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#' Capture a screenshot
#'
#' For the moment, the capture file is in the current working directory and named
#' `screenshot.png`. This will change, soon.
#'
#' A `magick` image object is returned.
#'
#' @md
#' @note The default Chrome filename is `screenshot.png`
#' @param url URL to read from
#' @param width,height screen size to emulate
#' @param path path (with optional output filename) for the generated PDF. If `NULL` then
#' and `overwrite` is `FALSE`, the fuction will will ensure a uniquely-named file is
#' placed in the current working directory by incrementing trailing numbers before
#' the end of it.
#' @param overwrite overwrite existing file? Default: `TRUE`
#' @param chrome_bin the path to Chrome (auto-set from `HEADLESS_CHROME` environment variable)
#' @return `magick`
#' @export
#' @examples
#' chrome_shot("https://www.r-project.org/logo/Rlogo.svg")
chrome_shot <- function(url, width=NULL, height=NULL, path=NULL, overwrite=TRUE,
chrome_bin=Sys.getenv("HEADLESS_CHROME")) {
curwd <- getwd()
on.exit(setwd(curwd), add = TRUE)
if (is.null(path)) path <- "."
path <- normalizePath(path.expand(path[1]))
if (!grepl("\\.pdf$", path)) {
fil_nam <- "screenshot.png"
dir_nam <- path
} else {
fil_nam <- basename(path)
dir_nam <- dirname(path)
}
fil_ext <- tools::file_ext(fil_nam)
fil_pre <- tools::file_path_sans_ext(fil_nam)
td <- tempdir()
setwd(td)
args <- c("--headless")
args <- c(args, "--disable-gpu")
args <- c(args, "--no-sandbox")
args <- c(args, "--allow-no-sandbox-job")
args <- c(args, sprintf("--user-data-dir=%s", .get_app_dir()))
args <- c(args, sprintf("--crash-dumps-dir=%s", .get_app_dir()))
args <- c(args, sprintf("--utility-allowed-dir=%s", .get_app_dir()))
args <- c(args, "--screenshot", url)
if (!is.null(width) & !is.null(height)) {
args <- c(args, sprintf("--window-size=%s,%s", height, width))
}
processx::run(
command = chrome_bin,
args = args,
error_on_status = FALSE,
echo_cmd = FALSE,
echo = FALSE
) -> res
first_fil <- file.path(dir_nam, sprintf("%s.%s", fil_pre, fil_ext))
out_fil <- first_fil
if (!overwrite) {
moar_fils <- sprintf(file.path(dir_nam, sprintf("%s%%04d.%s", fil_pre, fil_ext)), 0:9999)
fils <- c(first_fil, moar_fils)
out_fil <- fils[which(!file.exists(fils))[1]]
if (is.na(out_fil)) stop("Cannot create unique filename")
}
file.copy("screenshot.png", out_fil, overwrite = overwrite)
if (file.exists(out_fil)) magick::image_read(out_fil)
}