1 /*
2 * Portions Copyright 1999-2008 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 /*
28 * (C) Copyright IBM Corp. 1999, All rights reserved.
29 */
30
31 package sun.font;
32
33 import java.awt.Font;
34 import java.awt.GraphicsEnvironment;
35 import java.awt.font.TextAttribute;
36 import java.util.ArrayList;
37 import java.util.Map;
38 import sun.text.CodePointIterator;
39
40 /**
41 * This class maps an individual character to a Font family which can
42 * display it. The character-to-Font mapping does not depend on the
43 * character's context, so a particular character will be mapped to the
44 * same font family each time.
45 * <p>
46 * Typically, clients will call getIndexFor(char) for each character
47 * in a style run. When getIndexFor() returns a different value from
48 * ones seen previously, the characters up to that point will be assigned
49 * a font obtained from getFont().
50 */
51 public final class FontResolver {
52
53 // An array of all fonts available to the runtime. The fonts
54 // will be searched in order.
55 private Font[] allFonts;
56 private Font[] supplementaryFonts;
57 private int[] supplementaryIndices;
58
59 // Default size of Fonts (if created from an empty Map, for instance).
60 private static final int DEFAULT_SIZE = 12; // from Font
61
62 private Font defaultFont = new Font(Font.DIALOG, Font.PLAIN, DEFAULT_SIZE);
63
64 // The results of previous lookups are cached in a two-level
65 // table. The value for a character c is found in:
66 // blocks[c>>SHIFT][c&MASK]
67 // although the second array is only allocated when needed.
68 // A 0 value means the character's font has not been looked up.
69 // A positive value means the character's font is in the allFonts
70 // array at index (value-1).
71 private static final int SHIFT = 9;
72 private static final int BLOCKSIZE = 1<<(16-SHIFT);
73 private static final int MASK = BLOCKSIZE-1;
74 private int[][] blocks = new int[1<<SHIFT][];
75
76 private FontResolver() {
77 }
78
79 private Font[] getAllFonts() {
80 if (allFonts == null) {
81 allFonts =
82 GraphicsEnvironment.getLocalGraphicsEnvironment().getAllFonts();
83 for (int i=0; i < allFonts.length; i++) {
84 allFonts[i] = allFonts[i].deriveFont((float)DEFAULT_SIZE);
85 }
86 }
87 return allFonts;
88 }
89
90 /**
91 * Search fonts in order, and return "1" to indicate its in the default
92 * font, (or not found at all), or the index of the first font
93 * which can display the given character, plus 2, if it is not
94 * in the default font.
95 */
96 private int getIndexFor(char c) {
97
98 if (defaultFont.canDisplay(c)) {
99 return 1;
100 }
101 for (int i=0; i < getAllFonts().length; i++) {
102 if (allFonts[i].canDisplay(c)) {
103 return i+2;
104 }
105 }
106 return 1;
107 }
108
109 private Font [] getAllSCFonts() {
110
111 if (supplementaryFonts == null) {
112 ArrayList<Font> fonts = new ArrayList<Font>();
113 ArrayList<Integer> indices = new ArrayList<Integer>();
114
115 for (int i=0; i<getAllFonts().length; i++) {
116 Font font = allFonts[i];
117 Font2D font2D = FontManager.getFont2D(font);
118 if (font2D.hasSupplementaryChars()) {
119 fonts.add(font);
120 indices.add(Integer.valueOf(i));
121 }
122 }
123
124 int len = fonts.size();
125 supplementaryIndices = new int[len];
126 for (int i=0; i<len; i++) {
127 supplementaryIndices[i] = indices.get(i);
128 }
129 supplementaryFonts = fonts.toArray(new Font[len]);
130 }
131 return supplementaryFonts;
132 }
133
134 /* This method is called only for character codes >= 0x10000 - which
135 * are assumed to be legal supplementary characters.
136 * It looks first at the default font (to avoid calling getAllFonts if at
137 * all possible) and if that doesn't map the code point, it scans
138 * just the fonts that may contain supplementary characters.
139 * The index that is returned is into the "allFonts" array so that
140 * callers see the same value for both supplementary and base chars.
141 */
142 private int getIndexFor(int cp) {
143
144 if (defaultFont.canDisplay(cp)) {
145 return 1;
146 }
147
148 for (int i = 0; i < getAllSCFonts().length; i++) {
149 if (supplementaryFonts[i].canDisplay(cp)) {
150 return supplementaryIndices[i]+2;
151 }
152 }
153 return 1;
154 }
155
156 /**
157 * Return an index for the given character. The index identifies a
158 * font family to getFont(), and has no other inherent meaning.
159 * @param c the character to map
160 * @return a value for consumption by getFont()
161 * @see #getFont
162 */
163 public int getFontIndex(char c) {
164
165 int blockIndex = c>>SHIFT;
166 int[] block = blocks[blockIndex];
167 if (block == null) {
168 block = new int[BLOCKSIZE];
169 blocks[blockIndex] = block;
170 }
171
172 int index = c & MASK;
173 if (block[index] == 0) {
174 block[index] = getIndexFor(c);
175 }
176 return block[index];
177 }
178
179 public int getFontIndex(int cp) {
180 if (cp < 0x10000) {
181 return getFontIndex((char)cp);
182 }
183 return getIndexFor(cp);
184 }
185
186 /**
187 * Determines the font index for the code point at the current position in the
188 * iterator, then advances the iterator to the first code point that has
189 * a different index or until the iterator is DONE, and returns the font index.
190 * @param iter a code point iterator, this will be advanced past any code
191 * points that have the same font index
192 * @return the font index for the initial code point found, or 1 if the iterator
193 * was empty.
194 */
195 public int nextFontRunIndex(CodePointIterator iter) {
196 int cp = iter.next();
197 int fontIndex = 1;
198 if (cp != CodePointIterator.DONE) {
199 fontIndex = getFontIndex(cp);
200
201 while ((cp = iter.next()) != CodePointIterator.DONE) {
202 if (getFontIndex(cp) != fontIndex) {
203 iter.prev();
204 break;
205 }
206 }
207 }
208 return fontIndex;
209 }
210
211 /**
212 * Return a Font from a given font index with properties
213 * from attributes. The font index, which should have been produced
214 * by getFontIndex(), determines a font family. The size and style
215 * of the Font reflect the properties in attributes. Any Font or
216 * font family specifications in attributes are ignored, on the
217 * assumption that clients have already handled them.
218 * @param index an index from getFontIndex() which determines the
219 * font family
220 * @param attributes a Map from which the size and style of the Font
221 * are determined. The default size is 12 and the default style
222 * is Font.PLAIN
223 * @see #getFontIndex
224 */
225 public Font getFont(int index, Map attributes) {
226 Font font = defaultFont;
227
228 if (index >= 2) {
229 font = allFonts[index-2];
230 }
231
232 return font.deriveFont(attributes);
233 }
234
235 private static FontResolver INSTANCE;
236
237 /**
238 * Return a shared instance of FontResolver.
239 */
240 public static FontResolver getInstance() {
241 if (INSTANCE == null) {
242 INSTANCE = new FontResolver();
243 }
244 return INSTANCE;
245 }
246 }