use crate::geometry::{Line, Point, Rect, Size};
use crate::style::{AvailableSpace, Display, LengthPercentageAuto, Overflow, Position};
use crate::style_helpers::TaffyMaxContent;
use crate::tree::{CollapsibleMarginSet, Layout, LayoutInput, LayoutOutput, RunMode, SizingMode};
use crate::tree::{NodeId, PartialLayoutTree, PartialLayoutTreeExt};
use crate::util::debug::debug_log;
use crate::util::sys::f32_max;
use crate::util::sys::Vec;
use crate::util::MaybeMath;
use crate::util::{MaybeResolve, ResolveOrZero};
#[cfg(feature = "content_size")]
use super::common::content_size::compute_content_size_contribution;
struct BlockItem {
node_id: NodeId,
order: u32,
size: Size<Option<f32>>,
min_size: Size<Option<f32>>,
max_size: Size<Option<f32>>,
overflow: Point<Overflow>,
scrollbar_width: f32,
position: Position,
inset: Rect<LengthPercentageAuto>,
margin: Rect<LengthPercentageAuto>,
padding: Rect<f32>,
border: Rect<f32>,
padding_border_sum: Size<f32>,
computed_size: Size<f32>,
static_position: Point<f32>,
can_be_collapsed_through: bool,
}
pub fn compute_block_layout(tree: &mut impl PartialLayoutTree, node_id: NodeId, inputs: LayoutInput) -> LayoutOutput {
let LayoutInput { known_dimensions, parent_size, available_space, run_mode, .. } = inputs;
let style = tree.get_style(node_id);
let aspect_ratio = style.aspect_ratio;
let margin = style.margin.resolve_or_zero(parent_size.width);
let min_size = style.min_size.maybe_resolve(parent_size).maybe_apply_aspect_ratio(aspect_ratio);
let max_size = style.max_size.maybe_resolve(parent_size).maybe_apply_aspect_ratio(aspect_ratio);
let padding = style.padding.resolve_or_zero(parent_size.width);
let border = style.border.resolve_or_zero(parent_size.width);
let padding_border_size = (padding + border).sum_axes();
let clamped_style_size = if inputs.sizing_mode == SizingMode::InherentSize {
style.size.maybe_resolve(parent_size).maybe_apply_aspect_ratio(aspect_ratio).maybe_clamp(min_size, max_size)
} else {
Size::NONE
};
let min_max_definite_size = min_size.zip_map(max_size, |min, max| match (min, max) {
(Some(min), Some(max)) if max <= min => Some(min),
_ => None,
});
let available_space_based_size =
Size { width: available_space.width.into_option().maybe_sub(margin.horizontal_axis_sum()), height: None };
let styled_based_known_dimensions = known_dimensions
.or(min_max_definite_size)
.or(clamped_style_size)
.or(available_space_based_size)
.maybe_max(padding_border_size);
if run_mode == RunMode::ComputeSize {
if let Size { width: Some(width), height: Some(height) } = styled_based_known_dimensions {
return LayoutOutput::from_outer_size(Size { width, height });
}
}
debug_log!("BLOCK");
compute_inner(tree, node_id, LayoutInput { known_dimensions: styled_based_known_dimensions, ..inputs })
}
fn compute_inner(tree: &mut impl PartialLayoutTree, node_id: NodeId, inputs: LayoutInput) -> LayoutOutput {
let LayoutInput {
known_dimensions, parent_size, available_space, run_mode, vertical_margins_are_collapsible, ..
