Class WebAudio

java.lang.Object
org.vaadin.firitin.util.WebAudio
public class WebAudio extends Object
Utility for playing simple attention sounds via the browser's Web Audio API.

Handy when a Vaadin UI needs to grab the user's attention with a short beep without shipping any audio assets – the tones are synthesized directly in the browser.

Browsers require a user gesture (typically a click or key press) before an AudioContext is allowed to produce sound. If you want to play sounds triggered by something other than a direct user interaction, call resume() from inside e.g. some click handler once to unlock audio playback for the rest of the session.

WebAudio.get().playOkBeep();
WebAudio.get().playAlarm();
WebAudio.get().playBeep(150, 600, WebAudio.Waveform.SQUARE);

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static enum 
    WebAudio.Waveform
    Oscillator waveform.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final double
    DEFAULT_FREQUENCY_HZ
     

  • Constructor Summary

    Constructors
    Constructor
    Description
    WebAudio(com.vaadin.flow.component.UI ui)
     

  • Method Summary

    Modifier and Type
    Method
    Description
    static WebAudio
    get()
     
    CompletableFuture<Void>
    playAlarm()
    Plays a dramatic two-tone klaxon for warnings and errors: six cycles of alternating 880 Hz and 600 Hz square-wave tones (200 ms each), with a flat envelope so the sound stays loud throughout.
    void
    playBeep()
    Plays a short 100 ms beep at 800 Hz with a sine waveform.
    void
    playBeep(int durationMs)
    Plays a sine beep at 800 Hz with the given duration.
    void
    playBeep(int durationMs, double frequencyHz)
    Plays a sine beep with the given duration and frequency.
    void
    playBeep(int durationMs, double frequencyHz, WebAudio.Waveform waveform)
    Plays a beep with the given duration, frequency and waveform.
    CompletableFuture<Void>
    playBeeps(int count, int durationMs, int gapMs)
    Plays count sine beeps at 800 Hz, each lasting durationMs milliseconds, with gapMs milliseconds of silence between them.
    CompletableFuture<Void>
    playBeeps(int count, int durationMs, int gapMs, double frequencyHz)
    Plays count sine beeps with the given duration, frequency and gap.
    CompletableFuture<Void>
    playBeeps(int count, int durationMs, int gapMs, double frequencyHz, WebAudio.Waveform waveform)
    Plays count beeps with the given duration, frequency, gap and waveform.
    void
    playOkBeep()
    Plays a short, friendly 100 ms sine beep at 800 Hz – the kind of sound you'd use to confirm a successful action.
    CompletableFuture<Void>
    playStartSequence()
    Plays a "get ready" sequence: five short 800 Hz beeps spaced one second apart, followed by a longer 500 ms beep at 1000 Hz to indicate the actual start.
    CompletableFuture<Void>
    resume()
    Resumes the underlying AudioContext if it was suspended.

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

  • Constructor Details

    • WebAudio

      public WebAudio(com.vaadin.flow.component.UI ui)

  • Method Details

    • get

      public static WebAudio get()

    • playOkBeep

      public void playOkBeep()
      Plays a short, friendly 100 ms sine beep at 800 Hz – the kind of sound you'd use to confirm a successful action.

    • playBeep

      public void playBeep()
      Plays a short 100 ms beep at 800 Hz with a sine waveform.

    • playBeep

      public void playBeep(int durationMs)
      Plays a sine beep at 800 Hz with the given duration.
      Parameters:
      durationMs - the beep duration in milliseconds

    • playBeep

      public void playBeep(int durationMs, double frequencyHz)
      Plays a sine beep with the given duration and frequency.
      Parameters:
      durationMs - the beep duration in milliseconds
      frequencyHz - the tone frequency in Hertz

    • playBeep

      public void playBeep(int durationMs, double frequencyHz, WebAudio.Waveform waveform)
      Plays a beep with the given duration, frequency and waveform. A short exponential fade-out is applied so the tone doesn't end with an audible click. Use WebAudio.Waveform.SQUARE or WebAudio.Waveform.SAWTOOTH for a harsher, more attention-grabbing sound.
      Parameters:
      durationMs - the beep duration in milliseconds
      frequencyHz - the tone frequency in Hertz
      waveform - the oscillator waveform

    • playBeeps

      public CompletableFuture<Void> playBeeps(int count, int durationMs, int gapMs)
      Plays count sine beeps at 800 Hz, each lasting durationMs milliseconds, with gapMs milliseconds of silence between them.
      Parameters:
      count - the number of beeps to play
      durationMs - duration of each beep in milliseconds
      gapMs - silence between consecutive beeps in milliseconds
      Returns:
      a future that completes after the last beep has finished

    • playBeeps

      public CompletableFuture<Void> playBeeps(int count, int durationMs, int gapMs, double frequencyHz)
      Plays count sine beeps with the given duration, frequency and gap.
      Parameters:
      count - the number of beeps to play
      durationMs - duration of each beep in milliseconds
      gapMs - silence between consecutive beeps in milliseconds
      frequencyHz - the tone frequency in Hertz
      Returns:
      a future that completes after the last beep has finished

    • playBeeps

      public CompletableFuture<Void> playBeeps(int count, int durationMs, int gapMs, double frequencyHz, WebAudio.Waveform waveform)
      Plays count beeps with the given duration, frequency, gap and waveform. All beeps are scheduled in a single round trip to the browser, so timing is sample-accurate.
      Parameters:
      count - the number of beeps to play
      durationMs - duration of each beep in milliseconds
      gapMs - silence between consecutive beeps in milliseconds
      frequencyHz - the tone frequency in Hertz
      waveform - the oscillator waveform
      Returns:
      a future that completes after the last beep has finished

    • playAlarm

      public CompletableFuture<Void> playAlarm()
      Plays a dramatic two-tone klaxon for warnings and errors: six cycles of alternating 880 Hz and 600 Hz square-wave tones (200 ms each), with a flat envelope so the sound stays loud throughout. Total duration is roughly 2.4 seconds.
      Returns:
      a future that completes after the alarm has finished

    • playStartSequence

      public CompletableFuture<Void> playStartSequence()
      Plays a "get ready" sequence: five short 800 Hz beeps spaced one second apart, followed by a longer 500 ms beep at 1000 Hz to indicate the actual start. The returned future completes when the last beep has finished playing on the client.
      Returns:
      a future that completes after the sequence has finished

    • resume

      public CompletableFuture<Void> resume()
      Resumes the underlying AudioContext if it was suspended. Most browsers suspend audio contexts created outside of a user gesture; calling this once from inside a click handler is usually enough to unlock subsequent playback.
      Returns:
      a future that completes when the context is running again