Simple Bangle Touch Controller for Left, Right and Both touches with timings and more...

Here the code - about to be a module -with usage example:

// SBTouchCtrl.js
// 2020v1210_ao by allObjects
// Simple Bangle Touch Controller (module to be)
// Easy to use bangle touch controler by allObjects.
// Provides events for left, right, and both touch
// lifecycle w/ timings incl. on error and recovery. 
/*

` ` `
var l = function() { console.log.apply(console,arguments); };
  , sbtcMod = require("SBTouchCtrl");
  , sbtc; // instance of simple bangle touch controler
function onInit() {
sbtc = new SBTouchCtrl(
  // provide callback obj w/ named cbs for some events
  { L:(ts,tt,et)=>l("Left touch for",et,"[sec] at",tt)
  , E:()=>console.log("Error - recovered")
  }).watch(); // activate button touch button watching
  g.clear();
} setTimeout(onInit,999);
` ` `

*/
var SBTouchCtrl=function(cbs) { var _=0||this;
  _.cbs=cbs||{}; // obj w/ callbacks named after touchSignature
    // l: left touch down (touchSign,touchTime,elapsedTime,sbtctl)
    // r: right touch down
    // b: 2nd both touch down
    // p: 1st untouch of both touch
    // e: error in sequncing (no recovery other than untouch all
    // L: untouch of left button and completion of left touch
    // R: untouch of right button and completion of right touch
    // B: untouch of both buttons and completion of both touch
    // E: end of error sequencing - all untouched - ready to cont
  _.tt=0;  // touch time
  _.bt=0;  // both touch time(+/-=L/R)
  _.pt=0;  // both untouch time(+/-=L/R)
  _.ut=0;  // untouch time
  _.et=0;  // elapsed time
  _.st=0;  // signature time
  _.ts=""; // touch signature
  _.sb=0;  // status bits (for error resolution)
  _.s="s"; // status, s (start)
  _.wl=_.wr=_.wL=_.wR=null; // touch button watchers
} , p=SBTouchCtrl.prototype;
p.sl=(_,t,e)=>{_.ts=_.s=e;_.tt=t;return _.cbs[e];};
p.sr=(_,t,e)=>{_.ts=_.s=e;_.tt=t;return _.cbs[e];};
p.lL=(_,t,e)=>{_.ts=e;_.s="s";_.et=(_.ut=t)-_.tt;return _.cbs[e];};
p.rR=(_,t,e)=>{_.ts=e;_.s="s";_.et=(_.ut=t)-_.tt;return _.cbs[e];};
p.lr=(_,t,e)=>{_.ts=_.s="b";_.bt=t-_.tt; return _.cbs.b;};
p.rl=(_,t,e)=>{_.ts=_.s="b";_.bt=_.tt-t; return _.cbs.b;};
p.bL=(_,t,e)=>{_.ts="p";_.pt=t-_.tt; return _.cbs.p;};
p.bR=(_,t,e)=>{_.ts="p";_.pt=_.tt-t; return _.cbs.p;};
p.bLR=(_,t,e)=>{_.ts="B";_.s="s";_.et=(_.ut=t)-_.tt;return _.cbs.B;};
p.bRL=(_,t,e)=>{_.ts="B";_.s="s";_.et=(_.ut=t)-_.tt;return _.cbs.B;};
p.ign=(_,t,e,c,b)=>{ // p - s ignore from 1st err: evt already in _.s
  if ((c=((s=_.s).charAt(0)))=="b") { // 1st time here switch to e(rr)
    _.sb=3; _.ts=c="e"; _.s=c+s; } else {
    if ((_.sb=(_.sb^("RL".indexOf(e)+1))||("rl".indexOf(e)+1))) {
      _.ts="e"; _.s="e.."+e; } else { _.ts="E"; _.s="s"; } }
  return _.cbs[c]; };
p.ns=(_,e,b,f,t,cb)=>{ // dispatcher to state transitioners
  if ((cb=((f=_[_.s+=e])?f:_.ign).apply(_,[_,_.st=t=getTime(),e,b]))
  )cb(_.ts,t,_.et,_);}; // touchSignCharlrbpeLRBE,time,elapsed,BTouch
p.el=function(){this.ns(this,"l");}; // l touch event handler
p.er=function(){this.ns(this,"r");}; // r ...
p.eL=function(){this.ns(this,"L");}; // L untouch event handler
p.eR=function(){this.ns(this,"R");}; // R ..
p.watch=function(){var _=0||this,o;_.unwatch();// set watch on t btns
  _.wl=setWatch(_.el.bind(_),BTN4,o={repeat:true,edge:"rising"});
  _.wr=setWatch(_.er.bind(_),BTN5,o);
  _.wL=setWatch(_.eL.bind(_),BTN4,o={repeat:true,edge:"falling"});
  _.wR=setWatch(_.eR.bind(_),BTN5,o);
  return _; };
p.unwatch=function() { var _=0||this,o; // clear watches touch btns
  if(_.wl)_.wl=clearWatch(_.wl); if(_.wr)_.wr=clearWatch(_.wr);
  if(_.wL)_.wL=clearWatch(_.Wr); if(_.wR)_.wR=clearWatch(_.wR);
  return _; };
// exports=SBTouchCtrl; // ---------- end of SBTouchCtrl module


// slim logging function
var l = function(){console.log.apply(console,arguments); };

// var SBTouchCtrl = require("SBTouchCtrl");
var sbtc; // instance of simple bangle touch controler

function onInit() {
sbtc = new SBTouchCtrl(
  // provide callback obj w/ named cbs for some events
  { L:(ts,tt,et)=>l("Left touch for",et,"[sec] at",tt)
  , R:(ts,tt,et)=>l("Right touch for",et,"[sec]")
  , B:(ts,tt,et,ctl)=>{ var d=new Date(tt*1000); l(ts // touch sign
      ,"Both w/ details abt 2nd btn touch and 1st btn untouch"
      ,"\nat" ,d.getHours()+":"+d.getMinutes()+":"+d.getSeconds()
      ,"\nfor",et // elapsed in [s] from 1st touch to last untouch
      ,"\n2nd touch after 1st t",ctl.bt // +/- R/L[s] touched appart
      ,"\n1st untouch aft 1st t",ctl.pt // +/- R/L[s] before elapsed
      ,"\n2nd untouch aft 1st u",et-ctl.pt // +/- R/L[s]unt'd appart
      ,"\n2nd untouch aft 1st t",et,"=elapsed");} // +/- R/L[s]unt'd
  , e:(ts,tt,et,ctl)=>console.log("err",ts,ctl.sb)
  , E:()=>console.log("Error - recovered")
  }).watch(); // activate button touch button watching
  g.clear();
}

setTimeout(onInit,999);