Module fc 

solver3/fc.rs - Formatting Context Layout

This module implements the CSS Visual Formatting Model’s formatting contexts:

• Block Formatting Context (BFC): CSS 2.2 § 9.4.1 Block-level boxes in normal flow, with margin collapsing and float positioning.

• Inline Formatting Context (IFC): CSS 2.2 § 9.4.2 Inline-level content (text, inline-blocks) laid out in line boxes.

• Table Formatting Context: CSS 2.2 § 17 Table layout with column width calculation and cell positioning.

• Flex/Grid Formatting Contexts: CSS Flexbox/Grid via Taffy Delegated to the Taffy layout engine for modern layout modes.

Module Organization

1. Constants & Types - Magic numbers as named constants, core types
2. Entry Point - layout_formatting_context dispatcher
3. BFC Layout - Block formatting context implementation
4. IFC Layout - Inline formatting context implementation
5. Table Layout - Table formatting context implementation
6. Flex/Grid Layout - Taffy bridge wrappers
7. Helper Functions - Property getters, margin collapsing, utilities

Structs

BfcState

Manages all layout state for a single Block Formatting Context. This struct is created by the BFC root and lives for the duration of its layout.

BorderInfo

Information about a border for conflict resolution

FloatingContext

Manages the state of all floated elements within a Block Formatting Context.

LayoutConstraints

Input constraints for a layout function.

LayoutOutput

The result of laying out a formatting context.

LayoutResult

Result of a formatting context layout operation

MarginCollapseContext

Manages vertical margin collapsing within a BFC.

TableCellInfo

Information about a table cell for layout

TableColumnInfo

Lays out a Table Formatting Context. Table column information for layout calculations

Enums

BorderSource

Source of a border in the border conflict resolution algorithm

OverflowBehavior

The CSS overflow property behavior.

TextAlign

Text alignment options

Constants

SCROLLBAR_WIDTH_PX

Default scrollbar width in pixels (CSS Overflow Module Level 3). Used when overflow: scroll or overflow: auto triggers scrollbar display.

Functions

check_scrollbar_necessity

Helper to determine if scrollbars are needed.

layout_formatting_context

Main dispatcher for formatting context layout.

layout_table_fc

Main function to layout a table formatting context

translate_taffy_point_back

translate_taffy_size_back