} = inputs;
let style = tree.get_style(node_id);
let raw_padding = style.padding;
let raw_border = style.border;
let raw_margin = style.margin;
let aspect_ratio = style.aspect_ratio;
let size = style.size.maybe_resolve(parent_size).maybe_apply_aspect_ratio(aspect_ratio);
let min_size = style.min_size.maybe_resolve(parent_size).maybe_apply_aspect_ratio(aspect_ratio);
let max_size = style.max_size.maybe_resolve(parent_size).maybe_apply_aspect_ratio(aspect_ratio);
let padding = style.padding.resolve_or_zero(parent_size.width);
let border = style.border.resolve_or_zero(parent_size.width);
let scrollbar_gutter = {
let offsets = style.overflow.transpose().map(|overflow| match overflow {
Overflow::Scroll => style.scrollbar_width,
_ => 0.0,
});
Rect { top: 0.0, left: 0.0, right: offsets.x, bottom: offsets.y }
};
let padding_border = padding + border;
let padding_border_size = padding_border.sum_axes();
let content_box_inset = padding_border + scrollbar_gutter;
let container_content_box_size = known_dimensions.maybe_sub(content_box_inset.sum_axes());
let own_margins_collapse_with_children = Line {
start: vertical_margins_are_collapsible.start
&& !style.overflow.x.is_scroll_container()
&& !style.overflow.y.is_scroll_container()
&& style.position == Position::Relative
&& padding.top == 0.0
&& border.top == 0.0,
end: vertical_margins_are_collapsible.end
&& !style.overflow.x.is_scroll_container()
&& !style.overflow.y.is_scroll_container()
&& style.position == Position::Relative
&& padding.bottom == 0.0
&& border.bottom == 0.0
&& size.height.is_none(),
};
let has_styles_preventing_being_collapsed_through = style.display != Display::Block
|| style.overflow.x.is_scroll_container()
|| style.overflow.y.is_scroll_container()
|| style.position == Position::Absolute
|| padding.top > 0.0
|| padding.bottom > 0.0
|| border.top > 0.0
|| border.bottom > 0.0;
let mut items = generate_item_list(tree, node_id, container_content_box_size);
let container_outer_width = known_dimensions.width.unwrap_or_else(|| {
let available_width = available_space.width.maybe_sub(content_box_inset.horizontal_axis_sum());
let intrinsic_width = determine_content_based_container_width(tree, &items, available_width)
+ content_box_inset.horizontal_axis_sum();
intrinsic_width.maybe_clamp(min_size.width, max_size.width).maybe_max(Some(padding_border_size.width))
});
if let (RunMode::ComputeSize, Some(container_outer_height)) = (run_mode, known_dimensions.height) {
return LayoutOutput::from_outer_size(Size { width: container_outer_width, height: container_outer_height });
}
let resolved_padding = raw_padding.resolve_or_zero(Some(container_outer_width));
let resolved_border = raw_border.resolve_or_zero(Some(container_outer_width));
let resolved_content_box_inset = resolved_padding + resolved_border + scrollbar_gutter;
let (inflow_content_size, intrinsic_outer_height, first_child_top_margin_set, last_child_bottom_margin_set) =
perform_final_layout_on_in_flow_children(
tree,
&mut items,
container_outer_width,
content_box_inset,
resolved_content_box_inset,
own_margins_collapse_with_children,
);
let container_outer_height = known_dimensions
.height
.unwrap_or(intrinsic_outer_height.maybe_clamp(min_size.height, max_size.height))
.maybe_max(Some(padding_border_size.height));
let final_outer_size = Size { width: container_outer_width, height: container_outer_height };
if run_mode == RunMode::ComputeSize {
return LayoutOutput::from_outer_size(final_outer_size);
}
let absolute_position_inset = resolved_border + scrollbar_gutter;
let absolute_position_area = final_outer_size - absolute_position_inset.sum_axes();
let absolute_position_offset = Point { x: absolute_position_inset.left, y: absolute_position_inset.top };
