RE: column-span and margin-collapsing (was: [CSSWG] Minutes and Resolutions 2011-09-21)

± From: Håkon Wium Lie
± Sent: Monday, September 26, 2011 9:29 AM
± 
± In Opera's implementation, elements with 'column-span: all' create a BFC as per:
± 
±    http://www.w3.org/TR/css3-multicol/#column-span
± 
± Therefore, floats are not allowed to enter a spanner in Opera's implementation.
± 
± Spanners collapse vertically, just like these BFC-creating elements
± do:
± 
±    <div style="overflow: hidden; margin: 100px 0;"></div> 
±    <div style="overflow: hidden; margin: 100px 0;"></div>

But this behavior is different for what one would expect for what appeared to be your main use case:

	<h1 style="column-span:all">Title</h1>	
	<h2 style="column-span:all">Subtitle</h2>	
	<p style="column-span:all">Abstract...</p>

Having same vertical spacing in multicol as in normal flow or older browser. Child margins won't collapse with colspans so margins won't always be same.

If that use case is why you want margin collapsing, wouldn't the anonymous bfc wrapper work better?

Received on Monday, 26 September 2011 16:48:34 UTC