We now position inline-level boxes based on ascent and descent metrics
from the font in use. This makes our basic text layouts look a lot more
like those produced by other browsers. :^)
I've tried to match the terminology used by the CSS Inline Layout spec.
This will regress Acid2 a little bit, and probably various other sites,
but on the whole it's the direction we should be heading, so let's go.
This avoids a bunch of unnecessary work in Painter which not only took
time, but sometimes also led to alignment issues. draw_text_run() will
draw the text where we tell it, and that's it.
Unlike BFC root blocks with height:auto, when the block *isn't* a BFC
root, we don't have to look for the "bottommost" block-level child and
determine the width from that.
Instead, we should just look at the last in-flow block-level child.
This was already indicated in the spec comment next to the code, but
the code itself was wrong.
This makes the body element on Acid3 have the correct height. It also
introduces a small regression on Acid2 that we'll have to track down.
Preserve floating point precision and delay rounding until the last
moment when figuring out where to paint background layers. This fixes an
issue on Acid3 where a thin sliver of red was visible because the
background X position was incorrectly rounded by 1px.
When parsing the "style" attribute on elements, we'd previously ask the
CSS parser for a PropertyOwningCSSStyleDeclaration. Then we'd create a
new ElementCSSInlineStyleDeclaration and transfer the properties from
the first object to the second object.
This patch teaches the parser to make ElementCSSInlineStyleDeclaration
objects directly.
By using enclosing_int_rect(), borders and backgrounds of boxes were
sometimes 1 pixel off, making things slightly larger than they should
be. Fix this by using to_rounded() instead of enclosing_int_rect().
There's definitely more of these type of issues lurking in the code,
and we'll get to them in time.
Previously, we only allowed floats to take up its own border box's worth
of horizontal space when laid out inside an IFC.
We should instead consume the full margin box horizonally. This fixes an
issue where a floated box on Acid3 had {width:20px; margin-right:-20px;}
but still consumed 20px of the previously available space, despite being
moved out of the way by its own negative margin.
When doing max-content layout, we were not committing newlines even
though we were supposed to due to white-space:pre*.
This broke the WPT harness due to a VERIFY() in ChunkIterator where we
were assuming the commit would always succeed.
Thanks to Orphis for reporting this! :^)
When the spec tells us to measure from the top content edge of a block,
that just means we should measure from Y=0. We don't need to go looking
for a child box with a negative top offset and measure from there.
When encountering a @font-face rule, StyleComputer will now fire off
a resource request and download the first source URL specified.
Once downloaded, we try to parse it as a TrueType font file, and if it
works, it's added to a cache in StyleComputer. This effectively makes
fonts per-document since every document has its own StyleComputer.
This is very unoptimized and could definitely use some caching, etc.
But it does work on Acid3. :^)
This gets us a bit closer to the recommended algorithms in CSS 2.2 and
CSS Table Module 3.
A couple of table heavy websites (e.g. news.ycombinator.com,
html5test.com, etc.) now look quite okay. :^)
Previously, the whitespace collapsing code had a parameter telling it
whether the previous text node ended in whitespace. This was not
actually necessary, so let's get rid of it.
This patch reimplements inset property resolution based on the new
CSS Positioned Layout specification. Nothing should change for
left/right insets, but we gain support for top/bottom. :^)
Relatively positioned boxes should not affect the *layout* of their
siblings. So instead of applying relative inset as a layout-time
translation on the box, we now perform the adjustment at the paintable
level instead.
This makes position:relative actually work as expected, and exposes some
new bugs we need to take care of for Acid2. :^)
Before this the flex layout didn't take into account the applied
borders or padding while laying out the items.
The child's top and left borders would get painted over the
parent's borders, also due to it not taking borders into account,
children with borders would overlap each other.
Due to it not taking padding into account, the children would get
drawn outside the parent element.
If a C++ object already has a JS wrapper, we don't need to go through
the expensive type checks to figure out which kind of wrapper to create.
Instead, just return the wrapper we already have!
This gives a noticeable increase in smoothness on Acid3, where ~10% of
CPU time was previously spent doing RTTI type checks in wrap(). With
these changes, it's down to ~1%.