let absolute_content_size =
perform_absolute_layout_on_absolute_children(tree, &items, absolute_position_area, absolute_position_offset);
let len = tree.child_count(node_id);
for order in 0..len {
let child = tree.get_child_id(node_id, order);
if tree.get_style(child).display == Display::None {
tree.set_unrounded_layout(child, &Layout::with_order(order as u32));
tree.perform_child_layout(
child,
Size::NONE,
Size::NONE,
Size::MAX_CONTENT,
SizingMode::InherentSize,
Line::FALSE,
);
}
}
let all_in_flow_children_can_be_collapsed_through =
items.iter().all(|item| item.position == Position::Absolute || item.can_be_collapsed_through);
let can_be_collapsed_through =
!has_styles_preventing_being_collapsed_through && all_in_flow_children_can_be_collapsed_through;
#[cfg_attr(not(feature = "content_size"), allow(unused_variables))]
let content_size = inflow_content_size.f32_max(absolute_content_size);
LayoutOutput {
size: final_outer_size,
#[cfg(feature = "content_size")]
content_size,
first_baselines: Point::NONE,
top_margin: if own_margins_collapse_with_children.start {
first_child_top_margin_set
} else {
let margin_top = raw_margin.top.resolve_or_zero(parent_size.width);
CollapsibleMarginSet::from_margin(margin_top)
},
bottom_margin: if own_margins_collapse_with_children.end {
last_child_bottom_margin_set
} else {
let margin_bottom = raw_margin.bottom.resolve_or_zero(parent_size.width);
CollapsibleMarginSet::from_margin(margin_bottom)
},
margins_can_collapse_through: can_be_collapsed_through,
}
}
#[inline]
fn generate_item_list(
tree: &impl PartialLayoutTree,
node: NodeId,
node_inner_size: Size<Option<f32>>,
) -> Vec<BlockItem> {
tree.child_ids(node)
.map(|child_node_id| (child_node_id, tree.get_style(child_node_id)))
.filter(|(_, style)| style.display != Display::None)
.enumerate()
.map(|(order, (child_node_id, child_style))| {
let aspect_ratio = child_style.aspect_ratio;
let padding = child_style.padding.resolve_or_zero(node_inner_size);
let border = child_style.border.resolve_or_zero(node_inner_size);
BlockItem {
node_id: child_node_id,
order: order as u32,
size: child_style.size.maybe_resolve(node_inner_size).maybe_apply_aspect_ratio(aspect_ratio),
min_size: child_style.min_size.maybe_resolve(node_inner_size).maybe_apply_aspect_ratio(aspect_ratio),
max_size: child_style.max_size.maybe_resolve(node_inner_size).maybe_apply_aspect_ratio(aspect_ratio),
overflow: child_style.overflow,
scrollbar_width: child_style.scrollbar_width,
position: child_style.position,
inset: child_style.inset,
margin: child_style.margin,
padding,
border,
padding_border_sum: (padding + border).sum_axes(),
computed_size: Size::zero(),
static_position: Point::zero(),
can_be_collapsed_through: false,
}
})
.collect()
}
#[inline]
fn determine_content_based_container_width(
tree: &mut impl PartialLayoutTree,
items: &[BlockItem],
available_width: AvailableSpace,
) -> f32 {
let available_space = Size { width: available_width, height: AvailableSpace::MinContent };
let mut max_child_width = 0.0;
for item in items.iter().filter(|item| item.position != Position::Absolute) {
let known_dimensions = item.size.maybe_clamp(item.min_size, item.max_size);
let width = known_dimensions.width.unwrap_or_else(|| {
let item_x_margin_sum =
item.margin.resolve_or_zero(available_space.width.into_option()).horizontal_axis_sum();
let size_and_baselines = tree.perform_child_layout(
item.node_id,
known_dimensions,
Size::NONE,
available_space.map_width(|w| w.maybe_sub(item_x_margin_sum)),
SizingMode::InherentSize,
Line::TRUE,
);
size_and_baselines.size.width + item_x_margin_sum
});
let width = f32_max(width, item.padding_border_sum.width);
