1/* 2 * Copyright (c) 1998, 2006, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26/* 27 * (C) Copyright Taligent, Inc. 1996 - 1997, All Rights Reserved 28 * (C) Copyright IBM Corp. 1996 - 1998, All Rights Reserved 29 * 30 * The original version of this source code and documentation is 31 * copyrighted and owned by Taligent, Inc., a wholly-owned subsidiary 32 * of IBM. These materials are provided under terms of a License 33 * Agreement between Taligent and Sun. This technology is protected 34 * by multiple US and International patents. 35 * 36 * This notice and attribution to Taligent may not be removed. 37 * Taligent is a registered trademark of Taligent, Inc. 38 * 39 */ 40 41package java.awt.font; 42 43import java.awt.Graphics2D; 44import java.awt.Font; 45import java.awt.Shape; 46import java.awt.geom.AffineTransform; 47import java.awt.geom.Rectangle2D; 48 49/** 50 * This class is used with the CHAR_REPLACEMENT attribute. 51 * <p> 52 * The {@code GraphicAttribute} class represents a graphic embedded 53 * in text. Clients subclass this class to implement their own char 54 * replacement graphics. Clients wishing to embed shapes and images in 55 * text need not subclass this class. Instead, clients can use the 56 * {@link ShapeGraphicAttribute} and {@link ImageGraphicAttribute} 57 * classes. 58 * <p> 59 * Subclasses must ensure that their objects are immutable once they 60 * are constructed. Mutating a {@code GraphicAttribute} that 61 * is used in a {@link TextLayout} results in undefined behavior from the 62 * {@code TextLayout}. 63 */ 64public abstract class GraphicAttribute { 65 66 private int fAlignment; 67 68 /** 69 * Aligns top of graphic to top of line. 70 */ 71 public static final int TOP_ALIGNMENT = -1; 72 73 /** 74 * Aligns bottom of graphic to bottom of line. 75 */ 76 public static final int BOTTOM_ALIGNMENT = -2; 77 78 /** 79 * Aligns origin of graphic to roman baseline of line. 80 */ 81 public static final int ROMAN_BASELINE = Font.ROMAN_BASELINE; 82 83 /** 84 * Aligns origin of graphic to center baseline of line. 85 */ 86 public static final int CENTER_BASELINE = Font.CENTER_BASELINE; 87 88 /** 89 * Aligns origin of graphic to hanging baseline of line. 90 */ 91 public static final int HANGING_BASELINE = Font.HANGING_BASELINE; 92 93 /** 94 * Constructs a {@code GraphicAttribute}. 95 * Subclasses use this to define the alignment of the graphic. 96 * @param alignment an int representing one of the 97 * {@code GraphicAttribute} alignment fields 98 * @throws IllegalArgumentException if alignment is not one of the 99 * five defined values. 100 */ 101 protected GraphicAttribute(int alignment) { 102 if (alignment < BOTTOM_ALIGNMENT || alignment > HANGING_BASELINE) { 103 throw new IllegalArgumentException("bad alignment"); 104 } 105 fAlignment = alignment; 106 } 107 108 /** 109 * Returns the ascent of this {@code GraphicAttribute}. A 110 * graphic can be rendered above its ascent. 111 * @return the ascent of this {@code GraphicAttribute}. 112 * @see #getBounds() 113 */ 114 public abstract float getAscent(); 115 116 117 /** 118 * Returns the descent of this {@code GraphicAttribute}. A 119 * graphic can be rendered below its descent. 120 * @return the descent of this {@code GraphicAttribute}. 121 * @see #getBounds() 122 */ 123 public abstract float getDescent(); 124 125 /** 126 * Returns the advance of this {@code GraphicAttribute}. The 127 * {@code GraphicAttribute} object's advance is the distance 128 * from the point at which the graphic is rendered and the point where 129 * the next character or graphic is rendered. A graphic can be 130 * rendered beyond its advance 131 * @return the advance of this {@code GraphicAttribute}. 132 * @see #getBounds() 133 */ 134 public abstract float getAdvance(); 135 136 /** 137 * Returns a {@link Rectangle2D} that encloses all of the 138 * bits drawn by this {@code GraphicAttribute} relative to the 139 * rendering position. 140 * A graphic may be rendered beyond its origin, ascent, descent, 141 * or advance; but if it is, this method's implementation must 142 * indicate where the graphic is rendered. 143 * Default bounds is the rectangle (0, -ascent, advance, ascent+descent). 144 * @return a {@code Rectangle2D} that encloses all of the bits 145 * rendered by this {@code GraphicAttribute}. 146 */ 147 public Rectangle2D getBounds() { 148 float ascent = getAscent(); 149 return new Rectangle2D.Float(0, -ascent, 150 getAdvance(), ascent+getDescent()); 151 } 152 153 /** 154 * Return a {@link java.awt.Shape} that represents the region that 155 * this {@code GraphicAttribute} renders. This is used when a 156 * {@link TextLayout} is requested to return the outline of the text. 157 * The (untransformed) shape must not extend outside the rectangular 158 * bounds returned by {@code getBounds}. 159 * The default implementation returns the rectangle returned by 160 * {@link #getBounds}, transformed by the provided {@link AffineTransform} 161 * if present. 162 * @param tx an optional {@link AffineTransform} to apply to the 163 * outline of this {@code GraphicAttribute}. This can be null. 164 * @return a {@code Shape} representing this graphic attribute, 165 * suitable for stroking or filling. 166 * @since 1.6 167 */ 168 public Shape getOutline(AffineTransform tx) { 169 Shape b = getBounds(); 170 if (tx != null) { 171 b = tx.createTransformedShape(b); 172 } 173 return b; 174 } 175 176 /** 177 * Renders this {@code GraphicAttribute} at the specified 178 * location. 179 * @param graphics the {@link Graphics2D} into which to render the 180 * graphic 181 * @param x the user-space X coordinate where the graphic is rendered 182 * @param y the user-space Y coordinate where the graphic is rendered 183 */ 184 public abstract void draw(Graphics2D graphics, float x, float y); 185 186 /** 187 * Returns the alignment of this {@code GraphicAttribute}. 188 * Alignment can be to a particular baseline, or to the absolute top 189 * or bottom of a line. 190 * @return the alignment of this {@code GraphicAttribute}. 191 */ 192 public final int getAlignment() { 193 194 return fAlignment; 195 } 196 197 /** 198 * Returns the justification information for this 199 * {@code GraphicAttribute}. Subclasses 200 * can override this method to provide different justification 201 * information. 202 * @return a {@link GlyphJustificationInfo} object that contains the 203 * justification information for this {@code GraphicAttribute}. 204 */ 205 public GlyphJustificationInfo getJustificationInfo() { 206 207 // should we cache this? 208 float advance = getAdvance(); 209 210 return new GlyphJustificationInfo( 211 advance, // weight 212 false, // growAbsorb 213 2, // growPriority 214 advance/3, // growLeftLimit 215 advance/3, // growRightLimit 216 false, // shrinkAbsorb 217 1, // shrinkPriority 218 0, // shrinkLeftLimit 219 0); // shrinkRightLimit 220 } 221} 222