Layout nodes now only carry CSS computer values with them. The main
idea here is to give them only what they need to perform layout, and
leave the rest back in the DOM.
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().
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.
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!)
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/LayoutBlock.cpp (Browse further)
