adapt methods

---
 R/plot-construction.R | 39 ++++++++++++++++++++++-----------------
 R/plot.R              |  7 +++++++
 2 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/R/plot-construction.R b/R/plot-construction.R
index ec8060d88f..2648dcde68 100644
--- a/R/plot-construction.R
+++ b/R/plot-construction.R
@@ -1,3 +1,6 @@
+#' @include plot.R
+NULL
+
 #' Add components to a plot
 #'
 #' `+` is the key to constructing sophisticated ggplot2 graphics. It
@@ -91,25 +94,25 @@ add_ggplot <- function(p, object, objectname) {
 #' @export
 ggplot_add <- S7::new_generic("ggplot_add", c("object", "plot"))
 
-S7::method(ggplot_add, list(S7::class_any, class_ggplot)) <-
+S7::method(ggplot_add, list(S7::class_any, ggplot)) <-
   function(object, plot, object_name) {
     cli::cli_abort("Can't add {.var {object_name}} to a {.cls ggplot} object.")
   }
 
 # Cannot currently double dispatch on NULL directly
 # replace `S7::new_S3_class("NULL")` with `NULL` when S7 version > 0.1.1
-S7::method(ggplot_add, list(S7::new_S3_class("NULL"), class_ggplot)) <-
+S7::method(ggplot_add, list(S7::new_S3_class("NULL"), ggplot)) <-
   function(object, plot, object_name) {
     plot
   }
 
-S7::method(ggplot_add, list(S7::class_data.frame, class_ggplot)) <-
+S7::method(ggplot_add, list(S7::class_data.frame, ggplot)) <-
   function(object, plot, object_name) {
     plot$data <- object
     plot
   }
 
-S7::method(ggplot_add, list(S7::class_function, class_ggplot)) <-
+S7::method(ggplot_add, list(S7::class_function, ggplot)) <-
   function(object, plot, object_name) {
     cli::cli_abort(c(
       "Can't add {.var {object_name}} to a {.cls ggplot} object",
@@ -117,40 +120,42 @@ S7::method(ggplot_add, list(S7::class_function, class_ggplot)) <-
     ))
   }
 
-S7::method(ggplot_add, list(class_theme, class_ggplot)) <-
+S7::method(ggplot_add, list(class_theme, ggplot)) <-
   function(object, plot, object_name) {
     plot$theme <- add_theme(plot$theme, object)
     plot
   }
 
-S7::method(ggplot_add, list(class_scale, class_ggplot)) <-
+S7::method(ggplot_add, list(class_scale, ggplot)) <-
   function(object, plot, object_name) {
     plot$scales$add(object)
     plot
   }
 
-S7::method(ggplot_add, list(class_labels, class_ggplot)) <-
+S7::method(ggplot_add, list(class_labels, ggplot)) <-
   function(object, plot, object_name) {
     update_labels(plot, object)
   }
 
-S7::method(ggplot_add, list(class_guides, class_ggplot)) <-
+S7::method(ggplot_add, list(class_guides, ggplot)) <-
   function(object, plot, object_name) {
     update_guides(plot, object)
   }
 
-S7::method(ggplot_add, list(class_aes, class_ggplot)) <-
+S7::method(ggplot_add, list(class_aes, ggplot)) <-
   function(object, plot, object_name) {
-    plot$mapping <- defaults(object, plot$mapping)
+    mapping <- defaults(object, plot$mapping)
     # defaults() doesn't copy class, so copy it.
-    class(plot$mapping) <- class(object)
+    class(mapping) <- class(object)
+    S7::prop(plot, "mapping") <- mapping
+
 
     labels <- make_labels(object)
     names(labels) <- names(object)
     update_labels(plot, labels)
   }
 
-S7::method(ggplot_add, list(class_coord, class_ggplot)) <-
+S7::method(ggplot_add, list(class_coord, ggplot)) <-
   function(object, plot, object_name) {
     if (!isTRUE(plot$coordinates$default)) {
       cli::cli_inform("Coordinate system already present. Adding new coordinate system, which will replace the existing one.")
@@ -160,13 +165,13 @@ S7::method(ggplot_add, list(class_coord, class_ggplot)) <-
     plot
   }
 
