Qt Bindings WIP

08_things_are_getting_complex.png

09_day5.cr

require "./qt/version"
require "./qt/glue"
require "./qt/binding"
require "./qt/*"

qApp = Qt::Application.new # Decent #initialize
window = Qt::MainWindow.new # More classes!

# This method was once called `setWindowTitle()` in C++.
# `#window_title=` looks better though.  The generator knows this.
window.window_title = ".: Crystal/Qt :."

container = Qt::Widget.new # This is Qt noise..
window.central_widget = container

layout = Qt::VBoxLayout.new
container.layout = layout

# Oh hey, what's this?
class MyLabel < Qt::Label
  # Ever heard of C++ virtual methods?
  def has_height_for_width : Bool
    true
  end

  # Yeah, overwriting them works OOTB now!
  # It's decently portable too, it'll just work with any modern C++ compiler.
  # ARM and friends should work too, can't test this though.
  def height_for_width(width : Int32) : Int32
    width
  end
end

# Quickly build a simple UI
btn_box = Qt::HBoxLayout.new
btn_up = Qt::PushButton.new "Increment"
btn_down = Qt::PushButton.new "Decrement"
label = MyLabel.new "Counter: 0"

# We end up with Crystal classes for the wrappers, so it's no issue at all to
# Crystal-ize the API a bit more, apart from what the generator already does.
btn_box << btn_up << btn_down
layout << btn_box << label

# We will in-/de-crement `count` on each press on one of the buttons.
# Simple enough - Point is: Blocks work 100% as expected.
count = 0
btn_up.on_pressed do
  count += 1
  label.text = "Counter: #{count}"
end

btn_down.on_pressed do
  count -= 1
  label.text = "Counter: #{count}"
end

# Ah well, let's kick this off
window.show # Open the window
Qt::Application.exec # Start Qt's main loop

# And this is where it's at right now.  More to come.

10_signals_work.png

20_day3.cr

require "./qt/version"
require "./qt/glue"
require "./qt/binding"
require "./qt/*"

arguments = ARGV.clone
arg_count = arguments.size
qApp = Qt::Application.new(pointerof(arg_count), arguments.map(&.to_unsafe).to_unsafe)

btn = Qt::PushButton.new("Click Me!")

btn.pressed do
  puts "You pushed da button!"
end

btn.show
Qt::Application.exec

30_it_works.png

40_qt.cr

require "./qt/version"
require "./qt/glue"
require "./qt/binding"

arguments = ARGV.clone
arg_count = arguments.size

# Looks a bit funky, but eh, nothing a small hand-written #initialize can't solve!
qApp = Qt::Application.new(pointerof(arg_count), arguments.map(&.to_unsafe).to_unsafe)

label = Qt::Label.new("Hello, World!")
label.window_title = "Crystal \\m/"
label.show
Qt::Application.exec