Forum: Ruby Help me with Method Entry of Gtk

I'm a Ruby Newbie trying to do a App, where user log on, when the users
will write their password only show *, I've been used invisible_char but
when compiled it, I shows a error

set_invisible_char': wrong number of arguments (0 for 1) (ArgumentError)

I was missing an Argument but I don't what it is, the rest of code is
this

 entrypassword = Gtk::Entry.new
 entrypassword.set_invisible_char

Thank you for Attention

On Dec 15, 2012, at 9:54 PM, Alejandro Hernandez <lists@ruby-forum.com> 
wrote:

> entrypassword.set_invisible_char
>
> Thank you for Attention

Google: ruby Gtk set_invisible_char

One of the early hits: 
http://ruby-gnome2.sourceforge.jp/ja/hiki.cgi?Gtk%3A%3AEntry

And from there: 
http://ruby-gnome2.sourceforge.jp/ja/hiki.cgi?Gtk%...

set_invisible_char(ch)
Same as Gtk::Entry#invisible_char=
   ch: a Unicode character(Number)
   Returns: self

invisible_char=(ch)
Sets the character to use in place of the actual text when 
Gtk::Entry#visibility= has been called to set text visibility to false. 
i.e. this is the character used in "password mode" to show the user how 
many characters have been typed. The default invisible char is an 
asterisk ('*'). If you set the invisible char to 0, then the user will 
get no feedback at all; there will be no text on the screen as they 
type.
   ch: a Unicode character(Number)
   Returns: ch

Not that hard, is it?

Thank you, Gennady Bystritsky

the correct code is this

entrypassword = Gtk::Entry.new
entrypassword.set_visibility(false)

Thank you very much