R/theme_aidark.R

In michael-franke/aida-package: R package with helper functions for courses on _A_dvanced topics in and _I_ntro to _D_ata _A_nalysis

#' dark ggplot2 theme for the AIDA course
#' 
#' Because, according to Financial Times Datavizard John Burn-Murdoch, "they look cool".
#' 
#' @param title.size title element size in pts
#' @param text.size text element size in pts
#' @param legend.position either one of "none", "left", "right", "bottom", "top"
#' @param show.axis boolean or "x", "y"; should axis be drawn? Which?
#' @param show.grid boolean; should grid lines be drawn?
#' @param plot.margin margin around entire plot (unit with the sizes of the top, right, bottom, and left margins)
#' 
#' @references https://twitter.com/jburnmurdoch/status/1231235675229491200
#' 
#' @import ggplot2
#' @export
theme_aidark <- function(title.size = 16, text.size = 14, legend.position = "top", 
                         show.axis = FALSE, show.grid = TRUE,
                         plot.margin = c(.2, .1, .2, .1)){
    # baseline
    linecolor <- "#4d4d4d"
    textcolor <- "#d9d9d9"
    layout <- theme_classic()
    layout <- layout + theme(text = element_text(size = text.size,
                                                 color = textcolor),
                             title = element_text(size = title.size, 
                                                  face = "bold",
                                                  color = textcolor),
                             line = element_line(size = .5, 
                                                 color = linecolor))
    
    # override geom defaults
    new_def <- "#00b0a0"
    update_geom_defaults("point", list(colour = new_def))
    update_geom_defaults("line", list(colour = new_def))
    update_geom_defaults("area", list(colour = new_def, 
                                      fill   = new_def))
    update_geom_defaults("rect", list(colour = new_def, 
                                      fill   = new_def))
    update_geom_defaults("density", list(colour = new_def, 
                                         fill   = new_def))
    update_geom_defaults("bar", list(colour = new_def, 
                                     fill   = new_def))
    update_geom_defaults("col", list(colour = new_def, 
                                     fill   = new_def))
    update_geom_defaults("text", list(colour = new_def))
    
    # axis
    layout <- layout + theme(axis.line = element_line(color = "#d9d9d9"))
    if (inherits(show.axis, "character") | show.axis == FALSE){
        if (inherits(show.axis, "character")){
            show.axis <- tolower(show.axis)
            if (show.axis == "x"){
                layout <- layout + theme(axis.line.y = element_blank())
            }
            if (show.axis == "y"){
                layout <- layout + theme(axis.line.x = element_blank())
            }
        } else {
            layout <- layout + theme(axis.line.x = element_blank(),
                                     axis.line.y = element_blank())
        }
    }
    
    # grid lines
    if (show.grid == TRUE){
        layout <- layout + theme(panel.grid.major = element_line(size = .2, 
                                                                 color = linecolor, 
                                                                 linetype = "dotted"))
    }
    
    # subtitle
    layout <- layout + theme(plot.subtitle = element_text(face = "plain", 
                                                          color = "#8c8c8c"))
    
    # axis titles
    layout <- layout + theme(axis.title.x = element_text(margin = margin(t = 8)))
    
    # axis labels
    layout <- layout + theme(axis.text = element_text(face = "plain", 
                                                      color = textcolor))
    
    # legend
    layout <- layout + theme(legend.position = legend.position,
                             legend.background = element_blank(),
                             legend.key.height = unit(2, "line"))
    
    # facets 
    layout <- layout + theme(strip.background = element_blank(),
                             strip.text = element_text(size = title.size,
                                                       face = "bold"))
    
    # misc 
    layout <- layout + theme(panel.background = element_rect(fill = "#181818"),
                             plot.background = element_rect(fill = "#181818"), # or: #1a1a1a; OR #191919?!
                             plot.margin = unit(plot.margin, "cm"))
    
    layout
}