1. Make GUI Apps with Shoes
Brian Hogan

2. Shoes?

3. simple GUI toolkit

4. why ruby?
• Highly dynamic
• Very high level
• 100% object oriented
• 100% open-source
• Really easy to learn

5. simple code.
age = 42
first_name = "Homer"
start_date = Date.new 1980, 06, 05
annual_salary = 100000.00

6. Ruby is dynamically
typed

7. but strong-typed!

8. so a string and a
number can be
declared without a
type...

9. ...but you can’t just add
a number to a string
without converting it.
age = 25
"you are " + age.to_s + " years old!"

10. there’s a shortcut for
building strings though:
age = 25
"you are #{age} years old."

11. #{} embeds an
expression in a string,
converting the result to
a string!

12. Ruby has simple logic.
if on_probation(start_date)
puts "Yes"
else
puts "no"
end

13. Methods (functions) are
simple too.
# if start date + 6 months is > today
def on_probation?(start_date)
(start_date >> 6 > Date.today)
end

14. Classes can be boring...
class Person
@first_name
@last_name
def first_name=(f)
@first_name = f
end
def first_name
@first_name
end
def last_name=(l)
@last_name = l
end
def last_name
@last_name
end
end

15. ...or awesome!
class User
attr_accessor :first_name, :last_name
end

16. Everything is an
object... even integers
and strings!

17. Arrays
colors = ["Red", "Green", "Blue"]

18. Hashes (dictionaries)
attributes = {:age => 25,
:first_name => "Homer",
:last_name => "Simpson"}

19. =>

20. Hashes as parameters
for methods are very
common.

21. Blocks
some_method do
some_code_you_wrote
end

22. Blocks can iterate...
@colors = ["red", "green", "blue"]
@colors.each do |color|
puts color
end

23. and encapsulate code
create_table :products do |t|
t.string :name
t.text :description
t.boolean :visible
t.integer :price
end

24. You use them all the
time in Ruby.

25. in fact, every method
can take a block.
5.times do
puts "Hello!"
end

26. Blocks make it easy to
write your own
language.

27. DSL - Domain Specific
Language

28. Shoes is a DSL for
making GUI apps.

29. A Shoes app is an
object.

30. You use blocks to
define the user
interface and trigger
events,

31. Shoes.app :title => "Hello World" do
alert "Hello World"
end

32. Shoes.app :title => "Hello World" do
button "Click me" do
alert "Hello World"
end
end

33. Shoes.app :title => "Hello World",
:width => 320,
:height => 240 do
background red
end

34. Shoes.app :title => "Hello World",
:width => 320,
:height => 240 do
background red..black
end

35. stacks

36. Shoes.app :title => "Hello World",
:width => 320,
:height => 240 do
stack do
para "Hello"
para "World"
end
end

37. flows

38. Shoes.app :title => "Hello World",
:width => 320,
:height => 240 do
flow do
para "Hello"
para "World"
end
end

39. Combine stacks and
flows.

40. Shoes.app :title => "Hello World",
:width => 320,
:height => 240 do
stack :width => "100%" do
background gray
title "Hello World"
end
stack :width => "50%" do
flow :width => "100%" do
para "Left side has some text"
end
end
stack :width => "50%" do
background white
para "Right side has some text"
para "without an inner flow."
end
end

41. Shoes.app :title => "Hello World" do
stack do
banner "Hello there."
title "The quick"
subtitle "brown fox"
tagline "jumped"
caption "over"
para "the"
inscription "lazy dog"
end
end

42. edit_line
Shoes.app :title => "Hello World" do
para "Enter your name"
@name = edit_line
end

43. edit_line
Shoes.app :title => "text boxes" do
para "Password"
@pass = edit_line(:secret => true)
end

44. edit_box
Shoes.app :title => "text boxes" do
para "About Me"
@about = edit_box
end

45. list_box
Shoes.app :title => "text boxes" do
para "Colors"
@color = list_box :items => ["green", "red", "blue"]
end

46. Use .text to grab the
values in the boxes.
Shoes.app :title => "Hello World" do
para "Enter your name"
@name = edit_line
button "Go" do
name = @name.text
alert "Hello #{name}"
end
end

47. Since everything is an
object, you can work
with it... even stacks
and flows!

48. Shoes.app do
para "add name"
button "Add" do
@names.append do
para @name.text
end
@name.text = ""
end
@names = stack
end

49. Ooooh.. windows!
Shoes.app do
button "Open window" do
window :title => "Child" do
para "Hello!"
end
end
end

50. Shoes can load images,
play music, and play
movies.

51. You can use and embed
almost every Ruby
library

54. It can open browser
windows...

55. ..and hook into the
OS’s open, save, fonts,
and color pickers.

56. Make games with
Shoes!

57. You can build installers
for Windows, Linux, and
Mac.

58. What makes Shoes so
great?

59. It lets you build things
fast...

60. ...and have fun doing it.

61. http://github.com/napcs/shoes_demo_apps/
http://the-shoebox.org/
http://github.com/whymirror/shoes/

62. questions?
brianhogan@napcs.com
twitter: bphogan
http://www.napcs.com/