Currently, compute_scrollbar_data does not adjust the position of the
scrollbar thumb based on the actual scroll offset. This is because we
perform this offset in most cases inside the display list executor, in
order to allow us to avoid recomputing the display list.
However, there are cases where we do want the thumb rect with an offset
inside PaintableBox. We currently use scroll_thumb_rect to perform that
computation.
In an upcoming patch, we will need both this offset thumb rect and the
scrollbar gutter rect. So this patch moves the computation of the offset
to compute_scrollbar_data, performed behind an optional parameter.
When a scrollbar is not interacting with the mouse, we now draw the
scrollbar slightly slimmer. When the mouse enters the space occupied
by the scrollbar, we enlarge it for easier mouse interactivity.
Previously, all `GC::Cell` derived classes were Weakable. Marking only
those classes that require this functionality as Weakable allows us to
reduce the memory footprint of some frequently used classes.
This reduces the number of `.cpp` files that need to be recompiled when
one of the below header files changes as follows:
CSS/ComputedProperties.h: 1113 -> 49
CSS/ComputedValues.h: 1120 -> 209
Previous name for misleading because it checks if box could be scrolled
by user input event which is diffent from checking if box is scrollable.
For example box with `overflow: hidden` is scrollable but it can't be
scrolled by user input event.
My previous attempt at resolving the continuation chain tried to deal
with `pointer-events: none` by repeatedly falling back to the parent
paintable until one was found that _would_ want to handle pointer
events. But since we were no longer performing hit-tests on those
paintables, false positives could pop up. This could happen for
out-of-flow block elements that did not overlap with their parent rects,
for example.
This approach works much better since it only handles the continuation
case that's relevant (the "middle" anonymous box) and it does so during
hit-testing instead of after, allowing all the other relevant logic to
come into play.
Our layout tree requires that all containers either have inline or
non-inline children. In order to support the layout of non-inline
elements inside inline elements, we need to do a bit of tree
restructuring. It effectively simulates temporarily closing all inline
nodes, appending the block element, and resumes appending to the last
open inline node.
The acid1.txt expectation needed to be updated to reflect the fact that
we now hoist its <p> elements out of the inline <form> they were in.
Visually, the before and after situations for acid1.html are identical.
For a while we used the wider Paintable type for stacking context,
because it was allowed to be created by InlinePaintable and
PaintableBox. Now, when InlinePaintable type is gone, we can use more
specific PaintableBox type for a stacking context.
Resulting in a massive rename across almost everywhere! Alongside the
namespace change, we now have the following names:
* JS::NonnullGCPtr -> GC::Ref
* JS::GCPtr -> GC::Ptr
* JS::HeapFunction -> GC::Function
* JS::CellImpl -> GC::Cell
* JS::Handle -> GC::Root