All painting commands except SetClipRect are shifted by scroll offset
before command list execution. This change removes scroll offset
translation for sample/blit corner commands in
`PaintableWithLines::paint` so it is only applied once in
`CommandList::apply_scroll_offsets()`.
Currently, these only work when there are no CSS transforms (as the
stacking context painting is not set up to handle that case yet). This
is still enough to get most chat/comment markers working on GitHub
though :^)
Changes compute_absolute_padding_rect_with_css_transform_applied() to
use cached absolute rect and CSS transform instead of doing expensive
containing block chain traversal.
Reduces refresh_clip_state() from 4% to 2% in Discord profiles.
Fixes bug when CSS transform is applied twice to clip rect:
- While calculating absolute clip rectangles in `refresh_clip_state()`
- While executing `PushStackingContext` painting command.
Duplicated transform is already removed for PaintableBox and this change
adds this for InlinePaintable.
Instead of TextPaintable fragments being an offset+length view into the
layout node, they are now a view into the paintable instead.
This removes an awkward time window where we'd have bogus state in text
fragments after layout invalidation but before relayout. It also makes
the code slightly nicer in general, since there's less mixing of layout
and painting concepts.
From https://drafts.csswg.org/css-backgrounds-4/#background-clip
"The background is painted within (clipped to) the intersection of the
border box and the geometry of the text in the element and its in-flow
and floated descendants"
This change implements it in the following way:
1. Traverse the descendants of the element, collecting the Gfx::Path of
glyphs into a vector.
2. The vector of collected paths is saved in the background painting
command.
3. The painting commands executor uses the list of glyphs to paint a
mask for background clipping.
Co-authored-by: Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
Instead of allocating a new glyph run to scale glyph positions and
fonts, a scale factor could be encoded in a paint command and applied
later during command execution.
Every single client of this function was immediately calling paintable()
on the result anyway, so there was no need to return a layout node!
This automatically leverages the cached containing block pointer we
already have in Paintable, which melts away a bunch of unnecessary
traversal in hit testing and painting. :^)
Introduces the rendering of scroll thumbs in vertical and horizontal
directions. Currently, the thumbs are purely graphical elements that
do not respond to mouse events. Nevertheless, this is beneficial as it
makes it easier to identify elements that should respond to scrolling
events.
Painting of scrollbars uncovers numerous bugs in the calculation of
scrollable overflow rectangles highlighting all the places where
elements are made scrollable whey they shouldn't be. Positively, this
issue might motivate us to pay more attention to this problem to
eliminate unnecessary scrollbars.
Currently, the scrollbar style is uniform across all platforms: a
semi-transparent gray rectangle with rounded corners.
Also here we add `scrollbar-width: none` to all existing scrolling
ref-tests, so they keep working with this change.
The order is important because clip rectangles are calculated with the
scroll offset taken into account. Therefore, they need to be applied
before the scroll offset is changed, to avoid accounting for the scroll
offset twice.
Transforms are applied to both clip rectangle and position, so we need
to remove the transform from clip rectangle before checking if position
falls within the clip rectangle.
In this change, the removal of transform is moved into
`Paintable::clip_rect()` that is shared between hit-testing and
painting.
This change fixes hit-testing in Discord's multifactor authentication
form.
By moving scroll offset clamp from `PaintableBox::scroll_by()` to
`PaintableBox::set_scroll_offset()`, we ensure that updates from
`Element::set_scroll_top()` and `Element::set_scroll_left()` are
constrained to a valid range.
This change modifies hit_test() to no longer return the first paintable
encountered at a specified position. Instead, this function accepts a
callback that is invoked for each paintable located at a position, in
hit-testing order.
This modification will allow us to reuse this call for
`Document.elementsFromPoint()` in upcoming changes.
Refactor to resolve paint-only properties before painting, aiming to
stop using layout nodes during recording of painting commands.
Also adds a test, as we have not had any for outlines yet.
With this change, instead of applying only the border-radius clipping
from the closest containing block with hidden overflow, we now collect
all boxes within the containing block chain and apply the clipping from
all of them.
In this commit we have optimized the handling of scroll offsets and
clip rectangles to improve performance. Previously, the process
involved multiple full traversals of the paintable tree before each
repaint, which was highly inefficient, especially on pages with a
large number of paintables. The steps were:
1. Traverse the paintable tree to identify all boxes with scrollable or
clipped overflow.
2. Gather the accumulated scroll offset or clip rectangle for each box.
3. Perform another traversal to apply the corresponding scroll offset
and clip rectangle to each paintable.
