tk widget: variable or textvariable

[Martin C.]

In Ruby/Tk, is there an easy way to check whether a widget supports
setting variable or textvariable? respond_to? does not work.

 

[Hidetoshi NAGAI]

From: "Martin C." <[email protected]>
Subject: tk widget: variable or textvariable
Date: Wed, 8 Dec 2010 04:27:22 +0900

In Ruby/Tk, is there an easy way to check whether a widget supports
setting variable or textvariable? respond_to? does not work.

1. catch RuntimeError on TkWindow#cget or TkWindow#[] or TkWindow#configinfo.
If raised, the widget doesn't support the option.

2. check keys of a Hash returned by TkWindow.current_configinfo.
e.g. TkButton.new.current_configinfo.keys.find{|opt| opt =~ /variable/}