max_child_width = f32_max(max_child_width, width);
}
max_child_width
}
#[inline]
fn perform_final_layout_on_in_flow_children(
tree: &mut impl PartialLayoutTree,
items: &mut [BlockItem],
container_outer_width: f32,
content_box_inset: Rect<f32>,
resolved_content_box_inset: Rect<f32>,
own_margins_collapse_with_children: Line<bool>,
) -> (Size<f32>, f32, CollapsibleMarginSet, CollapsibleMarginSet) {
let container_inner_width = container_outer_width - content_box_inset.horizontal_axis_sum();
let parent_size = Size { width: Some(container_outer_width), height: None };
let available_space =
Size { width: AvailableSpace::Definite(container_inner_width), height: AvailableSpace::MinContent };
#[cfg_attr(not(feature = "content_size"), allow(unused_mut))]
let mut inflow_content_size = Size::ZERO;
let mut committed_y_offset = resolved_content_box_inset.top;
let mut first_child_top_margin_set = CollapsibleMarginSet::ZERO;
let mut active_collapsible_margin_set = CollapsibleMarginSet::ZERO;
let mut is_collapsing_with_first_margin_set = true;
for item in items.iter_mut() {
if item.position == Position::Absolute {
item.static_position.y = committed_y_offset;
} else {
let item_margin = item.margin.map(|margin| margin.resolve_to_option(container_outer_width));
let item_non_auto_margin = item_margin.map(|m| m.unwrap_or(0.0));
let item_non_auto_x_margin_sum = item_non_auto_margin.horizontal_axis_sum();
let known_dimensions = item
.size
.map_width(|width| Some(width.unwrap_or(container_inner_width - item_non_auto_x_margin_sum)))
.maybe_clamp(item.min_size, item.max_size);
let item_layout = tree.perform_child_layout(
item.node_id,
known_dimensions,
parent_size,
available_space.map_width(|w| w.maybe_sub(item_non_auto_x_margin_sum)),
SizingMode::InherentSize,
Line::TRUE,
);
let final_size = item_layout.size;
let top_margin_set = item_layout.top_margin.collapse_with_margin(item_margin.top.unwrap_or(0.0));
let bottom_margin_set = item_layout.bottom_margin.collapse_with_margin(item_margin.bottom.unwrap_or(0.0));
let free_x_space = f32_max(0.0, container_inner_width - final_size.width - item_non_auto_x_margin_sum);
let x_axis_auto_margin_size = {
let auto_margin_count = item_margin.left.is_none() as u8 + item_margin.right.is_none() as u8;
if auto_margin_count == 2 && item.size.width.is_none() {
0.0
} else if auto_margin_count > 0 {
free_x_space / auto_margin_count as f32
} else {
0.0
}
};
let resolved_margin = Rect {
left: item_margin.left.unwrap_or(x_axis_auto_margin_size),
right: item_margin.right.unwrap_or(x_axis_auto_margin_size),
top: top_margin_set.resolve(),
bottom: bottom_margin_set.resolve(),
};
let inset =
item.inset.zip_size(Size { width: container_inner_width, height: 0.0 }, |p, s| p.maybe_resolve(s));
let inset_offset = Point {
x: inset.left.or(inset.right.map(|x| -x)).unwrap_or(0.0),
y: inset.top.or(inset.bottom.map(|x| -x)).unwrap_or(0.0),
};
let y_margin_offset = if is_collapsing_with_first_margin_set && own_margins_collapse_with_children.start {
0.0
} else {
active_collapsible_margin_set.collapse_with_margin(resolved_margin.top).resolve()
};
item.computed_size = item_layout.size;
item.can_be_collapsed_through = item_layout.margins_can_collapse_through;
item.static_position = Point {
x: resolved_content_box_inset.left,
y: committed_y_offset + active_collapsible_margin_set.resolve(),
};
let location = Point {
x: resolved_content_box_inset.left + inset_offset.x + resolved_margin.left,
y: committed_y_offset + inset_offset.y + y_margin_offset,
};
let scrollbar_size = Size {
width: if item.overflow.y == Overflow::Scroll { item.scrollbar_width } else { 0.0 },
