Let's start moving away from using raw strings for CSS identifiers.
The idea here is to use IdentifierStyleValue with a CSS::ValueID inside
for all CSS identifier values.
Within the same stacking context, positioned elements must be painted
after non-positioned ones.
I added a Layout::Node::for_each_child_in_paint_order() to help with
this since it's also needed for hit testing.
This is definitely not fully-featured, but basically we now handle
the clear property by forcing the cleared box below the bottom-most
floated box on the relevant side.
I had guessed that floating boxes should somehow be hoisted up to the
nearest block ancestor that creates a block formatting context, but
that's just wrong. They move up to the nearest block ancestor like any
other box that's not absolutely (or fixed) positioned. :^)
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.
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.
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. :^)
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!)
2020-11-22 15:56:27 +01:00
Renamed from Libraries/LibWeb/Layout/LayoutNode.cpp (Browse further)
