R/chunk_images.R

In flextable: Functions for Tabular Reporting

#' @importFrom grDevices as.raster
#' @export
#' @title Image chunk wrapper
#' @description The function lets add images within flextable
#' objects with functions:
#' - [compose()] and [as_paragraph()],
#' - [append_chunks()],
#' - [prepend_chunks()]
#' \if{html}{\out{
#' <img src="https://www.ardata.fr/img/flextable-imgs/flextable-006.png" alt="as_image illustration" style="width:100\%;">
#' }}
#' @param src image filename
#' @param width,height size of the image file. It can be ignored
#' if parameter `guess_size=TRUE`, see parameter `guess_size`.
#' @param guess_size If package 'magick' is installed, this option
#' can be used (set it to `TRUE` and don't provide values for paramters
#' `width` and `height`). When the flextable will be printed,
#' the images will be read and width and height will be guessed. This
#' should be avoid if possible as it can be an extensive task when
#' several images.
#' @param unit unit for width and height, one of "in", "cm", "mm".
#' @param ... unused argument
#' @family chunk elements for paragraph
#' @note
#' This chunk option requires package officedown in a R Markdown
#' context with Word output format.
#'
#' PowerPoint cannot mix images and text in a paragraph, images
#' are removed when outputing to PowerPoint format.
#' @seealso [compose()], [as_paragraph()]
#' @examples
#' img.file <- file.path(
#'   R.home("doc"),
#'   "html", "logo.jpg"
#' )
#' if (require("magick")) {
#'   myft <- flextable(head(iris))
#'   myft <- compose(myft,
#'     i = 1:3, j = 1,
#'     value = as_paragraph(
#'       as_image(src = img.file),
#'       " ",
#'       as_chunk(Sepal.Length,
#'         props = fp_text_default(color = "red")
#'       )
#'     ),
#'     part = "body"
#'   )
#'   ft <- autofit(myft)
#'   ft
#' }
as_image <- function(src, width = NULL, height = NULL, unit = "in", guess_size = TRUE, ...) {
  width <- convin(unit = unit, x = width)
  height <- convin(unit = unit, x = height)

  if (length(src) > 1) {
    if (length(width) == 1) width <- rep(width, length(src))
    if (length(height) == 1) height <- rep(height, length(src))
  }

  if (guess_size && (is.null(width) || is.null(height))) {
    if (!requireNamespace("magick", quietly = TRUE)) {
      stop("package magick is required when using `guess_size` option.")
    }
    sizes <- lapply(src, function(x) {
      z <- magick::image_read(x)
      z <- magick::image_data(z)
      attr(z, "dim")[-1]
    })
    sizes <- do.call(rbind, sizes)
    width <- sizes[, 1] / 72
    height <- sizes[, 2] / 72
  }

  data <- chunk_dataframe(
    width = as.double(width),
    height = as.double(height),
    img_data = src
  )
  class(data) <- c("img_src", class(data))
  data
}


#' @export
#' @title Mini barplots chunk wrapper
#' @description This function is used to insert bars into
#' flextable with functions:
#' - [compose()] and [as_paragraph()],
#' - [append_chunks()],
#' - [prepend_chunks()].
#' @param value values containing the bar size
#' @param max max bar size
#' @param barcol bar color
#' @param bg background color
#' @param width,height size of the resulting png file in inches
#' @param unit unit for width and height, one of "in", "cm", "mm".
#' @note
#' This chunk option requires package officedown in a R Markdown
#' context with Word output format.
#'
#' PowerPoint cannot mix images and text in a paragraph, images
#' are removed when outputing to PowerPoint format.
#' @family chunk elements for paragraph
#' @examples
#' ft <- flextable(head(iris, n = 10))
#'
#' ft <- compose(ft,
#'   j = 1,
#'   value = as_paragraph(
#'     minibar(value = Sepal.Length, max = max(Sepal.Length))
#'   ),
#'   part = "body"
#' )
#'
#' ft <- autofit(ft)
#' ft
#' @importFrom grDevices as.raster col2rgb rgb
#' @seealso [compose()], [as_paragraph()]
minibar <- function(value, max = NULL, barcol = "#CCCCCC", bg = "transparent", width = 1, height = .2, unit = "in") {
  width <- convin(unit = unit, x = width)
  height <- convin(unit = unit, x = height)

  if (all(is.na(value))) {
    max <- 1
  }
  if (all(is.na(value)) || all(value == 0, na.rm = TRUE)) {
    max <- 1
  }

