MergingDataSource.java

/*
 * @(#)MergingDataSource.java	1.3 99/08/11
 *
 * Copyright 1996-1998 by Sun Microsystems, Inc.,
 * 901 San Antonio Road, Palo Alto, California, 94303, U.S.A.
 * All rights reserved.
 *
 * This software is the confidential and proprietary information
 * of Sun Microsystems, Inc. ("Confidential Information").  You
 * shall not disclose such Confidential Information and shall use
 * it only in accordance with the terms of the license agreement
 * you entered into with Sun.
 */

package com.ibm.media.protocol;

import java.io.*;
import java.util.Vector;
import java.lang.*;
import java.lang.reflect.*;
import javax.media.*;
import javax.media.protocol.*;


class MergingDataSource extends DataSource {
  
    DataSource[] sources;
    SourceStream[] streams = null;
    Object [] controls = null;

    
  /**
   * Constructor 
   */
  MergingDataSource(DataSource[] sources) {

    this.sources = sources;
  }

  /**
   * Returns the content-type of the merged streams. If all streams are RAW, 
   * the returned content-type is RAW. Otherwise, the return content-type is 
   * MIXED.
   */
  public String getContentType() {
    
      if (sources.length == 1)
	  return sources[0].getContentType();

    boolean isRaw = true;

    for (int index = 0; index < sources.length; index++) {
      if (!sources[index].getContentType().equals(ContentDescriptor.RAW)) {
	isRaw = false;
	break;
      }
    }
     
    if (isRaw)
      return ContentDescriptor.RAW;
    else if (sources.length == 1)
      return sources[0].getContentType();
    else
      return ContentDescriptor.MIXED;
  }
  
  public void connect() throws IOException {

    for (int i = 0; i < sources.length; i++)
      sources[i].connect();
  }
  
  public void disconnect() {

    for (int i = 0; i < sources.length; i++)
      sources[i].disconnect();
  }
  
  public void start() throws IOException {
    
    for (int i = 0; i < sources.length; i++)
      sources[i].start();
  }
  
  public void stop() throws IOException {
    
    for (int i = 0; i < sources.length; i++)
      sources[i].stop();
  }  

  /**
   * Obtain the collection of objects that
   * control the object that implements this interface.
   * <p>
   *
   * If no controls are supported, a zero length
   * array is returned.
   *
   * @return the collection of object controls
   */
  public Object[] getControls() {
      if (controls == null) {
	  Vector vcontrols = new Vector(1);
	  for (int i = 0; i < sources.length; i++) {
	      Object [] cs = (Object[]) sources[i].getControls();
	      if (cs.length > 0) {
		  for (int j = 0; j < cs.length; j++) {
		      vcontrols.addElement(cs[j]);
		  }
	      }
	  }
	  controls = new Object[vcontrols.size()];
	  for (int c = 0; c < vcontrols.size(); c++)
	      controls[c] = vcontrols.elementAt(c);
      }
	  
      return controls;
  }
  
  /**
   * Obtain the object that implements the specified
   * <code>Class</code> or <code>Interface</code>
   * The full class or interface name must be used.
   * <p>
   * 
   * If the control is not supported then <code>null</code>
   * is returned.
   *
   * @return the object that implements the control,
   * or <code>null</code>.
   */
  public Object getControl(String controlType) {
      try {
          Class  cls = Class.forName(controlType);
          Object cs[] = getControls();
          for (int i = 0; i < cs.length; i++) {
	      if (cls.isInstance(cs[i]))
		  return cs[i];
          }
          return null;
	  
      } catch (Exception e) {   // no such controlType or such control
	  return null;
      }      
  }

  /**
   * Get the duration of the media represented
   * by this object.
   * The value returned is the media's duration
   * when played at the default rate.
   * If the duration can't be determined  (for example, the media object is presenting live
   * video)  <CODE>getDuration</CODE> returns <CODE>DURATION_UNKNOWN</CODE>.
   *
   * @return A <CODE>Time</CODE> object representing the duration or DURATION_UNKNOWN.
   */
  public Time getDuration() {
    
    Time longest = new Time(0);

    for (int i = 0; i < sources.length; i++) {
      Time sourceDuration = sources[i].getDuration();
      if (sourceDuration.getSeconds() > longest.getSeconds())
	longest = sourceDuration;
    }

    return longest;
  }
  
}