height: if item.overflow.x == Overflow::Scroll { item.scrollbar_width } else { 0.0 },
};
tree.set_unrounded_layout(
item.node_id,
&Layout {
order: item.order,
size: item_layout.size,
#[cfg(feature = "content_size")]
content_size: item_layout.content_size,
scrollbar_size,
location,
padding: item.padding,
border: item.border,
},
);
#[cfg(feature = "content_size")]
{
inflow_content_size = inflow_content_size.f32_max(compute_content_size_contribution(
location,
final_size,
item_layout.content_size,
item.overflow,
));
}
if is_collapsing_with_first_margin_set {
if item.can_be_collapsed_through {
first_child_top_margin_set = first_child_top_margin_set
.collapse_with_set(top_margin_set)
.collapse_with_set(bottom_margin_set);
} else {
first_child_top_margin_set = first_child_top_margin_set.collapse_with_set(top_margin_set);
is_collapsing_with_first_margin_set = false;
}
}
if item.can_be_collapsed_through {
active_collapsible_margin_set = active_collapsible_margin_set
.collapse_with_set(top_margin_set)
.collapse_with_set(bottom_margin_set);
} else {
committed_y_offset += item_layout.size.height + y_margin_offset;
active_collapsible_margin_set = bottom_margin_set;
}
}
}
let last_child_bottom_margin_set = active_collapsible_margin_set;
let bottom_y_margin_offset =
if own_margins_collapse_with_children.end { 0.0 } else { last_child_bottom_margin_set.resolve() };
committed_y_offset += resolved_content_box_inset.bottom + bottom_y_margin_offset;
let content_height = f32_max(0.0, committed_y_offset);
(inflow_content_size, content_height, first_child_top_margin_set, last_child_bottom_margin_set)
}
#[inline]
fn perform_absolute_layout_on_absolute_children(
tree: &mut impl PartialLayoutTree,
items: &[BlockItem],
area_size: Size<f32>,
area_offset: Point<f32>,
) -> Size<f32> {
let area_width = area_size.width;
let area_height = area_size.height;
#[cfg_attr(not(feature = "content_size"), allow(unused_mut))]
let mut absolute_content_size = Size::ZERO;
for item in items.iter().filter(|item| item.position == Position::Absolute) {
let child_style = tree.get_style(item.node_id);
if child_style.display == Display::None || child_style.position != Position::Absolute {
continue;
}
let aspect_ratio = child_style.aspect_ratio;
let margin = child_style.margin.map(|margin| margin.resolve_to_option(area_width));
let padding = child_style.padding.resolve_or_zero(Some(area_width));
let border = child_style.border.resolve_or_zero(Some(area_width));
let padding_border_sum = (padding + border).sum_axes();
let left = child_style.inset.left.maybe_resolve(area_width);
let right = child_style.inset.right.maybe_resolve(area_width);
let top = child_style.inset.top.maybe_resolve(area_height);
let bottom = child_style.inset.bottom.maybe_resolve(area_height);
let style_size = child_style.size.maybe_resolve(area_size).maybe_apply_aspect_ratio(aspect_ratio);
let min_size = child_style
.min_size
.maybe_resolve(area_size)
.maybe_apply_aspect_ratio(aspect_ratio)
.or(padding_border_sum.map(Some))
.maybe_max(padding_border_sum);
let max_size = child_style.max_size.maybe_resolve(area_size).maybe_apply_aspect_ratio(aspect_ratio);
let mut known_dimensions = style_size.maybe_clamp(min_size, max_size);
if let (None, Some(left), Some(right)) = (known_dimensions.width, left, right) {
let new_width_raw = area_width.maybe_sub(margin.left).maybe_sub(margin.right) - left - right;
known_dimensions.width = Some(f32_max(new_width_raw, 0.0));
known_dimensions = known_dimensions.maybe_apply_aspect_ratio(aspect_ratio).maybe_clamp(min_size, max_size);
}
if let (None, Some(top), Some(bottom)) = (known_dimensions.height, top, bottom) {
let new_height_raw = area_height.maybe_sub(margin.top).maybe_sub(margin.bottom) - top - bottom;
