mediatracker.java

gcc的组建

  {
    long start = System.currentTimeMillis();
    boolean result = checkAll(true);
    synchronized (this)
    {
      while (result == false)
        {
          wait(ms);
          result = checkAll(true);
          if ((System.currentTimeMillis() - start) > ms)
            break;
        }
    }

    return result;
  }

  /**
   * Returns the status flags of all registered media objects ORed together.
   * If <code>load</code> is <code>true</code> then media objects that
   * are not already loading will be started to load.
   *
   * @param load if set to <code>true</code> then media objects that are
   *        not already loading are started
   *
   * @return the status flags of all tracked media objects ORed together
   */
  public int statusAll(boolean load)
  {
    int result = 0;
    MediaEntry e = head;
    while (e != null)
      {
        if (load && e.status == 0)
          {
            if (target.prepareImage(e.image, e))
              e.status = COMPLETE;
            else
	      {
                e.status = LOADING;
                int flags = target.checkImage(e.image, e);
		if ((flags & ImageObserver.ABORT) != 0)
		  e.status = ABORTED;
		else if ((flags & ImageObserver.ERROR) != 0)
		  e.status = ERRORED;
		else if ((flags & ImageObserver.ALLBITS) != 0)
		  e.status = COMPLETE;
	      }
          }
        result |= e.status;
        e = e.next;
      }
    return result;
  }

  /**
   * Checks if the media objects with <code>ID</code> have completed loading.
   *
   * @param id the ID of the media objects to check
   *
   * @return <code>true</code> if all media objects with <code>ID</code>
   *         have successfully finished
   */
  public boolean checkID(int id)
  {
    return checkID(id, false);
  }

  /**
   * Checks if the media objects with <code>ID</code> have completed loading.
   * If <code>load</code> is <code>true</code> then media objects that
   * are not already loading will be started to load.
   *
   * @param id the ID of the media objects to check
   * @param load if set to <code>true</code> then media objects that are
   *        not already loading are started
   *
   * @return <code>true</code> if all media objects with <code>ID</code>
   *         have successfully finished
   */
  public boolean checkID(int id, boolean load)
  {
    MediaEntry e = head;
    boolean result = true;
    
    while (e != null)
      {
        if (e.id == id && ((e.status & (COMPLETE | ABORTED | ERRORED)) == 0))
          {
            if (load && ((e.status & LOADING) == 0))
              {
                e.status = LOADING;
		if (target.prepareImage(e.image, e))
		  e.status = COMPLETE;
		else
		  {
		    int flags = target.checkImage(e.image, e);
		    if ((flags & ImageObserver.ABORT) != 0)
		      e.status = ABORTED;
		    else if ((flags & ImageObserver.ERROR) != 0)
		      e.status = ERRORED;
		    else if ((flags & ImageObserver.ALLBITS) != 0)
		      e.status = COMPLETE;
		  }
		boolean complete = (e.status
				    & (COMPLETE | ABORTED | ERRORED)) != 0;
		if (!complete)
		  result = false;
              }
            else
              result = false;
          }
        e = e.next;
      }
    return result;
  }

  /**
   * Returns <code>true</code> if any of the media objects with <code>ID</code>
   * have encountered errors during loading, false otherwise.
   *
   * @param id the ID of the media objects to check
   *
   * @return <code>true</code> if any of the media objects with <code>ID</code>
   *         have encountered errors during loading, false otherwise
   */
  public boolean isErrorID(int id)
  {
    MediaEntry e = head;    
    while (e != null)
      {
        if (e.id == id && ((e.status & ERRORED) != 0))
          return true;
        e = e.next;
      }
    return false;
  }

  /**
   * Returns all media objects with the specified ID that have encountered
   * an error.
   *
   * @param id the ID of the media objects to check
   *
   * @return an array of all media objects  with the specified ID that
   *         have encountered an error
   */
  public Object[] getErrorsID(int id)
  {
    MediaEntry e = head;
    ArrayList result = null;
    while (e != null)
      {
        if (e.id == id && ((e.status & ERRORED) != 0))
          {
            if (result == null)
              result = new ArrayList();
            result.add(e.image);
          }
        e = e.next;
      }
    if (result == null)
      return null;
    else
      return result.toArray();
  }

