servo/components/layout/table_wrapper.rs
2014-09-08 20:21:42 -06:00

325 lines
14 KiB
Rust

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
//! CSS table formatting contexts.
#![deny(unsafe_block)]
use block::{BlockFlow, MarginsMayNotCollapse, ISizeAndMarginsComputer};
use block::{ISizeConstraintInput, ISizeConstraintSolution};
use construct::FlowConstructor;
use context::LayoutContext;
use floats::FloatKind;
use flow::{TableWrapperFlowClass, FlowClass, Flow, ImmutableFlowUtils};
use fragment::Fragment;
use model::{Specified, Auto, specified};
use wrapper::ThreadSafeLayoutNode;
use servo_util::geometry::Au;
use servo_util::geometry;
use std::fmt;
use style::computed_values::table_layout;
pub enum TableLayout {
FixedLayout,
AutoLayout
}
/// A table wrapper flow based on a block formatting context.
pub struct TableWrapperFlow {
pub block_flow: BlockFlow,
/// Column inline-sizes
pub col_inline_sizes: Vec<Au>,
/// Table-layout property
pub table_layout: TableLayout,
}
impl TableWrapperFlow {
pub fn from_node_and_fragment(node: &ThreadSafeLayoutNode,
fragment: Fragment)
-> TableWrapperFlow {
let mut block_flow = BlockFlow::from_node_and_fragment(node, fragment);
let table_layout = if block_flow.fragment().style().get_table().table_layout ==
table_layout::fixed {
FixedLayout
} else {
AutoLayout
};
TableWrapperFlow {
block_flow: block_flow,
col_inline_sizes: vec!(),
table_layout: table_layout
}
}
pub fn from_node(constructor: &mut FlowConstructor,
node: &ThreadSafeLayoutNode)
-> TableWrapperFlow {
let mut block_flow = BlockFlow::from_node(constructor, node);
let table_layout = if block_flow.fragment().style().get_table().table_layout ==
table_layout::fixed {
FixedLayout
} else {
AutoLayout
};
TableWrapperFlow {
block_flow: block_flow,
col_inline_sizes: vec!(),
table_layout: table_layout
}
}
pub fn float_from_node(constructor: &mut FlowConstructor,
node: &ThreadSafeLayoutNode,
float_kind: FloatKind)
-> TableWrapperFlow {
let mut block_flow = BlockFlow::float_from_node(constructor, node, float_kind);
let table_layout = if block_flow.fragment().style().get_table().table_layout ==
table_layout::fixed {
FixedLayout
} else {
AutoLayout
};
TableWrapperFlow {
block_flow: block_flow,
col_inline_sizes: vec!(),
table_layout: table_layout
}
}
pub fn is_float(&self) -> bool {
self.block_flow.float.is_some()
}
/// Assign block-size for table-wrapper flow.
/// `Assign block-size` of table-wrapper flow follows a similar process to that of block flow.
///
/// inline(always) because this is only ever called by in-order or non-in-order top-level
/// methods
#[inline(always)]
fn assign_block_size_table_wrapper_base<'a>(&mut self, layout_context: &'a LayoutContext<'a>) {
self.block_flow.assign_block_size_block_base(layout_context, MarginsMayNotCollapse);
}
pub fn build_display_list_table_wrapper(&mut self, layout_context: &LayoutContext) {
debug!("build_display_list_table_wrapper: same process as block flow");
self.block_flow.build_display_list_block(layout_context);
}
}
impl Flow for TableWrapperFlow {
fn class(&self) -> FlowClass {
TableWrapperFlowClass
}
fn as_table_wrapper<'a>(&'a mut self) -> &'a mut TableWrapperFlow {
self
}
fn as_block<'a>(&'a mut self) -> &'a mut BlockFlow {
&mut self.block_flow
}
/* Recursively (bottom-up) determine the context's preferred and
minimum inline_sizes. When called on this context, all child contexts
have had their min/pref inline_sizes set. This function must decide
min/pref inline_sizes based on child context inline_sizes and dimensions of
any fragments it is responsible for flowing. */
fn bubble_inline_sizes(&mut self, ctx: &LayoutContext) {
// get column inline-sizes info from table flow
for kid in self.block_flow.base.child_iter() {
assert!(kid.is_table_caption() || kid.is_table());
if kid.is_table() {
self.col_inline_sizes.push_all(kid.as_table().col_inline_sizes.as_slice());
}
}
self.block_flow.bubble_inline_sizes(ctx);
}
/// Recursively (top-down) determines the actual inline-size of child contexts and fragments. When
/// called on this context, the context has had its inline-size set by the parent context.
///
/// Dual fragments consume some inline-size first, and the remainder is assigned to all child (block)
/// contexts.
fn assign_inline_sizes(&mut self, ctx: &LayoutContext) {
debug!("assign_inline_sizes({}): assigning inline_size for flow",
if self.is_float() {
"floated table_wrapper"
} else {
"table_wrapper"
});
// The position was set to the containing block by the flow's parent.
let containing_block_inline_size = self.block_flow.base.position.size.inline;
let inline_size_computer = TableWrapper;
inline_size_computer.compute_used_inline_size_table_wrapper(self, ctx, containing_block_inline_size);
let inline_start_content_edge = self.block_flow.fragment.border_box.start.i;
let content_inline_size = self.block_flow.fragment.border_box.size.inline;
match self.table_layout {
FixedLayout | _ if self.is_float() =>
self.block_flow.base.position.size.inline = content_inline_size,
_ => {}
}
// In case of fixed layout, column inline-sizes are calculated in table flow.
