Using int was a mistake. This patch changes String, StringImpl,
StringView and StringBuilder to use size_t instead of int for lengths.
Obviously a lot of code needs to change as a result of this.
This is going to be quite boring to do by hand for every single CSS
property. We'll probably want to come up with a way to auto-generate
some/most of the shorthand expansion code.
This patch moves the Selector object model closer to the specification
objects in Selectors Level 4.
A "Selector" in LibHTML is now a { Vector<ComplexSelector> }, which is
a { Relation, CompoundSelector }. A CompoundSelector is really just
a Vector<SimpleSelector>, and SimpleSelector is "Component" renamed.
This makes a lot more selectors actually match on the Ubuntu Apache2
default homepage. :^)
This patch adds a[foo] and a[foo=bar] attribute selectors.
Note that an attribute selector is an optional part of a selector
component, and not a component on its own.
This is a very bulky way of doing this, and doesn't seem sustainable to
implement every shorthand property this way, but it's a place to start.
The "margin" CSS property now expands into its four longhands as far as
my understanding of the specs.
Note that shorthand expansion happens when we *resolve* style, not when
we parse CSS. I'm not sure this is correct anymore, I think other UA's
may actually expand shorthands into the declaration directly at parse
these days. If so, we should do this at parsing as well.
Code for parsing and stringifying CSS properties is now generated based
on LibHTML/CSS/Properties.json
At the moment, the file tells us three things:
- The name of a property
- Its initial value
- Whether it's inherited
Also, for shorthand properties, it provides a list of all the longhand
properties it may expand too. This is not actually used in the engine
yet though.
This *finally* makes layout tree dumps show the names of CSS properties
in effect, instead of "CSS::PropertyID(32)" and such. :^)
It should be possible for the CSS parser to fail, and we'll know it
failed if it returns nullptr. Returning RefPtr's makes it actually
possible to return nullptr. :^)
In order for this to work nicely, I made the line box classes use float
instead of int for its geometry information.
Justification works by distributing all of the whitespace on the line
(including the trailing whitespace before the line break) evenly across
the spaces in-between words.
We should probably use floating point (or maybe fixed point?) for all
the layout metrics stuff. But one thing at a time. :^)
It's now possible to set a page background image via <body background>.
Also, HtmlView now officially handles rendering the body element's
background (color, image or both.) LayoutBox is responsible for all
other background rendering.
Note that it's not yet possible to use CSS background-image properties
directly, since we can't parse them yet. :^)
The FontCache caches the result of font lookups. The cache key is a
simple object called FontSelector which consists of the font family
and font weight (both strings.)
This drastically reduces time spent in font lookup.
This class introduces LayoutTable, LayoutTableRow and LayoutTableCell.
These are produced by "display" values table, table-row and table-cell
respectively.
Note that there's no layout happening yet, I'm just adding the classes.
This patch makes it possible to call Node::invalidate_style() and have
that node and all of its ancestors recompute their style.
We then figure out if the new style is visually different from the old
style, and if so do a paint invalidation with set_needs_display().
Note that the "are they visually different" code is very incomplete!
Use this to make hover effects a lot more efficient. They no longer
cause a full relayout+repaint, but only a style invalidation.
Style invalidations are still quite heavy though, and there's a lot of
room for improvement there. :^)
This is currently very aggressive. Whenever the Document's hovered node
changes, we invalidate all style and do a full relayout.
It does look cool though. So cool that I'm adding it to the default
stylesheet. :^)
We currently hard-code the line height to 140% of the font glyph height
and this patch doesn't fix the hard-coding, but at least moves it out
of LayoutText and into StyleProperties where it can be re-used until
the day we go and do a proper implementation of CSS line-height. :^)
Just in time for Serenity's 1st birthday, here is the <blink> element!
This patch adds a bunch of different mechanisms to enable partial
repaints of the layout tree (LayoutNode::set_needs_display()))
It also adds LayoutNode::is_visible(), which can be toggled to prevent
a LayoutNode from rendering anything (it still takes up space though.)
Instead of using string everywhere, have the CSS parser produce enum
values, since they are a lot nicer to work with.
In the future we should generate most of this code based on a list of
supported CSS properties.
This patch implements two more selector features:
- "div + p" matches the <p> sibling immediately after a <div>.
- "div ~ p" matches all <p> siblings after a <div>.
Since LayoutText inherits all of its style information from its parent
Element anyway, it makes more sense to load the font at a higher level.
And since the font depends only on the style and nothing else, this
patch moves font loading (and caching) into StyleProperties. This could
be made a lot smarter to avoid loading the same font many times, etc.
"div p" now generates a Selector with two components where the second
component is a type=TagName, value="p", relation=Descendant.
We still don't handle matching of these, but at least we parse them.
The default style for "a" tags now has { color: -libhtml-link; }.
We implement this vendor-specific property by querying the containing
document for the appropriate link color.
Currently we only use the basic link color, but in the future this can
be extended to remember visited links, etc.
The parser now kinda recognizes immediate child selectors, !important,
and various other little things.
It's still extremely far from robust and/or correct. :^)
Okay, I got that a bit wrong. Here's what CSS 2.1 says:
"The properties of anonymous boxes are inherited from the enclosing
non-anonymous box. Non-inherited properties have their initial value."
This patch implements a better behavior by only copying the inherited
properties from the parent style.
Instead of HtmlView clients having to worry about parsing and loading
the default CSS, just take care of it inside StyleResolver.
The default style is automatically inserted into the stylesheet list,
at the very start, so everyone else gets a chance to override it.
Add a simple is_inherited_property(name) lookup function and use that
to implement CSS property inheritance.
It's a bug that "text-decoration" is inherited, but we currently rely
on this in order to propagate e.g underline into linkified line boxes.
