Allow selecting the style used by RStudio addins.

* "styler.addins.style" option stores the selected style.
* New addin to set the style.
* Existing addins adapted to use the selected style.

Author: riccardoporreca

R/addins.R

@@ -20,8 +20,9 @@ NULL
 #'   `strict = TRUE`.
 #' @keywords internal
 style_active_file <- function() {
+  communicate_addins_style()
   context <- get_rstudio_context()
-  transformer <- make_transformer(tidyverse_style(),
+  transformer <- make_transformer(get_addins_style_fun()(),
     include_roxygen_examples = TRUE, warn_empty = is_plain_r_file(context$path)
   )
 
@@ -78,10 +79,11 @@ try_transform_as_r_file <- function(context, transformer) {
 #'   `.Rmd` file.
 #' @keywords internal
 style_selection <- function() {
+  communicate_addins_style()
   context <- get_rstudio_context()
   text <- context$selection[[1]]$text
   if (all(nchar(text) == 0)) stop("No code selected")
-  out <- style_text(text)
+  out <- style_text(text, style = get_addins_style_fun())
   rstudioapi::modifyRange(
     context$selection[[1]]$range, paste0(out, collapse = "\n"),
     id = context$id
@@ -94,3 +96,78 @@ style_selection <- function() {
 get_rstudio_context <- function() {
   rstudioapi::getActiveDocumentContext()
 }
+
+
+# Dedicated binding for package styling addin. Simple wrapper calling style_pkg
+# with the selected addins style.
+style_package <- function() {
+  communicate_addins_style()
+  style_pkg(style = get_addins_style_fun())
+}
+
+
+# `match.fun`-like utility covering "ns::name".
+exported_value_rx <- "^([^:]+)::([^:]+)$"
+is_exported_value <- function(x) {
+  rlang::is_scalar_character(x) && grepl(exported_value_rx, x)
+}
+extract_exported_ns <- function(x) {
+  sub(exported_value_rx, "\\1", x)
+}
+extract_exported_name <- function(x) {
+  sub(exported_value_rx, "\\2", x)
+}
+match_fun <- function(x) {
+  if (is_exported_value(x)) {
+    x <-
+      getExportedValue(
+        extract_exported_ns(x),
+        extract_exported_name(x)
+      )
+  }
+  match.fun(x)
+}
+
+# Binding for style-setting addin.
+prompt_style <- function() {
+  current_style <- get_addins_style()
+  new_style <-
+    rstudioapi::showPrompt(
+      "Select a style",
+      "Enter the name of a style function, e.g. `styler::tidyverse_style`",
+      current_style
+    )
+  if (!is.null(new_style)) {
+    set_addins_style(new_style)
+  }
+  invisible(current_style)
+}
+
+# Set/get style used by the addins.
+set_addins_style <- function(style_name) {
+  # match_fun ensures the provided name is a valid function
+  invisible(match_fun(style_name))
+  options(
+    styler.addins.style = style_name
+  )
+}
+
+get_addins_style <- function() {
+  # `default` could be an environment variable
+  getOption(
+    "styler.addins.style",
+    default = "styler::tidyverse_style"
+  )
+}
+
+get_addins_style_fun <- function() {
+  match_fun(
+    get_addins_style()
+  )
+}
+
+# How the addins communicate the style being used.
+communicate_addins_style <- function() {
+  style_name <- get_addins_style()
+  cat("Using style `", style_name, "`\n", sep = "")
+}

inst/rstudio/addins.dcf

@@ -1,6 +1,11 @@
+Name: Set style
+Description: Prompt for and set the style used by all STYLER addins
+Binding: prompt_style
+Interactive: true
+
 Name: Style package
 Description: Pretty-print package source code
-Binding: style_pkg
+Binding: style_package
 Interactive: true
 
 Name: Style active file