대비 검사기

InputColor 컨트롤을 사용해 색상을 선택하고 Color 클래스를 사용해 색상을 검사하여 접근성 표준을 준수할 만큼 충분한 대비를 제공하는지 확인합니다.

import 'bootstrap.css'; import '@grapecity/wijmo.styles/wijmo.css'; import './styles.css'; // import { InputColor } from '@grapecity/wijmo.input'; import { Color, toggleClass, format } from '@grapecity/wijmo'; // document.readyState === 'complete' ? init() : window.onload = init; // function init() { // create InputColor controls let cpFore = new InputColor('#icFore', { value: 'black', valueChanged: updateRatio }); let cpBack = new InputColor('#icBack', { value: 'white', valueChanged: updateRatio }); updateRatio(); // update the contrast ratio when the colors change function updateRatio() { // get lightness ratio let lFore = getRelativeLuminance(cpFore.value); let lBack = getRelativeLuminance(cpBack.value); let ratio = (Math.max(lFore, lBack) + .05) / (Math.min(lFore, lBack) + 0.05); // show sample text let sample = document.querySelectorAll('.sample'); for (let i = 0; i < sample.length; i++) { let style = sample[i].style; style.color = cpFore.value; style.background = cpBack.value; } // show the result let e = document.getElementById('ratio'); e.innerHTML = format('<b>{ratio:g1}</b>:1', { ratio: ratio }); e.style.borderColor = ratio < 7 ? 'whitesmoke' : 'darkgreen'; pass('aa-normal', ratio >= 4.5); pass('aa-large', ratio >= 3); pass('aaa-normal', ratio >= 7); pass('aaa-large', ratio >= 4.5); } function pass(id, pass) { let e = document.getElementById(id); e.textContent = pass ? 'Pass' : 'Fail'; toggleClass(e, 'fail', !pass); } // https://developer.mozilla.org/en-US/docs/Web/Accessibility/Understanding_Colors_and_Luminance function getRelativeLuminance(color) { let c = new Color(color); let r = getChannel(c.r); let g = getChannel(c.g); let b = getChannel(c.b); return (r * 0.2126 + g * 0.7152 + b * 0.0722); } function getChannel(rgb) { rgb /= 255; return rgb <= 0.03928 ? rgb / 12.92 : Math.pow((rgb + 0.055) / 1.055, 2.4); } }
<!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <title>GrapeCity InputColor Contrast Checker</title> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <!-- SystemJS --> <script src="node_modules/systemjs/dist/system.src.js"></script> <script src="systemjs.config.js"></script> <script> System.import('./src/app'); </script> </head> <body> <div class="container-fluid"> <h1> Contrast Checker </h1> <div class="row"> <div class="col-md-4"> <h3> Foreground Color </h3> <div id="icFore"></div> <h3> Background Color </h3> <div id="icBack"></div> </div> <div class="col-md-4"> <h3> Contrast Ratio </h3> <div id="ratio"></div> <h3> Result </h3> <p class="sample"> Normal Text </p> <p> WCAG AA: <span id="aa-normal" class="result"></span> WCAG AAA: <span id="aaa-normal" class="result"></span> </p> <p class="sample large"> Large Text </p> <p> WCAG AA: <span id="aa-large" class="result"></span> WCAG AAA: <span id="aaa-large" class="result"></span> </p> </div> </div> <h3> Explanation </h3> <p> WCAG 2.0 level AA requires a contrast ratio of at least 4.5:1 for normal text and 3:1 for large text. </p> <p> WCAG 2.1 requires a contrast ratio of at least 3:1 for graphics and user interface components (such as form input borders). </p> <p> WCAG Level AAA requires a contrast ratio of at least 7:1 for normal text and 4.5:1 for large text. </p> <p> For more details, please see <a href="https://developer.mozilla.org/en-US/docs/Web/Accessibility/Understanding_Colors_and_Luminance" target="_blank"> The Science of Color Contrast </a>. </p> </div> </body> </html>
#sample { padding: 12px; font-style: bold; } #ratio { font-size: 200%; padding: 12px; font-style: bold; text-align: center; border-radius: 4px; border: 2px solid whitesmoke; } .sample { padding: 6px; margin: 6px 0; border: 2px solid whitesmoke; } .large { font-size: 14pt; font-weight: bold; } .result { font-weight: bold; margin-right: 2em; padding: 3px 6px; border-radius: 6px; color: white; background: darkgreen; } .result.fail { background: darkred; }
