I’m glad that SambaPOS is extremely customizable! I’m done setting up with overpriced dumb pole display, and right now I’m setting up an affordable 7" second screen display (half the price of the pole display I bought) with 800*480px resolution (horizontal orientation).
Everything works fine except the live.js. The live.js is delayed everytime when POS screen is idle for less than 2 min (or more) - this kind of delay won’t happen with pole display OR creating new ticket right after ticket closed. I already modified the interval from 1000 to 50 in the live.js. Another thing is, how to avoid the blinking screen when items are being added? Is there any similar alternative to live.js?
Below is the video of my current situation:
By the way, I followed this instruction to setup my second screen (with some modification):
my live.js script:
/*
Live.js - One script closer to Designing in the Browser
Written for Handcraft.com by Martin Kool (@mrtnkl).
Version 4.
Recent change: Made stylesheet and mimetype checks case insensitive.
http://livejs.com
http://livejs.com/license (MIT)
@livejs
Include live.js#css to monitor css changes only.
Include live.js#js to monitor js changes only.
Include live.js#html to monitor html changes only.
Mix and match to monitor a preferred combination such as live.js#html,css
By default, just include live.js to monitor all css, js and html changes.
Live.js can also be loaded as a bookmarklet. It is best to only use it for CSS then,
as a page reload due to a change in html or css would not re-include the bookmarklet.
To monitor CSS and be notified that it has loaded, include it as: live.js#css,notify
*/
(function () {
var headers = { "Etag": 1, "Last-Modified": 1, "Content-Length": 1, "Content-Type": 1 },
resources = {},
pendingRequests = {},
currentLinkElements = {},
oldLinkElements = {},
interval = 50,
loaded = false,
active = { "html": 1, "css": 1, "js": 1 };
var Live = {
// performs a cycle per interval
heartbeat: function () {
if (document.body) {
// make sure all resources are loaded on first activation
if (!loaded) Live.loadresources();
Live.checkForChanges();
}
setTimeout(Live.heartbeat, interval);
},
// loads all local css and js resources upon first activation
loadresources: function () {
// helper method to assert if a given url is local
function isLocal(url) {
var loc = document.location,
reg = new RegExp("^\\.|^\/(?!\/)|^[\\w]((?!://).)*$|" + loc.protocol + "//" + loc.host);
return url.match(reg);
}
// gather all resources
var scripts = document.getElementsByTagName("script"),
links = document.getElementsByTagName("link"),
uris = [];
// track local js urls
for (var i = 0; i < scripts.length; i++) {
var script = scripts[i], src = script.getAttribute("src");
if (src && isLocal(src))
uris.push(src);
if (src && src.match(/\blive.js#/)) {
for (var type in active)
active[type] = src.match("[#,|]" + type) != null
if (src.match("notify"))
alert("Live.js is loaded.");
}
}
if (!active.js) uris = [];
if (active.html) uris.push(document.location.href);
// track local css urls
for (var i = 0; i < links.length && active.css; i++) {
var link = links[i], rel = link.getAttribute("rel"), href = link.getAttribute("href", 2);
if (href && rel && rel.match(new RegExp("stylesheet", "i")) && isLocal(href)) {
uris.push(href);
currentLinkElements[href] = link;
}
}
// initialize the resources info
for (var i = 0; i < uris.length; i++) {
var url = uris[i];
Live.getHead(url, function (url, info) {
resources[url] = info;
});
}
// add rule for morphing between old and new css files
var head = document.getElementsByTagName("head")[0],
style = document.createElement("style"),
rule = "transition: all .3s ease-out;"
css = [".livejs-loading * { ", rule, " -webkit-", rule, "-moz-", rule, "-o-", rule, "}"].join('');
style.setAttribute("type", "text/css");
head.appendChild(style);
style.styleSheet ? style.styleSheet.cssText = css : style.appendChild(document.createTextNode(css));
// yep
loaded = true;
},
// check all tracking resources for changes
checkForChanges: function () {
for (var url in resources) {
if (pendingRequests[url])
continue;
Live.getHead(url, function (url, newInfo) {
var oldInfo = resources[url],
hasChanged = false;
resources[url] = newInfo;
for (var header in oldInfo) {
// do verification based on the header type
var oldValue = oldInfo[header],
newValue = newInfo[header],
contentType = newInfo["Content-Type"];
switch (header.toLowerCase()) {
case "etag":
if (!newValue) break;
// fall through to default
default:
hasChanged = oldValue != newValue;
break;
}
// if changed, act
if (hasChanged) {
Live.refreshResource(url, contentType);
break;
}
}
});
}
},
// act upon a changed url of certain content type
refreshResource: function (url, type) {
switch (type.toLowerCase()) {
// css files can be reloaded dynamically by replacing the link element
case "text/css":
var link = currentLinkElements[url],
html = document.body.parentNode,
head = link.parentNode,
next = link.nextSibling,
newLink = document.createElement("link");
html.className = html.className.replace(/\s*livejs\-loading/gi, '') + ' livejs-loading';
newLink.setAttribute("type", "text/css");
newLink.setAttribute("rel", "stylesheet");
newLink.setAttribute("href", url + "?now=" + new Date() * 1);
next ? head.insertBefore(newLink, next) : head.appendChild(newLink);
currentLinkElements[url] = newLink;
oldLinkElements[url] = link;
// schedule removal of the old link
Live.removeoldLinkElements();
break;
// check if an html resource is our current url, then reload
case "text/html":
if (url != document.location.href)
return;
// local javascript changes cause a reload as well
case "text/javascript":
case "application/javascript":
case "application/x-javascript":
document.location.reload();
}
},
// removes the old stylesheet rules only once the new one has finished loading
removeoldLinkElements: function () {
var pending = 0;
for (var url in oldLinkElements) {
// if this sheet has any cssRules, delete the old link
try {
var link = currentLinkElements[url],
oldLink = oldLinkElements[url],
html = document.body.parentNode,
sheet = link.sheet || link.styleSheet,
rules = sheet.rules || sheet.cssRules;
if (rules.length >= 0) {
oldLink.parentNode.removeChild(oldLink);
delete oldLinkElements[url];
setTimeout(function () {
html.className = html.className.replace(/\s*livejs\-loading/gi, '');
}, 100);
}
} catch (e) {
pending++;
}
if (pending) setTimeout(Live.removeoldLinkElements, 50);
}
},
// performs a HEAD request and passes the header info to the given callback
getHead: function (url, callback) {
pendingRequests[url] = true;
var xhr = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject("Microsoft.XmlHttp");
xhr.open("HEAD", url, true);
xhr.onreadystatechange = function () {
delete pendingRequests[url];
if (xhr.readyState == 4 && xhr.status != 304) {
xhr.getAllResponseHeaders();
var info = {};
for (var h in headers) {
var value = xhr.getResponseHeader(h);
// adjust the simple Etag variant to match on its significant part
if (h.toLowerCase() == "etag" && value) value = value.replace(/^W\//, '');
if (h.toLowerCase() == "content-type" && value) value = value.replace(/^(.*?);.*?$/i, "$1");
info[h] = value;
}
callback(url, info);
}
}
xhr.send();
}
};
// start listening
if (document.location.protocol != "file:") {
if (!window.liveJsLoaded)
Live.heartbeat();
window.liveJsLoaded = true;
}
else if (window.console)
console.log("Live.js doesn't support the file protocol. It needs http.");
})();