TrafficLightsCSharp/TrafficLights/Pages/Index.cshtml

170 lines
6.8 KiB
Plaintext

@page
@model IndexModel
@{
Layout = null;
// ViewData["Title"] = "Home page";
}
<!doctype html>
<html>
<head>
<title>Traffic Light Simulation Frontend</title>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto+Condensed:normal,bold,italic" />
<style>
body {
font-family: 'Roboto Condensed';
}
.wrapper {
display: flex;
max-width: 600px;
font-family: 'Roboto Condensed';
}
.wrapper > div {
margin: .1em;
align-self: center;
flex: 1;
text-align: center;
}
div.light {
background-size: 100px;
background-repeat: no-repeat;
min-height: 230px;
min-width: 100px;
width: 100px;
}
div.north {
background-image: url(/images/red.png);
}
span#state-data {
color: #666666;
font-family: monospace;
}
</style>
</head>
<body>
<h1>Traffic light Simulation Demo</h1>
<p><strong>Period: </strong><span id="period">Awaiting first update...</span></p>
<p><strong>Simulation time: </strong><span id="time">Awaiting first update...</span></p>
<p><strong>Current state index: </strong><span id="state-index">Awaiting first update...</span></p>
<p><strong>Current state data: </strong><span id="state-data">Awaiting first update...</span></p>
<hr />
<p><strong>Time until next update: </strong><span id="time-remaining">Awaiting first update...</span> second(s)</p>
<p><strong>Time factor: </strong><span id="time-factor">Awaiting first update...</span></p>
<hr />
<div class="wrapper">
<div></div>
<div>NORTH</div>
<div id="north" class="light north"></div>
<div id="north-right" class="light"></div>
<div></div>
<div></div>
</div>
<div class="wrapper">
<div>WEST</div>
<div id="west" class="light"></div>
<div></div>
<div></div>
<div></div>
<div id="east" class="light"></div>
<div>EAST</div>
</div>
<div class="wrapper">
<div></div>
<div>SOUTH</div>
<div id="south" class="light"></div>
<div></div>
<div></div>
<div></div>
</div>
<script>
function sleep(ms)
{
return new Promise(resolve => setTimeout(resolve, ms))
}
async function ready()
{
const req = new XMLHttpRequest();
const MIN_UPDATE_TIME_MS = 100;
let isSending = false;
let nextUpdateTime = Date.now() + 1;
let timeFactor = null;
let lastSimulationTimestamp = null;
let lastUpdateTimestamp = null;
req.onload = function()
{
if (this.status !== 200)
{
console.log("Failed update: status " + this.status);
isSending = false;
return;
}
let static_path_prefix = "/images/";
let now = Date.now()
let light_status = JSON.parse(this.responseText);
lastSimulationTimestamp = light_status.currentSimulationTimestampMs;
lastUpdateTimestamp = now;
timeFactor = light_status.timeFactor;
document.getElementById("period").innerHTML = light_status.currentPeriod['verbose-name'];
document.getElementById("state-index").innerHTML = light_status.currentStateIndex;
document.getElementById("state-data").innerHTML = JSON.stringify(light_status.currentState);
document.getElementById("north").style.backgroundImage = "url(" + static_path_prefix + light_status.currentState.north + ".png)";
document.getElementById("north-right").style.backgroundImage = "url(" + static_path_prefix + light_status.currentState["north-right"] + "-right.png)";
document.getElementById("west").style.backgroundImage = "url(" + static_path_prefix + light_status.currentState.west + ".png)";
document.getElementById("east").style.backgroundImage = "url(" + static_path_prefix + light_status.currentState.east + ".png)";
document.getElementById("south").style.backgroundImage = "url(" + static_path_prefix + light_status.currentState.south + ".png)";
document.getElementById("time-factor").innerHTML = light_status.timeFactor.toFixed(2);
nextUpdateTime = light_status.nextChangeoverTimestampMs;
isSending = false;
};
while (true)
{
let now = Date.now();
if (!isSending && now >= nextUpdateTime)
{
isSending = true;
req.open("GET", "/GetStatus", false);
// Note try/catch is the only way to account for net::ERR_CONNECTION_REFUSED - this is NOT dealt with by XMLHttpRequest event hooks.
// In the case of net::ERR_CONNECTION_REFUSED should throw DOMException with name "NetworkError".
try
{
req.send();
}
catch (err)
{
console.dir(err);
isSending = false;
}
}
// Important note: Due to marginal overshoot of scheduled timing, it is possible for time-remaining to be very slightly negative
// It is undesirable to present this on the frontend, and therefore zero is the lowest number displayed
document.getElementById("time-remaining").innerHTML = Math.max(0, (nextUpdateTime - now) / 1000).toFixed(3);
document.getElementById("")
if (lastSimulationTimestamp !== null && lastUpdateTimestamp !== null)
{
let simulationDate = new Date(lastSimulationTimestamp + parseInt((now - lastUpdateTimestamp) * timeFactor));
document.getElementById("time").innerHTML = simulationDate.toUTCString().slice(17, 25); // Time section of date string only
}
await sleep(Math.min(MIN_UPDATE_TIME_MS, nextUpdateTime - now));
}
}
document.addEventListener("DOMContentLoaded", ready);
</script>
</body>
</html>