Copy a display list item and apply scroll offset instead of mutating
display list directly.
It's a preparation for upcoming changes where a display list will be
cached across repaints and used multiple times with different scroll
offsets.
This allows us to use HeapFunction all of the way down, allowing us
to remove the Handle usage in after_session_callback for
create_new_child_navigable.
...For the completion steps. This is quite nice, as we can simply
capture this in the heap function where it is used instead of
needing to establish a new root.
Note that with these changes, to represent 'an empty algorithm', we now
use a null HeapFunction and do not invoke the steps.
This change causes the viewport to be treated as a "scroll frame,"
similar to how it already works for boxes with "overflow: scroll."
This means that, instead of encoding the viewport translation into a
display list, the items will be assigned the scroll frame id of the
viewport and then shifted by the scroll offset before execution. In the
future it will allow us to reuse a display list for repainting if only
scroll offset has changed.
As a side effect, it also removes the need for special handling of
"position: fixed" because compensating for the viewport offset while
painting or hit-testing is no longer necessary. Instead, anything
contained within a "position: fixed" element is simply not assigned
a scroll frame id, which means it is not shifted by the scroll offset.
While introducing clip and scroll frame trees, I made a mistake by
assuming that the paintable tree includes boxes from nested navigables.
Therefore, this comment in the code was incorrect, and clip/scroll
frames were simply not assigned for iframes:
// NOTE: We only need to refresh the scroll state for traversables
// because they are responsible for tracking the state of all
// nested navigables.
As a result, anything with "overflow: scroll" is currently not
scrollable inside an iframe
This change fixes that by ensuring clip and scroll frames are assigned
and refreshed for each navigable. To achieve this, I had to modify the
display list building process to record a separate display list for each
navigable. This is necessary because scroll frame ids are local to a
navigable, making it impossible to call
`DisplayList::apply_scroll_offsets()` on a display list that contains
ids from multiple navigables.
`m_needs_repaint = true` is not enough because it doesn't schedule
repaint of a parent navigable.
Fixes the bug when an iframe is not repainted after scrolling.
Navigables are re-used for navigations within the same tab. Its current
ownership of the cursor position is a bit ad-hoc, so nothing in the spec
indicates when to reset the cursor, nor do we manually do so. So when a
cursor update happens on one page, that cursor is retained on the next
page.
Instead, let's have the document own the cursor. Each navigation results
in a new document, thus we don't need to worry about resetting cursors.
This also makes many of the callsites feel nicer. We were previously
often going from the node, to the document, to the navigable, to the
cursor. This patch removes the navigable hop.
Contrary to LibGfx, where corner clipping was implemented by sampling
and blitting pixels under corners into a temporary bitmap, Skia allows
us to simply apply a mask. As a result, we no longer need the
BlitCornerClipping command, which has become a no-op.
- SampleUnderCorners is renamed to AddRoundedRectClip
- The optimization that skipped unnecessary blit and sample commands has
been removed. However, this should not result in a performance
regression because Skia seems to perform mask rasterization lazily.
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
Before this change we were recording and executing sample/blit commands
for each painting phase, even if there are no painting commands
in-between sample and blit that produce result visible on a canvas.
This change adds an optimization pass that goes through recorded
painting commands list and marks sample and blit commands that could
be skipped.
Reduces sample and blit corners executing from 17% to 8% on Discord.
The only subclass was already GC-allocated, so let's hoist the JS::Cell
inheritance up one level. This ends up simplifying a bit of rather
dubious looking code where we were previously slicing ESOs.
Changes the signature of queue_global_task() from AK:Function to
JS::HeapFunction to be more clear to the user of the function that this
is what it uses internally.
Before this change JS console was initialise from
activate_history_entry() which is too late for about:blank documents
that are ready to run scripts immediately after creation.
...because existance of this method conflicts with the purpose of
having a queue as it allows to start executing next task in the middle
of ongoing task.
For example:
1. SHTQ timer starts executing a task.
2. Task does SHTQ::process().
Another example:
1. SHTQ::process() start executing a task.
2. task does SHTQ::process().
Workaround spec bug by explicitly carrying information whether
navigation is sync (History api, fragment change) or not.
See for more details https://github.com/whatwg/html/issues/10232
If navigation early returns before reaching "finalize a cross document
navigation" then we have to make sure delaying load events is disabled.
See spec issue https://github.com/whatwg/html/issues/10252
No need to force an allocation. This makes a future patch a bit simpler,
where we will have the encoding as a String. With this patch, we won't
have to convert it to a ByteString.
These changes do not solve hanging `location.reload()` and
`location.go()` but only align implementation with the latest edits in
the specification.
`WindowProxy-Get-after-detaching-from-browsing-context` test output is
affected because `iframe.remove();` no longer synchronously does
destruction of a document, but queues a task on event loop.
Co-Authored-By: Andrew Kaster <akaster@serenityos.org>
This URL library ends up being a relatively fundamental base library of
the system, as LibCore depends on LibURL.
This change has two main benefits:
* Moving AK back more towards being an agnostic library that can
be used between the kernel and userspace. URL has never really fit
that description - and is not used in the kernel.
* URL _should_ depend on LibUnicode, as it needs punnycode support.
However, it's not really possible to do this inside of AK as it can't
depend on any external library. This change brings us a little closer
to being able to do that, but unfortunately we aren't there quite
yet, as the code generators depend on LibCore.
When navigating to about:srcdoc we try to populate the session history
by calling populate_session_history_entry_document, if the resource is
an about:srcdoc this method will rely on the document_resource in the
SessionHistoryEntry to have a String in order for it call the right
method to create navigation params.
However when navigating to about:srcdoc directly, document_resource
will have an Empty, this leads populate_session_history_entry_document
to call the wrong method to create navigation params.
This fixes the issue by populating document_resource with an empty
string if it has an Empty and we're dealing with an about:srcdoc.
Issue: #23216
Resolves a performance regression from
8ba18dfd40, where moving paint scheduling
to `EventLoop::process()` led to unnecessary repaints.
This update introduces a flag to trigger repaints only when necessary,
addressing the issue where repaints previously occurred with each event
loop process, irrespective of actual changes.
Extends event loop processing steps to include gathering and
broadcasting resize observations.
Moves layout updates from Navigable::paint() to event loop processing
steps. This ensures resize observation processing occurs between layout
updates and painting.
Separating the recorder list from the painter will allow us to save it
for later execution without carrying along the painter's state. This
will be useful once we have a separate thread for executing painting
commands, to which we will have to transfer commands from the main
thread.
Preparation for https://github.com/SerenityOS/serenity/pull/23108
There's a chance that we try to choose a navigable before a previously
destroyed navigable is fully destroyed and GC'd. Investigating why this
can happen is a separate endeavor, let's just not crash for now.