  value[is.na(value)] <- 0

  if (is.null(max)) {
    max <- max(value, na.rm = TRUE)
  }

  stopifnot(value >= 0, max >= 0)
  barcol <- rgb(t(col2rgb(barcol)) / 255)
  bg <- ifelse(bg == "transparent", bg, rgb(t(col2rgb(bg)) / 255))
  if (any(value > max)) {
    warning("value > max, truncate to max")
    value[value > max] <- max
  }
  width_ <- as.integer(width * 72)
  value <- as.integer((value / max) * width_)
  n_empty <- width_ - value

  rasters <- mapply(
    function(count_on, count_off, bg_on, bg_off) {
      as.raster(matrix(c(rep(bg_on, count_on), rep(bg_off, count_off)), nrow = 1))
    }, value, n_empty,
    bg_on = barcol, bg_off = bg,
    SIMPLIFY = FALSE
  )
  z <- chunk_dataframe(
    width = as.double(rep(width, length(value))),
    height = as.double(rep(height, length(value))),
    img_data = rasters
  )

  class(z) <- c("img_chunk", class(z))
  z
}

#' @export
#' @title Mini linerange chunk wrapper
#' @description This function is used to insert lineranges into
#' flextable with functions:
#' - [compose()] and [as_paragraph()],
#' - [append_chunks()],
#' - [prepend_chunks()].
#' @param value values containing the bar size
#' @param min min bar size. Default min of value
#' @param max max bar size. Default max of value
#' @param rangecol bar color
#' @param stickcol jauge color
#' @param bg background color
#' @param width,height size of the resulting png file in inches
#' @param unit unit for width and height, one of "in", "cm", "mm".
#' @param raster_width number of pixels used as width
#' when interpolating value.
#' @note
#' This chunk option requires package officedown in a R Markdown
#' context with Word output format.
#'
#' PowerPoint cannot mix images and text in a paragraph, images
#' are removed when outputing to PowerPoint format.
#' @family chunk elements for paragraph
#' @examples
#' myft <- flextable(head(iris, n = 10))
#'
#' myft <- compose(myft,
#'   j = 1,
#'   value = as_paragraph(
#'     linerange(value = Sepal.Length)
#'   ),
#'   part = "body"
#' )
#'
#' autofit(myft)
#' @importFrom grDevices as.raster col2rgb rgb
#' @importFrom stats approx
#' @seealso [compose()], [as_paragraph()]
linerange <- function(value, min = NULL, max = NULL, rangecol = "#CCCCCC",
                      stickcol = "#FF0000", bg = "transparent", width = 1,
                      height = .2, raster_width = 30, unit = "in") {
  width <- convin(unit = unit, x = width)
  height <- convin(unit = unit, x = height)

  if (all(is.na(value))) {
    min <- 0
    max <- 1
  }

  if (raster_width < 2) {
    stop("raster_width must be greater than 1")
  }

  raster_nrow <- 9
  raster_center <- 5

  if (is.null(max)) {
    max <- max(value, na.rm = TRUE)
  }
  if (is.null(min)) {
    min <- min(value, na.rm = TRUE)
  }

  value[!is.finite(value)] <- max + 1 # to be sure not displayed

  stopifnot(!is.null(value), !is.null(min), !is.null(min))

  # transform color code
  stickcol <- rgb(t(col2rgb(stickcol)) / 255)
  rangecol <- rgb(t(col2rgb(rangecol)) / 255)
  bg <- ifelse(bg == "transparent", bg, rgb(t(col2rgb(bg)) / 255))


  # get value approx on range 1,raster_width
  stick_pos <- as.integer(approx(x = c(min, max), y = c(1, raster_width), xout = value)$y)
  base <- matrix(bg, nrow = raster_nrow, ncol = raster_width)
  base[, 1] <- rangecol
  base[, raster_width] <- rangecol
  base[raster_center, ] <- rangecol

  rasters <- lapply(stick_pos, function(val, def_mat, col) {
    newmat <- def_mat
    newmat[, val] <- col
    as.raster(newmat)
  }, base, stickcol)

  z <- chunk_dataframe(
    width = as.double(rep(width, length(value))),
    height = as.double(rep(height, length(value))),
    img_data = rasters
  )

