Instead of doing a CSS property lookup for the line style of each
border edge during paint, we now cache the final CSS::LineStyle to use
in the Layout::BorderData.
In order for inline elements (e.g <span>) to contribute padding etc.
to line boxes, we now create special "leading" and "trailing" fragments
for Layout::InlineNode and size them according to the horizontal
padding values.
The height of these fragments is taken from the tallest fragment on the
line. (Perhaps we should stop having per-fragment heights and just keep
a single height per line box, but that's a separate issue.)
In order to make things look nice, we now also adjust the height of all
fragments on a line so that nobody is shorter than the CSS line-height.
Fragment painting was very limited by only being called during the
foreground paint phase. We now paint fragments as part of every phase
(and the phase is passed to paint_fragment() of course!)
We were rejecting perfectly valid z-index values like '1000' since we
were passing all CSS values through the length parser and unit-less
lengths are not valid in this context.
It's yet another hack for the ad-hoc CSS parser (its days are numbered)
but this makes the top header links on google.com actually work. :^)
Calling Frame::set_size() already triggered a relayout, so calling
layout() again right after meant we did all the work one more time.
Not being dumb like this makes resizing significantly smoother. :^)
Layout was using an outdated viewport rect that we set *after* doing
a layout due to resize. That meant that layout-in-response-to-resize
was always lagging behind the current size of the view.
The root of this problem was how Frame kept both a viewport rect
(with both scroll offset and size) and a frame size. To fix this,
only store the viewport scroll offset, and always use the frame size.
This way they can't get out of sync and the problem goes away. :^)
Fixes#4250.
Note that we're taking a shortcut here and returning the elements as an
Array instead of HTMLCollection. One day we'll have to bite the bullet
and deal with HTMLCollection, but not today.
Note that this is the old CSS2 syntax, we don't support the CSS3 syntax
just yet. Also we don't actually implement the pseudo-elements, this is
really just to make the selectors distinct from the same ones without
these pseudo-elements.
Proxy is an "exotic object" and doesn't have its own prototype. Use the
regular object prototype instead, but most stuff is happening on the
target object anyway. :^)
We were incorrectly hoisting non-inline children of inline-block boxes
to the nearest non-inline ancestor.
Since inline-block boxes are only inline on the *outside*, it's fine
for them to have non-inline children.
Eventually we should clarify these relationships by making the inside
and outside display types more explicit.
Instead of hiding JS exceptions raised on the web, we now print them to
the debug log. This will make it a bit easier to work out why some web
pages aren't working right. :^)
We didn't notice that the layout tree had disappeared after dispatching
a mousedown event, because we only checked EventHandler::layout_root()
which happily returned the *new* layout tree after a window.reload().
This patch fixes that by verifying that the frame is still showing the
same DOM's layout tree after event dispatch.
Fixes#4224.
We can now build partial layout trees (this happens for example when an
element's "display" property is programmatically toggled from "none" to
something else.)
We can't say that "no replaced boxes can have children", since that
breaks SVG. Instead, let each LayoutNode decide whether it's allowed
to have children.
Fixes#4223.
We were messing up the box tree for tables by hoisting cells up to
become children of the table row group (instead of the table row.)
Table rows are non-block boxes, and it's fine for them to have cell
(block) children.
Fixes#4225.
We already have a wrap() in EventWrapperFactory.cpp. It would be nice
to generate that at some point but it will require a lot more work on
the wrapper generator.
Inline layout nodes cannot have block children (except inline-block,
of course.)
When encountering a block box child of an inline, we now hoist the
block up to the inline's containing block, and also wrap any preceding
inline siblings in an anonymous wrapper block.
This improves the ACID2 situation quite a bit (although we still need
floats to really bring it home.)
I also took this opportunity to move all tree building logic into
Layout::TreeBuilder, to continue the theme of absolving our LayoutNode
objects of responsibilities. :^)
Specification: https://dom.spec.whatwg.org/#concept-event-dispatch
This also introduces shadow roots due to it being a requirement of
the event dispatcher.
However, it does not introduce the full shadow DOM, that can be
left for future work.
This changes some event dispatches which require certain attributes
to be initialised to a value.
Bring the names of various boxes closer to spec language. This should
hopefully make things easier to understand and hack on. :^)
Some notable changes:
- LayoutNode -> Layout::Node
- LayoutBox -> Layout::Box
- LayoutBlock -> Layout::BlockBox
- LayoutReplaced -> Layout::ReplacedBox
- LayoutDocument -> Layout::InitialContainingBlockBox
- LayoutText -> Layout::TextNode
- LayoutInline -> Layout::InlineNode
Note that this is not strictly a "box tree" as we also hang inline/text
nodes in the same tree, and they don't generate boxes. (Instead, they
contribute line box fragments to their containing block!)
This is a first (huge) step towards modernizing the layout architecture
and bringing it closer to spec language.
Layout is now performed by a stack of formatting contexts, operating on
the box tree (or layout tree, if you will.)
There are currently three types of formatting context:
- BlockFormattingContext (BFC)
- InlineFormattingContext (IFC)
- TableFormattingContext (TFC)
Document::layout() creates the initial BlockFormattingContext (BFC)
which lays out the initial containing block (ICB), and then we recurse
through the tree, creating BFC, IFC or TFC as appropriate and handing
over control at the context boundaries.
The majority of this patch is just refactoring the old logic spread out
in LayoutBlock and LayoutTableRowGroup, and turning into these context
classes instead. A lot more cleanup will be needed.
There are many architectural wins here, the main one being that layout
is no longer performed by boxes themselves, which gives us much greater
flexibility in the outer/inner layout of a given box.
As per this line in the specification:
Unless stated otherwise, a document’s encoding is the utf-8 encoding,
content type is "application/xml", URL is "about:blank", origin is an
opaque origin, type is "xml", and its mode is "no-quirks".
https://dom.spec.whatwg.org/#document
