Palette infrastructure

NAMESPACE

@@ -33,6 +33,8 @@ export(ansi_hide_cursor)
 export(ansi_html)
 export(ansi_html_style)
 export(ansi_nchar)
+export(ansi_palette_show)
+export(ansi_palettes)
 export(ansi_regex)
 export(ansi_show_cursor)
 export(ansi_simplify)
@@ -213,6 +215,7 @@ export(symbol)
 export(test_that_cli)
 export(ticking)
 export(tree)
+export(truecolor)
 export(utf8_graphemes)
 export(utf8_nchar)
 export(utf8_substr)

NEWS.md

@@ -1,5 +1,8 @@
 # cli (development version)
 
+* Support for palettes, including a colorblind friendly palette.
+  See `?ansi_palettes` for details.
+
 * True color support: `num_ansi_colors()` now detects terminals with
   24 bit color support, and `make_ansi_style()` uses the exact RGB colors
   on these terminals.

R/ansi-palette.R

@@ -0,0 +1,219 @@
+
+get_palette_color <- function(style, colors = num_ansi_colors()) {
+  opt <- getOption("cli.palette")
+  if (is.null(opt) || colors < 256) return(style)
+  cache_palette_color(opt, style$palette, colors)
+}
+
+palette_cache <- new.env(parent = emptyenv())
+
+cache_palette_color <- function(pal, idx, colors = num_ansi_colors()) {
+  if (is_string(pal)) {
+    if (! pal %in% rownames(ansi_palettes)) {
+      stop("Cannot find cli ANSI palette '", pal, "'.")
+    }
+    pal <- ansi_palettes[pal, ]
+  }
+
+  bg <- idx < 0
+  idx <- abs(idx)
+  col <- pal[[idx]]
+
+  colkey <- as.character(colors)
+  key <- paste0(col, bg)
+  if (key %in% names(palette_cache[[colkey]])) {
+    return(palette_cache[[colkey]][[key]])
+  }
+
+  val <- ansi_style_from_r_color(
+    col,
+    bg = bg,
+    colors,
+    grey = FALSE
+  )
+
+  if (is.null(palette_cache[[colkey]])) {
+    palette_cache[[colkey]] <- new.env(parent = emptyenv())
+  }
+  palette_cache[[colkey]][[key]] <- val
+
+  return(val)
+}
+
+#' @details
+#' `truecolor` is an integer constant for the number of 24 bit ANSI colors.
+#'
+#' @format `truecolor` is an integer scalar.
+#'
+#' @export
+#' @rdname ansi_palettes
+
+truecolor <- as.integer(256 ^ 3)
+
+#' ANSI colors palettes
+#'
+#' If your platform supports at least 256 colors, then you can configure
+#' the colors that cli uses for the eight base and the eight bright colors.
+#' (I.e. the colors of [col_black()], [col_red()], and [col_br_black()],
+#' [col_br_red()], etc.
+#'
+#' To customize the default palette, set the `cli.palette` option to the
+#' name of a built-in palette (see `ansi_palettes()`), or the list of
+#' 16 colors. Colors can be specified with RGB colors strings:
+#' `#rrggbb` or R color names (see the output of [grDevices::colors()]).
+#'
+#' For example, you can put this in your R profile:
+#' ```r
+#' options(cli.palette = "vscode")
+#' ```
+#'
+#' It is currently not possible to configure the background colors
+#' separately, these will be always the same as the foreground colors.
+#'
+#' If your platform only has 256 colors, then the colors specified in the
+#' palette have to be interpolated. On true color platforms they RGB
+#' values are used as-is.
+#'
+#' `ansi_palettes` is a data frame of the built-in palettes, each row
+#' is one palette.
+#'
+#' `ansi_palette_show()` shows the colors of an ANSI palette on the screen.
+#'
+#' @format `ansi_palettes` is a data frame with one row for each palette,
+#'   and one column for each base ANSI color. `attr(ansi_palettes, "info")`
+#'   contains a list with information about each palette.
+#'
+#' @export
+#' @examples
+#' ansi_palettes
+#' ansi_palette_show("dichro", colors = truecolor)
+
+ansi_palettes <- rbind(
+  read.table(
+    "tools/ansi-palettes.txt",
+    comment = ";",
+    stringsAsFactors = FALSE
+  ),
+  read.table(
+    "tools/ansi-iterm-palettes.txt",
+    comment = ";",
+    stringsAsFactors = FALSE
+  )
+)
