Key mapping swap for DragonRuby

keymap.rb

module KeyMap
 def self.set(mapping)
   mapping.each_pair do |command,key|
    GTK::KeyboardKeys.send :alias_method, command, key
   end
 end

 def self.unset(mapping)
   mapping.each_pair do |command,key|
    GTK::KeyboardKeys.send :undef_method, command
   end
 end
end

main.rb

require 'lib/keymap.rb'

QWERTY_MAPPING  = { forward:      :w,
                    backward:     :s,
                    straf_left:   :a,
                    straf_right:  :d,
                    action1:      :e  }

AZERTY_MAPPING  = { forward:      :z,
                    backward:     :s,
                    straf_left:   :q,
                    straf_right:  :d,
                    action1:      :e  }





def setup(args)
  args.state.mapping      = :qwerty
  KeyMap::set QWERTY_MAPPING

  args.state.last_command = 'no command'

  args.state.setup_done   = true
end





def tick(args)
  # --- 1. Setup : ---
  setup(args) unless args.state.setup_done


  # --- 2. Inputs : ---

  # 2.1 Commands defined in the mappings :
  args.state.last_command = 'no command'
  args.state.last_command = 'forward'     if args.inputs.keyboard.key_held.forward
  args.state.last_command = 'backward'    if args.inputs.keyboard.key_held.backward
  args.state.last_command = 'straf left'  if args.inputs.keyboard.key_held.straf_left
  args.state.last_command = 'straf right' if args.inputs.keyboard.key_held.straf_right
  args.state.last_command = 'action1'     if args.inputs.keyboard.key_held.action1

  # 2.2 Switching between mappings :
  if args.inputs.keyboard.key_down.space then
    if args.state.mapping == :qwerty then
      puts 'switched to azerty'
      KeyMap::unset QWERTY_MAPPING
      args.state.mapping  = :azerty
      KeyMap::set   AZERTY_MAPPING

    elsif args.state.mapping == :azerty then
      puts 'switched to qwerty'
      KeyMap::unset AZERTY_MAPPING
      args.state.mapping  = :qwerty
      KeyMap::set   QWERTY_MAPPING

    end
  end


  # --- 3. Outputs : ---
  args.outputs.labels << [ 20, 680, "current mapping: #{args.state.mapping.to_s}" ]
  args.outputs.labels << [ 20, 640, args.state.last_command ]
end