/*
* @(#)TransformAttribute.java 1.23 05/11/17
*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*/
/*
* (C) Copyright Taligent, Inc. 1996 - 1997, All Rights Reserved
* (C) Copyright IBM Corp. 1996 - 1998, All Rights Reserved
*
* The original version of this source code and documentation is
* copyrighted and owned by Taligent, Inc., a wholly-owned subsidiary
* of IBM. These materials are provided under terms of a License
* Agreement between Taligent and Sun. This technology is protected
* by multiple US and International patents.
*
* This notice and attribution to Taligent may not be removed.
* Taligent is a registered trademark of Taligent, Inc.
*
*/
package java.awt.font;
import java.awt.geom.AffineTransform;
import java.io.Serializable;
import java.io.ObjectStreamException;
/**
* The <code>TransformAttribute</code> class provides an immutable
* wrapper for a transform so that it is safe to use as an attribute.
*/
public final class TransformAttribute implements Serializable {
/**
* The <code>AffineTransform</code> for this
* <code>TransformAttribute</code>, or <code>null</code>
* if <code>AffineTransform</code> is the identity transform.
*/
private AffineTransform transform;
/**
* Wraps the specified transform. The transform is cloned and a
* reference to the clone is kept. The original transform is unchanged.
* If null is passed as the argument, this constructor behaves as though
* it were the identity transform. (Note that it is preferable to use
* {@link #IDENTITY} in this case.)
* @param transform the specified {@link AffineTransform} to be wrapped,
* or null.
*/
public TransformAttribute(AffineTransform transform) {
if (transform != null && !transform.isIdentity()) {
this.transform = new AffineTransform(transform);
}
}
/**
* Returns a copy of the wrapped transform.
* @return a <code>AffineTransform</code> that is a copy of the wrapped
* transform of this <code>TransformAttribute</code>.
*/
public AffineTransform getTransform() {
AffineTransform at = transform;
return (at == null) ? new AffineTransform() : new AffineTransform(at);
}
/**
* Returns <code>true</code> if the wrapped transform is
* an identity transform.
* @return <code>true</code> if the wrapped transform is
* an identity transform; <code>false</code> otherwise.
* @since 1.4
*/
public boolean isIdentity() {
return transform == null;
}
/**
* A <code>TransformAttribute</code> representing the identity transform.
* @since 1.6
*/
public static final TransformAttribute IDENTITY = new TransformAttribute(null);
private void writeObject(java.io.ObjectOutputStream s)
throws java.lang.ClassNotFoundException,
java.io.IOException
{
// sigh -- 1.3 expects transform is never null, so we need to always write one out
if (this.transform == null) {
this.transform = new AffineTransform();
}
s.defaultWriteObject();
}
/*
* @since 1.6
*/
private Object readResolve() throws ObjectStreamException {
if (transform == null || transform.isIdentity()) {
return IDENTITY;
}
return this;
}
// Added for serial backwards compatability (4348425)
static final long serialVersionUID = 3356247357827709530L;
/**
* @since 1.6
*/
public int hashCode() {
return transform == null ? 0 : transform.hashCode();
}
/**
* Returns <code>true</code> if rhs is a <code>TransformAttribute</code>
* whose transform is equal to this <code>TransformAttribute</code>'s
* transform.
* @param rhs the object to compare to
* @return <code>true</code> if the argument is a <code>TransformAttribute</code>
* whose transform is equal to this <code>TransformAttribute</code>'s
* transform.
* @since 1.6
*/
public boolean equals(Object rhs) {
try {
TransformAttribute that = (TransformAttribute)rhs;
if (transform == null) {
return that.transform == null;
}
return transform.equals(that.transform);
}
catch (ClassCastException e) {
}
return false;
}
}