001 /* TransformAttribute.java -- 002 Copyright (C) 2003, 2005 Free Software Foundation, Inc. 003 004 This file is part of GNU Classpath. 005 006 GNU Classpath is free software; you can redistribute it and/or modify 007 it under the terms of the GNU General Public License as published by 008 the Free Software Foundation; either version 2, or (at your option) 009 any later version. 010 011 GNU Classpath is distributed in the hope that it will be useful, but 012 WITHOUT ANY WARRANTY; without even the implied warranty of 013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014 General Public License for more details. 015 016 You should have received a copy of the GNU General Public License 017 along with GNU Classpath; see the file COPYING. If not, write to the 018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 019 02110-1301 USA. 020 021 Linking this library statically or dynamically with other modules is 022 making a combined work based on this library. Thus, the terms and 023 conditions of the GNU General Public License cover the whole 024 combination. 025 026 As a special exception, the copyright holders of this library give you 027 permission to link this library with independent modules to produce an 028 executable, regardless of the license terms of these independent 029 modules, and to copy and distribute the resulting executable under 030 terms of your choice, provided that you also meet, for each linked 031 independent module, the terms and conditions of the license of that 032 module. An independent module is a module which is not derived from 033 or based on this library. If you modify this library, you may extend 034 this exception to your version of the library, but you are not 035 obligated to do so. If you do not wish to do so, delete this 036 exception statement from your version. */ 037 038 039 package java.awt.font; 040 041 import java.awt.geom.AffineTransform; 042 import java.io.Serializable; 043 044 /** 045 * This class provides a mechanism for using an {@link AffineTransform} as 046 * an <i>immutable</i> attribute (for example, in the 047 * {@link java.text.AttributedString} class). Any transform passed to 048 * this class is copied before being stored, and any transform handed out 049 * by this class is a copy of the stored transform. In this way, it is 050 * not possible to modify the stored transform. 051 * 052 * @author Michael Koch 053 */ 054 public final class TransformAttribute implements Serializable 055 { 056 private static final long serialVersionUID = 3356247357827709530L; 057 058 private AffineTransform affineTransform; 059 060 /** 061 * Creates a new attribute that contains a copy of the given transform. 062 * 063 * @param transform the transform (<code>null</code> not permitted). 064 * 065 * @throws IllegalArgumentException if <code>transform</code> is 066 * <code>null</code>. 067 */ 068 public TransformAttribute (AffineTransform transform) 069 { 070 if (transform == null) 071 { 072 throw new IllegalArgumentException("Null 'transform' not permitted."); 073 } 074 this.affineTransform = new AffineTransform (transform); 075 } 076 077 /** 078 * Returns a copy of the transform contained by this attribute. 079 * 080 * @return A copy of the transform. 081 */ 082 public AffineTransform getTransform () 083 { 084 return (AffineTransform) affineTransform.clone(); 085 } 086 087 /** 088 * Returns <code>true</code> if the transform contained by this attribute is 089 * an identity transform, and <code>false</code> otherwise. 090 * 091 * @return <code>true</code> if the transform contained by this attribute is 092 * an identity transform, and <code>false</code> otherwise. 093 * 094 * @since 1.4 095 */ 096 public boolean isIdentity () 097 { 098 return (affineTransform == null ? false : affineTransform.isIdentity ()); 099 } 100 }