rainbowLettersggplot.R

annotate_rainbow_letters<-function(ggbasePlot, string, initialx, y, letterDistance,
                                   wordDistance,uppcaseadditionalDistance){

spup<-strsplit(string, split = "")[[1]]
uppLett<-grepl("^[[:upper:]]+$", spup)
dostanceVector<-ifelse(spup == " ", wordDistance, letterDistance)

if(any(uppLett)){
  for(i in 1:length(which(uppLett))){
    dostanceVector[which(uppLett)+1]<-dostanceVector[which(uppLett)+1]+uppcaseadditionalDistance
  }
}

dostanceVector[1]<-0
posLetters<-cbind.data.frame(letter=spup, xPosition=cumsum(dostanceVector)+initialx)
posLetters<-posLetters[!posLetters$letter ==" ",]
posLetters<-cbind.data.frame(posLetters,col= rainbow(nrow(posLetters)))

ggbaseAdded <- ggbasePlot + lapply(seq_along(posLetters[,1]), function(i) {
  annotate("text", x = posLetters[i,2], y = y, label = posLetters[i,1],
           hjust = 0, family = "Pacifico", fontface = "bold",
           size = annotation_base_size * 1.75, lineheight = .8, color = posLetters[i,3])
})

return(ggbaseAdded)

}

#Test based on https://github.com/heidiesteiner/mylifeinmonths

#One line first
life_in_months_leopard_life<-annotate_rainbow_letters(
  ggbasePlot=life_in_months_leopard,
  string=c("My life in"),
  initialx=29.75,
  y=6.5,
  letterDistance=0.5,
  wordDistance=1,
  uppcaseadditionalDistance=1
)

##Then the other...
life_in_months_titled<-annotate_rainbow_letters(
  ggbasePlot=life_in_months_leopard_life,
  string=c("Months"),
  initialx=31,
  y=4,
  letterDistance=0.5,
  wordDistance=1,
  uppcaseadditionalDistance=1
)