R: Radio button group widget

gradio {gWidgets} | R Documentation

## Radio button group widget

### Description

A radio group allows the user to select one value from a set of items. The items may be displayed horizontally or vertically.

### Usage

    gradio(items, selected = 1, horizontal = FALSE, handler
    = NULL, action = NULL, container = NULL, ..., toolkit = guiToolkit())

### Arguments

`items` | Vector of values to select from
`selected` | The initial selected value (as an index). Radio groups must have a selection
`horizontal` | A logical specifying the layout for gradio
`handler` | Called when selection is changed
`action` | Passed to handler when called.
`container` | Optional container to attach widget to
`...` | Passed to `add` method of container
`toolkit` | Which GUI toolkit to use

### Details

The `svalue` method returns the selected value by name. If the extra argument `index=TRUE` is specified, the index of the selected value is given.

The `svalue<-` method can be used to set the selected value. One can specify the value by name or by index if `index=TRUE` is specified.

The `"["` method refers to the vector defining the items.

The `"[<-"` method can be used to change the vector defining the items.

The `"length"` method returns the number of items.

### See Also

The radio group is one of several widgets useful to selecting a value or values from a set of items. See also `gcheckbox`, `gcheckboxgroup`, `gcombobox`, and `gtable`

Methods for gComponent objects are detailed in `gWidgets-methods`.

Event Handlers are detailed in `gWidgets-handlers`.

### Examples

    ## Not run:

      flavors <- c("vanilla", "chocolate", "strawberry")

      w <- gwindow("Radio example", visible=FALSE)
      gp <- ggroup(container=w)
      glabel("Favorite flavor:",container=gp, anchor=c(0,1))
      rb <- gradio(flavors, container=gp)
      addHandlerClicked(rb, handler=function(h,..) {
       cat(sprintf("You picked %s\n", svalue(h$obj)))
      })
      visible(w) <- TRUE

      betterFlavors <- c("coffee", "mint chip")
      rb[] <- betterFlavors
      rb[] <- c(betterFlavors, "chocolate") # some toolkits don't allow change of length

      rb[3] <- "mango sorbet" ## can change a label name

      ## set values
      svalue(rb) <- "coffee"  ## by name
      svalue(rb, index=TRUE) <- 1  ## by index

      ## get selected values
      svalue(rb)
      svalue(rb, index=TRUE)

    ## End(Not run)

[Package gWidgets version 0.0-54 Index]