  class(z) <- c("img_chunk", class(z))
  z
}

#' @export
#' @title Mini lollipop chart chunk wrapper
#' @description This function is used to insert lollipop charts into
#' flextable with functions:
#' - [compose()] and [as_paragraph()],
#' - [append_chunks()],
#' - [prepend_chunks()].
#' @param value values containing the bar size
#' @param min min bar size. Default min of value
#' @param max max bar size. Default max of value
#' @param rangecol bar color
#' @param bg background color
#' @param width,height size of the resulting png file in inches
#' @param unit unit for width and height, one of "in", "cm", "mm".
#' @param raster_width number of pixels used as width
#' @param positivecol box color of positive values
#' @param negativecol box color of negative values
#' @param neutralcol box color of neutral values
#' @param neutralrange minimal and maximal range of neutral values (default: 0)
#' @param rectanglesize size of the rectangle (default: 2, max: 5)
#' when interpolating value.
#' @note
#' This chunk option requires package officedown in a R Markdown
#' context with Word output format.
#'
#' PowerPoint cannot mix images and text in a paragraph, images
#' are removed when outputing to PowerPoint format.
#' @family chunk elements for paragraph
#' @examples
#' iris$Sepal.Ratio <- (iris$Sepal.Length - mean(iris$Sepal.Length)) / mean(iris$Sepal.Length)
#' ft <- flextable(tail(iris, n = 10))
#'
#' ft <- compose(ft,
#'   j = "Sepal.Ratio", value = as_paragraph(
#'     lollipop(value = Sepal.Ratio, min = -.25, max = .25)
#'   ),
#'   part = "body"
#' )
#'
#' ft <- autofit(ft)
#' ft
#' @importFrom grDevices as.raster col2rgb rgb
#' @importFrom stats approx
#' @seealso [compose()], [as_paragraph()]
lollipop <- function(value, min = NULL, max = NULL, rangecol = "#CCCCCC",
                     bg = "transparent", width = 1,
                     height = .2, unit = "in", raster_width = 30, positivecol = "#00CC00",
                     negativecol = "#CC0000", neutralcol = "#CCCCCC", neutralrange = c(0, 0),
                     rectanglesize = 2) {
  width <- convin(unit = unit, x = width)
  height <- convin(unit = unit, x = height)

  if (all(is.na(value))) {
    min <- 0
    max <- 1
  }

  if (raster_width < 2) {
    stop("raster_width must be greater than 1")
  }

  raster_nrow <- 9
  raster_center <- 5

  if (rectanglesize > 5) {
    rectanglesize <- 5
  }

  if (is.null(max)) {
    max <- max(c(0, value), na.rm = TRUE)
  }
  if (is.null(min)) {
    min <- min(c(0, value), na.rm = TRUE)
  }

  value[!is.finite(value)] <- max + 1 # to be sure not displayed

  stopifnot(!is.null(value), !is.null(min), !is.null(min))

  # transform color code
  rangecol <- rgb(t(col2rgb(rangecol)) / 255)
  positivecol <- rgb(t(col2rgb(positivecol)) / 255)
  negativecol <- rgb(t(col2rgb(negativecol)) / 255)
  neutralcol <- rgb(t(col2rgb(neutralcol)) / 255)
  bg <- ifelse(bg == "transparent", bg, rgb(t(col2rgb(bg)) / 255))


  # get value approx on range 1,raster_width
  zero_pos <- as.integer(approx(x = c(min, max), y = c(1, raster_width), xout = 0)$y)

  base <- matrix(bg, nrow = raster_nrow, ncol = raster_width)
  base[, 1] <- rangecol
  base[, raster_width] <- rangecol
  base[, zero_pos] <- rangecol

  rasters <- lapply(value, function(val, def_mat) {
    stick_pos <- as.integer(approx(x = c(min, max), y = c(1, raster_width), xout = val)$y)

    newmat <- def_mat

    # fix switch statement and neutral color range
    value_position <- sign(val)
    value_position <- ifelse(val <= neutralrange[1] & val >= neutralrange[2], 0, value_position)

    rectangle_color <- switch(value_position + 2,
      negativecol,
      neutralcol,
      positivecol
    )

    # create middle stick
    if (value_position == -1) {
      newmat[row(newmat) == raster_center & col(newmat) < zero_pos & col(newmat) > stick_pos] <- rangecol
    } else {
      newmat[row(newmat) == raster_center & col(newmat) > zero_pos & col(newmat) < stick_pos] <- rangecol
    }

