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@ue-too/board / 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 ​

typescript
// 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:284

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:296

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:275

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 ​

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