gWidgets (version 0.0-53)

gedit: Constructor for widget to handle single-line text input

Description

The gedit widget is used to enter single lines of text.

Usage

gedit(text = "", width = 25, coerce.with = NULL, initial.msg="", 
handler = NULL, action = NULL, container = NULL, ..., toolkit = guiToolkit())

Arguments

text

Initial text in widget

width

Width of widget. For gedit, this means the number of characters.

coerce.with

For gedit, when the value is retrieved this function is applied to the result. (The stored value is always a character, this can be used to make it numerc, to quote it, ...

initial.msg

If text is empty, this initial message is displayed to give the user some indication of what to do

handler

Handler called when text is changed. For gedit, this means the enter key is pressed.

action

Passed to handler

container

Optional container to attach widget to

...

Passed to add method of container

toolkit

Which GUI toolkit to use

Details

The gedit widget has the following methods:

The svalue method retrieves the value. If a function is given to the argument coerce.with it is applied before the value is returned. This can be used to coerce the text value (always of class character) to a numeric, or to a date, or to be quoted, ...

The svalue<- method is used to set the value.

The "[" and "[<-" methods refer to the widgets "type-ahead" values. A familiar usage is when a url is typed into a web browser, matches appear from a users history that could possibly complete the typed url. The visible<- method is used to toggle whether characters are visible, or are replaced with a "*", such as is done with password entry.

Examples

gedit("type here", container=gwindow())
	
	## change handler
	obj <- gedit(container=gwindow())
	addhandlerchanged(obj, handler=function(h,...) 
	  cat("You typed", svalue(h$obj),"\n"))

	 ## coerce to numeric
	 obj <- gedit("7", container=gwindow(), coerce.with=as.numeric)
	 svalue(obj)