1 /*
2 * Copyright 1998-2006 Sun Microsystems, Inc. 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. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any 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
41 package java.awt.font;
42
43 import java.awt.Graphics2D;
44 import java.awt.Font;
45 import java.awt.Shape;
46 import java.awt.geom.AffineTransform;
47 import java.awt.geom.Rectangle2D;
48
49 /**
50 * This class is used with the CHAR_REPLACEMENT attribute.
51 * <p>
52 * The <code>GraphicAttribute</code> 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</code> that
61 * is used in a {@link TextLayout} results in undefined behavior from the
62 * <code>TextLayout</code>.
63 */
64 public 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</code>.
95 * Subclasses use this to define the alignment of the graphic.
96 * @param alignment an int representing one of the
97 * <code>GraphicAttribute</code> 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</code>. A
110 * graphic can be rendered above its ascent.
111 * @return the ascent of this <code>GraphicAttribute</code>.
112 * @see #getBounds()
113 */
114 public abstract float getAscent();
115
116
117 /**
118 * Returns the descent of this <code>GraphicAttribute</code>. A
119 * graphic can be rendered below its descent.
120 * @return the descent of this <code>GraphicAttribute</code>.
121 * @see #getBounds()
122 */
123 public abstract float getDescent();
124
125 /**
126 * Returns the advance of this <code>GraphicAttribute</code>. The
127 * <code>GraphicAttribute</code> 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</code>.
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</code> 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</code> that encloses all of the bits
145 * rendered by this <code>GraphicAttribute</code>.
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</code> 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</code>.
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</code>. This can be null.
164 * @return a <code>Shape</code> 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</code> 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</code>.
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</code>.
191 */
192 public final int getAlignment() {
193
194 return fAlignment;
195 }
196
197 /**
198 * Returns the justification information for this
199 * <code>GraphicAttribute</code>. 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</code>.
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 }
Save This Page