summaryrefslogtreecommitdiff
path: root/index.php
blob: 17aac812c6fed598c9e640747d8b47179ea923bc (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
<!doctype html>
<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
	<meta name="description" content="Berechnet die Preise für Pizza im Verhältnis zum Flächeninhalt. Lieber zwei kleine oder eine große Pizza kaufen?">
	<link rel='stylesheet' type='text/css' href="/css/bootstrap.min.css">
	<link rel='icon' href="https://iamfabulous.de/favicon.ico">
	<title>Beats per Minute</title>
	<style>
		html {
			width: 100%;
		}
		.main {
			margin-top: 1rem;
		}
	</style>
</head>
<body class="container main text-center">
	<span id="countBpm">
		<div class="jumbotron">
			<h1>Hier klicken um die BPMs zu zählen:</h1>
			<h2><span id="showBpm">0</span> BPM</h2>
		</div>
		<button class="btn btn-primary">Click</button>
	</span>
	<button id="reset" class="btn btn-secondary">Reset</button>

<script>
	function median(values){
		if ( values.length === 0 ) {
			return 0;
		}

		values.sort(function(a,b){
			return a-b;
		});

		var half = Math.floor(values.length / 2);

		if (values.length % 2) {
			return values[half];
		}

		return (values[half - 1] + values[half]) / 2.0;
	}
	function reset() {
		lastClick = 0;
		bpm = [];
		document.getElementById("showBpm").innerHTML = 0;
	}
	function display(bpm) {
		/* slice() copies by value, not by reference, so the median() doesn't mess with the array */
		document.getElementById("showBpm").innerHTML = Math.round(median(bpm.slice()));
	}
	window.addEventListener("load",function() {
		var lastClick = 0;
		var bpm = [];
		document.getElementById("countBpm").addEventListener("click", function(e){
			var d = new Date();
			var t = d.getTime();
			var seconds = ( t - lastClick ) / 1000;

			if ( 0 != lastClick ) {

				if ( seconds > 10 ) {
					// reset after 10 seconds delay
					reset();
				} else {
					var _bpm = 60 / seconds
					bpm.push( _bpm );
					if ( bpm.length > 10 ) {
						// keep only last 10 clicks
						bpm.shift();
					}
					display(bpm);
				}

			}
			lastClick = t;
		});
		document.getElementById("reset").addEventListener("click", function(e){
			reset();
		})
	});
</script>
</body>