directlabels - utility.function - Positioning Method - calc.boxes

Calculate boxes around labels, for collision detection.

calc.boxes <- function
### Calculate boxes around labels, for collision detection.
(d,
 debug=FALSE,
 ...
 ){
  vp <- current.viewport()
  convert <- function(worh){
    conv <- get(paste("convert",worh,sep=""))
    stri <- get(paste("string",worh,sep=""))
    with(d,sapply(seq_along(groups),function(i){
      if("cex"%in%names(d))vp$gp <- gpar(cex=cex[i])
      pushViewport(vp)
      if(debug)grid.rect() ##highlight current viewport
      w <- conv(stri(as.character(groups[i])),"cm")
      popViewport()
      w
    }))
  }
  ## abs since we have a weird bug with ggplot2 sometimes
  d$w <- abs(convert("Width"))
  d$h <- abs(convert("Height"))
  calc.borders(d)
}