It seems like both BFC and IFC can have absolutely positioned children.
It's a bit strange, but consider the following HTML:
<html><body>foobar<img style="position: absolute"></body></html>
In such a document, the <img> element is an absolutely positioned child
of a block-level element (<body>) with no block-level children.
An IFC is established for <body>, and needs to handle layout for <img>.
Various whitespace-related issues have been fixed, and support for the
different CSS white-space values is improved enough that I think we can
stop doing the hack where we just prune whitespace nodes from the tree
and actually let them show up.
This is a nice step forward for correctness with the slight downside of
cluttering up layout tree dumps with tons of whitespace text nodes.
But hey, that's the web we know & love. :^)
Fixes#4427.
The StyleResolver can find the specified CSS values for the parent
element via the DOM. Forcing everyone to locate specified values for
their parent was completely unnecessary.
Layout nodes now only carry CSS computer values with them. The main
idea here is to give them only what they need to perform layout, and
leave the rest back in the DOM.
Another step towards not having to carry the full specified style with
us everywhere. This isn't the ideal final layout, since we're mixing
computed and used values a bit randomly here, but one step at a time.
Just because an inline-block is inline doesn't mean it's ready to
accept random inline children. If it's a block, we may need to create
an anonymous wrapper first.
Fixes#4604.
Empty boxes should be fully collapsed, but a box with border and/or
padding is not empty.
This fixes an issue where <hr> elements were getting weirdly collapsed
since they have zero content height (but some border height.)
Now that we have RTTI in userspace, we can do away with all this manual
hackery and use dynamic_cast.
We keep the is<T> and downcast<T> helpers since they still provide good
readability improvements. Note that unlike dynamic_cast<T>, downcast<T>
does not fail in a recoverable way, but will assert if the object being
casted is not a T.
We were only pruning trailing whitespace on lines. This patch makes it
so we also don't add whitespace as the leading line box fragment on new
lines.
This logic is pretty crufty and I think we can do better, but for now
I've just made it handle this extra case so we can stop having lines
that start with a space character. :^)
Let's start moving away from using raw strings for CSS identifiers.
The idea here is to use IdentifierStyleValue with a CSS::ValueID inside
for all CSS identifier values.
Instead of storing them as CSS::Lengths, we now store the resolved
values for margin/padding/border/offset top/right/bottom/left with
each Layout::NodeWithStyleAndBoxModelMetrics.
This simplifies a lot of code since it's no longer necessary to
resolve values before using them.
This is definitely not 100% correct but I tried implementing the basic
algorithms described in CSS 2.2. It's good enough to render the penguin
on @linusg's homepage at the right size. :^)
Replaced elements are now laid out by the current formatting context.
Since the logic is almost identical in BFC and IFC, it's implemented
by static helpers in FormattingContext.