(function (global) { System.config({ transpiler: 'plugin-babel', babelOptions: { es2015: true }, meta: { '*.css': { loader: 'css' } }, paths: { // paths serve as alias 'npm:': 'node_modules/' }, // map tells the System loader where to look for things map: { 'jszip': 'npm:jszip/dist/jszip.js', '@grapecity/wijmo': 'npm:@grapecity/wijmo/index.js', '@grapecity/wijmo.input': 'npm:@grapecity/wijmo.input/index.js', '@grapecity/wijmo.styles': 'npm:@grapecity/wijmo.styles', '@grapecity/wijmo.cultures': 'npm:@grapecity/wijmo.cultures', '@grapecity/wijmo.chart': 'npm:@grapecity/wijmo.chart/index.js', '@grapecity/wijmo.chart.analytics': 'npm:@grapecity/wijmo.chart.analytics/index.js', '@grapecity/wijmo.chart.animation': 'npm:@grapecity/wijmo.chart.animation/index.js', '@grapecity/wijmo.chart.annotation': 'npm:@grapecity/wijmo.chart.annotation/index.js', '@grapecity/wijmo.chart.finance': 'npm:@grapecity/wijmo.chart.finance/index.js', '@grapecity/wijmo.chart.finance.analytics': 'npm:@grapecity/wijmo.chart.finance.analytics/index.js', '@grapecity/wijmo.chart.hierarchical': 'npm:@grapecity/wijmo.chart.hierarchical/index.js', '@grapecity/wijmo.chart.interaction': 'npm:@grapecity/wijmo.chart.interaction/index.js', '@grapecity/wijmo.chart.radar': 'npm:@grapecity/wijmo.chart.radar/index.js', '@grapecity/wijmo.chart.render': 'npm:@grapecity/wijmo.chart.render/index.js', '@grapecity/wijmo.chart.webgl': 'npm:@grapecity/wijmo.chart.webgl/index.js', '@grapecity/wijmo.gauge': 'npm:@grapecity/wijmo.gauge/index.js', '@grapecity/wijmo.grid': 'npm:@grapecity/wijmo.grid/index.js', '@grapecity/wijmo.grid.detail': 'npm:@grapecity/wijmo.grid.detail/index.js', '@grapecity/wijmo.grid.filter': 'npm:@grapecity/wijmo.grid.filter/index.js', '@grapecity/wijmo.grid.search': 'npm:@grapecity/wijmo.grid.search/index.js', '@grapecity/wijmo.grid.grouppanel': 'npm:@grapecity/wijmo.grid.grouppanel/index.js', '@grapecity/wijmo.grid.multirow': 'npm:@grapecity/wijmo.grid.multirow/index.js', '@grapecity/wijmo.grid.transposed': 'npm:@grapecity/wijmo.grid.transposed/index.js', '@grapecity/wijmo.grid.transposedmultirow': 'npm:@grapecity/wijmo.grid.transposedmultirow/index.js', '@grapecity/wijmo.grid.pdf': 'npm:@grapecity/wijmo.grid.pdf/index.js', '@grapecity/wijmo.grid.sheet': 'npm:@grapecity/wijmo.grid.sheet/index.js', '@grapecity/wijmo.grid.xlsx': 'npm:@grapecity/wijmo.grid.xlsx/index.js', '@grapecity/wijmo.grid.selector': 'npm:@grapecity/wijmo.grid.selector/index.js', '@grapecity/wijmo.grid.cellmaker': 'npm:@grapecity/wijmo.grid.cellmaker/index.js', '@grapecity/wijmo.nav': 'npm:@grapecity/wijmo.nav/index.js', '@grapecity/wijmo.odata': 'npm:@grapecity/wijmo.odata/index.js', '@grapecity/wijmo.olap': 'npm:@grapecity/wijmo.olap/index.js', '@grapecity/wijmo.pdf': 'npm:@grapecity/wijmo.pdf/index.js', '@grapecity/wijmo.pdf.security': 'npm:@grapecity/wijmo.pdf.security/index.js', '@grapecity/wijmo.viewer': 'npm:@grapecity/wijmo.viewer/index.js', '@grapecity/wijmo.xlsx': 'npm:@grapecity/wijmo.xlsx/index.js', '@grapecity/wijmo.undo': 'npm:@grapecity/wijmo.undo/index.js', '@grapecity/wijmo.interop.grid': 'npm:@grapecity/wijmo.interop.grid/index.js', '@grapecity/wijmo.touch': 'npm:@grapecity/wijmo.touch/index.js', '@grapecity/wijmo.cloud': 'npm:@grapecity/wijmo.cloud/index.js', '@grapecity/wijmo.barcode': 'npm:@grapecity/wijmo.barcode/index.js', '@grapecity/wijmo.barcode.common': 'npm:@grapecity/wijmo.barcode.common/index.js', '@grapecity/wijmo.barcode.composite': 'npm:@grapecity/wijmo.barcode.composite/index.js', '@grapecity/wijmo.barcode.specialized': 'npm:@grapecity/wijmo.barcode.specialized/index.js', 'jszip': 'npm:jszip/dist/jszip.js', 'bootstrap.css': 'npm:bootstrap/dist/css/bootstrap.min.css', 'css': 'npm:systemjs-plugin-css/css.js', 'plugin-babel': 'npm:systemjs-plugin-babel/plugin-babel.js', 'systemjs-babel-build':'npm:systemjs-plugin-babel/systemjs-babel-browser.js' }, // packages tells the System loader how to load when no filename and/or no extension packages: { src: { defaultExtension: 'js' }, "node_modules": { defaultExtension: 'js' }, } }); })(this);