This change is a preparation for the upcoming changes where display
list will be nested and the same display could be owned by multiple
display list items.
With this change display list player will be able to recurse into
executing another display list, without having to construct new display
list player. It is going to be useful in the upcoming changes to paint
a mask from a display list owned by a command.
Before this change, removing a style element from inside a shadow tree
would cause it to be unregistered with the document-level list of sheets
instead of the shadow-root-level list.
This would eventually lead to a verification failure if someone tried to
update the text contents of that style element, since it was still in
the shadow-root-level list, but now with a null owner element.
Fixes a crash on https://www.swedbank.se/
Enforce the use of the CPU backend in test mode to ensure that ref-tests
produce consistent results across different computers, as this
consistency cannot be achieved with the GPU backend.
GPU painter that uses AccelGfx is slower and way less complete compared
to both default Gfx::Painter and Skia painter. It does not make much
sense to keep it, considering Skia painter already uses Metal backend on
macOS by default and there is an option to enable GPU-accelerated
backend on linux.
Unit tests on macOS deadlock because the WebContent process is waiting
for the next opportunity to render before a screenshot is taken. For
some reason unknown to myself, this opportunity never arrives. In
order to not deadlock, screenshot requests are now also processed
separately from rendering.
And let the old shadow_root(), which was only supposed to be used by
bindings, be called shadow_root_for_bindings() instead.
This makes it much easier to read DOM code, and we don't have to worry
about when to use shadow_root_internal() or why.
This adds a motion preference to the browser UI similar to the existing
ones for color scheme and contrast.
Both AppKit UI and Qt UI has this new preference.
The auto value is currently the same as NoPreference, follow-ups can
address wiring that up to the actual preference for the OS.
The main intention of this change is to have a consistent look and
behavior across all scrollbars, including elements with
`overflow: scroll` and `overflow: auto`, iframes, and a page.
Before:
- Page's scrollbar is painted by Browser (Qt/AppKit) using the
corresponding UI framework style,
- Both WebContent and Browser know the scroll position offset.
- WebContent uses did_request_scroll_to() IPC call to send updates.
- Browser uses set_viewport_rect() to send updates.
After:
- Page's scrollbar is painted on WebContent side using the same style as
currently used for elements with `overflow: scroll` and
`overflow: auto`. A nice side effects: scrollbars are now painted for
iframes, and page's scrollbar respects scrollbar-width CSS property.
- Only WebContent knows scroll position offset.
- did_request_scroll_to() is no longer used.
- set_viewport_rect() is changed to set_viewport_size().
...instead of scheduling repaint timer in PageClient.
This change fixes flickering on Discord that happened because:
- Event loop schedules repainting by activating repaint timer
- `Document::tear_down_layout_tree()` destroys paintable tree
- Repaint timer invokes callback and renders an empty frame because
paintable tree was destroyed