+
+attr(ansi_palettes, "info") <-
+  list(
+    dichro = paste(
+      "Colorblind friendly palette, from",
+      "https://github.com/romainl/vim-dichromatic#dichromatic."
+    ),
+    vga = paste(
+      "Typical colors that are used when booting PCs and leaving them in",
+      "text mode, which used a 16-entry color table. The colors are",
+      "different in the EGA/VGA graphic modes.",
+      "From https://en.wikipedia.org/wiki/ANSI_escape_code#SGR."
+    ),
+    winxp = paste(
+      "Windows XP Console. Seen in Windows XP through Windows 8.1.",
+      "From https://en.wikipedia.org/wiki/ANSI_escape_code#SGR."
+    ),
+    vscode = paste(
+      "Visual Studio Debug console, 'Dark+' theme.",
+      "From https://en.wikipedia.org/wiki/ANSI_escape_code#SGR."
+    ),
+    win10 = paste0(
+      "Campbell theme, used as of Windows 10 version 1709. Also used",
+      "by PowerShell 6.",
+      "From https://en.wikipedia.org/wiki/ANSI_escape_code#SGR."
+    ),
+    macos = paste0(
+      "Terminal.app in macOS",
+      "From https://en.wikipedia.org/wiki/ANSI_escape_code#SGR."
+    ),
+    putty = paste0(
+      "From https://en.wikipedia.org/wiki/ANSI_escape_code#SGR."
+    ),
+    mirc = paste0(
+      "From https://en.wikipedia.org/wiki/ANSI_escape_code#SGR."
+    ),
+    xterm = paste0(
+      "From https://en.wikipedia.org/wiki/ANSI_escape_code#SGR."
+    ),
+    ubuntu = paste0(
+      "For virtual terminals, from /etc/vtrgb.",
+      "From https://en.wikipedia.org/wiki/ANSI_escape_code#SGR."
+    ),
+    eclipse = paste0(
+      "From https://en.wikipedia.org/wiki/ANSI_escape_code#SGR."
+    ),
+    iterm = "Built-in iTerm2 theme.",
+    "iterm-pastel" = "Built-In iTerm2 theme.",
+    "iterm-smoooooth" = "Built-In iTerm2 theme.",
+    "iterm-snazzy" = "From https://github.com/sindresorhus/iterm2-snazzy.",
+    "iterm-solarized" = "Built-In iTerm2 theme.",
+    "iterm-tango" = "Built-In iTerm2 theme."
+  )
+
+#' @param palette The palette to show, in the same format as for the
+#'   `cli.palette` option, so it can be the name of a built-in palette,
+#'   of a list of 16 colors.
+#' @param colors Number of ANSI colors to use the show the palette. If the
+#'   platform does not have sufficient support, the output might have
+#'   a lower color resolution. Without color support it will have no color
+#'   at all.
+#' @param rows The number of colored rows to print.
+#' @return `ansi_palette_show` returns a character vector, the rows that
+#'   are printed to the screen, invisibly.
+#'
+#' @export
+#' @rdname ansi_palettes
+
+ansi_palette_show <- function(palette = NULL, colors = num_ansi_colors(),
+                              rows = 4) {
+  opts <- options(
+    cli.palette = palette %||% getOption("cli.palette"),
+    cli.num_colors = colors
+  )
+  on.exit(options(opts), add = TRUE)
+
+  blk <- strrep(symbol$lower_block_8, 4)
+  blks <- c(
+    "blck" = col_black(blk),
+    "red " = col_red(blk),
+    "grn " = col_green(blk),
+    "yllw" = col_yellow(blk),
+    "blue" = col_blue(blk),
+    "mgnt" = col_magenta(blk),
+    "cyan" = col_cyan(blk),
+    "whte" = col_white(blk),
+    "blck" = col_br_black(blk),
+    "red " = col_br_red(blk),
+    "grn " = col_br_green(blk),
+    "yllw" = col_br_yellow(blk),
+    "blue" = col_br_blue(blk),
+    "mgnt" = col_br_magenta(blk),
+    "cyan" = col_br_cyan(blk),
+    "whte" = col_br_white(blk)
+  )
+
+  join <- function(x) {
+    paste0(
+      paste(x[1:8], collapse = " "),
+      "  ",
+      paste(x[9:16], collapse = " ")
+    )
+  }
+
+  nms <- join(names(blks))
+  str <- join(blks)
+
+  out <- c(
+    paste(strrep(" ", 52), "bright variants"),
+    nms,
+    "",
+    rep(str, rows)
+  )
+
+  cat_line(out)
+  invisible(out)
+}