    # create rectangle
    newmat[col(newmat) >= stick_pos - rectanglesize / 2 & col(newmat) <= stick_pos + rectanglesize / 2 &
      row(newmat) >= raster_center - rectanglesize & row(newmat) <= raster_center + rectanglesize] <- rectangle_color

    as.raster(newmat)
  }, base)

  z <- chunk_dataframe(
    width = as.double(rep(width, length(value))),
    height = as.double(rep(height, length(value))),
    img_data = rasters
  )

  class(z) <- c("img_chunk", class(z))
  z
}


#' @export
#' @title Mini plots chunk wrapper
#' @description This function is used to insert mini plots into
#' flextable with functions:
#' - [compose()] and [as_paragraph()],
#' - [append_chunks()],
#' - [prepend_chunks()].
#'
#' Available plots are 'box', 'line', 'points', 'density'.
#' @param value a numeric vector, stored in a list column.
#' @param width,height size of the resulting png file in inches
#' @param type type of the plot: 'box', 'line', 'points' or 'density'.
#' @param free_scale Should scales be free (TRUE or FALSE, the default value).
#' @param unit unit for width and height, one of "in", "cm", "mm".
#' @param ... arguments sent to plot functions (see [par()])
#' @note
#' This chunk option requires package officedown in a R Markdown
#' context with Word output format.
#'
#' PowerPoint cannot mix images and text in a paragraph, images
#' are removed when outputing to PowerPoint format.
#' @family chunk elements for paragraph
#' @examples
#' library(data.table)
#' library(flextable)
#'
#' z <- as.data.table(iris)
#' z <- z[, list(
#'   Sepal.Length = mean(Sepal.Length, na.rm = TRUE),
#'   z = list(.SD$Sepal.Length)
#' ), by = "Species"]
#'
#' ft <- flextable(z,
#'   col_keys = c("Species", "Sepal.Length", "box", "density")
#' )
#' ft <- mk_par(ft, j = "box", value = as_paragraph(
#'   plot_chunk(
#'     value = z, type = "box",
#'     border = "red", col = "transparent"
#'   )
#' ))
#' ft <- mk_par(ft, j = "density", value = as_paragraph(
#'   plot_chunk(value = z, type = "dens", col = "red")
#' ))
#' ft <- set_table_properties(ft, layout = "autofit", width = .6)
#' ft <- set_header_labels(ft, box = "boxplot", density = "density")
#' theme_vanilla(ft)
#' @importFrom grDevices dev.off
#' @importFrom graphics boxplot
#' @importFrom stats density
plot_chunk <- function(value, width = 1, height = .2,
                       type = "box", free_scale = FALSE, unit = "in", ...) {
  width <- convin(unit = unit, x = width)
  height <- convin(unit = unit, x = height)

  type <- match.arg(arg = type, choices = c("box", "line", "points", "density"), several.ok = FALSE)

  width <- as.double(rep(width, length(value)))
  height <- as.double(rep(height, length(value)))

  params <- list(...)
  params <- append(
    params,
    list(
      xlab = "", ylab = "", main = "", axes = FALSE
    )
  )

  lims <- NULL
  if (!free_scale) {
    lims <- range(unlist(value), na.rm = TRUE)
  }

  files <- mapply(
    function(x, width, height, type) {
      file <- tempfile(fileext = ".png")
      agg_png(
        filename = file,
        width = width, height = height,
        res = 200, units = "in",
        background = "transparent"
      )
      par(mar = rep(0, 4))
      parcall <- params

      if ("box" %in% type) {
        parcall$x <- x
        parcall$horizontal <- TRUE
        parcall$ylim <- lims
        do.call(boxplot, parcall)
      } else if ("line" %in% type) {
        parcall$x <- seq_along(x)
        parcall$y <- x
        parcall$type <- "l"
        parcall$ylim <- lims
        do.call(plot, parcall)
      } else if ("points" %in% type) {
        parcall$x <- seq_along(x)
        parcall$y <- x
        parcall$ylim <- lims
        do.call(plot, parcall)
      } else if ("density" %in% type) {
        parcall$x <- density(x)
        parcall$xlim <- lims
        do.call(plot, parcall)
      }
      dev.off()
      file
    },
    x = value,
    width = width, height = height,
    SIMPLIFY = FALSE,
    MoreArgs = list(type = type)
  )

  files <- as.character(unlist(files))

  z <- chunk_dataframe(width = width, height = height, img_data = files)
  class(z) <- c("img_chunk", class(z))
  z
}


