ConFluxPro: A toolkit for soil gas analysis

#' variable bar
#'
#' @description A custom ggplot2 stat that implements a variable-width bar plot.
#'
#'
#' @keywords internal


Statvariable_bar <-
  ggplot2::ggproto(
    "variable_bar", ggplot2::Stat,
    compute_group = function(data, scales) {
      parameter_x <- c("y", "xmax", "xmin")
      parameter_y <- c("x", "ymax", "ymin")
      data_columns <- names(data)

      if (all(parameter_x %in% data_columns) &
          !(any(parameter_y %in% data_columns))){

        data <-
          data.frame(x = (data$xmax + data$xmin) / 2,
                     y = data$y / 2,
                     width = data$xmax - data$xmin,
                     height = data$y,
                     xmax = data$xmax,
                     xmin = data$xmin
          )
      } else if (all(parameter_y %in% data_columns) &
                 !(any(parameter_x %in% data_columns))){

        data <-
          data.frame(y = (data$ymax + data$ymin) / 2,
                     x = data$x / 2,
                     height = data$ymax - data$ymin,
                     width = data$x,
                     ymax = data$ymax,
                     ymin = data$ymin

          )
      } else {
        stop("provide either x, ymin and ymax or y, xmin and xmax")
      }

      data
    }
  )

stat_variable_bar <- function(
    mapping = NULL, data = NULL, geom = "tile",
    position = "identity", na.rm = FALSE, show.legend = NA,
    inherit.aes = TRUE, ...) {

  ggplot2::layer(
    stat = Statvariable_bar, data = data, mapping = mapping, geom = geom,
    position = position, show.legend = show.legend, inherit.aes = inherit.aes,
    params = list(na.rm = na.rm, ...)
  )
}