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<div id="app">
<div id="svg"></div>
<input id="input" type="text" />
</div>
html, body {
height:100%;
display:flex;
flex-flow: column nowrap;
align-items:center;
justify-content:center;
}
svg, #input {
display:block;
width: 90vw;
max-width: 600px;
height: auto;
max-height: 50vh;
}
#app {
display:flex;
flex-flow: column nowrap;
align-items: center;
}
#input {
text-align: center;
padding: 0.4em 0;
border:none;
outline:none;
font-size: 2.2em;
text-transform: uppercase;
}
#input:hover {
opacity:0.75;
}
/*
* Code 39 barcode
*
* Based on the description at https://en.wikipedia.org/wiki/Code_39
*/
// user variables
const fill = '#333';
const qscode = window.location.search.match(/code=([^&]*)/);
const init_val = qscode ? decodeURI(qscode[1]) : 'codepen.io';
// thick bar - 1
// thin bar - 0
// index values: 1, 2, 4, 7, 0
const bars = [
[1,0,0,0,1], // 1+0=1
[0,1,0,0,1], // 2+0=2
[1,1,0,0,0], // 1+2=3
[0,0,1,0,1], // 4+0=4
[1,0,1,0,0], // 1+4=5
[0,1,1,0,0], // 2+4=6
[0,0,0,1,1], // 7+0=7
[1,0,0,1,0], // 1+7=8
[0,1,0,1,0], // 2+7=9
[0,0,1,1,0] // 4+7=11 for some reason (see wiki)
];
// 0 - 10 || |||
// A - J ||| ||
// K - T |||| |
// U - * | ||||
// index where extra space appears
const spaces = [2, 3, 4, 1];
// serializable chars
const chars = '1234567890abcdefghijklmnopqrstuvwxyz-._*';
// svg element function
const svgCreate = (tag, attrs) => {
const el = document.createElementNS('http://www.w3.org/2000/svg', tag);
for (let k in attrs) {
el.setAttribute(k, attrs[k]);
}
return el;
};
// omit all other characters function
const filter = (() => {
// range char needs to move to be in regex
const neglist = chars.replace('-','');
const regex = new RegExp(`[^-${neglist}]`, 'g');
return (input) => {
// weak sauce bad char filter
return input.replace(regex, '');
};
})();
const shape_padding = 7;
const height = 100;
// barcode logic, saved to SVG
const barcodeSVG = (input) => {
const svg = svgCreate('svg', {
width: 100,
height: 50,
viewBox: '0 0 100 50'
});
// always *'s around the input
// as start/stop delimiters
const fulltext = filter(`*${input}*`);
// svg shape start position
let x = 0;
for (let i = 0, len = fulltext.length; i < len; i++) {
let index = chars.indexOf(fulltext[i].toLowerCase());
let space_index = ~~(index / 10);
let bar_index = index % 10;
let div = len + (len - 1) * (shape_padding / 100);
for (let j = 0; j < 5; j++) {
if (j === spaces[space_index]) {
// one space
x += shape_padding * 2 / div;
}
if (bars[bar_index][j]) {
// thick bar
width = 20 / div;
} else {
// thin bar
width = 6 / div;
}
svg.appendChild(
svgCreate('rect', {
x,
width,
height,
fill,
})
);
x += width + (shape_padding / div);
}
}
return svg;
}
// output to HTML
const svg = document.getElementById('svg');
const input = document.getElementById('input');
input.style.color = fill;
const update = () => {
const barcode = barcodeSVG(input.value);
while (svg.firstChild) {
svg.removeChild(svg.firstChild);
}
svg.appendChild( barcode );
};
input.addEventListener('input', update);
// animated intro for the codepen geeks
(() => {
let i = 0;
let len = init_val.length;
let t = window.setInterval(() => {
input.value += init_val[i++];
update();
if (i === len) {
window.clearInterval(t);
}
}, 200);
})();
Also see: Tab Triggers