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Test Info:
- This WPT test may be referenced by the following Test IDs:
- /css/css-values/ch-unit-019.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Values and Units Test: support for the ch unit</title>
<link rel="author" title="Jason Leo" href="mailto:cgqaq@chromium.org">
<link rel="match" href="reference/ch-unit-019-ref.html">
<meta name="assert" content="The ch unit should fallback to 0.5em or 1em respectively when it's impossible to derive the width of the “0” (ZERO, U+0030) glyph in the font used to render it">
<style>
@font-face {
font-family: "icon-font";
src: url("data:font/woff2;base64,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") format("woff2");
}
div {
height: 10px;
background-color: blue;
margin-top: 10px;
}
div::before {
content: "\e00b";
display: none;
}
.test {
/* 50px + 10 * (0.5em)*/
/* 50px + 10 * (0.5 * 10px) = 100px*/
width: calc(50px + 10ch);
}
.test-upright {
writing-mode: vertical-rl;
text-orientation: upright;
/* 50px + 5 * (1em)*/
/* 50px + 5 * (1 * 10px) = 100px*/
width: calc(50px + 5ch);
}
.ref {
width: 100px;
}
</style>
<p>The test passes if there are two blue rectangles of equal length.</p>
<!-- In the cases where it is impossible or impractical to determine
the measure of the “0” glyph, it must be assumed to be 0.5em
wide by 1em tall. Thus, the ch unit falls back to 0.5em in the general case-->
<div class="test" style="font: 10px icon-font"></div>
<!-- and to 1em when it would be typeset upright (i.e. writing-mode
is vertical-rl or vertical-lr and text-orientation is upright).-->
<div class="test-upright" style="font: 10px icon-font"></div>
<div class="ref"></div>