R/themes.R

In eokodie/fivethemes: Minimal ggplot themes

#' theme_five
#'
#' @param grid (string) Grid lines. Options include any
#' combination of "X", "Y", "x" and "y"
#' @param ... Other arguments passed to ggplot methods.
theme_five <- function(grid = "none", ...) {
  stopifnot(is.character(grid))
  out <- ggplot2::theme(
    plot.title = ggplot2::element_text(color = "gray10", size = 16, face = "bold"),
    plot.subtitle = ggplot2::element_text(color = "gray40", size = 12),
    axis.title.x = ggplot2::element_text(color = "grey20", margin = ggplot2::margin(t = 10, r = 0, b = 0, l = 0)),
    axis.title.y = ggplot2::element_text(color = "grey20", margin = ggplot2::margin(t = 0, r = 10, b = 0, l = 0)),
    axis.ticks = ggplot2::element_blank(), legend.position = "none",
    axis.line = ggplot2::element_blank(),
    panel.grid.major = ggplot2::element_line(color = "grey80", size = 0.25),
    panel.grid.minor = ggplot2::element_line(color = "grey80", size = 0.25)
  )
  if (grid != "none") {
    if (!stringr::str_detect(grid, "Y")) out <- out + ggplot2::theme(panel.grid.major.x = ggplot2::element_blank())
    if (!stringr::str_detect(grid, "X")) out <- out + ggplot2::theme(panel.grid.major.y = ggplot2::element_blank())
    if (!stringr::str_detect(grid, "y")) out <- out + ggplot2::theme(panel.grid.minor.x = ggplot2::element_blank())
    if (!stringr::str_detect(grid, "x")) out <- out + ggplot2::theme(panel.grid.minor.y = ggplot2::element_blank())
  } else {
    out <- out + ggplot2::theme(panel.grid = ggplot2::element_blank())
  }
  out
}

#' theme_5classic
#'
#' @param grid (string) Grid lines. Options include any
#' combination of "X", "Y", "x" and "y"
#' @param ... Other arguments passed to ggplot methods.
#' @export
#'
#' @examples
#' \dontrun{
#' library(ggplot2)
#' p <- ggplot(mtcars, ggplot2::aes(cyl, mpg)) +
#'   geom_point() +
#'   annotate(
#'     "text", x = 4.5, y = 34,
#'     label = "2019", parse = TRUE
#'     ) +
#'   labs(
#'     title = "Example title",
#'     subtitle = "Sample subtitle",
#'     caption = "Example caption"
#'   )
#' p + theme_5classic(grid = "Xx")
#' }
#'
theme_5classic <- function(grid = NULL) {
  ggplot2::theme_classic() + theme_five(grid)
}

#' theme_5minimal
#'
#' @param grid (string) Grid lines. Options include any
#' combination of "X", "Y", "x" and "y"
#' @param bg_fill (string) Plot backgroud file colour.
#' @export
#'
#' @examples
#' \dontrun{
#' library(ggplot2)
#' p <- ggplot(mtcars, ggplot2::aes(cyl, mpg)) +
#'   geom_point() +
#'   annotate(
#'     "text", x = 4.5, y = 34,
#'     label = "2019", parse = TRUE
#'     ) +
#'   labs(
#'     title = "Example title",
#'     subtitle = "Sample subtitle",
#'     caption = "Example caption"
#'   )
#' p + theme_5minimal()
#' }
#'
theme_5minimal <- function(grid = "none", bg_fill = "#F3F3F3") {
  ggplot2::theme_minimal() +
    theme_five(grid) +
    ggplot2::theme(
      strip.background = ggplot2::element_blank(),
      plot.background = ggplot2::element_rect(fill = bg_fill, color = NA),
      panel.background = ggplot2::element_rect(fill = bg_fill, color = NA)
    )
}

