ruby - EventMachine 如何编写对按键使用react的键盘处理程序

Question

我使用 EventMachine LineText2 协议(protocol)，我想在每次按下键盘上的字符时触发 receive_line 方法，而不仅仅是在输入新行时触发。有没有办法改变这种默认行为？

class KeyboardHandler < EM::Connection
  include EM::Protocols::LineText2

  def initialize(q)
    @queue = q
  end

  def receive_line(data)
    @queue.push(data)
  end
end

EM.run {
  q = EM::Queue.new

  callback = Proc.new do |line|
    # puts on every keypress not on "\n"
    puts line
    q.pop(&callback)
  end
  q.pop(&callback)

  EM.open_keyboard(KeyboardHandler, q)
}

Answer 1

如果你想从终端接收无缓冲的输入，你应该关闭标准输入的规范模式。 (我还关闭了 echo 以使屏幕更易于阅读。)在您的代码调用 #open_keyboard 之前或在您的处理程序初始化程序中添加:

require 'termios'
# ...
attributes = Termios.tcgetattr($stdin).dup
attributes.lflag &= ~Termios::ECHO # Optional.
attributes.lflag &= ~Termios::ICANON
Termios::tcsetattr($stdin, Termios::TCSANOW, attributes)

例如:

require 'termios'
require 'eventmachine'

module UnbufferedKeyboardHandler
  def receive_data(buffer)
    puts ">>> #{buffer}"
  end
end

EM.run do
  attributes = Termios.tcgetattr($stdin).dup
  attributes.lflag &= ~Termios::ECHO
  attributes.lflag &= ~Termios::ICANON
  Termios::tcsetattr($stdin, Termios::TCSANOW, attributes)

  EM.open_keyboard(UnbufferedKeyboardHandler)
end