Chris Waterson wrote:
> It's a work-in-progress, with questions in red italics. If you
> know the answer, please pass it along to me so I can update the
> document.
<snip>
> In nsLineLayout, a "span" is a container inline frame, and a
> "frame" is one of its children. Perhaps PerParentData and
> PerChildData would be better names?
It's been a year since I've really looked at nsLineLayout, but IIRC..
PerFrameData is associated with a frame.
PerSpanData is also associated with a frame, and is linked to a
PerFrameData for that frame.
The PerSpanData holds information about which frames are contained
by the PerSpanData frame, how they are contained, and relevant
metrics whereas the PerFrameData holds information about the
frame itself.
The name Per*Frame*Data emphasizes the fact that the struct
describes the frame while PerSpanData emphasizes that struct's
relation with spanning child frames. The name may have come
from <span>, the most generic of HTML inline elements.
PerSpanData carries different connotations than PerParentData.
For one thing, it has less emphasis on the parent part--which
is not necessarily a bad thing, since PerSpanData does more
than just hold child nodes.
At least, that's my take on it. Mostly speculation--correct
me if I'm wrong, etc. [standard disclaimer]
~fantasai
