R/gslider.R

In gWidgets: gWidgets API for Building Toolkit-Independent, Interactive GUIs

##' @include gspinbutton.R

##' slider class
setClass("gSlider",
         contains="guiComponentRangeSelector",
         prototype=prototype(new("guiComponentRangeSelector"))
         )

##' slider widget constructor
##'
##' @param from If a number of length one then a starting point, in
##' which case to, by are passed to \code{seq}. Otherwise a sequence
##' of values for which sort(unique(from)) will order
##' @param to ending point when from is starting point
##' @param by step size if not specified by \code{from}
##' @param length.out in place of by
##' @param along.with in place of length.out
##' @export
gslider <- function(
                    from = 0, to = 100, by = 1, length.out=NULL, along.with=NULL,
                    value = from[1], horizontal = TRUE,
                    handler = NULL, action = NULL, container = NULL, ... ,
                    toolkit=guiToolkit()){
  
  ## mostly from seq.default
  ## Wanted to just call seq.default, but that didn't work with length.out bit
  if (!missing(along.with)) {
    length.out <- length(along.with)
  } else if(!missing(length.out)) {
    len <- length(length.out)
    if (!len) 
      stop("argument 'length.out' must be of length 1")
    if (len > 1L) {
      warning("first element used of 'length.out' argument")
      length.out <- length.out[1L]
    }
    length.out <- ceiling(length.out)
  }
  if(!is.null(length.out)) {
    ## set up by to be for length,out
    by <- (to - from)/(length.out[1] - 1)
  }

  
  widget <- .gslider (toolkit,
                      from=from, to=to, by=by, value=value, horizontal=horizontal,
                      handler=handler, action=action, container=container ,...
                      )
  obj <- new( 'guiComponent',widget=widget,toolkit=toolkit) 
  return(obj)
}
 
##' generic for toolkit dispatch
##' @alias gslider
setGeneric( '.gslider' ,
           function(toolkit,
                    from = 0, to = 100, by = 1, value = from, horizontal = TRUE,
                    handler = NULL, action = NULL, container = NULL, ... ) standardGeneric( '.gslider' ))


##' svalue referst o value of slider
##'
##' @param index if non \code{NULL} and \code{TRUE} and sequence specified at once then index