  /**
   * Waits for all media objects with the specified ID to finish loading,
   * either by completing successfully or by aborting or encountering an error.
   *
   * @param id the ID of the media objects to wait for
   *
   * @throws InterruptedException if another thread interrupted the
   *         current thread while waiting
   */
  public void waitForID(int id) throws InterruptedException
  {
    MediaEntry e = head;
    synchronized (this)
    {
      while (checkID (id, true) == false)
        wait();
    }
  }

  /**
   * Waits for all media objects with the specified ID to finish loading,
   * either by completing successfully or by aborting or encountering an error.
   *
   * This method waits at most <code>ms</code> milliseconds. If the
   * media objects have not completed loading within this timeframe, this
   * method returns <code>false</code>, otherwise <code>true</code>.
   *
   * @param id the ID of the media objects to wait for
   * @param ms timeframe in milliseconds to wait for the media objects to
   *        finish
   *
   * @return <code>true</code> if all media objects have successfully loaded
   *         within the timeframe, <code>false</code> otherwise
   *
   * @throws InterruptedException if another thread interrupted the
   *         current thread while waiting
   */
  public boolean waitForID(int id, long ms) throws InterruptedException
  {
    MediaEntry e = head;
    long start = System.currentTimeMillis();
    boolean result = checkID(id, true);

    synchronized (this)
    {
      while (result == false)
        {
          wait(ms);
          result = checkID(id, true);
          if ((System.currentTimeMillis() - start) > ms)
            break;
        }
    }

    return result;
  }

  /**
   * Returns the status flags of the media objects with the specified ID
   * ORed together.
   *
   * If <code>load</code> is <code>true</code> then media objects that
   * are not already loading will be started to load.
   *
   * @param load if set to <code>true</code> then media objects that are
   *        not already loading are started
   *
   * @return the status flags of all tracked media objects ORed together
   */
  public int statusID(int id, boolean load)
  {
    int result = 0;
    MediaEntry e = head;
    while (e != null)
      {
        if (e.id == id)
          {
            if (load && e.status == 0)
              {
		if (target.prepareImage(e.image, e))
                  e.status = COMPLETE;
		else
		  {
		    e.status = LOADING;
		    int flags = target.checkImage(e.image, e);
		    if ((flags & ImageObserver.ABORT) != 0)
		      e.status = ABORTED;
		    else if ((flags & ImageObserver.ERROR) != 0)
		      e.status = ERRORED;
		    else if ((flags & ImageObserver.ALLBITS) != 0)
		      e.status = COMPLETE;
		  }
              }
            result |= e.status;
          }
        e = e.next;
      }
    return result;
  }

  /**
   * Removes an image from this MediaTracker.
   *
   * @param image the image to be removed
   */
  public void removeImage(Image image)
  {
    synchronized (this)
      {
        MediaEntry e = head;
        MediaEntry prev = null;
        while (e != null)
          {
            if (e.image == image)
              {
                if (prev == null)
                  head = e.next;
                else
                  prev.next = e.next;
              }
            prev = e;
            e = e.next;
          }
      }
  }

  /**
   * Removes an image with the specified ID from this MediaTracker.
   *
   * @param image the image to be removed
   */
  public void removeImage(Image image, int id)
  {
    synchronized (this)
      {
        MediaEntry e = head;
        MediaEntry prev = null;
        while (e != null)
          {
            if (e.id == id && e.image == image)
              {
                if (prev == null)
                  head = e.next;
                else
                  prev.next = e.next;
              }
            else
              prev = e;
            e = e.next;
          }
      }
  }

  /**
   * Removes an image with the specified ID and scale from this MediaTracker.
   *
   * @param image the image to be removed
   */
  public void removeImage(Image image, int id, int width, int height)
  {
    synchronized (this)
      {
        MediaEntry e = head;
        MediaEntry prev = null;
        while (e != null)
          {
            if (e.id == id && e.image == image
                && e.width == width && e.height == height)
              {
                if (prev == null)
                  head = e.next;
                else
                  prev.next = e.next;
              }
            else
              prev = e;
            e = e.next;
          }
      }
  }
}