Whether an absbox is positioned below or to the right of its previous
sibling in an `InlineFormattingContext` is determined by the
display-outside value before blockification, so we store the
pre-blockification `display` value in `ComputedValues` to access it in
`InlineFormattingContext` and position the box accordingly.
Previously, we were collapsing whitespace in Layout::TextNode and then
passed the resulting string for further processing through ChunkIterator
-> InlineLevelIterator -> InlineFormattingContext -> LineBuilder ->
LineBoxFragment -> PaintableFragment. Our painting tree is where we deal
with things like range offsets into the underlying text nodes, but since
we modified the original string, the offsets were wrong.
This changes the way we generate fragments:
* Layout::TextNode no longer collapses whitespace as part of its
stored "text for rendering", but moves this logic to ChunkIterator
which splits up this text into separate views whenever whitespace
needs to be collapsed.
* Layout::LineBox now only extends the last fragment if its end offset
is equal to the new fragment's start offset. Otherwise, there's a
gap caused by collapsing whitespace and we need to generate a
separate fragment for that in order to have a correct start offset.
Some tests need new baselines because of the fixed start offsets.
Fixes#566.
Not every user of this requires an `auto` state, but most do.
This has quite a big diff but most of that is mechanical:
LengthPercentageOrAuto has `resolved_or_auto()` instead of `resolved()`,
and `to_px_or_zero()` instead of `to_px()`, to make their output
clearer.
If we were calculating the static position for an absolutely positioned
inline box that resides in the last line of its containing block, we
would not have yet provided the fragments in that line with their
final positions. Additionally, we would always move the box beneath the
fragment, which was incorrect.
Fixes#5867.
Currently we're relying on LineBuilder's destructor to handle updating
the last line, if required. In order to fix an issue with our absolute
positioning code, we need to be able to update the last line earlier
than that. Remove the destructor and replace it with an explicit call to
LineBuilder::update_last_line().
No functional changes.
We currently have a mixup in LibWeb between code unit offset and glyph
offset during hit testing. These extra fields will allow us to correct
this discrepency.
We should calculate whether we need to truncate text with an ellipsis
exclusive of any trailing collapsible whitespace.
This was causing issues where an inline element was automatically sized
(e.g. min-content) as we would calculate available width exclusive of
trailing collapsible whitespace and then our text chunk would be wider,
always inserting an ellipsis.
Fixes the visual element of #4048 but we still are incorrect in how we
collapse whitespace more generally
In 89ba00304c, the box' X position was
capped at 0 to prevent negative X positions to act as if there were
intruding floats on the left side. Instead, we need to check whether the
left side float intrusion we are going to calculate matters at all -
because if there's no matching float box, the intrusion is always going
to be 0 and we don't need to take the box' X position into account.
Fixes the floating publication images on https://lexfridman.com/.
This migrates TextNode::text_for_rendering() to Utf16String and deals
with the fallout. As a consequence, this effectively reverts commit
3df83dade8.
The layout test expecation file updates are because we now express text
lengths and offsets in UTF-16 code units.
The selection-over-multiple-code-units expectation file update actually
represents a correctness fix. Our result now matches Firefox.
This exposed a few bugs which caused the following tests to behave
incorrectly:
- `tab-size-text-wrap.html`: This previously relied on a bug where we
incorrectly treated `white-space: pre` as allowing text wrapping. The
fix here is to implement the text-wrap CSS shorthand property.
- `execCommand-preserveWhitespace.html`: We don't correctly serialize
shorthand properties. This is covered by an existing FIXME in
`CSSStyleProperties::serialized()`
- `white-space-shorthand.html`: The last 5 subtests here fail as we
don't correctly handle shorthand properties in
`CSSStyleProperties::remove_property()`. This is covered by an
existing FIXME in said function.
If a block with inline children ends with a line break clearing any
floats, we not only need to take the introduced clearance into account
for the next line box, but the containing block needs to set the correct
height as well.
Since the spec calls for using the last line box' bottom as the resolved
height (if treated as auto), we now correctly apply the clearance to the
previous line box' bottom coordinate.
Fixes#4058.
Whenever we generate line boxes, we might end up with a residual
vertical float clearance by way of having a `<br>` with `clear: ..` set.
Set the Y offset of the next block level box to place by this vertical
clearance.
Relates to #4058.
We were introducing a line break and applying vertical clearance to the
inline formatting context, but that vertical clearance only applied to
new floating boxes. We should move the current block offset to the
vertical clearance to make sure the next line box starts beyond the
cleared floats.
There was a layout test for `<br>` with `clear: ..` set, but that test
did not actually do anything - removing the `clear` property would
result in the same layout. Replace that test with something that
actually tests float clearing.
Relates to #4058.
We used to always clear the side data after encountering a box with
`clear: ..`, but this is not the right thing to do if that same box also
has `float: ..` set. For example, with `clear: right` and `float: left`
it might be that the next box still wants to clear the right side, and
since the previous box is floating it did not push the next box down far
enough to justify clearing the side data at that point.
This changes the logic to only clear the float side if the clearing box
itself is not floating. We also no longer clear the opposite side after
placing a floating box; that doesn't seem to be necessary anymore.
Fixes#4102.
positioned element is a descendant of inline-block
Sets inline block offsets in InlineFormattingContext.cpp, but this is
not enough. When static position rect is calculated during layout,
not all ancestors of abspos box may have their offsets calculated yet
(more info here: https://github.com/LadybirdBrowser/ladybird/pull/2583#issuecomment-2507140272).
So now static position rect is calculated relative to static containing
block during layout and calculation relative to actual containing block
is done later in
FormattingContext::layout_absolutely_positioned_element.
Fixes wpt/css/CSS2/abspos/static-inside-inline-block.html
This commit introduces proper handling of three intrinsic size keywords
when used for CSS heights:
- min-content
- max-content
- fit-content
This necessitated a few plumbing changes, since we can't resolve these
values without having access to containing block widths.
This fixes some visual glitches on https://www.supabase.com/ as well
as a number of WPT tests. It also improves the appearance of dialogs.
compute_inset() was incorrectly retrieving the containing block size
because containing_block() is unaware of grid areas that form a
containing block for grid items but do not exist in the layout tree.
With this change, we explicitly pass the containing block into
compute_inset(), allowing it to correctly provide the containing block
sizes for grid items.
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>.
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.
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.
The width of a line box is the distance from the left edge of the first
fragment to the right edge of the last fragment. We don't have to loop
over all the fragments to figure this out. :^)
The BFC "context box" is now the outer box of the block formatting
context. Previously the context box was always the current target box,
which made it hard to reason about who was really the containing block
of whom in various places.
Note that IFC still has the containing block as its context box, this
change only affects BFC. However, to clarify the situation in IFC,
I've added a containing_block() getter than returns the context_box().
I don't know why basing the available space between floats on the y
coordinate in the middle of each line seemed like a good idea. It just
creates situations with a few pixels of floats overlapping text!
I'm not sure what this was trying to achieve, but it was moving all
line fragments upwards and a lot of things look a lot better if we
just stop doing that.
Boxes can now be floated left or right, which makes text within the
same block formatting context flow around them.
We were creating way too many block formatting contexts. As it turns
out, we don't need one for every new block, but rather there's a set
of rules that determines whether a given block creates a new block
formatting context.
Each BFC keeps track of the floating boxes within it, and IFC's can
then query it to find the available space for line boxes.
There's a huge hack in here where we assume all lines are the exact
line-height. Making this work with vertically non-uniform lines will
require some architectural changes.
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.
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.
