We were passing the wrong length argument to substring() when
stringifying a range where start and end are the same text node.
Also, make sure we visit all the contained text nodes when appending
them to the output.
This was caught by an Acid3 subtest.
I came across some websites that change an elements CSS "opacity" in
their :hover selectors. That caused us to relayout on hover, which we'd
like to avoid.
With this patch, we now check if a property only affects the stacking
context tree, and if nothing layout-affecting has changed, we only
invalidate the stacking context tree, causing it to be rebuilt on next
paint or hit test.
This makes :hover { opacity: ... } rules much faster. :^)
There's no actual need to build the stacking context tree before
performing layout. Instead, make it lazy and build the tree when it's
actually needed for something.
This avoids a bunch of work in situations where multiple synchronous
layouts are forced (typically by JavaScript) without painting or hit
testing taking place in between.
It also opens up for style invalidations that only target the stacking
context tree.
When updating layout inside a nested browsing context, try first to
perform layout in the parent document (the nested browsing context's
container's document).
This ensures that nested browsing contexts have the right viewport
dimensions in case the parent layout changes them somehow.
We were hanging on to element inline style, even after the style
attribute was removed. This made inline style sticky and impossible to
remove. This patch fixes that. :^)
Add a flag to DOM::Document that means the whole document needs a style
update. This saves us the trouble of traversing the entire DOM to mark
all nodes as needing a style update.
The old mode names, while mechanically accurate, didn't really reflect
their relationship to the CSS specifications.
This patch renames them as follows:
Default => Normal
AllPossibleLineBreaks => MinContent
OnlyRequiredLineBreaks => MaxContent
There's also now an explainer comment with the LayoutMode enum about the
specific implications of layout in each mode.
It makes no sense to require passing a global object and doing a stack
space check in some cases where running out of stack is highly unlikely,
we can't recover from errors, and currently ignore the result anyway.
This is most commonly in constructors and when setting things up, rather
than regular function calls.
This was causing us to miss layout invalidations. With this fixed, we
can remove the invalidation from Element::recompute_style() along with
the associated FIXME.
Thanks to Idan for spotting this! :^)
Instead of invalidating style for the entire document, we now locate the
nearest common ancestor between the old and new innermost hovered node,
and only invalidate that ancestor and its descendants.
This drastically reduces the amount of style update work when mousing
around on GitHub (and any other pages, really.) It's actually really
really snappy now. Very cool! :^)
Use the new CSS::property_affects_layout() helper to figure out if we
actually need to perform a full relayout after recomputing style.
There are three tiers of required invalidation after an element receives
new style: none, repaint only, or full relayout.
This avoids the need to rebuild the layout tree (and perform layout on
it) when trivial properties like "color" etc are changed.
This commit is messy due to the Paintable and Layout classes being
tangled together.
The RadioButton, CheckBox and ButtonBox classes are now subclasses of
FormAssociatedLabelableNode. This subclass separates these layout nodes
from LabelableNode, which is also the superclass of non-form associated
labelable nodes (Progress).
ButtonPaintable, CheckBoxPaintable and RadioButtonPaintable no longer
call events on DOM nodes directly from their mouse event handlers;
instead, all the functionality is now directly in EventHandler, which
dispatches the related events. handle_mousedown and related methods
return a bool indicating whether the event handling should proceed.
Paintable classes can now return an alternative DOM::Node which should
be the target of the mouse event. Labels use this to indicate that the
labeled control should be the target of the mouse events.
HTMLInputElement put its activation behavior on run_activation_behavior,
which wasn't actually called anywhere and had to be manually called by
other places. We now use activation_behavior which is used by
EventDispatcher.
This commit also brings HTMLInputElement closer to spec by removing the
did_foo functions that did ad-hoc event dispatching and unifies the
behavior under run_input_activation_behavior.
We were not actually walking past the first ancestor when setting
child-needs-update bit upwards.
Also, let's walk all the way to the root, even if there's a
child-needs-update bit already set. This ensures that we always leave
this function with the ancestor chain in a sane state.
- Access members directly instead of going through accessors,
avoiding a lot of redundant traversal done by accessors.
- Cross shadow boundaries and make sure that shadow trees get their
dirty bits updated as well.
- Do the minimum amount of traversal needed when setting the "child
needs style update" bit upwards through ancestors.
Let's make it very clear that these are *computed* values, and not at
all the specified values. The specified values are currently discarded
by the CSS cascade algorithm.
The style update mechanism was happily ignoring shadow subtrees.
Fix this by checking if an element has a shadow root, and recursing into
it if needed.
Before this change, style invalidation didn't propagate upwards across
shadow boundaries, so our shadow trees were sitting there with invalid
style, never actually getting updated.
Input events have nothing to do with layout, so let's not send them to
layout nodes.
The job of Paintable starts to become clear. It represents a paintable
item that can be rendered into the viewport, which means it can also
be targeted by the mouse cursor.
The "paintable" state in Layout::Box was actually not safe to access
until after layout had been performed.
As a first step towards making this harder to mess up accidentally,
this patch moves painting information from Layout::Box to a new class:
Painting::Box. Every layout can have a corresponding paint box, and
it holds the final used metrics determined by layout.
The paint box is created and populated by FormattingState::commit().
I've also added DOM::Node::paint_box() as a convenient way to access
the paint box (if available) of a given DOM node.
Going forward, I believe this will allow us to better separate data
that belongs to layout vs painting, and also open up opportunities
for naturally invalidating caches in the paint box (since it's
reconstituted by every layout.)
Let's get this right before trying to make it fast. This patch removes
the code that tried to do less work when an element's style changes,
and instead simply invalidates the entire document.
Note that invalidations are still coalesced, and will not be
synchronized until update_style() and/or update_layout() is used.
If the style is dirty, update_style() may cause layout to become dirty.
Therefore we must always update style when updating layout, to ensure
up-to-date results.
