Only simple alphabetic and numeric counter styles are supported. (This
is most of them though.)
Although this PR adds a sequential pass to layout, I verified that on
pages that contain a reasonable number of ordered lists (Reddit
`/r/rust`), the time spent in generated content resolution is dwarfed by
the time spent in the parallelizable parts of layout. So I don't expect
this to negatively affect our parallelism expect perhaps in pathological
cases.
Moved from #4544, because Critic.
Fixes#4544.
§ 12.3-12.5.
Only simple alphabetic and numeric counter styles are supported. (This
is most of them though.)
Although this PR adds a sequential pass to layout, I verified that on
pages that contain a reasonable number of ordered lists (Reddit
`/r/rust`), the time spent in generated content resolution is dwarfed by
the time spent in the parallelizable parts of layout. So I don't expect
this to negatively affect our parallelism expect perhaps in pathological
cases.
through display list building.
The old `flow_origin` concept was ill-defined (sometimes the border box
plus the flow origin, sometimes including horizontal margins and
sometimes not, sometimes including relative position and sometimes not),
leading to brittleness and test failures. This commit reworks the logic
to always pass border box origins in during display list building.
The rendering is still wrong beause of #2795, but at least we get a rendering.
(This test change is just for readability, it should be equivalent to before.)
r? @mbrubeck
The rendering is still wrong beause of #2795, but at least we get a rendering.
(This test change is just for readability, it should be equivalent to before.)
The exact rendering is ill-spec'd. Some things are ugly (especially the
width and height of list style images) but they are infrequently used
and I believe this implementation matches the spec. Numeric lists are
not supported yet, since they will require a separate layout pass.
The implementation is a subclass of `BlockFlow`, on advice from Robert
O'Callahan.
I had to use a somewhat unconventional method of computing text
indentation (propagating from blocks down to inlines) because of the way
containing blocks are handled in Servo.
(As a side note, neither Gecko nor WebKit correctly handles percentages
in `text-align`, at least incrementally -- i.e. when the percentages are
relative to the viewport and the viewport is resized.)
By "idempotent" I mean that later passes do not stomp on data from
earlier passes, so that we can run the passes individually for
incremental reflow. The main change here was to stop overwriting the
"minimum inline-size" field of each column with the column's computed
inline-size.
This adds the infrastructure necessary to support stacking contexts that
are not containing blocks for absolutely-positioned elements. Our
infrastructure did not support that before. This minor revamp actually
ended up simplifying the logic around display list building and
stacking-relative position computation for absolutely-positioned flows,
which was nice.
first-class.
This implements the scheme described here:
https://groups.google.com/forum/#!topic/mozilla.dev.servo/sZVPSfPVfkg
This commit changes Servo to generate one display list per stacking
context instead of one display list per layer. This is purely a
refactoring; there are no functional changes. Performance is essentially
the same as before. However, there should be numerous future benefits
that this is intended to allow for:
* It makes the code simpler to understand because the "new layer needed"
vs. "no new layer needed" code paths are more consolidated.
* It makes it easy to support CSS properties that did not fit into our
previous flat display list model (without unconditionally layerizing
them):
o `opacity` should be easy to support because the stacking context
provides the higher-level grouping of display items to which opacity
is to be applied.
o `transform` can be easily supported because the stacking context
provides a place to stash the transformation matrix. This has the side
benefit of nicely separating the transformation matrix from the
clipping regions.
* The `flatten` logic is now O(1) instead of O(n) and now only needs to
be invoked for pseudo-stacking contexts (right now: just floats),
instead of for every stacking context.
* Layers are now a proper tree instead of a flat list as far as layout
is concerned, bringing us closer to a production-quality
compositing/layers framework.
* This commit opens the door to incremental display list construction at
the level of stacking contexts.
Future performance improvements could come from optimizing allocation of
display list items, and, of course, incremental display list
construction.
Instead of creating a display list for the entire page, only create one
for an area that expands around the viewport. On my machine this makes
incremental layout of http://timecube.com 50% faster.
Instead of looking at the display tree, have ContentBox(es)Query consult
the flow tree. This allow optimizing away parts of the display tree
later. To do this we need to be more careful about how we send reflow
requests, only querying the flow tree when possible.
Fixes#3790.
