HtmlView will now invoke the on_link_hover hook when the cursor enters
or leaves a DOM node that has an enclosing link element.
This patch also updates the meaning of Node::enclosing_link_element()
to find the nearest HTMLAnchorElementAncestor *with an href attribute*.
Use a zero-timer to schedule a style update after invalidating style
on any node. Nodes now have a needs_style_update flag which helps us
batch and coalesce the work.
We also start style updates at the root and work our way through the
document, updating any node that has the needs_style_update flag set.
This is slower than what we were doing before, but far more correct.
There is a ton of room for improvement here. :^)
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. :^)
If the current line box already has zero width, there's no point in
inserting a line break to make space, since we'll just be at x=0 after
breaking as well.
This removes an ugly unnecessary line break before images wider than
their containing block. :^)
Capture a weak pointer to the element and pass that to the load finish
callback in HTMLImageElement::load_image(). This allows us to ignore
completed loads if the <img> element is no longer around.
When loading a URL that ends in ".png", we now construct a simple
DOM document to contain the image. It also shows the image dimensions
in the document title.
Because we use <img src> to load the image into the synthetic document,
we end up loading the image resource twice. This issue will go away
once we have a smarter, caching, loader mechanism.
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.
Some inline stylesheets use HTML comments like "<!--blah blah-->".
The HTML parser currently generates a comment child node of the <style>
element whenever this happens, and we don't want the comment itself to
be interpreted as part of the stylesheet.
This is a total hack to get around the auto-detection mechanism for
whether a block has inline or block children. We'll say that tables
never have inline children for now, and then anything that actually
turns out to be an inline child will just be ignored by layout.
Instead of computing whether a block's children are inline based on the
first child, make it an imperatively-set flag.
This gives us some flexibility to ignore things like text nodes inside
a <table>, for example. I'm still unsure what the "correct" way to deal
with those will be. We'll find out sooner or later. :^)
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.
We now wait until the pixels are actually needed before fully decoding
images in <img> elements.
This needs some more work and is currently a bit memory-wasteful since
we'll hang on to the raw image data forever.
If a LayoutNode is split into line box fragments, we need to walk our
fragments and invalidate them. It was not enough to do this only for
LayoutBox nodes.
To streamline the layout tree and remove irrelevant data from classes
that don't need it, this patch adds two new LayoutNode subclasses.
LayoutNodeWithStyleAndBoxModelMetrics should be inherited by any layout
node that cares about box model metrics (margin, border, and padding.)
LayoutBox should be inherited by any layout node that can have a rect.
This makes LayoutText significantly smaller (from 140 to 40 bytes) and
clarifies a lot of things about the layout tree.
I'm also adding next_sibling() and previous_sibling() overloads to
LayoutBlock that return a LayoutBlock*. This is okay since blocks only
ever have block siblings.
Do also note that the semantics of is<T> slightly change in this patch:
is<T>(nullptr) now returns true, to facilitate allowing to<T>(nullptr).
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. :^)
Replaced elements will now properly create line breaks when they use up
the available horizontal space.
This fixes an issue with <img>'s lining up instead of breaking.
If you do a layout and it turns out that the page contents don't fit in
the viewport vertically, we add a vertical scrollbar. Since the
scrollbar takes up some horizontal space, this reduces the amount of
space available to the page. So we have to do a second layout pass. :^)
Fixes#650.
When style is invalidated (for example when an external stylesheet
finishes loading) we delete the whole layout tree and build a new one.
This is necessary since the new style information may result in a
different layout tree.
When layout is invalidated (window resized, image dimensions learned,
etc..) we keep the existing layout tree but run the layout algorithm
once again.
There's obviously lots of room for improvement here. :^)
The layout root is now kept alive via Document::m_layout_root.
This will allow us to do more layout-related things inside the inner
layer of LibHTML without reaching out to the HtmlView.
I'd like to keep HtmlView at a slightly higher level, to prevent it
from getting too complex.
This patch also fixes accidental disconnection of the layout tree from
the DOM after doing a layout tree rebuild. ~LayoutNode() now only
unsets the DOM node's layout_node() if it's itself.
This patch adds the CharacterData subclass of Node, which is now the
parent class of Text and a new Comment class.
A Comment node is one of these in HTML: <!--hello friends-->
Since these occur somewhat frequently on the web, we need to be able
to parse them.
This patch also adds a child rejection mechanism to the DOM tree.
Nodes can now override is_child_allowed(Node) and return false if they
don't want a particular Node to become a child of theirs. This is used
to prevent Document from taking on unwanted children.