R/ansi.R

@@ -1,5 +1,21 @@
 
-TRUE_COLORS <- as.integer(256^3)
+palette_idx <- function(id) {
+  ifelse(
+    id < 38,
+    id - (30 - 1),
+  ifelse(
+    id < 48,
+    -(id - (40 - 1)),
+  ifelse(
+    id < 98,
+    id - (90 - 9),
+    -(id - (100 - 9))
+  )))
+}
+
+palette_color <- function(x) {
+  c(x, palette = palette_idx(x[[1]]))
+}
 
 ansi_builtin_styles <- list(
   reset = list(0, c(0, 22, 23, 24, 27, 28, 29, 39, 49)),
@@ -11,42 +27,42 @@ ansi_builtin_styles <- list(
   hidden = list(8, 28),
   strikethrough = list(9, 29),
 
-  black = list(30, 39),
-  red = list(31, 39),
-  green = list(32, 39),
-  yellow = list(33, 39),
-  blue = list(34, 39),
-  magenta = list(35, 39),
-  cyan = list(36, 39),
-  white = list(37, 39),
+  black = palette_color(list(30, 39)),
+  red = palette_color(list(31, 39)),
+  green = palette_color(list(32, 39)),
+  yellow = palette_color(list(33, 39)),
+  blue = palette_color(list(34, 39)),
+  magenta = palette_color(list(35, 39)),
+  cyan = palette_color(list(36, 39)),
+  white = palette_color(list(37, 39)),
   silver = list(90, 39),
 
-  br_black = list(90, 39),
-  br_red = list(91, 39),
-  br_green = list(92, 39),
-  br_yellow = list(93, 39),
-  br_blue = list(94, 39),
-  br_magenta = list(95, 39),
-  br_cyan = list(96, 39),
-  br_white = list(97, 39),
-
-  bg_black = list(40, 49),
-  bg_red = list(41, 49),
-  bg_green = list(42, 49),
-  bg_yellow = list(43, 49),
-  bg_blue = list(44, 49),
-  bg_magenta = list(45, 49),
-  bg_cyan = list(46, 49),
-  bg_white = list(47, 49),
-
-  bg_br_black = list(100, 39),
-  bg_br_red = list(101, 39),
-  bg_br_green = list(102, 39),
-  bg_br_yellow = list(103, 39),
-  bg_br_blue = list(104, 39),
-  bg_br_magenta = list(105, 39),
-  bg_br_cyan = list(106, 39),
-  bg_br_white = list(107, 39),
+  br_black = palette_color(list(90, 39)),
+  br_red = palette_color(list(91, 39)),
+  br_green = palette_color(list(92, 39)),
+  br_yellow = palette_color(list(93, 39)),
+  br_blue = palette_color(list(94, 39)),
+  br_magenta = palette_color(list(95, 39)),
+  br_cyan = palette_color(list(96, 39)),
+  br_white = palette_color(list(97, 39)),
+
+  bg_black = palette_color(list(40, 49)),
+  bg_red = palette_color(list(41, 49)),
+  bg_green = palette_color(list(42, 49)),
+  bg_yellow = palette_color(list(43, 49)),
+  bg_blue = palette_color(list(44, 49)),
+  bg_magenta = palette_color(list(45, 49)),
+  bg_cyan = palette_color(list(46, 49)),
+  bg_white = palette_color(list(47, 49)),
+
+  bg_br_black = palette_color(list(100, 39)),
+  bg_br_red = palette_color(list(101, 39)),
+  bg_br_green = palette_color(list(102, 39)),
+  bg_br_yellow = palette_color(list(103, 39)),
+  bg_br_blue = palette_color(list(104, 39)),
+  bg_br_magenta = palette_color(list(105, 39)),
+  bg_br_cyan = palette_color(list(106, 39)),
+  bg_br_white = palette_color(list(107, 39)),
 
   # similar to reset, but only for a single property
   no_bold          = list(c(0,     23, 24, 27, 28, 29, 39, 49), 22),
@@ -97,19 +113,21 @@ ansi_style_str <- function(x) {
   paste0("\u001b[", x, "m", collapse = "")
 }
 
-create_ansi_style_tag <- function(name, open, close) {
+create_ansi_style_tag <- function(name, open, close, palette = NULL) {
   structure(
-    list(list(open = open, close = close)),
+    list(list(open = open, close = close, palette = palette)),
     names = name
   )
 }
 
 create_ansi_style_fun <- function(styles) {
   fun <- eval(substitute(function(...) {
-    mystyles <- .styles
     txt <- paste0(...)
-    if (num_ansi_colors() > 1) {
+    nc <- num_ansi_colors()
+    if (nc > 1) {
+      mystyles <- .styles
       for (st in rev(mystyles)) {
+        if (!is.null(st$palette)) st <- get_palette_color(st, nc)
         txt <- paste0(
           st$open,
           gsub(st$close, st$open, txt, fixed = TRUE),
@@ -129,7 +147,8 @@ create_ansi_style_fun <- function(styles) {
 create_ansi_style <- function(name, open = NULL, close = NULL) {
   open <- open %||% ansi_style_str(ansi_builtin_styles[[name]][[1]])
   close <- close %||% ansi_style_str(ansi_builtin_styles[[name]][[2]])
-  style <- create_ansi_style_tag(name, open, close)
+  palette <- ansi_builtin_styles[[name]]$palette
+  style <- create_ansi_style_tag(name, open, close, palette)
   create_ansi_style_fun(style)
 }
 
@@ -263,7 +282,7 @@ ansi_style_8_from_rgb <- function(rgb, bg) {
 
 ansi_style_from_rgb <- function(rgb, bg, num_colors, grey) {
   if (num_colors < 256) { return(ansi_style_8_from_rgb(rgb, bg)) }
-  if (num_colors < TRUE_COLORS || grey) return(ansi256(rgb, bg, grey))
+  if (num_colors < truecolor || grey) return(ansi256(rgb, bg, grey))
   return(ansitrue(rgb, bg))
 }