[Edbrowse-dev] explanation of patch 20170813

[Kevin Carhart <kevin@carhart.net>]

On Sun, 13 Aug 2017, Karl Dahlke wrote:

> Indeed you do, but yours takes no arguments, and the one in acid is given 2 arguments.
> Something doesn't line up.
>
> Karl Dahlke
>

Ok, I researched this a little and wrote a patch.  Here are some notes on 
what is going on.

What's defaultView?

document.defaultView just returns window.

Why does the acid3 test say document.defaultView.getComputedStyle?

According to MDN, this is redundant.  So I just put in code so that
document.defaultView.getComputedStyle
will call window.getComputedStyle and proceed.

What is the point of window.getComputedStyle?

I think the point is that there is supposed to be a cascading effect in 
the values of styles.  As the comment says "whether removing an element 
that is the last child correctly recomputes styles for the new last child"

Why are there two arguments and what do the arguments do?

Here's the syntax for window.getComputedStyle, from MDN:
var style = window.getComputedStyle(element[, pseudoElt]);

The first argument is the element to return the styles for.  The second 
argument is optional.  It refers to pseudoelements.  I'm leaving aside 
what those are, for now.

Onwards and upwards.... this doesn't make test zero pass yet, but it's 
important to fix.  The element called 'penultimate' isn't working 
correctly, but there is no longer a syntactical problem trying to say:

document.defaultView.getComputedStyle(penultimate, '').whiteSpace

Kevin