Re: [cp-patches] Patch: RFC: make applet use javax.sound.sampled

[Thomas Fitzsimmons]

On Mon, 2005-11-14 at 12:24 -0700, Tom Tromey wrote:
> I'm not checking this in yet -- I would like someone more familiar
> with Applet to look at it first.
> 
> This changes Applet to use javax.sound.sampled to implement
> AudioClip.  It also updates DummyAppletContext to use this.
> 
> I don't know why there is a separate newAudioClip... is the idea that
> a typical AppletContext should do caching?

newAudioClip is static so it can be used in applications.  Apparently it
was added in 1.2 so that non-applets could load and play sound clips
without using the impure sun.audio package.

This patch looks good, please commit.

Tom

> 
> Tom
> 
> 
> 2005-11-14  Tom Tromey  <address@hidden>
> 
>       * java/applet/Applet.java (URLAudioClip): New class.
>       (newAudioClip): Implemented.
>       * gnu/java/beans/DummyAppletContext.java (getAudioClip): Use
>       Applet.newAudioClip.
>       (DUMMY_CLIP): Removed.
>       (DummyAudioClip): Removed.
> 
> Index: gnu/java/beans/DummyAppletContext.java
> ===================================================================
> RCS file: 
> /cvsroot/classpath/classpath/gnu/java/beans/DummyAppletContext.java,v
> retrieving revision 1.2
> diff -u -r1.2 DummyAppletContext.java
> --- gnu/java/beans/DummyAppletContext.java    2 Jul 2005 20:32:12 -0000       
> 1.2
> +++ gnu/java/beans/DummyAppletContext.java    14 Nov 2005 18:27:02 -0000
> @@ -63,7 +63,6 @@
>  class DummyAppletContext implements AppletContext
>  {
>    private static final Enumeration EMPTY_ENUMERATION = 
> Collections.enumeration(Collections.EMPTY_SET);
> -  private static final AudioClip DUMMY_CLIP = new DummyAudioClip();
>  
>    DummyAppletContext()
>    {
> @@ -80,14 +79,7 @@
>     */
>    public AudioClip getAudioClip(URL url)
>    {
> -    try
> -      {
> -     return (url.openConnection() != null ? DUMMY_CLIP : null);
> -      }
> -    catch (IOException ioe)
> -      {
> -     return null;
> -      }
> +    return Applet.newAudioClip(url);
>    }
>  
>    /** Loads the <code>Image</code> instance by delegating to
> @@ -169,32 +161,5 @@
>    public Iterator getStreamKeys()
>    {
>      return Collections.EMPTY_SET.iterator();
> -  }
> -
> -  /** Dummy <code>AudioClip</code> implementation that does nothing but
> -   * preventing <code>NullPointerException</code>S being thrown in programs
> -   * that expect a valid <code>AudioClip</code> instance to be returned by
> -   * their Applet.
> -   *
> -   * @author Robert Schuster
> -   */
> -  static class DummyAudioClip implements AudioClip
> -  {
> -    public void play()
> -    {
> -    }
> -
> -    public void stop()
> -    {
> -    }
> -
> -    public void loop()
> -    {
> -    }
> -
> -    public String toString()
> -    {
> -      return "DummyAudioClip never plays anything - implement javax.sound 
> and make us happy :)";
> -    }
>    }
>  }
> Index: java/applet/Applet.java
> ===================================================================
> RCS file: /cvsroot/classpath/classpath/java/applet/Applet.java,v
> retrieving revision 1.14
> diff -u -r1.14 Applet.java
> --- java/applet/Applet.java   5 Jul 2005 14:46:11 -0000       1.14
> +++ java/applet/Applet.java   14 Nov 2005 18:27:03 -0000
> @@ -54,6 +54,10 @@
>  import javax.accessibility.AccessibleRole;
>  import javax.accessibility.AccessibleState;
>  import javax.accessibility.AccessibleStateSet;
> +import javax.sound.sampled.AudioSystem;
> +import javax.sound.sampled.Clip;
> +import javax.sound.sampled.LineUnavailableException;
> +import javax.sound.sampled.UnsupportedAudioFileException;
>  
>  /**
>   * This is the base applet class.  An applet is a Java program that
> @@ -257,8 +261,6 @@
>     * Returns an audio clip from the specified URL. This clip is not tied to
>     * any particular applet.
>     *
> -   * XXX Classpath does not yet implement this.
> -   *
>     * @param url the URL of the audio clip
>     * @return the retrieved audio clip
>     * @throws NullPointerException if url is null
> @@ -267,8 +269,7 @@
>     */
>    public static final AudioClip newAudioClip(URL url)
>    {
> -    // This requires an implementation of AudioClip in gnu.java.applet.
> -    throw new Error("Not implemented");
> +    return new URLAudioClip(url);
>    }
>  
>    /**
> @@ -521,4 +522,71 @@
>        return s;
>      }
>    } // class AccessibleApplet
> +
> +  private static class URLAudioClip implements AudioClip
> +  {
> +    // The URL we will try to play.
> +    // This is null if we have already tried to create an
> +    // audio input stream from this URL.
> +    private URL url;
> +
> +    // The real audio clip.  This is null before the URL is read,
> +    // and might be null afterward if we were unable to read the URL
> +    // for some reason.
> +    private Clip clip;
> +    
> +    public URLAudioClip(URL url)
> +    {
> +      this.url = url;
> +    }
> +
> +    private synchronized Clip getClip()
> +    {
> +      if (url == null)
> +        return clip;
> +      try
> +        {
> +          clip = AudioSystem.getClip();
> +          clip.open(AudioSystem.getAudioInputStream(url));
> +        }
> +      catch (LineUnavailableException _)
> +        {
> +          // Ignore.
> +        }
> +      catch (IOException _)
> +        {
> +          // Ignore.
> +        }
> +      catch (UnsupportedAudioFileException _)
> +        {
> +          // Ignore.
> +        }
> +      url = null;
> +      return clip;
> +    }
> +
> +    public void loop()
> +    {
> +      Clip myclip = getClip();
> +      if (myclip != null)
> +        myclip.loop(Clip.LOOP_CONTINUOUSLY);
> +    }
> +
> +    public void play()
> +    {
> +      Clip myclip = getClip();
> +      if (myclip != null)
> +        myclip.start();
> +    }
> +
> +    public void stop()
> +    {
> +      Clip myclip = getClip();
> +      if (myclip != null)
> +        {
> +          myclip.stop();
> +          myclip.setFramePosition(0);
> +        }
> +    }
> +  }
>  } // class Applet
> 
> 
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