From: Ara.T.Howard@...
Date: 2004-01-07T10:36:42+09:00
Subject: tkscrollframe.rb


rtk'rs-

this took me a bit too long to do this, so perhaps you'll find it useful -
it's pretty basic but seems to do the job: a generic scrollable frame -


#
#  tkscrollframe.rb : a sample of Scrollable TkComposite TkFrame
#
#
require 'tk'

class TkScrollFrame < TkFrame
#{{{
  include TkComposite

  def initialize_composite(keys={})
  # munge keys
    keys = _symbolkey2str(keys)

  # create scrollbars
    @v_scroll = TkScrollbar.new @frame, :orient=>'vertical'
    @h_scroll = TkScrollbar.new @frame, :orient=>'horizontal'

  # create a canvas - frame - window combo to scroll 
    @c_frame = TkCanvas.new @frame
    @f_frame = TkFrame.new @c_frame
    @w_frame = TkcWindow.new @c_frame, 0, 0, :window=>@f_frame, :anchor=>'nw'

  # assign scrollbars
    @c_frame.xscrollbar(@h_scroll)
    @c_frame.yscrollbar(@v_scroll)
    #@h_scroll.assign @c_frame
    #@v_scroll.assign @c_frame

  # set up scrollregion to always be frame's extent
    set_scrollregion
    @f_frame.bind('Configure', proc{ set_scrollregion })

  # allignment
    TkGrid.rowconfigure(@frame, 0, 'weight'=>1, 'minsize'=>0)
    TkGrid.columnconfigure(@frame, 0, 'weight'=>1, 'minsize'=>0)

    @c_frame.grid('row'=>0, 'column'=>0, 'sticky'=>'news')
    @h_scroll.grid('row'=>1, 'column'=>0, 'sticky'=>'ew')
    @v_scroll.grid('row'=>0, 'column'=>1, 'sticky'=>'ns')

  # set up @frame
    configure keys unless keys.empty?
  end
  private :initialize_composite

  def set_scrollregion w=@f_frame.winfo_reqwidth, h=@f_frame.winfo_reqheight
    @c_frame.scrollregion [0, 0, w, h] 
  end

  # use these to get a handle on frame to put widgets in
  attr :f_frame
  alias scrollframe f_frame
#}}}
end


################################################
# demo
################################################
if __FILE__ == $0
#{{{

# root frame
  r = TkRoot.new

# note that the parent of all widgets bound for scrollframe **MUST** be f
  sf = TkScrollFrame.new r
  f = sf.scrollframe

# set up first frame
  frame0 = TkFrame.new f
  l = TkLabel.new frame0, :text => 'foobar'
  l.pack

# set up second frame
  frame1 = TkFrame.new f
  42.times do |i|
    42.times do |j|
      text = '%s, %s' % [i, j]
      l = TkLabel.new frame1, :text=>text, :relief=>'raised', :borderwidth=>1
      l.grid :row=>i, :column=>j, :sticky=>'news'
    end
  end


# set up botton which toggles view/scrolls between frames
  b = TkButton.new r,
    :text => 'press-me',
    :command => proc {
      @show ||= 'frame0'
      if @show == 'frame0'
        frame1.pack_forget
        frame0.pack
        @show = 'frame1'
      else
        frame0.pack_forget
        frame1.pack
        @show = 'frame0'
      end
    }

# main 
  b.pack :expand=>true, :fill=>'x'
  sf.pack :expand=>true, :fill=>'both'
  Tk.mainloop

#}}}
end


-a
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