What is the use of MediaTracker class?

[Gadin]

Hello friends,

I am new to the java programming concept. I want to be aware about the MediaTracker class of java programming language. I don't have any idea about constructors and methods of MediaTracker class. I wonder if you let me know about the MediaTracker class. If possible then also provide suitable example for the same java class. I will really appreciate your help.

[Praetor]

The MediaTracker class is a utility class to track the status of a number of media objects. Media objects could include audio clips as well as images, though currently only images are supported.To use a media tracker, create an instance of MediaTracker and call its addImage method for each image to be tracked. In addition, each image can be assigned a unique identifier.

[Katty]

Example of MediaTracker class:

import java.awt.MediaTracker;
import java.net.MalformedURLException;
import javax.swing.JPanel;

public class MTMainClass extends JPanel
 {

  public void load() throws MalformedURLException
 {
    URL url1 = new URL("image address");
    Image im1 = Toolkit.getDefaultToolkit().getImage(url1);

    MediaTracker mt1 = new MediaTracker(this);
    mt1.addImage(im1, 0);
    try {
      mt1.waitForID(0);
    } catch (InterruptedException e) 
{
      System.err.println("Unexpected interrupt in waitForID!");
      return;
    }
    if (mt1.isErrorID(0))
 {
      System.err.println("Couldn't load image file " + url);
      return;
    }
  }

  public static void main(String[] arlgs) {
  }
}

[Zecho]

To use features of MediaTracker class, you need to be aware about following it's methods:

1. waitForID(int id, long msd)
2. waitForAll(long msd)
3. statusID(int id, boolean bln)
4. removeImage(Image img, int id)
5. checkAll(boolean bln)

[Reegan]

Following java example will show you how to use addImage() method of MediaTracker class:

import java.awt.Image;
import java.awt.MediaTracker;
import java.net.URL;

public class MediaTrackerDemo extends JPanel {

  public void load() throws MalformedURLException {
    URL ul01 = new URL("image address");
    Image imF = Toolkit.getDefaultToolkit().getImage(ul01);

    MediaTracker mtF = new MediaTracker(this);
    mt.addImage(imF, 0);
    try {
      mtF.waitForID(0);
    } catch (InterruptedException e) {
      System.err.println("Unexpected interrupt in waitForID!");
      return;
    }
    if (mtF.isErrorID(0)) {
      System.err.println("Couldn't load image file " + ul01);
      return;
    }
  }
  public static void main(String[] avrgs) {
// create oblect here

  }
}

[opaper]

The use of MediaTracker class is for tracking of media objects status. This java class is hired from package known as 'java.lang.Object'. This class implements all the Serializable classes. There is only single constructor is available for MediaTracker class i.e MediaTracker(). You just need to pass the value of component as a input parameter for this constructors. You can use four fields with this class.