known_dimensions.height = Some(f32_max(new_height_raw, 0.0));
known_dimensions = known_dimensions.maybe_apply_aspect_ratio(aspect_ratio).maybe_clamp(min_size, max_size);
}
let layout_output = tree.perform_child_layout(
item.node_id,
known_dimensions,
area_size.map(Some),
Size {
width: AvailableSpace::Definite(area_width.maybe_clamp(min_size.width, max_size.width)),
height: AvailableSpace::Definite(area_height.maybe_clamp(min_size.height, max_size.height)),
},
SizingMode::ContentSize,
Line::FALSE,
);
let measured_size = layout_output.size;
let final_size = known_dimensions.unwrap_or(measured_size).maybe_clamp(min_size, max_size);
let non_auto_margin = Rect {
left: if left.is_some() { margin.left.unwrap_or(0.0) } else { 0.0 },
right: if right.is_some() { margin.right.unwrap_or(0.0) } else { 0.0 },
top: if top.is_some() { margin.top.unwrap_or(0.0) } else { 0.0 },
bottom: if bottom.is_some() { margin.left.unwrap_or(0.0) } else { 0.0 },
};
let auto_margin = {
let absolute_auto_margin_space = Point {
x: right.map(|right| area_size.width - right - left.unwrap_or(0.0)).unwrap_or(final_size.width),
y: bottom.map(|bottom| area_size.height - bottom - top.unwrap_or(0.0)).unwrap_or(final_size.height),
};
let free_space = Size {
width: absolute_auto_margin_space.x - final_size.width - non_auto_margin.horizontal_axis_sum(),
height: absolute_auto_margin_space.y - final_size.height - non_auto_margin.vertical_axis_sum(),
};
let auto_margin_size = Size {
width: {
let auto_margin_count = margin.left.is_none() as u8 + margin.right.is_none() as u8;
if auto_margin_count == 2
&& (style_size.width.is_none() || style_size.width.unwrap() >= free_space.width)
{
0.0
} else if auto_margin_count > 0 {
free_space.width / auto_margin_count as f32
} else {
0.0
}
},
height: {
let auto_margin_count = margin.top.is_none() as u8 + margin.bottom.is_none() as u8;
if auto_margin_count == 2
&& (style_size.height.is_none() || style_size.height.unwrap() >= free_space.height)
{
0.0
} else if auto_margin_count > 0 {
free_space.height / auto_margin_count as f32
} else {
0.0
}
},
};
Rect {
left: margin.left.map(|_| 0.0).unwrap_or(auto_margin_size.width),
right: margin.right.map(|_| 0.0).unwrap_or(auto_margin_size.width),
top: margin.top.map(|_| 0.0).unwrap_or(auto_margin_size.height),
bottom: margin.bottom.map(|_| 0.0).unwrap_or(auto_margin_size.height),
}
};
let resolved_margin = Rect {
left: margin.left.unwrap_or(auto_margin.left),
right: margin.right.unwrap_or(auto_margin.right),
top: margin.top.unwrap_or(auto_margin.top),
bottom: margin.bottom.unwrap_or(auto_margin.bottom),
};
let item_offset = Point {
x: left
.map(|left| left + resolved_margin.left)
.or(right.map(|right| area_size.width - final_size.width - right - resolved_margin.right))
.unwrap_or(resolved_margin.left),
y: top
.map(|top| top + resolved_margin.top)
.or(bottom.map(|bottom| area_size.height - final_size.height - bottom - resolved_margin.bottom))
.unwrap_or(item.static_position.y + resolved_margin.top),
};
let scrollbar_size = Size {
width: if item.overflow.y == Overflow::Scroll { item.scrollbar_width } else { 0.0 },
height: if item.overflow.x == Overflow::Scroll { item.scrollbar_width } else { 0.0 },
};
let location = area_offset + item_offset;
tree.set_unrounded_layout(
item.node_id,
&Layout {
order: item.order,
size: final_size,
#[cfg(feature = "content_size")]
content_size: layout_output.content_size,
scrollbar_size,
location,
padding,
border,
},
);
#[cfg(feature = "content_size")]
{
absolute_content_size = absolute_content_size.f32_max(compute_content_size_contribution(
location,
final_size,
layout_output.content_size,
item.overflow,
));
}
}
absolute_content_size
}