From: Hidetoshi NAGAI <nagai@...>
Date: 2004-08-19T16:22:55+09:00
Subject: Re: Fake Tk events

Hi, 

From: "Phlip" <phlip_cpp@yahoo.com>
Subject: Re: Fake Tk events
Date: Wed, 18 Aug 2004 15:40:56 +0900
Message-ID: <wQCUc.3907$Y94.3738@newssvr33.news.prodigy.com>
> BTW 3 Tk books at Fry's had NOTHING about event generation, send, etc.

One of the examples of remote control with Tcl's send command 
is 'ext/tk/lib/remote-tk.rb' (included in 1.8.2 preview). 
The library can create a remote interpreter object to control 
a Tk interpreter on the other process.
'ext/tk/sample/remote-ip_sample*.rb' are samples of the library. 

About 'event generation', I wrote an example in my Ruby/Tk book
(Japanese). The following is the example (but a little changed).
It is also an example of 'Tk.callback_continue/callback_break', 
'bindtag' and 'virtual event'. 
--------------------------------------------------------
require 'tk'

root = TkRoot.new{ title('Hello Message') }

v = TkVariable.new('someone')
f1 = TkFrame.new.pack('side'=>'top', 'anchor'=>'w')

TkLabel.new(f1, 'text'=>'Input Your Name : ', 
		'font'=>'times').pack('side'=>'left')

e = TkEntry.new(f1, 'textvariable'=>v).pack('side'=>'left')
asc_only = TkBindTag.new
asc_only.bind('Key', proc{|a| 
                 if a.kind_of?(String) &&           
                    ( a == ' ' || a[0] < 0x20 ||    
                      (a[0] >= ?a && a[0] <= ?z) || 
                      (a[0] >= ?A && a[0] <= ?Z) )  
                    Tk.callback_continue
                 end
                 Tk.callback_break
              }, '%A')
e.bindtags(e.bindtags.unshift(asc_only))
ev_EXIT = TkVirtualEvent.new(['Control-x', 'Control-c'], 
                             'Control-q', ['Escape', 'q'], 'Alt-q')

# generate Bitmap
exit_bmp =  TkBitmapImage.new('data'=><<'END')
#define exit-door_width 35
#define exit-door_height 22
static unsigned char exit-door_bits[] = {
   0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xfc, 0xff, 0x01, 0x00, 0x00,
   0x7c, 0x00, 0x01, 0x00, 0x00, 0x7c, 0x00, 0x01, 0x00, 0x00, 0x7c, 0x00,
   0x01, 0x00, 0x00, 0x7c, 0x00, 0x01, 0x00, 0x08, 0x7c, 0x00, 0x01, 0x00,
   0x18, 0x7c, 0x00, 0x01, 0x00, 0x38, 0x7c, 0x00, 0x01, 0xe9, 0x7f, 0x7c,
   0x00, 0x01, 0xd2, 0xff, 0x7c, 0x03, 0x01, 0xa4, 0xff, 0x7d, 0x03, 0x01,
   0xd2, 0xff, 0x7c, 0x00, 0x01, 0xe9, 0x7f, 0x7c, 0x00, 0x01, 0x00, 0x38,
   0x7c, 0x00, 0x01, 0x00, 0x18, 0x7c, 0x00, 0x01, 0x00, 0x08, 0x7c, 0x00,
   0x01, 0x00, 0x00, 0x7c, 0x00, 0x01, 0x00, 0x00, 0x7c, 0x00, 0x01, 0x00,
   0x00, 0x7c, 0x00, 0x01, 0x00, 0x00, 0xfc, 0xff, 0x01, 0x00, 0x00, 0x00,
   0x00, 0x00};
END
TkButton.new(nil, 'image'=>exit_bmp, 'anchor'=>'e', 
             'command'=>proc{TkRoot.new.destroy}) {|b|
  root.bind(ev_EXIT, proc{b.flash; b.invoke})

  # create a label widget on a button widget
  txt = TkLabel.new(b, 'text'=>'EXIT', 
		    'padx'=>2).place('anchor'=>'w', 'x'=>2, 'rely'=>0.5)

  # set button width to 'padding of place' + 'label width' + 'image width'
  width (2 + TkWinfo.reqwidth(txt) + exit_bmp.width)

  # transfer events on the label to the button
  bindtags.each{|tags| 
    tags.bindinfo.each{|ev|
      txt.bind(ev, proc{Tk.event_generate(b, ev)})
    }
  }

  # control 'Enter' and 'Leave' event
  # NOT send 'Enter' and 'Leave' on the label to the button
  txt.bind_remove('Enter')
  txt.bind_remove('Leave')
  # change the labels background when 'Enter' or 'Leave' on the button
  b.bind_append('Enter', proc{txt.background(b.activebackground)})
  b.bind_append('Leave', proc{txt.background(b.background)})
}.pack('side'=>'bottom', 'anchor'=>'e')

font = TkFont.new(['courier', 16, ['italic']])
TkFrame.new{|f2|
  TkLabel.new(f2, 'text'=>'Hello, ', 'font'=>font).pack('side'=>'left')
  TkLabel.new(f2, 'text'=>v.value, 'font'=>font){|l|
    e.bind('Return', proc{l.text v.value})
  }.pack('side'=>'left')
  TkLabel.new(f2, 'text'=>'!!', 'font'=>font).pack('side'=>'left')
}.pack('side'=>'bottom')

Tk.mainloop

print "Bye, #{v.value} ...\n"
--------------------------------------------------------
-- 
                                  Hidetoshi NAGAI (nagai@ai.kyutech.ac.jp)