Kirill Rogovoy Kirill Rogovoy - 3 months ago 18
CSS Question

Flexbox: wrong width calculation when flex-direction: column, flex-wrap: wrap

I ran into a problem when using flexbox.

I'm using a container with

flex-direction: column; flex-wrap: wrap
, so my inner items can actually be placed in multiple columns.

The problem is that the browser still calculates the container's width as a sum of inner items' widths!

My container block should have a smaller width (based on content size), but it is actually huge.

Anyway, it's also very unnatural to calculate container's width this way when using columns, not rows.

Take a look at the green block in my code. It has a huge with, but it isn't supposed to have so. Also, it gets smaller as you remove an item from the container.

What I expect is to have the container with small width, so it wouldn't take more than a half of the available space.

Checked this on the latest Safari and Chrome on the latest OS X.

JSFiddle



.container {
display: flex;
flex-wrap: wrap;
flex-direction: column;
background: #aa0000;
height: 100px;
}
.group {
display: flex;
flex-wrap: wrap;
flex-direction: column;
align-content: flex-start;
}
.g1 {
background: #00aa00;
}
.g2 {
background: #0000aa;
}

<div class="container">
<div class="group g1">
<div class="item">Item</div>
<div class="item">Item</div>
<div class="item">Item</div>
<div class="item">Item</div>
<div class="item">Item</div>
<div class="item">Item</div>
<div class="item">Item</div>
</div>
<div class="group g2">
<div class="item">Item</div>
</div>
</div>




Answer

This appears to be yet another bug in the Flexible Box Layout Module involving flex-direction: column and flex-wrap: wrap.

Browsers seem to be all over the place on this issue.

In this particular case, as stated in a bug report:

It seems to me that the width is calculated as if the inside elements were laid out horizontally (flex-direction: row) instead of vertically.

In other cases, the opposite occurs:

In both cases, there are currently no flex methods to resolve the problem.

For this particular question, one developer offers a CSS workaround, but I'm not sure it works in all browsers. Also, I wouldn't recommend it unless you're truly desperate:

In some instances, you may be able to workaround this issue by using vertical writing mode.

That is, instead of using flex-direction: column;, use flex-direction: row; writing-mode: vertical-lr;. Remember to reset to writing-mode: initial; in the children of the flexbox.

https://bugs.chromium.org/p/chromium/issues/detail?id=507397

Bug reports: