From: "Albert L. Wagner" <alwagner@...>
Date: 2001-10-17T22:01:01+09:00
Subject: [ruby-talk:22672] Re: Ruby/Tk  How to set a text mark

Thank you, Hidetoshi.  That's just what I needed.  I'll let you
know how it works out.

nagai@ai.kyutech.ac.jp wrote:
> 
> Hi, Hidetoshi
> 
> From: Albert Wagner <alwagner@tcac.net>
> Subject: [ruby-talk:22660] Ruby/Tk  How to set a text mark
> Date: Wed, 17 Oct 2001 10:58:59 +0900
> Message-ID: <20011017015718.OQWU18411.io@there>
> alwagner> Can you help me to set a text mark?
> 
> A text index must be String.
> If you give a index 'line.char' as Float,
> sometimes Ruby/Tk misunderstands it.
> ( for example, 2.10 ==> '2.1' )
> 
> If you want to use TkTextMark with modifires,
> you will have to use TkTextMark#id method.
> The method returns the mark name on Tk.
> By using the name, you must generate index description.
> 
> For example,
> ------------------------------------------------
> t = TkText.new.pack
> t.insert('1.0', "0123456789\nABCDEFGHIJKLMN\nabcdefghijklmn\n")
> m1 = TkTextMark.new(t, '1.end')
> m2 = TkTextMark.new(t, '2.10')
> m3 = TkTextMark.new(t, '@20,40')         # coordinate on the text widget
> p t.mark_names                           #=> return array of TkTextMark objects
> p t.index(m1)                            #=> "1.10"
> p t.index(m3)                            #=> for example, "3.2"
> p t.index(m2.id + ' lineend')            #=> "2.14"
> p t.index(m2.id + ' + 1 lines - 5 chars')#=> "3.5"
> p t.compare(m1, '<', m2)                 #=> true
> p t.compare(m1, '>', m2)                 #=> false
> p t.get(m1,m2)                           #=> "\nABCDEFGHIJ"
> p t.get(m2,m1)                           #=> ""
> m1.set(m1.id + '+1chars')
> p t.index(m1)                            #=> "2.0"
> p t.get(m1,m2)                           #=> "ABCDEFGHIJ"
> ------------------------------------------------
> 
> And, I found bad implements in TkTextMark class.
> Current definitions of TkTextMark#next and TkTextMark#previous are
> ------------------------------------------------
>   def next(index)
>     @t.tagid2obj(tk_call(@t.path, 'mark', 'next', index))
>   end
> 
>   def previous(index)
>     @t.tagid2obj(tk_call(@t.path, 'mark', 'previous', index))
>   end
> ------------------------------------------------
> These should be followings.
> ------------------------------------------------
>   def next
>     @t.tagid2obj(tk_call(@t.path, 'mark', 'next', @id))
>   end
> 
>   def previous
>     @t.tagid2obj(tk_call(@t.path, 'mark', 'previous', @id))
>   end
> ------------------------------------------------
> --
>                                   Hidetoshi NAGAI (nagai@ai.kyutech.ac.jp)

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