#!/usr/bin/env ruby

# browse --
# This script generates a directory browser, which lists the working 
# directory and allow you to open files or subdirectories by 
# double-clicking. 

require 'tk'

class Browse
  BROWSE_WIN_COUNTER = TkVariable.new(0)

  def initialize(dir)
    BROWSE_WIN_COUNTER.value = BROWSE_WIN_COUNTER.to_i + 1

    # create base frame
    base = TkToplevel.new {
      minsize(1,1)
      title('Browse : ' + dir)
    }

    # Create a scrollbar on the right side of the main window and a listbox 
    # on the left side.
    list = TkListbox.new(base, 'relief'=>'sunken', 
			 'width'=>20, 'height'=>20, 'setgrid'=>'yes') {|l|
      TkScrollbar.new(base, 'command'=>proc{|*args| l.yview *args}) {|s|
	pack('side'=>'right', 'fill'=>'y')
	l.yscrollcommand(proc{|first,last| s.set(first,last)})
      }

      pack('side'=>'left', 'fill'=>'both', 'expand'=>'yes')

      # Fill the listbox with a list of all the files in the directory (run 
      # the "ls" command to get that information).
      open("|ls -a #{dir}", 'r'){|fid| fid.readlines}.each{|fname|
	l.insert('end', fname.chomp)
      }

    }

    # Set up bindings for the browser.
    base.bind('Destroy', proc{
		Browse::BROWSE_WIN_COUNTER.value = \
		                Browse::BROWSE_WIN_COUNTER.to_i - 1
	      })
    base.bind('Control-c', proc{base.destroy})
    list.bind('Double-Button-1', 
	 proc{TkSelection.get.each{|f| self.browse dir, f}})
  end

  # The method below is invoked to open a browser on a given file;  if the 
  # file is a directory then another instance of this program is invoked; if 
  # the file is a regular file then the Mx editor is invoked to display 
  # the file. 
  def browse (dir, file)
    file = dir + File::Separator + file if dir != '.'
    type = File.ftype(file)
    if type == 'directory'
      Browse.new(file)
    else
      if type == 'file'
	if ENV['EDITOR']
	  system(ENV['EDITOR'] + ' ' + file + ' &')
	else
	  system('xedit ' + file + ' &')
	end
      else
	STDOUT.print "\"#{file}\" isn't a directory or regular file"
      end
    end
  end

end

Browse.new(ARGV[0] ? ARGV[0] : '.')

TkRoot.new {
  withdraw
  Browse::BROWSE_WIN_COUNTER.trace('w', proc{exit if Browse::BROWSE_WIN_COUNTER.to_i == 0})
}

Tk.mainloop
