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copied!<p>Check the <a href="http://jsfiddle.net/gfcarv/66nVn/" rel="nofollow">modified fiddle</a></p> <p>I added a way to detect when running in a touch device and a switch to map the mouse events to touch events.</p> <p>Also notice that when touchend occurred we need to use <code>event.changedTouches</code> to get the <code>coors</code> correctly.</p> <pre><code>window.addEventListener('load', function () { // get the canvas element and its context var canvas = document.getElementById('sketchpad'); var context = canvas.getContext('2d'); // create a drawer which tracks touch movements var drawer = { isDrawing: false, touchstart: function (coors) { context.beginPath(); context.moveTo(coors.x, coors.y); this.isDrawing = true; }, touchmove: function (coors) { if (this.isDrawing) { context.lineTo(coors.x, coors.y); context.stroke(); } }, touchend: function (coors) { if (this.isDrawing) { this.touchmove(coors); this.isDrawing = false; } } }; // create a function to pass touch events and coordinates to drawer function draw(event) { var type = null; // map mouse events to touch events switch(event.type){ case "mousedown": event.touches = []; event.touches[0] = { pageX: event.pageX, pageY: event.pageY }; type = "touchstart"; break; case "mousemove": event.touches = []; event.touches[0] = { pageX: event.pageX, pageY: event.pageY }; type = "touchmove"; break; case "mouseup": event.touches = []; event.touches[0] = { pageX: event.pageX, pageY: event.pageY }; type = "touchend"; break; } // touchend clear the touches[0], so we need to use changedTouches[0] var coors; if(event.type === "touchend") { coors = { x: event.changedTouches[0].pageX, y: event.changedTouches[0].pageY }; } else { // get the touch coordinates coors = { x: event.touches[0].pageX, y: event.touches[0].pageY }; } type = type || event.type // pass the coordinates to the appropriate handler drawer[type](coors); } // detect touch capabilities var touchAvailable = ('createTouch' in document) || ('ontouchstart' in window); // attach the touchstart, touchmove, touchend event listeners. if(touchAvailable){ canvas.addEventListener('touchstart', draw, false); canvas.addEventListener('touchmove', draw, false); canvas.addEventListener('touchend', draw, false); } // attach the mousedown, mousemove, mouseup event listeners. else { canvas.addEventListener('mousedown', draw, false); canvas.addEventListener('mousemove', draw, false); canvas.addEventListener('mouseup', draw, false); } // prevent elastic scrolling document.body.addEventListener('touchmove', function (event) { event.preventDefault(); }, false); // end body.onTouchMove }, false); // end window.onLoad </code></pre>

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