Synth event handler

The Synthesizer Event Handler

The synthesizer supports event handling. For example, the MIDI Keyboard in the demo uses handling to visualize key-presses.

It is accessible via the synth.eventHandler property.

Event types can be found here

Managing the events

Adding event listener

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synth.eventHandler.addEvent(name, id, callback);

• name - the type of the event. Refer to the event types table.
• id - a unique string identifier for this listener. Required; use it to remove the listener later or to overwrite an existing one with the same id.
• callback - a function that gets called on the event. It receives an object argument; the properties depend on the event type. Refer to the event types table.

Example:

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// log every note played
synth.eventHandler.addEvent("noteOn", "note-on-listener", (data) => {
    console.log(
        `Note ${data.midiNote} played for channel ${data.channel} with velocity ${data.velocity}.`
    );
});

Removing event listener

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synth.eventHandler.removeEvent(name, id);

• name - the type of the event.
• id - the unique id of the event you wish to remove.

Example:

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// remove the listener we set above
synth.eventHandler.removeEvent("noteOn", "note-on-listener");

Delaying the event system

If you need to delay the events (for example, to sync up with something), you can use the timeDelay property.

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synth.eventHandler.timeDelay = 5;

The delay time is specified in seconds. Set to 0 to disable (instant callback). Default is 0.