-S7::method(ggplot_add, list(class_facet, class_ggplot)) <-
+S7::method(ggplot_add, list(class_facet, ggplot)) <-
   function(object, plot, object_name) {
     plot$facet <- object
     plot
   }
 
-S7::method(ggplot_add, list(S7::class_list, class_ggplot)) <-
+S7::method(ggplot_add, list(S7::class_list, ggplot)) <-
   function(object, plot, object_name) {
     for (o in object) {
       plot <- plot %+% o
@@ -174,14 +179,14 @@ S7::method(ggplot_add, list(S7::class_list, class_ggplot)) <-
     plot
   }
 
-S7::method(ggplot_add, list(class_by, class_ggplot)) <-
+S7::method(ggplot_add, list(class_by, ggplot)) <-
   function(object, plot, object_name) {
-    S7::method(ggplot_add, list(class_list, class_ggplot))(
+    S7::method(ggplot_add, list(class_list, ggplot))(
       object, plot, object_name
     )
   }
 
-S7::method(ggplot_add, list(class_layer, class_ggplot)) <-
+S7::method(ggplot_add, list(class_layer, ggplot)) <-
   function(object, plot, object_name) {
     plot$layers <- append(plot$layers, object)
 
diff --git a/R/plot.R b/R/plot.R
index 794dc49eb4..5876772c4b 100644
--- a/R/plot.R
+++ b/R/plot.R
@@ -156,8 +156,15 @@ ggplot <- S7::new_class(
   }
 )
 
+S7::method(`$`, ggplot) <- function(x, i) {
+  if (!S7::prop_exists(x, i)) {
+    return(NULL)
+  }
+  S7::prop(x, i)
 }
 
+S7::method(`$<-`, ggplot) <- function(x, ...) {
+  S7::`prop<-`(x, ...)
 }
 
 plot_clone <- function(plot) {

From 33f242b69d91a4c4cf502c8f9d0c488b114e5954 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Mon, 27 Nov 2023 16:51:04 +0100
Subject: [PATCH 09/13] roxygenate

---
 DESCRIPTION                   | 3 ++-
 NAMESPACE                     | 2 --
 tests/testthat/_snaps/plot.md | 4 ++--
 3 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/DESCRIPTION b/DESCRIPTION
index 3d44dff8ec..e90be52897 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -91,6 +91,7 @@ Collate:
     'compat-plyr.R'
     'utilities.R'
     'aes.R'
+    'all-classes.R'
     'utilities-checks.R'
     'legend-draw.R'
     'geom-.R'
@@ -197,9 +198,9 @@ Collate:
     'margins.R'
     'performance.R'
     'plot-build.R'
+    'plot.R'
     'plot-construction.R'
     'plot-last.R'
-    'plot.R'
     'position-.R'
     'position-collide.R'
     'position-dodge.R'
diff --git a/NAMESPACE b/NAMESPACE
index b24d627889..c3a6b4c81e 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -49,8 +49,6 @@ S3method(fortify,tbl_df)
 S3method(get_alt_text,ggplot)
 S3method(get_alt_text,ggplot_built)
 S3method(get_alt_text,gtable)
-S3method(ggplot,"function")
-S3method(ggplot,default)
 S3method(ggplot_build,ggplot)
 S3method(ggplot_gtable,ggplot_built)
 S3method(grid.draw,absoluteGrob)
diff --git a/tests/testthat/_snaps/plot.md b/tests/testthat/_snaps/plot.md
index 6dd7cfd427..85882c7ccd 100644
--- a/tests/testthat/_snaps/plot.md
+++ b/tests/testthat/_snaps/plot.md
@@ -1,12 +1,12 @@
 # ggplot() throws informative errors
 
     `mapping` should be created with `aes()`.
-    x You've supplied a <character> object
+    x You've supplied a <character> object.
 
