https://openjdk.java.net/ 
/*
 * Copyright (c) 1998, 2005, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * (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 TransformAttribute class provides an immutable
wrapper for a transform so that it is safe to use as an attribute.

/**
 * 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 AffineTransform for this
TransformAttribute, or null
if AffineTransform is the identity transform.

/**
     * 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 IDENTITY in this case.) 
Params:
/**
     * 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.

Returns:a AffineTransform that is a copy of the wrapped
transform of this TransformAttribute.
/**
     * 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 true if the wrapped transform is
an identity transform.

Returns:true if the wrapped transform is
an identity transform; false otherwise.
Since:1.4
/**
     * 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 TransformAttribute representing the identity transform.

Since:1.6
/**
     * 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 compatibility (4348425)
    static final long serialVersionUID = 3356247357827709530L;

    
Since:1.6
/**
     * @since 1.6
     */
    public int hashCode() {
        return transform == null ? 0 : transform.hashCode();
    }

    
Returns true if rhs is a TransformAttribute
whose transform is equal to this TransformAttribute's
transform.

Params:
  • rhs – the object to compare to
Returns:true if the argument is a TransformAttribute
whose transform is equal to this TransformAttribute's
transform.
Since:1.6
/**
     * 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;
    }
}