gistfile1.txt

window.addEventListener("load", main)


let env = {
	holdtime: 65,
}

function main(){
	test()
	console.log("Test");
}
function log(x){
  let s = "" + x
  let t = document.createTextNode(s)
  document.body.appendChild(
    document.createElement("br"))
  document.body.appendChild(t)
  console.log(s)
}

function test(){
	let logger = KeyLogger(true)
  let logtext = ""
	window.addEventListener("keydown", logger.keydown)
	window.addEventListener("keyup", logger.keyup)
	setInterval(flush, 1000)
	
	function flush(){
		let s = logger.flush()
		if(s.length){
      logtext += s
      log(s)
    } 
	}
}

// key logger allows us to record a keyboard sequence and 
// interpret it after the fact, so that keyboard implementations
// dont need to handle events.

function parseLog(s){
	let list = s.split(/\s+/)
	if(list[0].length == 0) list.unshift()
	let log = []
	let t = 0
	for(let i=0; i<list.length; ++i){
		let entry = list[i]
		let j = entry.indexOf(":")
		let action = {"+": "down", "=":"hold", "-":"up"}[entry[0]]
		let code = j>0? entry.substring(1,j) : entry.substring(1)
		let time = j>0? parseInt(entry.substring(j+1)) : 0
		t += time
		time = t
		log.push({action, code, time})
	}
	return log
}
// log a sequence of keypresses
// a short press of space is not sufficient to trigger a chord,
// you need a keyhold
// even if overlapped
// action_code:dt
// keydown +112:0000
// keyhold =112:0000
// keyup -112:0000
// 
function KeyLogger(keeptime){
	
	let ready = ""
	let pending = ""
	let down = {}
	let last = Date.now()

	let keytimes = {}
	return {keydown, keyup, flush}

	
	function flush(){
		let s = ready
		ready = ""
		return s
	}
	function cleartime(code){
		delete keytimes[code]
        console.log(keytimes)
		if(Object.keys(keytimes).length == 0){
			ready += pending
			pending = ""
		}
	}
	function delta(){
		let now = Date.now()
		let dt = now - last
		last = now
		return dt
	}
	function action(symbol, code){
		let dt = delta()
		pending += ' ' + symbol + code + (keeptime? ":" + dt : "") 
		//ready += ' ' + symbol + code + (keeptime? ":" + dt : "") 
	}	
		
	function keyhold(code, t){
		if(keytimes[code] == t){
		  action("=", code)
		  cleartime(code)
		}
	}
	function keydown(e){
		let code = e.keyCode
		if(keytimes.hasOwnProperty(code)) return
		//console.log('code', code)
		let dt = delta
		action("+", code)
		keytimes[code] = last
		setTimeout(keyhold, env.holdtime, code, last)
	}
	function keyup(e){
		let code = e.keyCode
		action("-", code)
		cleartime(code)
	}
}