QuickTime for Java: A Developer's Notebook

Discovering All Installed Components

I hope that by this point you’re at least a little interested in what other kinds of components are available in QuickTime. It’s easy to discover them all, in much the same way we discovered the various MovieExporters and GraphicExporters: by providing a ComponentDescription template and using ComponentIdentifier.find( ). With a “blank” template, all components can be revealed.

How do I do that?

Example 4-4 discovers all installed components and logs their type, subtype, and description to standard out.

Example 4-4. Discovering all installed components

package com.oreilly.qtjnotebook.ch04;
 
import quicktime.*;
import quicktime.std.*;
import quicktime.std.comp.*;
import quicktime.util.QTUtils;
 
import com.oreilly.qtjnotebook.ch01.QTSessionCheck;
 
public class ComponentTour {
 
  public static void main (String[  ] args) {
      try {
          QTSessionCheck.check( );
          /* use this wildcard to show all components in QT
          */
          ComponentDescription wildcard =
              new ComponentDescription( ); 
          ComponentIdentifier ci = null;
          while ( (ci = ComponentIdentifier.find(ci, wildcard)) != null) {
              ComponentDescription cd = ci.getInfo( );
              System.out.println (cd.getName( ) + 
                                  " (" + 
                                  QTUtils.fromOSType (cd.getType( )) +
                                  "/" +
                                  QTUtils.fromOSType (cd.getSubType( )) +
                                  ") " + 
                                  cd.getInformationString( ));
          }
          
      } catch (QTException qte) {
          qte.printStackTrace( );
      }
  }
 
}

The resulting output is hundreds of lines long, looking something like this:

run-ch04-componenttour: [java] Apple MP3 Decoder (adec/.mp3) An ...