15. User Interfaces

# This test program demonstrates parsing program arguments.
# It uses the optparse library, which is included with ruby 1.8
# It handles classic unix style and gnu style options
require 'optparse'

@debugmode = false
@verbose = false

ARGV.options do |opts|
    opts.banner = "Usage: ruby #{$0} [OPTIONS] INPUTFILES"

    opts.on("-h", "--help", "show this message") {
        puts opts
        exit
    }
    # The OptionParser#on method is called with a specification of short
    # options, of long options, a data type spezification and user help
    # messages for this option.
    # The method analyses the given parameter and decides what it is,
    # so you can leave out the long option if you don't need it
    opts.on("-v", "--[no-]verbose=[FLAG]", TrueClass, "run verbosly") {
        |@verbose|   # sets @verbose to true or false
    }
    opts.on("-D", "--DEBUG", TrueClass, "turns on debug mode" ){
        |@debugmode|   # sets @debugmode to true
    }
    opts.on("-c", "--count=NUMBER", Integer, "how many times we do it" ){
        |@count|      # sets @count to given integer
    }
    opts.on("-o", "--output=FILE", String, "file to write output to"){
        |@outputfile|   # sets @outputfile to given string
    }
    opts.parse!
end

# example to use the options in the main program
puts "Verbose is on" if @verbose
puts "Debugmode is on" if @debugmode
puts "Outfile is #{@outputfile}" if defined? @outputfile
puts "Count is #{@count}" if defined? @count
ARGV.each { |param|
    puts "Got parameter #{param}"
}

buf = "\0" * 8
$stdout.ioctl(0x5413, buf)
ws_row, ws_col, ws_xpixel, ws_ypixel = buf.unpack("S4")

raise "You must have at least 20 characters" unless ws_col >= 20
max = 0
values = (1..5).collect { rand(20) }  # generate an array[5] of rand values
for i in values
    max = i if max < i
end
ratio = Float(ws_col-12)/max          # chars per unit
for i in values
    printf "%8.1f %s\n", i, "*" * (ratio*i)
end

# gives, for example:
#   15.0 *******************************
#   10.0 *********************
#    5.0 **********
#   14.0 *****************************
#   18.0 **************************************

# Ruby's standard distribution doesn't have an ANSI color module, but we can use
# Term::ANSIColor (http://term-ansicolor.rubyforge.org/) instead.
#-----------------------------
require 'term/ansicolor'
include Term::ANSIColor

# Text can be colored using constants
print red, "Danger Will Robinson!", reset, "\n"
print "This is just normal text\n"
print blink, "Do you hurt yet?", reset, "\n"
#-----------------------------
# Or by using functions. Functions automatically reset colors at the end.
print red("Danger Will Ronbinson!"), "\n"
print red( on_black( "venom lack" )), "\n"
print red( on_yellow( "kill that fellow" )), "\n"
print green( on_cyan( blink( "garish!" ))), "\n"
#-----------------------------
# Or by using block forms. Block forms automatically reset colors at the end.
print red { "Danger Will Robinson!" }, "\n"
print red { on_black { "venom lack" } }, "\n"
print red { on_yellow { "kill that fellow" } }, "\n"
#-----------------------------
# Or by using a String Mixin
class String
    include Term::ANSIColor
end

print "Danger Will Robinson!".red, "\n"
print "venom lack".red.on_black, "\n"
print "kill that fellow".red.on_yellow, "\n"

#-----------------------------
# To color text without using a third party library, constants can be created
# manually using ANSI escape codes. (A complete list of all codes can be found
# at http://en.wikipedia.org/wiki/Ansi_escape_codes)
# Note that \e means \033 (The escape character)
#-----------------------------
# Foreground constants
BLACK = "\e[30m"
RED = "\e[31m"
GREEN = "\e[32m"
WHITE = "\e[37m"

# Background constants
ON_BLACK = "\e[40m"
ON_WHITE = "\e[47m"
ON_YELLOW = "\e[43m"
ON_CYAN = "\e[46m"

# Style constants
BLINK = "\e[5m"
NOBLINK = "\e[25m"
BOLD = "\e[1m"
NOBOLD = "\e[22m"

RESET = "\e[0m"
#-----------------------------
puts "#{RED}Danger Will Ronbinson!#{RESET}"
puts "This is just normal text."
puts "#{BLINK}Do you hurt yet?#{NOBLINK}"
#-----------------------------
puts "#{RED}Danger Will Ronbinson!#{RESET}"
puts "#{RED}#{ON_BLACK}venom lack"
puts "#{RED}#{ON_YELLOW}kill that fellow"
puts "#{GREEN}#{ON_CYAN}#{BLINK}garish!"
#-----------------------------
print BLACK, ON_WHITE, "black on white\n"
print WHITE, ON_BLACK, "white on black\n"
print GREEN, ON_CYAN, BLINK, "garish!\n"

print RESET
#-----------------------------