Creating Signals

As an alternative to loading the applet inside Q desktop, a developer can use the the command line and the buit-in Q desktop logging facility.

An applet communicates with the Das Keyboard Signal Center by returning Signal objects. A Signal object includes a 2-D array of Point objects, along with an optional name and description.

For example, the simplest Signal object would be:

  return new q.Signal({ points: [[new q.Point('#FF0000)]] });

To light up a row of keys, send a single row of Points, e.g.:

  return new q.Signal({
    points: [[
      new q.Point('#FF0000),
      new q.Point('#00FF00),
      new q.Point('#0000FF),
      ]],
    name: 'My Applet Name',
    description: 'Some description of the signal'  
    });

To light up a rectangular region, send multiple rows of points, e.g:

  return new q.Signal({
    points: [
      [new q.Point('#FF0000), new q.Point('#00FF00), new q.Point('#0000FF)],
      [new q.Point('#FF0000), new q.Point('#00FF00), new q.Point('#0000FF)],
      [new q.Point('#FF0000), new q.Point('#00FF00), new q.Point('#0000FF)],
      ]});

Signal options

The Signal class takes the following options in its constructor:

• points: A 2-D array of Point objects.
• name: Will be displayed as the title of any signal dialog.
• message: Detailed message that will be displayed within a signal dialog.
• isMuted: Boolean value. If set to false, the signal will invoke an on-screen notification.
• action: The action of the signal, typically DRAW. This is the default. Possible values are:
  • DRAW: Light a key until the signal is dismissed.
  • ERROR: The signal will relay an error message to the host service.
  • FLASH: The signal will cause the key(s) to flash.
• errors: In the case of an ERROR action, errors should contain an array of error messages.

Creating a signal within a callback function

There are cases when a run() function may have to use a callback, and so cannot directly pass a Signal object as its return. In this case, a developer can either return a promise, or use the this.signal() function, e.g.:

  this.signal(new q.Signal({ points: [[new q.Point('#FF0000)]] }));

The Point Class

Each Point should specify, at a minimum, the RGB color that the key should be illuminated to:

  let point = new q.Point('#FF0000');

An effect can also be specified:

  let point = new q.Point('#FF0000', q.Effects.BLINK);