Hi. I’m trying to emulate touch events in Chrome for daaaaays but nothing happens. Can anybody tell me what’s wrong? Thanks.
var cvs = null;
var cb_ctx = null;
var cb_lastPoints = null;
var cb_easing = 0.4;
// Setup event handlers
window.onload = init;
function init(e) {
cb_canvas = document.getElementById("cbook");
cb_lastPoints = Array();
if (cb_canvas.getContext) {
cb_ctx = cvs.getContext('2d');
cb_ctx.lineWidth = 2;
cb_ctx.strokeStyle = "rgb(0, 0, 0)";
cb_ctx.beginPath();
cvs.onmousedown = startDraw;
cvs.onmouseup = stopDraw;
cvs.ontouchstart = startDraw;
cvs.ontouchstop = stopDraw;
cvs.ontouchmove = drawMouse;
}
}
function startDraw(e) {
if (e.touches) {
// Touch event
for (var i = 1; i <= e.touches.length; i++) {
cb_lastPoints[i] = getCoords(e.touches[i - 1]); // Get info for finger #1
}
}
else {
// Mouse event
cb_lastPoints[0] = getCoords(e);
cvs.onmousemove = drawMouse;
}
return false;
}
// Called whenever cursor position changes after drawing has started
function stopDraw(e) {
e.preventDefault();
cvs.onmousemove = null;
}
function drawMouse(e) {
if (e.touches) {
// Touch Enabled
for (var i = 1; i <= e.touches.length; i++) {
var p = getCoords(e.touches[i - 1]); // Get info for finger i
cb_lastPoints[i] = drawLine(cb_lastPoints[i].x, cb_lastPoints[i].y, p.x, p.y);
}
}
else {
// Not touch enabled
var p = getCoords(e);
cb_lastPoints[0] = drawLine(cb_lastPoints[0].x, cb_lastPoints[0].y, p.x, p.y);
}
cb_ctx.stroke();
cb_ctx.closePath();
cb_ctx.beginPath();
return false;
}
// Draw a line on the canvas from (s)tart to (e)nd
function drawLine(sX, sY, eX, eY) {
cb_ctx.moveTo(sX, sY);
cb_ctx.lineTo(eX, eY);
return { x: eX, y: eY };
}
// Get the coordinates for a mouse or touch event
function getCoords(e) {
if (e.offsetX) {
return { x: e.offsetX, y: e.offsetY };
}
else if (e.layerX) {
return { x: e.layerX, y: e.layerY };
}
else {
return { x: e.pageX - cvs.offsetLeft, y: e.pageY - cvs.offsetTop };
}
}