We previously only invalidated the cached color-stop data when the
painted area's size changed. However, multiple elements can use the
same gradient and be the same size, but have different parameters that
affect the gradient stop positions, for example if a stop has an em
position. This can also change for the same element over time.
The new cache instead uses these parameters as the cache key. So we
recompute the cache if lengths would resolve differently, or the area's
size is different.
The included test fails without this change.
This reverts commit 76daba3069.
We're going to need separate types for the JS-exposed style values, so
it doesn't make sense for us to match their names with our internal
types.
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!)
These are pretty rare, but they do come up in some places and it's not
hard to support. The Gfx::Font information is approximate (and bad)
but we can fix that separately.
This patch also adds the ability for Length to contain percentage
values. This is a little off-spec, but will make storing and dealing
with lengths a lot easier.
To resolve a Length to a px-or-auto Length, there are now helpers
for that. After calling them, you no longer have to think about
em, rem, %, and such things.
This patch introduces support for more than just "absolute px" units in
our Length class. It now also supports "em" and "rem", which are units
relative to the font-size of the current layout node and the <html>
element's layout node respectively.
