swipey js

swipey.js

window.onload = function(){
  var display = document.getElementsByTagName("body"); //could be any element
  var touched = false; // a useful flag for restructing otehr actions
  var increment = 0; // the amount we increment

  var addRotateTouches = function(){
    display.addEventListener("touchstart", rotateStart ,false);
    display.addEventListener("touchmove", rotateMove ,false);
    display.addEventListener("touchend", rotateEnd ,false);
  }

  var removeRotateTouches = function(){
    display.removeEventListener("touchstart", rotateStart ,false);
    display.removeEventListener("touchmove", rotateMove ,false);
    display.removeEventListener("touchend", rotateEnd ,false);
  }

  var rotateStart = function(){
    touched = true;
    startX = window.Touch ? event.touches[0].pageX : event.pageX;
    event.preventDefault();
  }
  
  var rotateMove = function(event){
    var velocityLimit = window.Touch ? 20 : 10;
    event.preventDefault();
    var newX = (window.Touch ? event.touches[0].pageX : event.pageX);
    var curX = newX - startX;
    if (curX > velocityLimit || curX < -velocityLimit) {
      var delta = parseInt(curX / velocityLimit);
      startX = newX;
      increment += delta;
      increment = (((increment % 36) + 36) % 36);// a modulus fix.
      console.log(increment);
    }
  }
  var rotateEnd = function(){
    touched = false;
  }
};