There is an issue in Google Chrome where elements expand/collapse in different directions relative to the viewport when placed inside a flexbox container with an adjacent flex item having space-between or center justified content.
This is not a problem in Firefox, IE11, Edge, or Safari as the elements always expand downward.
I'm curious:
- Does Chrome's behavior here follow some spec? If so, which one?
- If not, then why was this done in Chrome? (IMHO, it is horrible UX for the click trigger to disappear offscreen randomly.)
- Can Chrome's behavior be modified or disabled in someway? Eg. through CSS or meta-tag?
Update 1: I've filed issue #739860 on chromium bug tracker seeking insight/explanation from Chromium devs, if possible.
Here are two examples inserted below. The full test suite describing the problem can be found in this pen: https://codepen.io/jameswilson/full/xrpRPg/ I've chosen to use slideToggle in this example so that the expand/collapse motion is animated and visible to the eye. The same behavior happens with the details tag, but cross-browser support is not there yet, and the expand/collapse is too janky.
Ex 1: Chrome's expand/collapse behavior for space-between justified flexbox
$('button').click(function() {
$(this).next().slideToggle();
})body {
margin: 30px;
font-family: sans-serif;
}
aside,
aside div,
summary,
main,
button,
details p,
button + p {
background: rgba(0,0,0,.09);
border: none;
padding: 20px;
margin: 0;
}
.flexcontainer {
display: flex;
}
aside {
flex: 1;
position: relative;
max-width: 25%;
background: mintcream;
display: flex;
flex-direction: column;
position: relative;
}
aside.space-between {
justify-content: space-between;
}
aside.center {
justify-content: center;
}
main {
flex: 3;
position: relative;
max-width: 75%;
background: aliceblue;
vertical-align: top;
height: 100%;
}
main > * + * {
margin-top: 20px;
}
button + p {
display: none;
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<section class="flexcontainer">
<aside class="space-between">
<div>Top Sidebar</div>
<div>Bottom Sidebar</div>
</aside>
<main>
<div>
<button>slideToggle</button>
<p>Other browsers: always expands downward.<br>
Chrome: Should always expand downward because Top Sidebar is always visible.</p>
</div>
<div>
<button>slideToggle (usually expands down)</button>
<p>Other browsers: always expands downward.<br>
Chrome: Should expand downward while Bottom Sidebar and Top Sidebar are both visible. But will expand upward if you scroll down far enough so that Top Sidebar is off-screen.</p>
</div>
<div>
<button>slideToggle (usually expands down)</button>
<p>Other browsers: always expands downward.<br>
Chrome: Should expand downward while Bottom Sidebar and Top Sidebar are both visible. But will expand upward if you scroll down far enough so that Top Sidebar is off-screen.</p>
</div>
</main>
</section>Ex 2: Chrome's expand/collapse behavior for center justified flexbox
$('button').click(function() {
$(this).next().slideToggle();
})body {
margin: 30px;
font-family: sans-serif;
}
aside,
aside div,
summary,
main,
button,
details p,
button + p {
background: rgba(0,0,0,.09);
border: none;
padding: 20px;
margin: 0;
}
.flexcontainer {
display: flex;
}
aside {
flex: 1;
position: relative;
max-width: 25%;
background: mintcream;
display: flex;
flex-direction: column;
position: relative;
}
aside.space-between {
justify-content: space-between;
}
aside.center {
justify-content: center;
}
main {
flex: 3;
position: relative;
max-width: 75%;
background: aliceblue;
vertical-align: top;
height: 100%;
}
main > * + * {
margin-top: 20px;
}
button + p {
display: none;
}<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<section class="flexcontainer">
<aside class="center">
<div>Center Sidebar</div>
</aside>
<main>
<div>
<button>slideToggle (usually expands downwards)</button>
<p>Other browsers: always expands downward.<br>
Chrome: Usually expands downwards. Expands in both directions when the top-edge of the container scrolls out of the viewport.</p>
</div>
<div>
<button>slideToggle</button>
<p>Other browsers: always expands downward.<br>
Chrome: Usually expands downwards. Expands in both directions when the top-edge of the container scrolls out of the viewport.</p>
</div>
<div>
<button>slideToggle (usually expands downwards)</button>
<p>Other browsers: always expands downward.<br>
Chrome: Usually expands downwards. Expands in both directions when the top-edge of the container scrolls out of the viewport, but then resumes expanding downwards again when Center Sidebar scrolls out of view.</p>
</div>
</main>
</section>