 ---
 
     `data` cannot be a function.
-    i Have you misspelled the `data` argument in `ggplot()`
+    i Have you misspelled the `data` argument in `ggplot()`?
 
 # construction have user friendly errors
 

From 1fc5bea097bbefcb35233fc0e066bec0f94b0abe Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Mon, 27 Nov 2023 16:57:15 +0100
Subject: [PATCH 10/13] add method registration

---
 R/zzz.R | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/R/zzz.R b/R/zzz.R
index 0dcfd407cf..3158922541 100644
--- a/R/zzz.R
+++ b/R/zzz.R
@@ -30,6 +30,10 @@ on_load(
     vars <- dplyr::vars
   }
 )
+on_load(
+  S7::methods_register()
+)
+
 .onLoad <- function(...) {
   run_on_load()
 }

From 75b860c9d808920d28e2b2269025cf829c50ceb2 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Tue, 28 Nov 2023 10:21:03 +0100
Subject: [PATCH 11/13] Bring back classic `ggplot()`

---
 NAMESPACE             |  3 ++
 R/plot-construction.R | 28 +++++++-------
 R/plot.R              | 89 ++++++++++++++++++++++++-------------------
 3 files changed, 66 insertions(+), 54 deletions(-)

diff --git a/NAMESPACE b/NAMESPACE
index c3a6b4c81e..7dd13e633a 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -49,6 +49,8 @@ S3method(fortify,tbl_df)
 S3method(get_alt_text,ggplot)
 S3method(get_alt_text,ggplot_built)
 S3method(get_alt_text,gtable)
+S3method(ggplot,"function")
+S3method(ggplot,default)
 S3method(ggplot_build,ggplot)
 S3method(ggplot_gtable,ggplot_built)
 S3method(grid.draw,absoluteGrob)
@@ -212,6 +214,7 @@ export(PositionJitter)
 export(PositionJitterdodge)
 export(PositionNudge)
 export(PositionStack)
+export(S7_ggplot)
 export(Scale)
 export(ScaleBinned)
 export(ScaleBinnedPosition)
diff --git a/R/plot-construction.R b/R/plot-construction.R
index 2648dcde68..6b04a20502 100644
--- a/R/plot-construction.R
+++ b/R/plot-construction.R
@@ -94,25 +94,25 @@ add_ggplot <- function(p, object, objectname) {
 #' @export
 ggplot_add <- S7::new_generic("ggplot_add", c("object", "plot"))
 
-S7::method(ggplot_add, list(S7::class_any, ggplot)) <-
+S7::method(ggplot_add, list(S7::class_any, S7_ggplot)) <-
   function(object, plot, object_name) {
     cli::cli_abort("Can't add {.var {object_name}} to a {.cls ggplot} object.")
   }
 
 # Cannot currently double dispatch on NULL directly
 # replace `S7::new_S3_class("NULL")` with `NULL` when S7 version > 0.1.1
-S7::method(ggplot_add, list(S7::new_S3_class("NULL"), ggplot)) <-
+S7::method(ggplot_add, list(S7::new_S3_class("NULL"), S7_ggplot)) <-
   function(object, plot, object_name) {
     plot
   }
 
-S7::method(ggplot_add, list(S7::class_data.frame, ggplot)) <-
+S7::method(ggplot_add, list(S7::class_data.frame, S7_ggplot)) <-
   function(object, plot, object_name) {
     plot$data <- object
     plot
   }
 
-S7::method(ggplot_add, list(S7::class_function, ggplot)) <-
+S7::method(ggplot_add, list(S7::class_function, S7_ggplot)) <-
   function(object, plot, object_name) {
     cli::cli_abort(c(
       "Can't add {.var {object_name}} to a {.cls ggplot} object",
@@ -120,29 +120,29 @@ S7::method(ggplot_add, list(S7::class_function, ggplot)) <-
     ))
   }
 
-S7::method(ggplot_add, list(class_theme, ggplot)) <-
+S7::method(ggplot_add, list(class_theme, S7_ggplot)) <-
   function(object, plot, object_name) {
     plot$theme <- add_theme(plot$theme, object)
     plot
   }
 
