rust_browser/docs/component-inventory.md

Component Inventory — rust_browser

Generated: 2026-03-05 | Scan Level: Deep

Crate Inventory by Layer

Layer 0: Foundation

Crate	Files	Key Exports	Purpose
shared	3	Point, Size, Rect, Color, NodeId, StyleId, LayoutId, BrowserUrl, EdgeSizes, CornerRadii, FontStyle, FontWeight, ImageId	Common types, geometry primitives, ID types, error handling

Layer 1: JavaScript Engine

Crate	Files	Key Exports	Purpose
js_parser	35	JsParser, Tokenizer, Program, Statement, Expression, Token, ParseError	JavaScript tokenization and AST parsing
js_vm	48	JsVm, JsValue, Interpreter, Environment, VmConfig, HostEnvironment, JsFunction, RuntimeError, OutputSink	JavaScript interpreter/virtual machine
js	1	JsEngine, JsError (+ re-exports from js_parser, js_vm)	High-level JS engine facade

Layer 1: Document/Style Pipeline

Crate	Files	Key Exports	Purpose
html	9	HtmlParser (parse, parse_into, parse_fragment, tokenize)	HTML5 tokenization and tree building
dom	10	Document, Node, NodeKind, ElementData, Attribute, TreeIterator	Arena-based DOM tree representation
css	36	CssParser, CssTokenizer, Stylesheet, CssValue, Declaration, Rule, Selector, Unit, FontFaceRule	CSS parsing, tokenization, data structures
selectors	17	SelectorEngine, MatchedRule, Selector, SimpleSelector, Combinator, PseudoClass, PseudoElement, Specificity, AncestorFilter	CSS selector matching, specificity, cascade
style	34	StyledDocument, StyleContext, ComputedStyles, Display, Position, Float, Clear, BoxSizing, Overflow, TextAlign, VerticalAlign	Style computation: cascade, inheritance, UA defaults

Layer 1: Layout & Rendering

Crate	Files	Key Exports	Purpose
layout	60	LayoutEngine, LayoutNode, TextMeasurer, FixedWidthTextMeasurer, ProportionalTextMeasurer, FontMetrics	Layout engine: block, inline, flex, table, positioned
display_list	13	DisplayListBuilder, DisplayItem (SolidRect, Border, Text, Image, BackgroundImage, LinearGradient, BoxShadow, PushClip, PopClip), DisplayList	Backend-agnostic painting commands
render	14	Renderer, CpuRasterizer, PixelBuffer	CPU rasterization of display lists
graphics	1	GraphicsBackend	Graphics backend abstraction (placeholder)

Layer 1: Infrastructure

Crate	Files	Key Exports	Purpose
net	7	NetworkStack, HttpLoader, FileLoader, DataUriLoader, Response, LoadResult, LoadId	HTTP/HTTPS, file://, data: URI loading with caching
image	1	ImageStore, ImagePipeline, DecodedImage	Image decoding: PNG, JPEG, GIF, WebP, SVG
fonts	5	FontProvider, FontRequest, TextMetrics, ScaledFontMetrics, GlyphMask	Font loading, metrics, text measurement, rasterization
storage	1	StorageEngine	Persistent storage (placeholder)
platform	4	PlatformContext, EventLoop, Window, WindowConfig, WindowEvent, KeyCode, MouseButton, Modifiers	OS window/event loop abstraction (winit + softbuffer)
web_api	14	WebApiFacade, EventTarget, EventListenerRegistry, TaskQueue, MicrotaskQueue, PromiseRegistry, DispatchResult	JS↔DOM bridge, events, scheduling, promises

Layer 2: Browser Runtime

Crate	Files	Key Exports	Purpose
browser_runtime	5	BrowserRuntime, BrowsingContext, Navigation, NavigationState, NavigationId	Tab management, navigation lifecycle, history

Layer 3: Application Shell

Crate	Files	Key Exports	Purpose
app_browser	31	main(), run_windowed_mode(), run_render_mode()	Desktop binary: CLI, pipeline orchestration, browser chrome, hit testing, form handling

Application Shell Components (app_browser)

Module	Purpose
main	CLI argument parsing, mode selection
app_state	Mutable browser state (page, scroll, focus)
chrome	Browser UI chrome (URL bar, status)
pipeline	HTML → styled DOM → layout → display list → render
event_handler	User input dispatch (keyboard, mouse)
render_mode	Offline rendering orchestration
net_utils	URL loading helpers
hit_test	Click target resolution from display list
form	Form input state and handling
focus_outline	Keyboard focus visualization

Display List Item Types

Item	Purpose
SolidRect	Colored rectangle fill
Border	Border edge rendering (4 sides)
Text	Rendered text with font/color/position
Image	Raster image content
BackgroundImage	Background image with position/repeat/size
LinearGradient	CSS linear gradient fill
BoxShadow	Drop shadow and inset shadow
PushClip / PopClip	Clipping region stack

CSS Property Coverage

The style system handles properties across these categories:

Category	Examples
Box Model	margin, padding, border, width, height, box-sizing
Display/Flow	display, position, float, clear, overflow
Text	font-family/size/weight/style, text-align, text-transform, line-height, white-space
Color/Background	color, background-color/image/position/repeat/size, opacity
Flexbox	flex-direction, justify-content, align-items, flex-grow/shrink/basis
Table	table-layout, border-collapse, border-spacing
Visual	visibility, z-index, box-shadow, border-radius
CSS Variables	Custom properties with var() substitution

See docs/CSS2.1_Implementation_Checklist.md for detailed property-level status.

JavaScript Feature Coverage

The JS engine supports:

Category	Features
Values	undefined, null, boolean, number, string, object, array, function, symbol (partial)
Operators	Arithmetic, comparison, logical, bitwise, assignment, typeof, instanceof
Control Flow	if/else, for, while, do-while, switch, for-in, for-of, try/catch/finally
Functions	Declarations, expressions, arrow functions, closures, rest/spread, default params
Objects	Literals, methods, getters/setters, computed properties, destructuring
Built-ins	Math, JSON, Array methods, String methods, Object methods, Date, RegExp, Map, Set
ES6+	let/const, template literals, classes, promises, iterators, generators (partial)

See docs/js_feature_matrix.md for detailed feature-level status.