diff options
Diffstat (limited to 'components')
| -rw-r--r-- | components/layout_2020/positioned.rs | 62 |
1 files changed, 42 insertions, 20 deletions
diff --git a/components/layout_2020/positioned.rs b/components/layout_2020/positioned.rs index f9e5671e9db..7c3c2588d7c 100644 --- a/components/layout_2020/positioned.rs +++ b/components/layout_2020/positioned.rs @@ -833,7 +833,11 @@ impl<'a> AbsoluteAxisSolver<'a> { self.box_offsets.end.non_auto(), ) { (None, None) => solve_for_anchor(if self.flip_anchor { - Anchor::End(self.containing_size - self.static_position_rect_axis.origin) + Anchor::End( + self.containing_size - + self.static_position_rect_axis.origin - + self.static_position_rect_axis.length, + ) } else { Anchor::Start(self.static_position_rect_axis.origin) }), @@ -911,40 +915,58 @@ impl<'a> AbsoluteAxisSolver<'a> { } fn origin_for_alignment_or_justification(&self, margin_box_axis: RectAxis) -> Option<Au> { - let alignment_container = match ( + let (alignment_container, flip_anchor) = match ( self.box_offsets.start.non_auto(), self.box_offsets.end.non_auto(), ) { - (None, None) => self.static_position_rect_axis, + (None, None) => (self.static_position_rect_axis, self.flip_anchor), (Some(start), Some(end)) => { let start = start.to_used_value(self.containing_size); let end = end.to_used_value(self.containing_size); - - RectAxis { + let alignment_container = RectAxis { origin: start, length: self.containing_size - (end + start), - } + }; + (alignment_container, false) }, _ => return None, }; - let mut value_after_safety = self.alignment.value(); - if self.alignment.flags() == AlignFlags::SAFE && - margin_box_axis.length > alignment_container.length + // Here we resolve the alignment to either start, center, or end. + // Note we need to handle both self-alignment values (when some inset isn't auto) + // and distributed alignment values (when both insets are auto). + // The latter are treated as their fallback alignment. + let alignment = match self.alignment.value() { + // https://drafts.csswg.org/css-align/#valdef-self-position-end + // https://drafts.csswg.org/css-align/#valdef-self-position-flex-end + AlignFlags::END | AlignFlags::FLEX_END => AlignFlags::END, + // https://drafts.csswg.org/css-align/#valdef-self-position-center + // https://drafts.csswg.org/css-align/#valdef-align-content-space-around + // https://drafts.csswg.org/css-align/#valdef-align-content-space-evenly + AlignFlags::CENTER | AlignFlags::SPACE_AROUND | AlignFlags::SPACE_EVENLY => { + AlignFlags::CENTER + }, + // TODO(#34282): handle missing values: self-start, self-end, left, right. + _ => AlignFlags::START, + }; + + if alignment == AlignFlags::START || + self.alignment.flags() == AlignFlags::SAFE && + margin_box_axis.length > alignment_container.length { - value_after_safety = AlignFlags::START; + // Aligning to start is no-op, so just return `None`. This should be equivalent + // to returning `Some(alignment_container.origin + free_space)` if `flip_anchor`, + // or `Some(alignment_container.origin)` otherwise. + return None; } - match value_after_safety { - AlignFlags::CENTER | AlignFlags::SPACE_AROUND | AlignFlags::SPACE_EVENLY => Some( - alignment_container.origin + - ((alignment_container.length - margin_box_axis.length) / 2), - ), - AlignFlags::FLEX_END | AlignFlags::END => Some( - alignment_container.origin + alignment_container.length - margin_box_axis.length, - ), - _ => None, - } + let free_space = alignment_container.length - margin_box_axis.length; + Some(match alignment { + AlignFlags::CENTER => alignment_container.origin + free_space / 2, + AlignFlags::END if flip_anchor => alignment_container.origin, + AlignFlags::END => alignment_container.origin + free_space, + _ => unreachable!(), + }) } fn solve_alignment( |