-S7::method(ggplot_add, list(class_scale, ggplot)) <-
+S7::method(ggplot_add, list(class_scale, S7_ggplot)) <-
   function(object, plot, object_name) {
     plot$scales$add(object)
     plot
   }
 
-S7::method(ggplot_add, list(class_labels, ggplot)) <-
+S7::method(ggplot_add, list(class_labels, S7_ggplot)) <-
   function(object, plot, object_name) {
     update_labels(plot, object)
   }
 
-S7::method(ggplot_add, list(class_guides, ggplot)) <-
+S7::method(ggplot_add, list(class_guides, S7_ggplot)) <-
   function(object, plot, object_name) {
     update_guides(plot, object)
   }
 
-S7::method(ggplot_add, list(class_aes, ggplot)) <-
+S7::method(ggplot_add, list(class_aes, S7_ggplot)) <-
   function(object, plot, object_name) {
     mapping <- defaults(object, plot$mapping)
     # defaults() doesn't copy class, so copy it.
@@ -155,7 +155,7 @@ S7::method(ggplot_add, list(class_aes, ggplot)) <-
     update_labels(plot, labels)
   }
 
-S7::method(ggplot_add, list(class_coord, ggplot)) <-
+S7::method(ggplot_add, list(class_coord, S7_ggplot)) <-
   function(object, plot, object_name) {
     if (!isTRUE(plot$coordinates$default)) {
       cli::cli_inform("Coordinate system already present. Adding new coordinate system, which will replace the existing one.")
@@ -165,13 +165,13 @@ S7::method(ggplot_add, list(class_coord, ggplot)) <-
     plot
   }
 
-S7::method(ggplot_add, list(class_facet, ggplot)) <-
+S7::method(ggplot_add, list(class_facet, S7_ggplot)) <-
   function(object, plot, object_name) {
     plot$facet <- object
     plot
   }
 
-S7::method(ggplot_add, list(S7::class_list, ggplot)) <-
+S7::method(ggplot_add, list(S7::class_list, S7_ggplot)) <-
   function(object, plot, object_name) {
     for (o in object) {
       plot <- plot %+% o
@@ -179,14 +179,14 @@ S7::method(ggplot_add, list(S7::class_list, ggplot)) <-
     plot
   }
 
-S7::method(ggplot_add, list(class_by, ggplot)) <-
+S7::method(ggplot_add, list(class_by, S7_ggplot)) <-
   function(object, plot, object_name) {
     S7::method(ggplot_add, list(class_list, ggplot))(
       object, plot, object_name
     )
   }
 
-S7::method(ggplot_add, list(class_layer, ggplot)) <-
+S7::method(ggplot_add, list(class_layer, S7_ggplot)) <-
   function(object, plot, object_name) {
     plot$layers <- append(plot$layers, object)
 
