mirror of
https://github.com/servo/servo.git
synced 2025-08-03 20:50:07 +01:00
layout 2020: Implement justify-content in flexbox
Align the items along the main-axis per justify-content.
This commit is contained in:
Pu Xingyu
parent
f29834608a
commit
debcd30b21
2 changed files with 61 additions and 19 deletions
|
|
@ -22,9 +22,11 @@ use style::properties::longhands::align_self::computed_value::T as AlignSelf;
|
|||
use style::properties::longhands::box_sizing::computed_value::T as BoxSizing;
|
||||
use style::properties::longhands::flex_direction::computed_value::T as FlexDirection;
|
||||
use style::properties::longhands::flex_wrap::computed_value::T as FlexWrap;
|
||||
use style::properties::longhands::justify_content::computed_value::T as JustifyContent;
|
||||
use style::values::computed::length::Size;
|
||||
use style::values::computed::Length;
|
||||
use style::values::generics::flex::GenericFlexBasis as FlexBasis;
|
||||
use style::values::CSSFloat;
|
||||
use style::Zero;
|
||||
|
||||
// FIMXE: “Flex items […] `z-index` values other than `auto` create a stacking context
|
||||
|
|
@ -45,6 +47,7 @@ struct FlexContext<'a> {
|
|||
main_start_cross_start_sides_are: MainStartCrossStart,
|
||||
container_definite_inner_size: FlexRelativeVec2<Option<Length>>,
|
||||
align_items: AlignItems,
|
||||
justify_content: JustifyContent,
|
||||
}
|
||||
|
||||
/// A flex item with some intermediate results
|
||||
|
|
@ -259,6 +262,7 @@ fn layout<'context, 'boxes>(
|
|||
FlexWrap::WrapReverse => true,
|
||||
};
|
||||
let align_items = containing_block.style.clone_align_items();
|
||||
let justify_content = containing_block.style.clone_justify_content();
|
||||
|
||||
let mut flex_context = FlexContext {
|
||||
layout_context,
|
||||
|
|
@ -269,6 +273,7 @@ fn layout<'context, 'boxes>(
|
|||
container_is_single_line,
|
||||
flex_axis,
|
||||
align_items,
|
||||
justify_content,
|
||||
main_start_cross_start_sides_are: MainStartCrossStart::from(
|
||||
flex_direction,
|
||||
flex_wrap_reverse,
|
||||
|
|
@ -669,10 +674,37 @@ impl FlexLine<'_> {
|
|||
|
||||
// Distribute any remaining free space
|
||||
// https://drafts.csswg.org/css-flexbox/#algo-main-align
|
||||
let item_main_margins = self.resolve_auto_main_margins(remaining_free_space);
|
||||
let (item_main_margins, free_space_distributed) =
|
||||
self.resolve_auto_main_margins(remaining_free_space);
|
||||
|
||||
// FIXME: “Align the items along the main-axis per justify-content.”
|
||||
// For now we hard-code `justify-content` to `flex-start`.
|
||||
// Align the items along the main-axis per justify-content.
|
||||
let item_count = self.items.len();
|
||||
let main_start_position = if free_space_distributed {
|
||||
Length::zero()
|
||||
} else {
|
||||
match flex_context.justify_content {
|
||||
JustifyContent::FlexEnd => remaining_free_space,
|
||||
JustifyContent::Center => remaining_free_space / 2.0,
|
||||
JustifyContent::SpaceAround => remaining_free_space / (item_count * 2) as CSSFloat,
|
||||
_ => Length::zero(),
|
||||
}
|
||||
};
|
||||
|
||||
let item_main_interval = if free_space_distributed {
|
||||
Length::zero()
|
||||
} else {
|
||||
match flex_context.justify_content {
|
||||
JustifyContent::SpaceBetween => {
|
||||
if item_count > 1 {
|
||||
remaining_free_space / (item_count - 1) as CSSFloat
|
||||
} else {
|
||||
Length::zero()
|
||||
}
|
||||
},
|
||||
JustifyContent::SpaceAround => remaining_free_space / item_count as CSSFloat,
|
||||
_ => Length::zero(),
|
||||
}
|
||||
};
|
||||
|
||||
// https://drafts.csswg.org/css-flexbox/#algo-cross-margins
|
||||
let item_cross_margins = self.items.iter().zip(&item_used_cross_sizes).map(
|
||||
|
|
@ -697,8 +729,12 @@ impl FlexLine<'_> {
|
|||
)
|
||||
.collect::<Vec<_>>();
|
||||
// https://drafts.csswg.org/css-flexbox/#algo-main-align
|
||||
let items_content_main_start_positions =
|
||||
self.align_along_main_axis(&item_used_main_sizes, &item_margins);
|
||||
let items_content_main_start_positions = self.align_along_main_axis(
|
||||
&item_used_main_sizes,
|
||||
&item_margins,
|
||||
main_start_position,
|
||||
item_main_interval,
|
||||
);
|
||||
|
||||
// https://drafts.csswg.org/css-flexbox/#algo-cross-align
|
||||
let item_content_cross_start_posititons = self
|
||||
|
|
@ -1029,11 +1065,12 @@ impl<'items> FlexLine<'items> {
|
|||
}
|
||||
|
||||
// Return the main-start and main-end margin of each item in the line,
|
||||
// with `auto` values resolved.