#' @export
#' @title 'ggplots' chunk wrapper
#' @description This function is used to insert mini gg plots into
#' flextable with functions:
#' - [compose()] and [as_paragraph()],
#' - [append_chunks()],
#' - [prepend_chunks()].
#'
#' @param value gg objects, stored in a list column; or a list
#' of 'ggplot' objects.
#' @param width,height size of the resulting png file.
#' @param unit unit for width and height, one of "in", "cm", "mm".
#' @param res resolution of the png image in ppi
#' @note
#' This chunk option requires package officedown in a R Markdown
#' context with Word output format.
#'
#' PowerPoint cannot mix images and text in a paragraph, images
#' are removed when outputing to PowerPoint format.
#' @family chunk elements for paragraph
#' @examples
#' library(data.table)
#' library(flextable)
#' if (require("ggplot2")) {
#'   my_cor_plot <- function(x) {
#'     cols <- colnames(x)[sapply(x, is.numeric)]
#'     x <- x[, .SD, .SDcols = cols]
#'     cormat <- as.data.table(cor(x))
#'     cormat$var1 <- colnames(cormat)
#'     cormat <- melt(cormat,
#'       id.vars = "var1", measure.vars = cormat$var1,
#'       variable.name = "var2", value.name = "correlation"
#'     )
#'     ggplot(data = cormat, aes(x = var1, y = var2, fill = correlation)) +
#'       geom_tile() +
#'       coord_equal() +
#'       scale_fill_gradient2(
#'         low = "blue",
#'         mid = "white", high = "red", limits = c(-1, 1),
#'         guide = FALSE
#'       ) +
#'       theme_void()
#'   }
#'   z <- as.data.table(iris)
#'   z <- z[, list(gg = list(my_cor_plot(.SD))), by = "Species"]
#'   ft <- flextable(z)
#'   ft <- mk_par(ft,
#'     j = "gg",
#'     value = as_paragraph(
#'       gg_chunk(value = gg, width = 1, height = 1)
#'     )
#'   )
#'   ft
#' }
gg_chunk <- function(value, width = 1, height = .2, unit = "in", res = 300) {
  width <- convin(unit = unit, x = width)
  height <- convin(unit = unit, x = height)

  width <- as.double(rep(width, length(value)))
  height <- as.double(rep(height, length(value)))

  files <- mapply(
    function(x, width, height) {
      file <- tempfile(fileext = ".png")
      agg_png(
        filename = file, width = width, height = height,
        units = "in", background = "transparent", res = res
      )
      print(x)
      dev.off()
      file
    },
    x = value,
    width = width, height = height,
    SIMPLIFY = FALSE
  )

  files <- as.character(unlist(files))

  z <- chunk_dataframe(width = width, height = height, img_data = files)
  class(z) <- c("img_chunk", class(z))
  z
}

#' @export
#' @title 'Grid Graphics' chunk wrapper
#' @description This function is used to insert grid objects into
#' flextable with functions:
#' - [compose()] and [as_paragraph()],
#' - [append_chunks()],
#' - [prepend_chunks()].
#'
#' @param value grid objects, stored in a list column; or a list
#' of grid objects.
#' @param width,height size of the resulting png file
#' @param unit unit for width and height, one of "in", "cm", "mm".
#' @param res resolution of the png image in ppi
#' @note
#' This chunk option requires package officedown in a R Markdown
#' context with Word output format.
#'
#' PowerPoint cannot mix images and text in a paragraph, images
#' are removed when outputing to PowerPoint format.
#' @family chunk elements for paragraph
#' @examples
#' library(flextable)
#' ft_1 <- flextable(head(cars))
#' if (require("grid")) {
#'   ft_1 <- prepend_chunks(
#'     x = ft_1, i = 2, j = 2,
#'     grid_chunk(
#'       list(
#'         circleGrob(gp = gpar(
#'           fill = "#ec11c2",
#'           col = "transparent"
#'         ))
#'       ),
#'       width = .15, height = .15
#'     )
#'   )
#' }
#' ft_1
grid_chunk <- function(value, width = 1, height = .2, unit = "in", res = 300) {
  if (!requireNamespace("grid", quietly = TRUE)) {
    stop(sprintf(
      "'%s' package should be installed to create a flextable from an object of type '%s'.",
      "grid", "grid"
    ))
  }

  width <- convin(unit = unit, x = width)
  height <- convin(unit = unit, x = height)

  width <- as.double(rep(width, length(value)))
  height <- as.double(rep(height, length(value)))
  files <- mapply(
    function(x, width, height) {
      file <- tempfile(fileext = ".png")
      agg_png(
        filename = file, width = width, height = height,
        units = "in", background = "transparent", res = res
      )
      grid::grid.draw(x)
      dev.off()
      file
    },
    x = value,
    width = width, height = height,
    SIMPLIFY = FALSE
  )

  files <- as.character(unlist(files))

  z <- chunk_dataframe(width = width, height = height, img_data = files)
  class(z) <- c("img_chunk", class(z))
  z
}