RTCDTMFToneChangeEvent

{{APIRef("WebRTC")}}

The RTCDTMFToneChangeEvent interface represents events sent to indicate that {{Glossary("DTMF")}} tones have started or finished playing. This interface is used by the tonechange event.

{{InheritanceDiagram}}

Instance properties

In addition to the properties of {{domxref("Event")}}, this interface offers the following:

• {{domxref("RTCDTMFToneChangeEvent.tone")}} {{ReadOnlyInline}}
  • : A string specifying the tone which has begun playing, or an empty string ("") if the previous tone has finished playing.

Constructors

• {{domxref("RTCDTMFToneChangeEvent.RTCDTMFToneChangeEvent()", "RTCDTMFToneChangeEvent()")}}
  • : Returns a new RTCDTMFToneChangeEvent. It takes two parameters, the first being a string representing the type of the event (always "tonechange"); the second a dictionary containing the initial state of the properties of the event.

Instance methods

Supports the methods defined in {{domxref("Event")}}. There are no additional methods.

Examples

This snippet is derived loosely from the full, working example you'll find in the section on When a tone finishes playing. It appends each tone to a display box as it's played, and, once all tones have been sent, re-enabled a previously-disabled "Send" button, allowing the next DTMF string to be entered.

dtmfSender.addEventListener("change", (event) => {
  if (event.tone !== "") {
    dialStringBox.innerText += event.tone;
  } else {
    sendDTMFButton.disabled = false;
  }
});

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• WebRTC
• Its usual target: {{domxref("RTCDTMFSender")}}.