# KEYBOARD

Path: | docs/KEYBOARD
Last Update: | Thu Jul 02 15:04:50 -0600 2009

EventMachine (EM) can respond to keyboard events. This gives your event-driven programs the ability to respond to input from local users.

Programming EM to handle keyboard input in Ruby is simplicity itself. Just use EventMachine#open_keyboard, and supply the name of a Ruby module or class that will receive the input:

     require 'rubygems'
     require 'eventmachine'

     module MyKeyboardHandler
            def receive_data keystrokes
                    puts "I received the following data from the keyboard: #{keystrokes}"
            end
     end

     EM.run {
            EM.open_keyboard(MyKeyboardHandler)
     }

If you want EM to send line-buffered keyboard input to your program, just include the LineText2 protocol module in your handler class or module:

     require 'rubygems'
     require 'eventmachine'

     module MyKeyboardHandler
            include EM::Protocols::LineText2
            def receive_line data
                    puts "I received the following line from the keyboard: #{data}"
            end
     end

     EM.run {
            EM.open_keyboard(MyKeyboardHandler)
     }

As we said, simplicity itself. You can call EventMachine#open_keyboard at any time while the EM reactor loop is running. In other words, the method invocation may appear anywhere in an EventMachine#run block, or in any code invoked in the run block.

[Validate]