mirrors/ladybird
1
0
Fork 0
mirror of https://github.com/LadybirdBrowser/ladybird.git synced 2025-04-21 12:05:15 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 10

LibWeb: Simplify determination of flex item's hypothetical cross size

Browse source 
The spec tells us to treat `auto` as `fit-content` when determining
flex item cross sizes, so let's just do *that* instead of awkwardly
doing an uncacheable nested layout of the item.

This was the only instance of `LayoutState` nesting outside of intrinsic
sizing, so removing it is an important step towards simplifying layout.
Turns out it was a lot easier than expected.
This commit is contained in:
Andreas Kling 2025-02-11 10:54:52 +01:00 • committed by Andreas Kling
parent 49c5c0bb8a
commit 4cbd975b66
Notes: github-actions[bot] 2025-02-11 13:24:12 +00:00
1 changed files with 8 additions and 41 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

49
Libraries/LibWeb/Layout/FlexFormattingContext.cpp
View file

@ -1093,12 +1093,7 @@ void FlexFormattingContext::determine_hypothetical_cross_size_of_item(FlexItem&
return;
}
auto computed_cross_size = [&]() -> CSS::Size {
// "... treating auto as fit-content"
if (should_treat_cross_size_as_auto(item.box))
return CSS::Size::make_fit_content();
return this->computed_cross_size(item.box);
}();
auto computed_cross_size = this->computed_cross_size(item.box);
if (computed_cross_size.is_min_content()) {
item.hypothetical_cross_size = css_clamp(calculate_min_content_cross_size(item), clamp_min, clamp_max);
@ -1110,44 +1105,16 @@ void FlexFormattingContext::determine_hypothetical_cross_size_of_item(FlexItem&
return;
}
if (computed_cross_size.is_fit_content()) {
CSSPixels fit_content_cross_size = 0;
if (is_row_layout()) {
auto available_width = item.main_size.has_value() ? AvailableSize::make_definite(item.main_size.value()) : AvailableSize::make_indefinite();
auto available_height = AvailableSize::make_indefinite();
fit_content_cross_size = calculate_fit_content_height(item.box, AvailableSpace(available_width, available_height));
} else {
fit_content_cross_size = calculate_fit_content_width(item.box, m_available_space_for_items->space);
}
item.hypothetical_cross_size = css_clamp(fit_content_cross_size, clamp_min, clamp_max);
return;
}
// For indefinite cross sizes, we perform a throwaway layout and then measure it.
LayoutState throwaway_state(&m_state);
auto& box_state = throwaway_state.get_mutable(item.box);
// "... treating auto as fit-content"
auto fit_content_cross_size = calculate_fit_content_cross_size(item);
if (is_row_layout()) {
box_state.set_content_width(item.main_size.value());
auto available_width = item.main_size.has_value() ? AvailableSize::make_definite(item.main_size.value()) : AvailableSize::make_indefinite();
auto available_height = AvailableSize::make_indefinite();
fit_content_cross_size = calculate_fit_content_height(item.box, AvailableSpace(available_width, available_height));
} else {
box_state.set_content_height(item.main_size.value());
fit_content_cross_size = calculate_fit_content_width(item.box, m_available_space_for_items->space);
}
// Item has definite main size, layout with that as the used main size.
auto independent_formatting_context = create_independent_formatting_context_if_needed(throwaway_state, LayoutMode::Normal, item.box);
// NOTE: Flex items should always create an independent formatting context!
VERIFY(independent_formatting_context);
auto available_width = is_row_layout() ? AvailableSize::make_definite(item.main_size.value()) : AvailableSize::make_indefinite();
auto available_height = is_row_layout() ? AvailableSize::make_indefinite() : AvailableSize::make_definite(item.main_size.value());
independent_formatting_context->run(AvailableSpace(available_width, available_height));
auto automatic_cross_size = is_row_layout() ? independent_formatting_context->automatic_content_height()
: independent_formatting_context->automatic_content_width();
item.hypothetical_cross_size = css_clamp(automatic_cross_size, clamp_min, clamp_max);
item.hypothetical_cross_size = css_clamp(fit_content_cross_size, clamp_min, clamp_max);
}
// https://www.w3.org/TR/css-flexbox-1/#algo-cross-line