A UGen that detects a specific keyboard stroke. When the given key is not pressed, the lo value is output, while the key is pressed the hi value is output. If lag is greater than zero, a Lag -type operation is applied for a smoother transition between lo and hi .

Examples

// determine codes
play {
  val code = Phasor.kr(lo = 0, hi = 127)
  val k    = KeyState.kr(code, lag = 0)
  val x    = Gate.kr(code, k)
  val ch   = x sig_!= Delay1.kr(x)
  // when a code change is detected, print it
  x.poll(ch, "code")
  ()
}

// gate sound using the 'A' key
play {
  // on Linux, key-code 38 denotes the 'A' key
  SinOsc.ar(800) * KeyState.kr(38, 0, 0.1)
}