@ue-too/board / index / VanillaTouchEventParser

Class: VanillaTouchEventParser

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:95

DOM event parser for touch input.

Remarks

This parser converts raw DOM TouchEvents into state machine events and coordinates with the orchestrator to process outputs. It serves as the entry point for all touch input in the input interpretation pipeline.

Event Flow:

DOM TouchEvents → Parser → State Machine → Parser → Orchestrator → Camera/Observers

Responsibilities:

1. Listen for DOM touch events (touchstart/move/end/cancel)
2. Extract touch point data (identifier, x, y)
3. Convert to state machine event format
4. Send events to the state machine
5. Forward state machine outputs to the orchestrator

Touch Point Extraction:

• touchstart/touchend: Uses changedTouches (only new/removed touches)
• touchmove: Uses targetTouches (all touches on the canvas)

Gesture Control: Individual gesture types (pan, zoom, rotate) can be disabled independently, though currently the state machine outputs are filtered by the orchestrator rather than the parser.

The parser prevents default touch behavior to avoid browser scroll/zoom interfering with canvas gestures.

Example

const canvasElement = document.getElementById("canvas");
const stateMachine = createTouchInputStateMachine(context);
const orchestrator = new InputOrchestrator(cameraMux, cameraRig, publisher);
const parser = new VanillaTouchEventParser(stateMachine, orchestrator, canvasElement);

parser.setUp(); // Starts listening for touch events

// Disable zoom gestures temporarily
parser.zoomDisabled = true;

// Cleanup when done
parser.tearDown();

Implements

• TouchEventParser

Constructors

Constructor

new VanillaTouchEventParser(touchInputStateMachine, orchestrator, canvas?): VanillaTouchEventParser

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:107

Parameters

touchInputStateMachine

TouchInputStateMachine

orchestrator

InputOrchestrator

canvas?

HTMLCanvasElement | SVGSVGElement

Returns

VanillaTouchEventParser

Accessors

disabled

Get Signature

get disabled(): boolean

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:179

Whether all touch input is disabled

Returns

boolean

Whether all touch input is disabled

Implementation of

TouchEventParser.disabled

---

orchestrator

Get Signature

get orchestrator(): InputOrchestrator

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:121

Returns

InputOrchestrator

---

stateMachine

Get Signature

get stateMachine(): TouchInputStateMachine

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:125

The state machine this parser dispatches into, when the implementation exposes one. Optional so existing external parser implementations remain valid, but note this member is typed to the full TouchInputStateMachine — unlike KMTEventParser.stateMachine's minimal { happens } contract, an external implementation is more likely to need adjustment to satisfy this member's shape. Intended for tooling/introspection — dispatch through the parser, not through this reference.

Returns

TouchInputStateMachine

The state machine this parser dispatches into, when the implementation exposes one. Optional so existing external parser implementations remain valid, but note this member is typed to the full TouchInputStateMachine — unlike KMTEventParser.stateMachine's minimal { happens } contract, an external implementation is more likely to need adjustment to satisfy this member's shape. Intended for tooling/introspection — dispatch through the parser, not through this reference.

Implementation of

TouchEventParser.stateMachine

Methods

attach()

attach(canvas): void

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:267

Attaches to a new canvas element

Parameters

canvas

HTMLCanvasElement

Returns

void

Implementation of

TouchEventParser.attach

---

bindListeners()

bindListeners(): void

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:129

Returns

void

---

disable()

disable(): void

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:183

Disables the parser; the event listeners are still attached just not processing any events

Returns

void

Implementation of

TouchEventParser.disable

---

disableStrategy()

disableStrategy(): void

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:140

Returns

void

---

enable()

enable(): void

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:187

Enables the parser

Returns

void

Implementation of

TouchEventParser.enable

---

enableStrategy()

enableStrategy(): void

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:136

Returns

void

---

setUp()

setUp(): void

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:144

Initializes event listeners

Returns

void

Implementation of

TouchEventParser.setUp

---

tearDown()

tearDown(): void

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:173

Removes event listeners and cleans up

Returns

void

Implementation of

TouchEventParser.tearDown

---

touchcancelHandler()

touchcancelHandler(e): void

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:221

Parameters

e

TouchEvent

Returns

void

---

touchendHandler()

touchendHandler(e): void

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:236

Parameters

e

TouchEvent

Returns

void

---

touchmoveHandler()

touchmoveHandler(e): void

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:251

Parameters

e

TouchEvent

Returns

void

---

touchstartHandler()

touchstartHandler(e): void

Defined in: packages/board/src/input-interpretation/raw-input-parser/vanilla-touch-event-parser.ts:204

Parameters

e

TouchEvent

Returns

void