From: daz <dooby@...10.karoo.co.uk>
Date: 2003-12-09T22:42:03+09:00
Subject: Re: Idea: Linux PIM in Ruby

Hal Fulton wrote:
> Curt Hibbs wrote:
>> Emmanuel Touzery wrote:
>>
>>> Hal Fulton wrote:
>>>
>>>> Then for example it would easy(-ier) to switch later from Fox
>>>> to GTK or wxWin or whatever, or even make alternatives.
>>>
>>> wouldn't it be smarter to have a core which knows nothing about GUI and
>>> then several GUI layers ontop of it?
>>> you think application directing GUI. how about GUI directing
>>> application? seems cleaner to me, but then again..
>>
>> I think that is pretty much what Hal is saying.
>
> Yes, that is what I meant.
>
>> I would also like to reinforce this theme: A core "engine" with no gui. The
>> gui can then be developed independently or, if you wish, separate (but
>> similar) gui applications can be written that all use this same core engine.
>
> In practice, I find this difficult.
>
> To get back to basics: I think the GUI serves as an I/O mechanism.
>
> Sometimes the engine drives (calls) the GUI, to fill a window with data
> or throw up a window or whatever.
>
> Sometime the GUI drives the engine: The user pushes a button, and an
> engine method gets called.
>
> Hmm, can we separate these logically? Make two modules or classes,
> perhaps?
>


I shall regret posting the moment I thump 'send' :-)

Any repliers, please DELETE the whole script first ... once is enough.


This paltry effort has, I hope, full separation of concerns.
The PIM is a server to whatever the TUI/GUI client.

As a non-programmer (SysProg), the challenging part of OOP is
leaving the 'real world' and getting right inside the object
rather than opening a class and force-feeding it with data
through accessors from an external 'main' method as most of
us start doing.



#---------------------------------------------------------------
# 'ui_text'

class UI
  Version = 'Text 0.0.1 (boxy)'
  #Text-only version (FX | VR | TK | WX etc. coming soon... :)
  def initialize(pim)
    @pim   = pim
    @setup = false
    @cmd   = 'setup'
  end

  def msgloop
    loop do
      @args = @cmd.split(/\s+/)
      @cmd = @args.shift
      # Sophisticated command parser ... cuh!
      case @cmd
      when /setup/
        unless @setup
          @setup = true
          puts 'Initialising layout manager :-))'
          help()
        end
      when /nt/
        draw_box_each()
      when /q(uit)?/, /exit/
        return @cmd
      when /h(elp)?/
        help()
      when /^\n/
      else
        puts "I'm afraid I can't do ... #{@cmd} #{@args}"
      end
      print "\nReady > "
      @cmd = gets
      puts
    end
  end

  def help
    puts '', 'Minimally useful commands available:'
    puts '  h(elp) - ... this'
    puts '  q(uit) - Exit'
    puts '  nt     - list of Name & Tel'
  end

  #  Cruft alert - plz ignore this meth.
  def draw_box_each
    # calls  each_'cmd' (e.g. each_nt)  in PIM for content
    bar =''
    @pim.method("each_#{@cmd}".intern).call do |row, nt, det|
      if row == 0
        #  Title
        line_width = 0
        det.each {|n| line_width += (n+2)-1}
        bar = ' |---| ' << '-' * line_width << '|'
        puts bar
        print ' | n '
        nt.each_with_index do |nm, eix|
          printf("| %-*s", det[eix], nm)  #  heading
        end
        puts '|', bar
      else
        printf(" |%2d ", row)
        nt.each_with_index do |ent, col|
          printf("| %-*s", det[col], ent)  #  entries
        end
        puts '|'
      end
    end
    puts bar
  end
end

#---------------------------------------------------------------

class PIM
  Version = '0.0.1 (alpha)'

  private_class_method :new
  def initialize
    @nt_struct  = Struct.new(:name, :tel)
    @nt_detail =             [30,    15]  # field widths
    @nta = nil
  end

  def PIM.run
    UI.new(new).msgloop  # Pass PIM object to whatever UI
    puts "\nThank you for using PIM #{Version} with #{UI::Version}\n\n"
    sleep 2
  end

  #######
  private
  #######

  def each_nt
    @nta || load_nt
    # Column titles first (index = 0)
    yield 0, @nt_struct.members.map {|e| e.capitalize}, @nt_detail
    @nta.each_with_index do |nt, ix|
      yield ix+1, nt, @nt_detail
    end
  end

  def load_nt
    @nta = []
    while nt = DATA.gets
      nt = nt.chomp.split(/,\s*/)
      @nta << @nt_struct.new(*nt)
    end
  end
end

#require 'ui_text'

PIM.run  # Return when UI receives quit

# Test data follows __END__
# NOT suitable for this kind of app!!

__END__
Yukihiro Matsumoto, 11-111-1111
bbb b bbbbbb, 22-222-2222
ccccccc  ccccc, 33-333-3333

#-----<CUT>-----


This isn't a bid to join (or be banned from) a team.

If anything develops, it may be converted from
a Linux PIM (what's that ?) to a splendid vruby/swin
PIM (?) targeted at we occupants of the sinking ship
Hal (apparently) can't wait to abandon :-)

'Scuse the cheek.
Maximum respect to all open-sourcerers.


daz