|
||||
// with `auto` values resolved,
|
||||
// and return whether free space has been distributed.
|
||||
fn resolve_auto_main_margins(
|
||||
&self,
|
||||
remaining_free_space: Length,
|
||||
) -> impl Iterator<Item = (Length, Length)> + '_ {
|
||||
) -> (impl Iterator<Item = (Length, Length)> + '_, bool) {
|
||||
let each_auto_margin = if remaining_free_space > Length::zero() {
|
||||
let auto_margins_count = self
|
||||
.items
|
||||
|
|
@ -1050,12 +1087,15 @@ impl<'items> FlexLine<'items> {
|
|||
} else {
|
||||
Length::zero()
|
||||
};
|
||||
self.items.iter().map(move |item| {
|
||||
(
|
||||
item.margin.main_start.auto_is(|| each_auto_margin),
|
||||
item.margin.main_end.auto_is(|| each_auto_margin),
|
||||
)
|
||||
})
|
||||
(
|
||||
self.items.iter().map(move |item| {
|
||||
(
|
||||
item.margin.main_start.auto_is(|| each_auto_margin),
|
||||
item.margin.main_end.auto_is(|| each_auto_margin),
|
||||
)
|
||||
}),
|
||||
each_auto_margin > Length::zero(),
|
||||
)
|
||||
}
|
||||
|
||||
/// Return the coordinate of the main-start side of the content area of each item
|
||||
|
|
@ -1063,11 +1103,11 @@ impl<'items> FlexLine<'items> {
|
|||
&'a self,
|
||||
item_used_main_sizes: &'a [Length],
|
||||
item_margins: &'a [FlexRelativeSides<Length>],
|
||||
main_start_position: Length,
|
||||
item_main_interval: Length,
|
||||
) -> impl Iterator<Item = Length> + 'a {
|
||||
// “Align the items along the main-axis”
|
||||
// FIXME: “per justify-content.”
|
||||
// For now we hard-code the behavior for `justify-content: flex-start`.
|
||||
let mut main_position_cursor = Length::zero();
|
||||
let mut main_position_cursor = main_start_position;
|
||||
self.items
|
||||
.iter()
|
||||
.zip(item_used_main_sizes)
|
||||
|
|
@ -1079,7 +1119,8 @@ impl<'items> FlexLine<'items> {
|
|||
main_position_cursor += main_content_size +
|
||||
item.padding.main_end +
|
||||
item.border.main_end +
|
||||
margin.main_end;
|
||||
margin.main_end +
|
||||
item_main_interval;
|
||||
content_main_start_position
|
||||
})
|
||||
}
|
||||
|
|
|
|||
|
|
@ -92,12 +92,13 @@ ${helpers.single_keyword(
|
|||
gecko_enum_prefix = "StyleFlexWrap",
|
||||
)}
|
||||
|
||||
% if engine == "servo-2013":
|
||||
% if engine in ["servo-2013", "servo-2020"]:
|
||||
// FIXME: Update Servo to support the same Syntax as Gecko.
|
||||
${helpers.single_keyword(
|
||||
"justify-content",
|
||||
"flex-start stretch flex-end center space-between space-around",
|
||||
engines="servo-2013",
|
||||
engines="servo-2013 servo-2020",
|
||||
servo_2020_pref="layout.flexbox.enabled",
|
||||
extra_prefixes="webkit",
|
||||
spec="https://drafts.csswg.org/css-align/#propdef-justify-content",
|
||||
animation_value_type="discrete",
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue