Creo en nosotros. Wikipedia.
ShareCode
Permalink: http://www.treeweb.es/u/974/ 01/02/2011

ShareCode

1  var ongoingTouches = new Array;2 3 function colorForTouch(touch) {4  var id = touch.identifier;5  id = id.toString(16); // make it a hex digit6  return "#" + id + id + id;7 }8 9 function ongoingTouchIndexById(idToFind) {10  for (var i=0; i<ongoingTouches.length; i++) {11  var id = ongoingTouches[i].identifier;12  13  if (id == idToFind) {14  return i;15  }16  }17  return -1; // not found18 }19 20 function handleStart(evt) {21  evt.preventDefault();22  var el = document.getElementById("canvas");23  var ctx = el.getContext("2d");24  var touches = evt.changedTouches;25  26  for (var i=0; i<touches.length; i++) {27  ongoingTouches.push(touches[i]);28  var color = colorForTouch(touches[i]);29  ctx.fillStyle = color;30  ctx.fillRect(touches[i].pageX-2, touches[i].pageY-2, 4, 4);31  }32 }33 34 function handleMove(evt) {35  evt.preventDefault();36  var el = document.getElementById("canvas");37  var ctx = el.getContext("2d");38  var touches = evt.changedTouches;39  40  ctx.lineWidth = 4;41  42  for (var i=0; i<touches.length; i++) {43  var color = colorForTouch(touches[i]);44  var idx = ongoingTouchIndexById(touches[i].identifier);45 46  ctx.fillStyle = color;47  ctx.beginPath();48  ctx.moveTo(ongoingTouches[idx].pageX, ongoingTouches[idx].pageY);49  ctx.lineTo(touches[i].pageX, touches[i].pageY);50  ctx.closePath();51  ctx.stroke();52  ongoingTouches.splice(idx, 1, touches[i]); // swap in the new touch record53  }54 }55 56 function handleEnd(evt) {57  evt.preventDefault();58  var el = document.getElementById("canvas");59  var ctx = el.getContext("2d");60  var touches = evt.changedTouches;61  62  ctx.lineWidth = 4;63  64  for (var i=0; i<touches.length; i++) {65  var color = colorForTouch(touches[i]);66  var idx = ongoingTouchIndexById(touches[i].identifier);67  68  ctx.fillStyle = color;69  ctx.beginPath();70  ctx.moveTo(ongoingTouches[i].pageX, ongoingTouches[i].pageY);71  ctx.lineTo(touches[i].pageX, touches[i].pageY);72  ongoingTouches.splice(i, 1); // remove it; we're done73  }74 }75 76 function handleCancel(evt) {77  evt.preventDefault();78  var touches = evt.changedTouches;79  80  for (var i=0; i<touches.length; i++) {81  ongoingTouches.splice(i, 1); // remove it; we're done82  }83 }84 85 86 function startup() {87  var el = document.getElementById("canvas");88  el.addEventListener("touchstart", handleStart, false);89  el.addEventListener("touchend", handleEnd, false);90  el.addEventListener("touchcancel", handleCancel, false);91  el.addEventListener("touchleave", handleEnd, false);92  el.addEventListener("touchmove", handleMove, false);93 }94 95 96 window.addEventListener('load', function(e){97  startup();98 }, true);
Enlace
El enlace para compartir es:

Powered by TreeWeb
© TreeWeb 2010. Todos los derechos reservados