To address this, we've adopted a new strategy that separates the
assignment of the scroll/clip frame from the refresh of accumulated
scroll offsets and clip rectangles, thus reducing the workload:
1. Post-relayout: Identify all boxes with overflow and link each
paintable to the state of its containing scroll/clip frame.
2. Pre-repaint: Update the clip rectangle and scroll offset only in the
previously identified boxes.
This adjustment ensures that the costly tree traversals are only
necessary after a relayout, substantially decreasing the amount of work
required before each repaint.
This change addresses an issue with overflow clipping in scenarios
where `overflow: hidden` is applied to boxes nested within elements
with `overflow: scroll`.
Fixes https://github.com/SerenityOS/serenity/issues/22733
This change makes hit-testing more consistent in the handling of hidden
overflow by reusing the same clip-rectangles.
Also, it fixes bugs where the box is visible for hit-testing even
though it is clipped by the hidden overflow of the containing block.
Hit-testing relies on updated clip rectangles and containing scroll
offsets, so it's necessary to ensure that paintables have these elements
updated.
This also removes the enclosing scroll offsets update from
`Internals::hit_test()`, as it is no longer needed.
Paintable boxes should not hold information stored in device pixels.
It should be converted from CSS pixels only by the time painting
command recording occurs.
The hit-testing position is now shifted by the scroll offsets before
performing any checks for containment. This is implemented by assigning
each PaintableBox/InlinePaintable an offset corresponding to the scroll
frame in which it is contained. The non-scroll-adjusted position is
still passed down when recursing to children because the assigned
offset accumulated for nested scroll frames.
With this change, hit testing works in the Inspector.
Fixes https://github.com/SerenityOS/serenity/issues/22068
This is a fix for regression introduced in
0bf82f748f
All CSS transforms need to be removed from the clip rectangle before
applying it. However, it is still necessary to calculate it with
applied transforms to find the correct intersection of all clip
rectangles in the containing block chain.
With this change, clip rectangles for boxes with hidden overflow or the
clip property are no longer calculated during the recording of painting
commands. Instead, it has moved to the "pre-paint" phase, along with
the assignment of scrolling offsets, and works in the following way:
1. The paintable tree is traversed to collect all paintable boxes that
have hidden overflow or use the CSS clip property. For each of these
boxes, the "final" clip rectangle is calculated by intersecting clip
rectangles in the containing block chain for a box.
2. The paintable tree is traversed another time, and a clip rectangle
is assigned for each paintable box contained by a node with hidden
overflow or the clip property.
This way, clipping becomes much easier during the painting commands
recording phase, as it only concerns the use of already assigned clip
rectangles. The same approach is applied to handle scrolling offsets.
Also, clip rectangle calculation is now implemented more correctly, as
we no longer stop at the stacking context boundary while intersecting
clip rectangles in the containing block chain.
Fixes:
https://github.com/SerenityOS/serenity/issues/22932https://github.com/SerenityOS/serenity/issues/22883https://github.com/SerenityOS/serenity/issues/22679https://github.com/SerenityOS/serenity/issues/22534
This change introduces a method for direct access to the paintable of
a PaintableFragment. This method is intended to replace the usage of
the layout node pointer. Currently, we are only eliminating the use
of `layout_node()` in hit testing.
Additionally, we no longer check if a fragment's layout node is a
`BlockContainer` before recursing into its children during hit testing.
This check was likely relevant when all fragments were owned by
`PaintableWithLines`, but now it should be safe to remove this check.
The paintable tree structure more closely matches the painting order
when fragments are owned by corresponding inline paintables. This
change does not affect the layout tree, as it is more convenient for
layout purposes to have all fragments owned by a block container in
one place.
Additionally, this improves performance significantly on pages with
many fragments, as we no longer have to walk the ancestor chain up
to the closest block container to determine if a fragment belongs
to an inline paintable.
Rather than resolving the text-shadow each time painting commands are
recorded, we can resolve it once during the layout commit and save the
resolved values in paintable fragments. This is also step towards
getting rid of layout node pointer in paintable fragment.
This is a part of refactoring towards making the paintable tree
independent of the layout tree. Now, instead of transferring text
fragments from the layout tree to the paintable tree during the layout
commit phase, we allocate separate PaintableFragments that contain only
the information necessary for painting. Doing this also allows us to
get rid LineBoxes, as they are used only during layout.
CSSPixels should not be wrapped into CSS::Length before being passed
to resolved() to end up resolving percentages without losing
precision.
Fixes thrashing layout when 33.3333% width is used together with
"box-sizing: border-box".
With this change, a stacking context can be established by any
paintable, including inline paintables. The stacking context traversal
is updated to remove the assumption that the stacking context root is
paintable box.
