...but never allow the resulting height to become negative. This solves
an issue seen on Acid3 where elements with negative vertical margins
expanded the size of their height:auto container instead of shrinking
it, which is the correct behavior. This now works :^)
CSS 2.2 says "Horizontal margins never collapse."
So instead of collapsing them, we now add them together, which makes
negative margins between floating boxes work beautifully.
Instead of TextNode::ChunkIterator having two bool members to remember
things across calls to next(), this patch reorganizes the loop in next()
so that preserved newline/whitespace chunks are emitted right away
instead of in an awkward deferred way.
Instead of emitting a Text item with the "should_force_break" flag set
to true, newlines in newline-preserving text content now timply turn
into ForcedBreak items. This makes the <pre> element work again.
From the HTML spec:
Modulo platform conventions, it is suggested that the following
elements should be considered as focusable areas and be sequentially
focusable:
...
- button elements
- select elements
- textarea elements
...
Also add a spec link to the existing HTMLAnchorElement::is_focusable().
Note that this still doesn't allow triggering keyboard-focused buttons,
checkboxes, or radio buttons - we don't seem to run the expected
activation behavior for any of them.
From the HTML spec:
Modulo platform conventions, it is suggested that the following
elements should be considered as focusable areas and be sequentially
focusable:
...
- input elements whose type attribute are not in the Hidden state
...
I believe this is all of them, but I may have missed some.
Several properties technically do not allow negative numbers but the
description says to accept these as valid, and then clamp them
afterwards to the desired range. As such, we don't reject them during
parsing.
This might not be entirely correct, but neither was using the completely
ad-hoc parse_html_length(), and this is the last user of that API so
let's move off of it.
For layers that require indirect painting (due to opacity, transform,
etc.) we create a nested PaintContext. Until now, that PaintContext
was created fresh without transferring all the state from the parent
PaintContext.
This commit moves the regular handling of links to the anchor elements'
activation behavior, and implements a few auxiliary algorithms as
defined by the HTML specification.
Note that certain things such as javascript links, fragments and opening
a new tab are still handled directly in EventHandler, but they have been
moved to handle_mouseup so that it behaves closer to how it would if it
was entirely up-to-spec.
Instead of using the absolute_rect(), use absolute_border_box_rect() -
at least for PaintableBox - and inflate it by 2px on each side.
This looks much nicer for text input elements, especially when they have
padding, which would be applied outside the focus rect previously.
BFC roots with children_are_inline()==true can still have floating boxes
as well. children_are_inline() is only concerned with in-flow children.
For this reason, we have to always consider floats when calculating
height:auto for BFC roots.
Rather than dividing the rect width and high by the border lengths,
this change multiples those lengths by the reciprocal of the width
and height because this is a faster operation. When mousing around on
the html spec website, the profile showed that inline painting
went from ~15% to ~3%
This fixes the placement of several background images on Acid2, most
notably the background of the eyes and the red rectangle near the bottom
of the head.
Collect all the preceding block-level siblings whose vertical margins
are collapsible. Both margin-top and margin-bottom now (previously,
we only considered the margin-bottom of siblings.)
Use the right margin in part-negative and all-negative situations.
We now distribute the line-height evenly between the space above and
below inline-level boxes. This noticeably improves our baseline
alignment in many cases.
Note that the "vertical-align: <length>" case is quite awkward, as the
extra height added by the offset baseline must count towards the line
box height.
There's a lot of room for improvement here, but this makes the buckets
container on Acid3 show up in the right place, with the right size.
Specifically HTMLIFrameElement and HTMLObjectElement. HTMLEmbedElement
will gain it automatically once it's also converted to inherit from
BrowsingContextContainer.
Make sure we use the create_anonymous_wrapper() helper function whenever
wrapping inline content in anonymous wrapper blocks. We were forgetting
to do this in one case, which led to some wrapper blocks having 0px
font-size and line-height.
