rp.combo: A `combo' for a panel

Description

This function adds a `combobox' to the panel. When an item is pressed, a variable is set and an action function is called.

Usage

rp.combo(panel, variable, prompt=NULL, vals, initval=vals[1], pos=NULL, action=I,
  foreground=NULL, background=NULL, font=NULL, editable=FALSE,
  parentname=deparse(substitute(panel)), name=paste("combo", .nc(), sep=""), ...)

Arguments

panel

the panel in which the combobox should appear.

variable

the name of the variable whose value is set by the combobox.

prompt

the label for the combobox.

vals

the values of variable used by the combo.

initval

the initial value of variable (optional). The initial value can also be specified in the call to rp.control.

pos

the layout instructions. Please see the rp.pos example and help for full details.

action

the function which is called when an item is chosen.

foreground

colour of the text

background

colour of the text background

font

font to be used

editable

whether the combobox can be edited or not.

parentname

this specifies the widget inside which the combobox should appear.

name

name assigned to the combobox, used for disposing of the widget

...

Value

If the parameter panel is the panelname string the same string is returned. If the panel object is used the altered panel is assigned to both the calling level and panel's environment level.

Warning

The action function should return the panel. Without this assignment any widgets added or alterations made to panel parameters within the action function will be lost.

Details

The function action should take one argument, which should be the panel to which the combobox is attached.

See rp.grid for details of the grid layout system.

References

rpanel: Simple interactive controls for R functions using the tcltk package. Journal of Statistical Software, 17, issue 9.

Examples

Run this code

# NOT RUN {
   callback <- function(panel) {
      print(panel$option)
      panel
   }
   panel <- rp.control()
   rp.combo(panel, option, "Pick an option:", 
            c("Option1","Option2","Other options"), action=callback)
# }

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