GestureHandler

• Constructor
• Methods
• Events
• Examples
• Useful repositories

This object allows you to connect to the QuantumLeap framework and call functions based on events from QuantumLeap.

import GestureHandler from 'quantumleapjs';

Constructor

new GestureHandler([options]);

Options

Options can be passed as a parameter at instantiation:

let gestureHandler = new GestureHandler({ timeout: 5000, requireRegistration: false });

• timeout - integer - Default: 10000 - The maximum time in milliseconds to wait for a connection to succeed before closing and retrying.
• interval - boolean - Default: 3000 - The number of milliseconds between two reconnection attempts.
• requireRegistration - boolean - Default: true - If set to true, gesture events are only triggered for recognized gesture that have been registered using the registerGesture method. If set to false, gesture events are triggered for any recognized gestures.

Methods

addListener(eventName, listener)

Attach the handler function to the event. The function will be triggered each time the event occurs. Any number of listeners can be attached to an event.

• eventName - string - The name of event.
• listener - function - A listener function.

gestureHandler.addListener('frame', (event) => {
  console.log('Frame received!');
});

connect([addr])

Connect to the QuantumLeap framework.

• addr - string - Default: 'ws://127.0.0.1:6442' - The address of a running instance of QuantumLeap framework.

gestureHandler.connect();

disconnect()

Disconnect from the QuantumLeap framework.

gestureHandler.disconnect();

registerGestures(type, names)

Register gestures to the QuantumLeap framework. If requireRegistration is set to true, gesture events are triggered for each registered gesture.

• type - 'static' | 'dynamic' - The type of the gesture(s) to register.
• names - string | string[] - The name(s) of the gesture(s) to register.

gestureHandler.registerGestures('dynamic', ['circle', 'tap']);

removeAllListeners([eventName])

Remove all listeners attached to the event. If eventName is omitted, all listeners attached to all events will be removed.

• eventName - string - The name of event. If omitted, all listeners will be removed for all events.

let listener1 = () => {
  // ...
};
let listener2 = () => {
  // ...
};
gestureHandler.addListener('frame', listener);
gestureHandler.addListener('frame', listener2);
gestureHandler.removeAllListeners('frame');

removeListener(eventName, listener)

Remove the listener attached to the event.

• eventName - string - The name of event.
• listener - function - The listener function to remove.

let listener = () => {
  // ...
};
gestureHandler.addListener('frame', listener);
gestureHandler.removeListener('frame', listener);

unregisterGestures(type, names)

Unregister gestures from the QuantumLeap framework. If requireRegistration is set to true, gesture events will not be triggered anymore for unregistered gestures.

• type - 'static' | 'dynamic' - The type of the gesture(s) to unregister.
• names - string | string[] - The name(s) of the gesture(s) to unregister.

gestureHandler.unregisterGestures('dynamic', ['circle', 'tap']);

Events

Event: 'frame'

Emitted after a frame is received from the QuantumLeap framework.

Properties

• Event.frame - Data corresponding to the current frame.

Event: 'gesture'

Emitted after a gesture is recognized by the QuantumLeap framework. If requireRegistration was set to true, an event is emitted only is the recognized gesture was previously registered. Otherwise, an event is emitted for any recognized gesture.

Properties

• Event.gesture - Data corresponding to the recognized gesture.
  • Event.gesture.type - The type of the recognized gesture.
  • Event.gesture.name - The name of the recognized gesture.
  • Event.gesture.data - Additional data corresponding to the recognized gesture.
• Event.frame - Data corresponding to the current frame.

Event: 'connect'

Emitted after the connection with the QuantumLeap framework.

Properties

• Event.message - A message describing the event.

Event: 'disconnect'

Emitted when a disconnection with the QuantumLeap framework occurs.

Properties

• Event.message - A message describing the event.

Event: 'error'

Emitted when a connection error with the QuantumLeap framework occurs.

Properties

• Event.message - A message describing the event.

Event: 'newListener'

Emitted just before the new event listener is added.

Properties

• Event.eventName - The name of the event being listened for.
• Event.listener - The event handler function.

Event: 'removeListener'

Emitted after the listener is removed.

Properties

• Event.eventName - The name of the event being listened for.
• Event.listener - The event handler function.

Examples

import GestureHandler from 'quantumleapjs' 

let gestureHandler = new GestureHandler();

gestureHandler.registerGestures('dynamic', ['circle', 'tap']);
gestureHandler.registerGestures('static', 'thumb up');

gestureHandler.addListener('gesture', (event) => {
  if (event.gesture.type === 'dynamic') {
    console.log('Dynamic gesture detected.');
  }
  if (event.gesture.name === 'thumb up') {
    console.log('Like');
  }
});

gestureHandler.connect();

Useful repositories

• QuantumLeap: the QuantumLeap framework.
• LeapGesturePlayback: a simple tool for recording and playing gestures with the Leap Motion Controller.
• LUI project: a QuantumLeap-enabled application for browsing multimedia contents.