#' theme_5dark
#'
#' @param grid (string) Grid lines. Options include any
#' combination of "X", "Y", "x" and "y".
#' @export
#'
#' @examples
#' \dontrun{
#' library(ggplot2)
#' p <- ggplot(mtcars, ggplot2::aes(cyl, mpg)) +
#'   geom_point() +
#'   annotate(
#'     "text", x = 4.5, y = 34,
#'     label = "2019", parse = TRUE
#'     ) +
#'   labs(
#'     title = "Example title",
#'     subtitle = "Sample subtitle",
#'     caption = "Example caption"
#'   )
#' p + theme_5dark(grid = "Xx")
#' }
theme_5dark <- function(grid = TRUE) {
  title_colour <- "#F5F5F5"
  subtitle_colour <- "#A0A0A0"
  caption_colour <- "#888888"
  axes_colour <- "#8F9394"
  grid_colour <- "#606060"
  text_colour <- "#5D5E62"
  axes_label_colour <- "#b1b1b1"
  background_colour <- "#36373B"

  bg_rect <- ggplot2::element_rect(fill = background_colour, color = background_colour)

  theme_five(grid) +
    ggplot2::theme(
      text = ggplot2::element_text(),
      plot.background = bg_rect,
      panel.background = bg_rect,
      legend.background = bg_rect,
      plot.title = ggplot2::element_text(color = title_colour, size = 16, face = "bold"),
      plot.subtitle = ggplot2::element_text(color = subtitle_colour, size = 12, face = "bold"),
      plot.caption = ggplot2::element_text(color = caption_colour, size = 11),
      axis.title.x = ggplot2::element_text(color = axes_label_colour, face = "bold", margin = ggplot2::margin(t = 10, r = 0, b = 0, l = 0)),
      axis.title.y = ggplot2::element_text(color = axes_label_colour, face = "bold", margin = ggplot2::margin(t = 0, r = 10, b = 0, l = 0)),
      axis.text = ggplot2::element_text(color = caption_colour, size = 9),
      panel.grid.major = ggplot2::element_line(color = grid_colour, size = 0.25),
      panel.grid.minor = ggplot2::element_line(color = grid_colour, size = 0.25)
    )
}

#' plot_candlesticks
#'
#' @param quotes_tbl A dataframe containing OHCL data.
#' @param title (string) Plot title.
#'
#' @keywords internal
plot_candlestick <- function(quotes_tbl, title) {
  # checks
  if(nrow(quotes_tbl) == 0) stop("quotes_tbl is empty")
  missing_cols <- dplyr::setdiff(
    c("volume", "open", "close", "high", "low"),
    names(quotes_tbl)
  )
  if(!rlang::is_empty(missing_cols)){
    stop('quotes_tbl should contain: "volume", "open", "close", "high" and "low"')
  }
  # Prepare data
  red <- "#E7625F"
  green <- "#18A558"
  .palette = c(green, red)

  candlestick_tbl <- quotes_tbl %>%
    dplyr::mutate(
      color = dplyr::case_when(open >= close ~ red,TRUE ~ green),
      mid = (open + close)/2
    )
  # Plot Candlesticks
  out <- ggplot2::ggplot(
    data = candlestick_tbl,
    ggplot2::aes(
      x      = time,
      ymin   = low,
      lower  = open,
      middle = mid,
      upper  = close,
      ymax   = high,
      color  = color,
      fill   = color
    )
  ) +
    ggplot2::geom_boxplot(
      ggplot2::aes(group = interaction(time, color)),
      position = ggplot2::position_dodge(width = 2),
      alpha    = 1,
      width    = 200,
      stat     ="identity"
    ) +
    ggplot2::scale_fill_manual(values =  .palette) +
    ggplot2::scale_color_identity() +
    ggplot2::labs(title = title, x = "Time", y = "Share Price") +
    theme_5dark(grid = "Xx") +
    ggplot2::theme(legend.position = "none") +
    ggplot2::theme(plot.title = ggplot2::element_text(hjust = 0.5))
  out
}