font-display-intervention.html | Explore in Territory

<!DOCTYPE html>
<title>Test for font-display @font-face descriptor with User-Agent Intervention</title>
<style>
.hidden { display: none; }
</style>
<link rel="preload" href="/resources/Ahem.ttf" as="font" crossorigin>
<p>Tests how text with a font that takes <i>delay</i> seconds to load look like after <i>T</i> seconds from load start.</p>
<table id="container">
 <tr>
  <th>T[sec]</th>
  <th>delay[sec]</th>
  <th>auto</th>
  <th>block</th>
  <th>swap</th>
  <th>fallback</th>
  <th>optional</th>
 </tr>
</table>
<script>
if (window.testRunner)
    testRunner.waitUntilDone();

// Slow network that allows effectively 3G cellular network speed will cause an
// User-Agent Intervention. Under the situation, 'auto' should behave as 'swap'.
if (window.internals) {
    internals.setNetworkConnectionInfoOverride(true, 'cellular3g', '3g', 2000, 0.1);

    // Reset the state of the singleton network state notifier.
    window.addEventListener('beforeunload', function() {
        internals.clearNetworkConnectionInfoOverride();
    }, false);
}

var fontDisplayValues = ['auto', 'block', 'swap', 'fallback', 'optional'];
var configs = [{time: 0, delay: 1000},
               {time: 1000, delay: 0},
               {time: 1000, delay: 500},
               {time: 1000, delay: 3000},
               {time: 5000, delay: 2000},
               {time: 5000, delay: 4000},
               {time: 5000, delay: 8000}];

function makeFontFaceDeclaration(family, config, display) {
    var url = '/resources/Ahem.ttf';
    if (config.delay > 0)
        url = 'slow-ahem-loading.cgi?delay=' + config.delay + '&t=' + config.time;
    return '@font-face { font-family: ' + family + '; src: url(' + url + '); font-display: ' + display + '; }';
}


var maxTime = Math.max.apply(null, configs.map((config) => config.time));
var table = document.getElementById('container');

window.onload = function() {
    for (var config, i = 0; config = configs[i]; i++) {
        var tr = document.createElement('tr');
        tr.classList.add('hidden');
        var td1 = document.createElement('td');
        td1.textContent = config.time / 1000;
        tr.appendChild(td1);
        var td2 = document.createElement('td');
        td2.textContent = config.delay / 1000;
        tr.appendChild(td2);

        for (var display, j = 0; display = fontDisplayValues[j]; j++) {
            var family = [display, config.time, config.delay].join('-');
            var rule = makeFontFaceDeclaration(family, config, display);
            document.styleSheets[0].insertRule(rule, 0);
            var td = document.createElement('td');
            td.textContent = 'a';
            td.style.fontFamily = family + ', Arial';
            tr.appendChild(td);
        }
        table.appendChild(tr);
        if (config.time == 0) {
            setTimeout((function(tr){
                tr.classList.remove('hidden');
                if (window.testRunner)
                    testRunner.notifyDone();
            }).bind(null, tr), maxTime);
        } else {
            setTimeout((function(tr){tr.classList.remove('hidden')}).bind(null, tr), maxTime - config.time);
        }
    }
}

</script>
chromium/third_party/blink/web_tests/http/tests/webfont/font-display-intervention.html
