13949712720901ForOSX

There's a campaign called “Vote For Java 6 On Leopard“ to nag Apple into producing a Java 6 JDK for OS X. Somehow, it's supposed to help if you stick this in your blog: 13949712720901ForOSX

There's also Landon Fuller's project SoyLatte to port FreeBSD's port of the JDK to OS X. Fight the power: Donate here!

Personally, I plan to eat a pint of chocolate ice-cream every night and sleep in an extra 15 minutes every morning until Apple delivers a Java 6 JDK. Take that, Steve Jobs! Hya! 13949712720901ForOSX! Nyaaa!

Formatting Ruby source code in HTML

BTW, I used the syntax library to format the Ruby source code snippets to HTML. It works like this:

require 'rubygems'
require 'syntax/convertors/html'

code = File.read("my_nifty_program.rb")
convertor = Syntax::Convertors::HTML.for_syntax "ruby"
code_html = convertor.convert( code )
print code_html

You'll also need the corresponding CSS:

pre {
    background-color: #f1f1f3;
    border: 1px dashed #333333;
    padding: 10px;
    overflow: auto;
    margin: 4px 0px;
    width: 95%;
}

/* Syntax highlighting */
pre .normal {}
pre .comment { color: #999999; font-style: italic; }
pre .keyword { color: #006699; font-weight: bold; }
pre .method { color: #077; }
pre .class { color: #074; }
pre .module { color: #050; }
pre .punct { color: #000099; font-weight: bold; }
pre .symbol { color: #099; }
pre .string { color: #00CC00; }
pre .char { color: #00CC00; }
pre .ident { color: #333333; }
pre .constant { color: #0099CC; }
pre .regex { color: #00CC00; }
pre .number { color: #0099CC; }
pre .attribute { color: #5bb; }
pre .global { color: #7FB; }
pre .expr { color: #227; }
pre .escape { color: #277; }

I found this nifty information in an article called, "Howto format ruby code for blogs".

Powersets in Ruby

Another nifty exercise in Ruby - this one generates all subsets of a given array. Maybe I should have used a set.

# Powerset
# find all subsets of a set

# recursively compute the all subsets of the given set
# based on the idea that for any given subset, either an
# item is in the subset or it isn't
def powerset(set)
  if (set.length == 0)
    return [set]
  end
  result = []
  
  # remove an item from the list
  item = set.shift
  
  # compute the powerset of the smaller list
  sps = powerset(set)
  
  # for each subset, either readd the item or don't
  sps.each do |subset|
    result << subset
    result << (subset + [item])
  end
  return result
end

set = %w{ a b c d }
p = powerset(set)

# sort by length of subset
p.sort! do |a,b|
  a.length - b.length
end

p.each do |subset|
  puts "[#{subset.join(", ")}]"
end

Permutations in Ruby

During the long weekend I decided to break it down geek style with some Ruby, because that's the way I roll. Or anyway, I'm starting to learn a little Ruby and here's a first little exercise. I'm not sure if it's officially sanctioned Ruby idiom, but it's a start.

# find and print all permutations of a list

# find permutations recursively based on the idea that
# for each item in the list, there is a set of permutations
# that start with that item followed by some permutation of
# the remaining items.
def permute(list)
 if (list.length <= 1)
   return [list]
 end
 permutations = []
 list.each do |item|
   sublist_permutations = permute(list - [item])
   sublist_permutations.each do |permutation|
     permutation.unshift(item)
     permutations << permutation
   end
 end
 return permutations
end

# test our permute function
list = %w{ a b c d }
p = permute(list)
p.each do |permutation|
 puts "#{permutation.join(", ")}"
end

A digithead's to-do list

Programming related stuff I want to learn, if I ever get time.

• Learn
  • Ruby and Rails
  • Adobe Flex/AIR
  • LISP
• Fool around with:
  • Scala
  • Groovy
  • ERLang
  • Haskell
• Study:
  • Algorithms:
    • Levitin book
    • Algorithm Design Manual
    • Algorithmics
  • Math:
    • Concrete Mathematics
    • Intro to Stats w/ R
• Finish SICP

More Swing Misery

Making a ListCellRenderer containing a word-wrapping JTextArea is apparently asking for trouble. The root of the problem is that there isn't a specified protocol for the negotiation between container and contained gui components to establish size. What you want here is for the JList to compute its width independent of the JTextAreas in the cells. The JTextAreas get their width from the JList and wrap appropriately. Finally, the JTextAreas now know their heights, so the JList can compute its height.

To laugh at my suffering see these forum threads:

• http://forum.java.sun.com/thread.jspa?threadID=702740
• http://forum.java.sun.com/thread.jspa?threadID=5235906
• http://forums.java.net/jive/message.jspa?messageID=245121

Cruft and loathing in Java/Swing

Why am I writing a Swing app in 2007? That's what I'm asking myself. It's a conspiracy, I tell you, involving the dreaded secret society the FuglyPLAF Posse. Anyway, onward to more pissing and moaning...

Take the humble MouseEvent (alias java.awt.event.MouseEvent). The integer constants on MouseEvent include:

• BUTTON1
• BUTTON1_MASK
• BUTTON1_DOWN_MASK

BUTTON1 is for use with the getButton() method, which (you'd think) might return the button being pressed when the event was generated. It actually does that on the Apple Java 5 JVM. On the Sun JVMs, apparently, getButton() returns the button "whose state has changed". If you're holding down a mouse button and dragging, getButton() lamely returns zero. Thanks for nothing.

BUTTON1_MASK is for use with getModifiers(). According to the JavaDocs, it's now recommended to use BUTTON1_DOWN_MASK which goes with getModifiersEx().

And, before you can say "Type-safe Enumeration", stop to ponder how many constants are needed to represent mouse buttons. How about none? Wouldn't a plain integer do just fine? How about a boolean function: event.buttonDown(int button)? OK, maybe it's useful to expose the bitmasking of the modifiers to the user, but the resulting mess argues that it would have been more useful not to.

Three different constants for a concept with all the complexity of mouse buttons? I sincerely hope someone was taken out and given an over-the-head turbo-wedgie for that one.