diff --git a/R/plot.R b/R/plot.R
index 5876772c4b..3d50ada468 100644
--- a/R/plot.R
+++ b/R/plot.R
@@ -104,7 +104,52 @@ gg <- S7::new_class("gg", abstract = TRUE)
 #'     mapping = aes(x = group, y = group_mean), data = group_means_df,
 #'     colour = 'red', size = 3
 #'   )
-ggplot <- S7::new_class(
+ggplot <- function(data = NULL, mapping = aes(), ...,
+                   environment = parent.frame()) {
+  UseMethod("ggplot")
+}
+
+#' @export
+ggplot.default <- function(data = NULL, mapping = aes(), ...,
+                           environment = parent.frame()) {
+  if (!missing(mapping) && !inherits(mapping, "uneval")) {
+    cli::cli_abort(c(
+      "{.arg mapping} should be created with {.fn aes}.",
+      "x" = "You've supplied a {.cls {class(mapping)[1]}} object."
+    ))
+  }
+
+  data <- fortify(data, ...)
+
+  p <- S7_ggplot(
+    data    = data,
+    layers  = list(),
+    scales  = scales_list(),
+    guides  = guides_list(),
+    mapping = mapping,
+    theme   = theme(),
+    coordinates = coord_cartesian(default = TRUE),
+    facet   = facet_null(),
+    labels  = make_labels(mapping),
+    plot_env = environment
+  )
+
+  set_last_plot(p)
+  p
+}
+
+#' @export
+ggplot.function <- function(data = NULL, mapping = aes(), ...,
+                            environment = parent.frame()) {
+  cli::cli_abort(c(
+    "{.arg data} cannot be a function.",
+    "i" = "Have you misspelled the {.arg data} argument in {.fn ggplot}?"
+  ))
+}
+
+#' @export
+#' @rdname ggplot
+S7_ggplot <- S7::new_class(
   name = "ggplot", parent = gg,
   properties = list(
     data        = S7::class_any,
@@ -117,53 +162,17 @@ ggplot <- S7::new_class(
     facet       = class_facet,
     labels      = S7::class_list,
     plot_env    = S7::class_environment
-  ),
-  constructor = function(data = NULL, mapping = aes(), ...,
-                         environment = parent.frame()) {
-
-    if (!missing(mapping) && !inherits(mapping, "uneval")) {
-      cli::cli_abort(c(
-        "{.arg mapping} should be created with {.fn aes}.",
-        "x" = "You've supplied a {.cls {class(mapping)[1]}} object."
-      ))
-    }
-
-    if (is.function(data)) {
-      cli::cli_abort(c(
-        "{.arg data} cannot be a function.",
-        "i" = "Have you misspelled the {.arg data} argument in {.fn ggplot}?"
-      ))
-    }
-
-    data <- fortify(data, ...)
-
-    obj <- S7::new_object(
-      S7::S7_object(),
-      data    = data,
-      layers  = list(),
-      scales  = scales_list(),
-      guides  = guides_list(),
-      mapping = mapping,
-      theme   = theme(),
-      coordinates = coord_cartesian(default = TRUE),
-      facet   = facet_null(),
-      labels  = make_labels(mapping),
-      plot_env = environment
-    )
-
-    set_last_plot(obj)
-    obj
-  }
+  )
 )
 
-S7::method(`$`, ggplot) <- function(x, i) {
+S7::method(`$`, S7_ggplot) <- function(x, i) {
   if (!S7::prop_exists(x, i)) {
     return(NULL)
   }
   S7::prop(x, i)
 }
 
-S7::method(`$<-`, ggplot) <- function(x, ...) {
+S7::method(`$<-`, S7_ggplot) <- function(x, ...) {
   S7::`prop<-`(x, ...)
 }
 

From 7e7a0b1a6c64c5d07bd54fe7961a26adbd5cad19 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Tue, 28 Nov 2023 10:23:19 +0100
Subject: [PATCH 12/13] deal with bug

---
 R/plot.R | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/R/plot.R b/R/plot.R
index 3d50ada468..6df6b50437 100644
--- a/R/plot.R
+++ b/R/plot.R
@@ -176,6 +176,9 @@ S7::method(`$<-`, S7_ggplot) <- function(x, ...) {
   S7::`prop<-`(x, ...)
 }
 
+# Deal with S7 bug: https://github.com/RConsortium/S7/issues/390
+rm(`$`, `$<-`)
+
 plot_clone <- function(plot) {
   p <- plot
   p$scales <- plot$scales$clone()

From 30edf644c04edd9afd444617367a056c3ccbfb61 Mon Sep 17 00:00:00 2001
From: Teun van den Brand <tahvdbrand@gmail.com>
Date: Tue, 28 Nov 2023 10:45:08 +0100
Subject: [PATCH 13/13] Document S7_ggplot class separately

---
 R/plot.R         | 31 +++++++++++++++++++++++++-
 man/S7_ggplot.Rd | 58 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 88 insertions(+), 1 deletion(-)
 create mode 100644 man/S7_ggplot.Rd

diff --git a/R/plot.R b/R/plot.R
index 6df6b50437..818a34ca70 100644
--- a/R/plot.R
+++ b/R/plot.R
@@ -147,8 +147,37 @@ ggplot.function <- function(data = NULL, mapping = aes(), ...,
   ))
 }
 
