If we've already established the used width for a flex item, we need
to take it into account when calculating the min-content and max-content
heights for that item.
We were already doing this when calculating cross sizes. This patch adds
the same consideration for main sizes.
Previously block auto height calculation was changed to skip boxes with
collapsed margins and then condition to skip anonymous boxes with no
lines was also removed in 6c5ba10bb0 to
avoid skipping anonymous wrappers of tables.
Skipping boxes with collapsed margins (currently it's check that
height is 0) is wrong because it makes empty boxes with clearance to
be skipped which is not correct while anonymous boxes with no lines
should be skipped and it's no longer causes problems with tables
(fixed in 87f0e835eb)
Commit 7dc0edcb86 was supposed to prevent
floats from being placed higher than preceding boxes but the change
turned out to be completely wrong and caused regressions because:
1. Call to `clear()` in `layout_block_level_children` would reset
floating boxes only after layout of box with _not_ inline children
although the same should happen after layout of IFC.
2. `clear()` causes offset y of floats to be reset but it also clears
all currently enocuntered floating boxes which means the next box
that has actual clearance will get wrong y position.
Per CSS-SIZING-3, the min-content block size should be equivalent to the
max-content block size for some boxes.
Honoring this gives more correct results, and avoids unnecessary work in
many cases since the cached max-content size can be reused.
Grid containers were incorrectly represented as BlockContainer before.
Furthermore, GridFormattingContext had a bogus inheritance relationship
with BlockFormattingContext.
This patch brings our architecture closer to spec by making grid
containers be plain boxes and making GFC not inherit from BFC.
There is a difference in y offset position calculation for floats when
LineBuilder provides final y position while for blocks it needs to be
adjusted by `y_offset`. This difference already accounted in floating
box position calculation and this patch also makes it accounted in check
whether a floating boxes on the same line intersect between each other.
If valid grid-template-areas were given, then place grid items within
these areas. Grid-template-areas take precedence over named line
tracks, meaning if there are grid-areas as well as named tracks, should
use the grid-areas.
When starting the GridFormattingContext, calculate the valid grid areas
as declared in the `grid-template-areas` property. Since this doesn't
change, are able to do this once and store the results.
In some sections of the code, previously would use the values passed to
`grid-column-start`, `grid-row-end`, etc. literally. Since these values
start at grid-column 1 instead of 0 (as represented in most areas in
the code), this made the code unnecessarily complicated.
Now the values are zero-indexed from the getgo.
Change `compute_auto_height_for_block_level_element` to use max height
(`m_automatic_content_height` produced from TFC) for tables with auto
height which is more correct behaviour than treating them like block
containers.
CSS 2.2 section 9.5.1:
The outer top of a floating box may not be higher than the
outer top of any _block_ or floated box generated by an
element earlier in the source document.
Where block is `BlockContainer` in LibWeb type system.
Which means `current_boxes` need to be cleared before
leaving block container.
```html
<style>
.wrapper {
width: 100px;
height: 300px;
background-color: lightgray;
}
.box {
margin: 10px;
width: 50px;
height: 50px;
float: left;
}
.a { background-color: salmon; }
.b { background-color: slateblue; }
.c { background-color: green; }
</style>
<div class="wrapper">
<div class="box a"></div>
<div class="box b"></div>
</div>
<div class="box c">
</div>
```
Introduce `TableWrapper` type so table wrappers could be
distinguished from block containers and override width
calculation for table wrappers (CSS 2.2 spec, section 17.5.2)
inside BFCs in the way that their width should be equal to
width of table box they wrap.
Before this patch, we were expressing the current selection as a range
between two points in the layout tree. This was a made-up concept I
called LayoutRange (2x LayoutPosition) and as it turns out, we don't
actually need it!
Instead, we can just use the Selection API from the Selection API spec.
This API expresses selection in terms of the DOM, and we already had
many of the building blocks implemented.
To ensure that selections get visually updated when the underlying Range
of an active Selection is programmatically manipulated, Range now has
an "associated Selection". If a range is updated while associated with
a selection, we recompute layout tree selection states and repaint the
page to make it user-visible.
This simplifies the ownership model between DOM/layout/paint nodes
immensely by deferring to the garbage collector for figuring out what's
live and what's not.
This change fixes problem that y position of blocks with
clearance might not include border_top and padding_top
by changing `place_block_level_element_in_normal_flow_vertically`
to accept y position without `border_box_top` and adding it
on the last step when clearance is already taken in account.
Bug reproducer:
```html
<style>
.a {
border: 10px salmon solid;
width: 50px;
height: 50px;
float: left;
}
.b {
clear: both;
border: 20px slateblue solid;
width: 50px;
height: 50px;
}
</style>
<div class="a"></div><div class="b"></div><div class="c"></div>
```
Introduce `table_box()` function that returns table formatting
context root box casted to `TableBox` similar to how it's done
in other formatting contexts like `root()` in BFC and
`flex_container` in FFC. And replace `context_box()` calls
in TFC with calls to `table_box()`.
It is incorrect to skip anonymous block containers without
line boxes during block auto height calculation because there
might be table roots wrapped in anonymous table boxes after fixup
and their height should be taken in account so leaving just
condition to skip child boxes which margins are "collapsed
through" (`border_box_height() == 0`) sufficient to skip
anonymous blocks without lines but still consider table wrappers.
According to table fixup algorithm:
https://www.w3.org/TR/css-tables-3/#fixup-algorithm
around every table-root should be generated anonymous
box wrapper.
Also this patch implements important part of CSS 2.2
spec that is currently not present in CSS Tables 3
spec draft: https://www.w3.org/TR/CSS22/tables.html#model
that portion of computed properties should be moved
from table-root to table wrapper box. Without having
this part implemented height of absolutely positioned
table with `height: auto` won't be computed correctly.
Fixup rule that table roots need to be wrapped in anonymous
block boxes need to be implemeted instead of having `TableBox`
inherited from `BlockContainer`.
