@ue-too/board / index / InputOrchestrator

Class: InputOrchestrator

Defined in: packages/board/src/input-interpretation/input-orchestrator.ts:75

Central orchestrator that coordinates input interpretation and camera control for the infinite canvas.

Remarks

The InputOrchestrator serves as the mediator between input state machines and camera control systems. It implements a permission-based architecture where:

1. Event Flow: State machines produce high-level gesture events (pan, zoom, rotate)
2. Permission Check: Events are sent to CameraMux for permission validation
3. Execution: If allowed, gestures are executed on CameraRig
4. Broadcasting: Raw events are simultaneously broadcast to observers via UserInputPublisher

Architecture Pattern:

State Machines → Orchestrator → CameraMux (permission) → CameraRig (execution)
                      ↓
                UserInputPublisher (observers)

This design decouples state machines from camera control, allowing state machines to focus solely on gesture recognition while the orchestrator handles the complexities of camera coordination, permission management, and event distribution.

Key Benefits:

• Single point of control for all camera operations
• State machines remain unaware of camera implementation
• Parallel path for observers to react to raw input events
• Consistent handling of KMT and Touch input modalities

Example

// Create the orchestrator
const cameraMux = new CameraMux();
const cameraRig = new CameraRig(camera, viewport);
const publisher = new RawUserInputPublisher();
const orchestrator = new InputOrchestrator(cameraMux, cameraRig, publisher);

// State machines send their output to the orchestrator
const kmtStateMachine = createKmtInputStateMachine(kmtContext);
const result = kmtStateMachine.happens("leftPointerMove", {x: 100, y: 200});
orchestrator.processInputEventOutput(result.output);

// Observers can subscribe to raw input events
publisher.on("pan", (event) => {
  console.log("Pan gesture detected:", event.diff);
});

Constructors

Constructor

new InputOrchestrator(cameraMux, cameraRig, publisher?): InputOrchestrator

Defined in: packages/board/src/input-interpretation/input-orchestrator.ts:91

Creates a new InputOrchestrator instance.

Parameters

cameraMux

CameraMux

The camera multiplexer that validates and controls camera operation permissions

cameraRig

CameraRig

The camera rig that executes camera transformations

publisher?

UserInputPublisher

Optional publisher for broadcasting raw input events to observers

Returns

InputOrchestrator

Remarks

The publisher parameter is optional to support scenarios where event broadcasting is not needed. When provided, all input events are broadcast in parallel to camera control execution.

Accessors

cameraMux

Get Signature

get cameraMux(): CameraMux

Defined in: packages/board/src/input-interpretation/input-orchestrator.ts:288

Gets the CameraMux instance for direct access to permission control.

Returns

CameraMux

The camera multiplexer instance

Set Signature

set cameraMux(cameraMux): void

Defined in: packages/board/src/input-interpretation/input-orchestrator.ts:300

Sets a new CameraMux instance.

Remarks

Allows dynamic reconfiguration of camera permission logic at runtime.

Parameters

cameraMux

CameraMux

The new camera multiplexer to use for permission control

Returns

void

---

publisher

Get Signature

get publisher(): UserInputPublisher | undefined

Defined in: packages/board/src/input-interpretation/input-orchestrator.ts:279

Gets the UserInputPublisher for direct access to event subscription.

Remarks

Allows external code to subscribe to raw input events without going through the orchestrator.

Returns

UserInputPublisher | undefined

The publisher instance, or undefined if not configured

Methods

processInputEvent()

processInputEvent(input): void

Defined in: packages/board/src/input-interpretation/input-orchestrator.ts:136

Parameters

input

OutputEvent

Returns

void

---

processInputEventOutput()

processInputEventOutput(output): void

Defined in: packages/board/src/input-interpretation/input-orchestrator.ts:122

Processes output events from state machines and routes them to camera control and observers.

Parameters

output

any

The output from a state machine, can be a single event, array of events, or any value

Returns

void

Remarks

This method serves as the main entry point for state machine outputs. It:

1. Validates whether the output is a valid OutputEvent
2. Handles both single events and arrays of events
3. Routes each valid event through the camera control pipeline
4. Broadcasts events to observers via the publisher

Called by event parsers after the state machine processes an input and produces output. The method uses type guards to ensure type safety when handling dynamic output types.

Example

const result = stateMachine.happens("scroll", {deltaX: 0, deltaY: 10, x: 100, y: 200});
orchestrator.processInputEventOutput(result.output);