+#' ggplot class
+#'
+#' The ggplot class is implemented using S7 and has properties needed to
+#' build and render a plot.
+#'
+#' @param data Any object that can be used with [`fortify()`] to yield a
+#'   `<data.frame>`.
+#' @param layers A `<list>` containing `<LayerInstance>` objects. Typically
+#'   an empty `<list>` that will be filled when adding layers using `+`.
+#' @param scales A `<ScalesList>` ggproto object that manages scales that
+#'   are added to the plot.
+#' @param guides A `<Guides>` ggproto object that manages guides that are
+#'   added to the plot.
+#' @param mapping An `<uneval>` object constructed with [`aes()`] containing
+#'   the default aesthetic mappings.
+#' @param theme A `<theme>` object constructed with [`theme()`] containing
+#'   non-data visual settings.
+#' @param coordinates A `<Coord>` ggproto object that manages the interpretation
+#'   of position aesthetics.
+#' @param facet A `<Facet>` ggproto object that manages the display of data
+#'   subsets.
+#' @param labels A named `<list>` of `character`s and `expression`s giving
+#'   aesthetic-label pairs.
+#' @param plot_env An `<environment>` in which the plot was created.
+#'
+#' @details
+#' The purpose of the ggplot class object is to allow developers to extend
+#' their own versions of a ggplot class. Users should instead use the
+#' [`ggplot()`] interface to construct a new plot.
+#'
 #' @export
-#' @rdname ggplot
 S7_ggplot <- S7::new_class(
   name = "ggplot", parent = gg,
   properties = list(
diff --git a/man/S7_ggplot.Rd b/man/S7_ggplot.Rd
new file mode 100644
index 0000000000..f413d55ce8
--- /dev/null
+++ b/man/S7_ggplot.Rd
@@ -0,0 +1,58 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/plot.R
+\name{S7_ggplot}
+\alias{S7_ggplot}
+\title{ggplot class}
+\usage{
+S7_ggplot(
+  data = class_missing,
+  layers = class_missing,
+  scales = class_missing,
+  guides = class_missing,
+  mapping = class_missing,
+  theme = class_missing,
+  coordinates = class_missing,
+  facet = class_missing,
+  labels = class_missing,
+  plot_env = class_missing
+)
+}
+\arguments{
+\item{data}{Any object that can be used with \code{\link[=fortify]{fortify()}} to yield a
+\verb{<data.frame>}.}
+
+\item{layers}{A \verb{<list>} containing \verb{<LayerInstance>} objects. Typically
+an empty \verb{<list>} that will be filled when adding layers using \code{+}.}
+
+\item{scales}{A \verb{<ScalesList>} ggproto object that manages scales that
+are added to the plot.}
+
+\item{guides}{A \verb{<Guides>} ggproto object that manages guides that are
+added to the plot.}
+
+\item{mapping}{An \verb{<uneval>} object constructed with \code{\link[=aes]{aes()}} containing
+the default aesthetic mappings.}
+
+\item{theme}{A \verb{<theme>} object constructed with \code{\link[=theme]{theme()}} containing
+non-data visual settings.}
+
+\item{coordinates}{A \verb{<Coord>} ggproto object that manages the interpretation
+of position aesthetics.}
+
+\item{facet}{A \verb{<Facet>} ggproto object that manages the display of data
+subsets.}
+
+\item{labels}{A named \verb{<list>} of \code{character}s and \code{expression}s giving
+aesthetic-label pairs.}
+
+\item{plot_env}{An \verb{<environment>} in which the plot was created.}
+}
+\description{
+The ggplot class is implemented using S7 and has properties needed to
+build and render a plot.
+}
+\details{
+The purpose of the ggplot class object is to allow developers to extend
+their own versions of a ggplot class. Users should instead use the
+\code{\link[=ggplot]{ggplot()}} interface to construct a new plot.
+}