Re: [css3-regions] Clarification on getRegionFlowRanges with display:none nodes

On 6/25/12 4:04 PM, "Tab Atkins Jr." <jackalmage@gmail.com> wrote:

>On Thu, Jun 21, 2012 at 2:02 PM, Alan Stearns <stearns@adobe.com> wrote:
>> The getRegionFlowRanges method returns the "fragment from the named flow
>> that is laid out in the region."
>>
>> I am assuming the fragment includes nodes with display:none. If an node
>> with display:none falls on a fragmentation boundary, there is some
>> ambiguity as to which region the element is "laid out in."
>>
>> I propose to add this to the definition of getRegionFlowRanges:
>>
>> ---
>> The Ranges returned may include nodes with display:none situated between
>> other nodes laid out in the region. If a node with display:none falls
>>on a
>> fragmentation boundary, it is considered "laid out" in the region with
>>the
>> previous node. If the first node of a named flow has display:none it is
>> considered "laid out" in the first region of the region chain.
>> ---
>
>You're mixing levels here.  getRegionFlowRanges cares about the box
>tree.  Elements that are display:none don't generate boxes at all.
>Thus, they don't appear in the region at all, and won't be part of the
>list of ranges returned by the function.

Yes, I think you're right. My assumption about including nodes with
display:none is suspect. I was looking at the Range object returning DOM
fragments and thinking of what's "in" the region at that level. But we've
already left that level based on which elements in the DOM are added to
the named flow. So while each Range object may represent DOM, the sequence
of Ranges returned can represent the box tree in more useful detail.

Here's an example to see whether I'm thinking through this clearly now. In
the style and markup below, if named-flow is contained in a single region,
that region's getRegionFlowRanges() would return an sequence of three
Range objects.

.flow-content { flow-into: named-flow; }
.none { display:none; }

<p class="flow-content">1
<p class="not-flow">2
<p class="flow-content">3
<p class="flow-content none">4
<p class="flow-content">5


Thanks,

Alan

Received on Monday, 25 June 2012 23:54:59 UTC