HTML5 Clocks

  • Reading time:4 mins read
HTML5 Clocks

HTML5 Clocks

For our new lesson I have prepared nice pure HTML5 clocks. This is pretty easy script, but it is very easy and impressive (as usual). Of course – anything necessary will be at canvas object.

Here are our demo and downloadable package:

Live Demo
download in package

Ok, download the source files and lets start coding !

Step 1. HTML

This is markup of our clocks. Here it is.

index.html

<!DOCTYPE html>
<html lang="en" >
    <head>
        <meta charset="utf-8" />
        <title>HTML5 Clocks | Dev School</title>
        <link href="css/main.css" rel="stylesheet" type="text/css" />
        <script src="http://code.jquery.com/jquery-latest.min.js"></script>
        <script src="js/script.js"></script>
    </head>
    <body>
        <header>
            <h2>HTML5 Clocks</h2>
            <a href="https://dev-school.net/html5-clocks/" class="stuts">Back to original tutorial on <span>Dev School</span></a>
        </header>
        <div class="clocks">
            <canvas id="canvas" width="500" height="500"></canvas>
        </div>
    </body>
</html>

Step 2. CSS

Here are all required stylesheets

css/main.css

.clocks {
    height: 500px;
    margin: 25px auto;
    position: relative;
    width: 500px;
}

Step 3. JS

js/script.js

// inner variables
var canvas, ctx;
var clockRadius = 250;
var clockImage;

// draw functions :
function clear() { // clear canvas function
    ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
}

function drawScene() { // main drawScene function
    clear(); // clear canvas

    // get current time
    var date = new Date();
    var hours = date.getHours();
    var minutes = date.getMinutes();
    var seconds = date.getSeconds();
    hours = hours > 12 ? hours - 12 : hours;
    var hour = hours + minutes / 60;
    var minute = minutes + seconds / 60;

    // save current context
    ctx.save();

    // draw clock image (as background)
    ctx.drawImage(clockImage, 0, 0, 500, 500);

    ctx.translate(canvas.width / 2, canvas.height / 2);
    ctx.beginPath();

    // draw numbers
    ctx.font = '36px Arial';
    ctx.fillStyle = '#000';
    ctx.textAlign = 'center';
    ctx.textBaseline = 'middle';
    for (var n = 1; n <= 12; n++) {
        var theta = (n - 3) * (Math.PI * 2) / 12;
        var x = clockRadius * 0.7 * Math.cos(theta);
        var y = clockRadius * 0.7 * Math.sin(theta);
        ctx.fillText(n, x, y);
    }

    // draw hour
    ctx.save();
    var theta = (hour - 3) * 2 * Math.PI / 12;
    ctx.rotate(theta);
    ctx.beginPath();
    ctx.moveTo(-15, -5);
    ctx.lineTo(-15, 5);
    ctx.lineTo(clockRadius * 0.5, 1);
    ctx.lineTo(clockRadius * 0.5, -1);
    ctx.fill();
    ctx.restore();

    // draw minute
    ctx.save();
    var theta = (minute - 15) * 2 * Math.PI / 60;
    ctx.rotate(theta);
    ctx.beginPath();
    ctx.moveTo(-15, -4);
    ctx.lineTo(-15, 4);
    ctx.lineTo(clockRadius * 0.8, 1);
    ctx.lineTo(clockRadius * 0.8, -1);
    ctx.fill();
    ctx.restore();

    // draw second
    ctx.save();
    var theta = (seconds - 15) * 2 * Math.PI / 60;
    ctx.rotate(theta);
    ctx.beginPath();
    ctx.moveTo(-15, -3);
    ctx.lineTo(-15, 3);
    ctx.lineTo(clockRadius * 0.9, 1);
    ctx.lineTo(clockRadius * 0.9, -1);
    ctx.fillStyle = '#0f0';
    ctx.fill();
    ctx.restore();

    ctx.restore();
}

// initialization
$(function(){
    canvas = document.getElementById('canvas');
    ctx = canvas.getContext('2d');

    // var width = canvas.width;
    // var height = canvas.height;

clockImage = new Image();
clockImage.src = 'images/cface.png';

    setInterval(drawScene, 1000); // loop drawScene
});

I have defined main timer to redraw scene. Each step (tick) script defines current time, and draw clock arrows (hour arrow, minute arrow and second arrow).

Live Demo
download in package

Conclusion

Hope that today’s html5 clocks was impressive for you as always. We have made another one nice html5 tutorial. I will be glad to see your thanks and comments. Good luck!