let assigned_col_inline_sizes = match self.table_layout {
FixedLayout => None,
AutoLayout => Some(self.col_inline_sizes.clone())
};
self.block_flow.propagate_assigned_inline_size_to_children(inline_start_content_edge, content_inline_size, assigned_col_inline_sizes);
}
fn assign_block_size<'a>(&mut self, ctx: &'a LayoutContext<'a>) {
if self.is_float() {
debug!("assign_block_size_float: assigning block_size for floated table_wrapper");
self.block_flow.assign_block_size_float(ctx);
} else {
debug!("assign_block_size: assigning block_size for table_wrapper");
self.assign_block_size_table_wrapper_base(ctx);
}
}
fn compute_absolute_position(&mut self) {
self.block_flow.compute_absolute_position()
}
}
impl fmt::Show for TableWrapperFlow {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
if self.is_float() {
write!(f, "TableWrapperFlow(Float): {}", self.block_flow.fragment)
} else {
write!(f, "TableWrapperFlow: {}", self.block_flow.fragment)
}
}
}
struct TableWrapper;
impl TableWrapper {
fn compute_used_inline_size_table_wrapper(&self,
table_wrapper: &mut TableWrapperFlow,
ctx: &LayoutContext,
parent_flow_inline_size: Au) {
let input = self.compute_inline_size_constraint_inputs_table_wrapper(table_wrapper,
parent_flow_inline_size,
ctx);
let solution = self.solve_inline_size_constraints(&mut table_wrapper.block_flow, &input);
self.set_inline_size_constraint_solutions(&mut table_wrapper.block_flow, solution);
self.set_flow_x_coord_if_necessary(&mut table_wrapper.block_flow, solution);
}
fn compute_inline_size_constraint_inputs_table_wrapper(&self,
table_wrapper: &mut TableWrapperFlow,
parent_flow_inline_size: Au,
ctx: &LayoutContext)
-> ISizeConstraintInput {
let mut input = self.compute_inline_size_constraint_inputs(&mut table_wrapper.block_flow,
parent_flow_inline_size,
ctx);
let computed_inline_size = match table_wrapper.table_layout {
FixedLayout => {
let fixed_cells_inline_size = table_wrapper.col_inline_sizes.iter().fold(Au(0),
|sum, inline_size| sum.add(inline_size));
let mut computed_inline_size = input.computed_inline_size.specified_or_zero();
let style = table_wrapper.block_flow.fragment.style();
// Get inline-start and inline-end paddings, borders for table.
// We get these values from the fragment's style since table_wrapper doesn't have it's own border or padding.
// input.available_inline-size is same as containing_block_inline-size in table_wrapper.
let padding = style.logical_padding();
let border = style.logical_border_width();
let padding_and_borders =
specified(padding.inline_start, input.available_inline_size) +
specified(padding.inline_end, input.available_inline_size) +
border.inline_start +
border.inline_end;
// Compare border-edge inline-sizes. Because fixed_cells_inline-size indicates content-inline-size,
// padding and border values are added to fixed_cells_inline-size.
computed_inline_size = geometry::max(
fixed_cells_inline_size + padding_and_borders, computed_inline_size);
computed_inline_size
},
AutoLayout => {
// Automatic table layout is calculated according to CSS 2.1 § 17.5.2.2.
let mut cap_min = Au(0);
let mut cols_min = Au(0);
let mut cols_max = Au(0);
let mut col_min_inline_sizes = &vec!();
let mut col_pref_inline_sizes = &vec!();
for kid in table_wrapper.block_flow.base.child_iter() {
if kid.is_table_caption() {
cap_min = kid.as_block().base.intrinsic_inline_sizes.minimum_inline_size;
} else {
assert!(kid.is_table());
cols_min = kid.as_block().base.intrinsic_inline_sizes.minimum_inline_size;
cols_max = kid.as_block().base.intrinsic_inline_sizes.preferred_inline_size;
col_min_inline_sizes = kid.col_min_inline_sizes();
col_pref_inline_sizes = kid.col_pref_inline_sizes();
}
}
// 'extra_inline-size': difference between the calculated table inline-size and minimum inline-size
// required by all columns. It will be distributed over the columns.
let (inline_size, extra_inline_size) = match input.computed_inline_size {
Auto => {
if input.available_inline_size > geometry::max(cols_max, cap_min) {
if cols_max > cap_min {
table_wrapper.col_inline_sizes = col_pref_inline_sizes.clone();
(cols_max, Au(0))
} else {
(cap_min, cap_min - cols_min)
}
} else {
let max = if cols_min >= input.available_inline_size && cols_min >= cap_min {
table_wrapper.col_inline_sizes = col_min_inline_sizes.clone();
cols_min
} else {
geometry::max(input.available_inline_size, cap_min)
};
(max, max - cols_min)
}
},
Specified(inline_size) => {
let max = if cols_min >= inline_size && cols_min >= cap_min {
table_wrapper.col_inline_sizes = col_min_inline_sizes.clone();
cols_min
} else {
geometry::max(inline_size, cap_min)
};
(max, max - cols_min)
}
};
// The extra inline-size is distributed over the columns
if extra_inline_size > Au(0) {
let cell_len = table_wrapper.col_inline_sizes.len() as f64;
table_wrapper.col_inline_sizes = col_min_inline_sizes.iter().map(|inline_size| {
inline_size + extra_inline_size.scale_by(1.0 / cell_len)
}).collect();
}
inline_size
}
};
input.computed_inline_size = Specified(computed_inline_size);
input
}
}
impl ISizeAndMarginsComputer for TableWrapper {
/// Solve the inline-size and margins constraints for this block flow.
fn solve_inline_size_constraints(&self, block: &mut BlockFlow, input: &ISizeConstraintInput)
-> ISizeConstraintSolution {
self.solve_block_inline_size_constraints(block, input)
}
}