gcc/libjava/classpath/javax/imageio/metadata/IIOMetadata.java

/* IIOMetadata.java --
   Copyright (C) 2004  Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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02110-1301 USA.

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making a combined work based on this library.  Thus, the terms and
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permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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package javax.imageio.metadata;

/**
 * @author Michael Koch (konqueror@gmx.de)
 */
public abstract class IIOMetadata
{
  protected IIOMetadataController controller;
  protected IIOMetadataController defaultController;
  protected String[] extraMetadataFormatClassNames;
  protected String[] extraMetadataFormatNames;
  protected String nativeMetadataFormatClassName;
  protected String nativeMetadataFormatName;
  protected boolean standardFormatSupported;

  /**
   * Creates a <code>IIOMetaData</code> object.
   */
  protected IIOMetadata()
  {
    // Do nothing here.
  }

  /**
   * Creates a <code>IIOMetaData</code> object with the given arguments.
   *
   * @param standardMetadataFormatSupported
   * @param nativeMetadataFormatName
   * @param nativeMetadataFormatClassName
   * @param extraMetadataFormatNames
   * @param extraMetadataFormatClassNames
   *
   * @throws IllegalArgumentException if extraMetadataFormatNames has length of
   * zero or extraMetadataFormatNames and extraMetadataFormatClassNames are
   * neither both null, not have the same length
   */
  protected IIOMetadata(boolean standardMetadataFormatSupported,
                        String nativeMetadataFormatName,
                        String nativeMetadataFormatClassName,
                        String[] extraMetadataFormatNames,
                        String[] extraMetadataFormatClassNames)
  {
    if (extraMetadataFormatNames != null
        && extraMetadataFormatNames.length == 0)
      throw new IllegalArgumentException
        ("extraMetadataFormatNames may not be empty");

    if (((extraMetadataFormatNames == null)
         && (extraMetadataFormatClassNames != null))
        || ((extraMetadataFormatNames != null)
            && (extraMetadataFormatClassNames == null))
        || ((extraMetadataFormatNames != null)
            && (extraMetadataFormatClassNames != null)
            && (extraMetadataFormatNames.length !=
                extraMetadataFormatClassNames.length)))
      throw new IllegalArgumentException
        ("extraMetadataFormatNames and extraMetadataFormatClassNames " +
         "have different lengths");

    this.standardFormatSupported = standardMetadataFormatSupported;
    this.nativeMetadataFormatName = nativeMetadataFormatName;
    this.nativeMetadataFormatClassName = nativeMetadataFormatClassName;
    this.extraMetadataFormatNames = extraMetadataFormatNames;
    this.extraMetadataFormatClassNames = extraMetadataFormatClassNames;
  }

  public boolean activateController()
  {
    if (! hasController())
      return false;

    return getDefaultController().activate(this);
  }

  public IIOMetadataController getController()
  {
    return controller;
  }

  public IIOMetadataController getDefaultController()
  {
    return defaultController;
  }

  public String[] getExtraMetadataFormatNames()
  {
    return (String[]) extraMetadataFormatNames.clone();
  }

  public IIOMetadataFormat getMetadataFormat(String formatName)
  {
    if (formatName == null)
      throw new IllegalArgumentException("formatName may not be null");
    
    String formatClassName = null;

    if (isStandardMetadataFormatSupported()
	&& formatName.equals(nativeMetadataFormatName))
      formatClassName = nativeMetadataFormatClassName;
    else
      {
	String[] extraFormatNames = getExtraMetadataFormatNames();
	
	for (int i = extraFormatNames.length - 1; i >= 0; --i)
	  if (extraFormatNames[i].equals(formatName))
	    {
	      formatClassName = extraFormatNames[i];
	      break;
	    }
      }

    if (formatClassName == null)
      throw new IllegalArgumentException("unknown format");

    IIOMetadataFormat format;
    
    try
      {
	format = (IIOMetadataFormat) Class.forName(formatClassName)
					  .newInstance();
      }
    catch (Exception e)
      {
	IllegalStateException ise = new IllegalStateException();
	ise.initCause(e);
	throw ise;
      }

    return format;
  }

  public String[] getMetadataFormatNames()
  {
    String[] formatNames = getExtraMetadataFormatNames();
    
    if (isStandardMetadataFormatSupported())
      {
        // Combine native metadata format name and extra metadata format names
	// into one String array.
	String[] tmp = new String[formatNames.length + 1];
	tmp[0] = getNativeMetadataFormatName();

	for (int i = 1; i < tmp.length; ++i)
	  tmp[i] = formatNames[i - 1];

	formatNames = tmp;
      }

    return formatNames;
  }

  public String getNativeMetadataFormatName()
  {
    return nativeMetadataFormatName;
  }

  public boolean hasController()
  {
    return getController() != null;
  }

  public abstract boolean isReadOnly();

  public boolean isStandardMetadataFormatSupported()
  {
    return standardFormatSupported;
  }

  public abstract void reset();

  public void setController(IIOMetadataController controller)
  {
    this.controller = controller;
  }
}