1 /*
2 * Copyright (c) 1999, 2014, 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 /*
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.text.AttributedCharacterIterator;
37 import java.util.ArrayList;
38 import java.util.Map;
39 import sun.text.CodePointIterator;
40
41 /**
42 * This class maps an individual character to a Font family which can
43 * display it. The character-to-Font mapping does not depend on the
44 * character's context, so a particular character will be mapped to the
45 * same font family each time.
46 * <p>
47 * Typically, clients will call getIndexFor(char) for each character
48 * in a style run. When getIndexFor() returns a different value from
49 * ones seen previously, the characters up to that point will be assigned
50 * a font obtained from getFont().
51 */
52 public final class FontResolver {
53
54 // An array of all fonts available to the runtime. The fonts
55 // will be searched in order.
56 private Font[] allFonts;
57 private Font[] supplementaryFonts;
58 private int[] supplementaryIndices;
59
60 // Default size of Fonts (if created from an empty Map, for instance).
61 private static final int DEFAULT_SIZE = 12; // from Font
62
63 private Font defaultFont = new Font(Font.DIALOG, Font.PLAIN, DEFAULT_SIZE);
64
65 // The results of previous lookups are cached in a two-level
66 // table. The value for a character c is found in:
67 // blocks[c>>SHIFT][c&MASK]
68 // although the second array is only allocated when needed.
69 // A 0 value means the character's font has not been looked up.
70 // A positive value means the character's font is in the allFonts
71 // array at index (value-1).
72 private static final int SHIFT = 9;
73 private static final int BLOCKSIZE = 1<<(16-SHIFT);
74 private static final int MASK = BLOCKSIZE-1;
75 private int[][] blocks = new int[1<<SHIFT][];
76
77 private FontResolver() {
78 }
79
80 private Font[] getAllFonts() {
81 if (allFonts == null) {
82 allFonts =
83 GraphicsEnvironment.getLocalGraphicsEnvironment().getAllFonts();
84 for (int i=0; i < allFonts.length; i++) {
85 allFonts[i] = allFonts[i].deriveFont((float)DEFAULT_SIZE);
86 }
87 }
88 return allFonts;
89 }
90
91 /**
92 * Search fonts in order, and return "1" to indicate its in the default
93 * font, (or not found at all), or the index of the first font
94 * which can display the given character, plus 2, if it is not
95 * in the default font.
96 */
97 private int getIndexFor(char c) {
98
99 if (defaultFont.canDisplay(c)) {
100 return 1;
101 }
102 for (int i=0; i < getAllFonts().length; i++) {
103 if (allFonts[i].canDisplay(c)) {
104 return i+2;
105 }
106 }
107 return 1;
108 }
109
110 private Font [] getAllSCFonts() {
111
112 if (supplementaryFonts == null) {
113 ArrayList<Font> fonts = new ArrayList<Font>();
114 ArrayList<Integer> indices = new ArrayList<Integer>();
115
116 for (int i=0; i<getAllFonts().length; i++) {
117 Font font = allFonts[i];
118 Font2D font2D = FontUtilities.getFont2D(font);
119 if (font2D.hasSupplementaryChars()) {
120 fonts.add(font);
121 indices.add(Integer.valueOf(i));
122 }
123 }
124
125 int len = fonts.size();
126 supplementaryIndices = new int[len];
127 for (int i=0; i<len; i++) {
128 supplementaryIndices[i] = indices.get(i);
129 }
130 supplementaryFonts = fonts.toArray(new Font[len]);
131 }
132 return supplementaryFonts;
133 }
134
135 /* This method is called only for character codes >= 0x10000 - which
136 * are assumed to be legal supplementary characters.
137 * It looks first at the default font (to avoid calling getAllFonts if at
138 * all possible) and if that doesn't map the code point, it scans
139 * just the fonts that may contain supplementary characters.
140 * The index that is returned is into the "allFonts" array so that
141 * callers see the same value for both supplementary and base chars.
142 */
143 private int getIndexFor(int cp) {
144
145 if (defaultFont.canDisplay(cp)) {
146 return 1;
147 }
148
149 for (int i = 0; i < getAllSCFonts().length; i++) {
150 if (supplementaryFonts[i].canDisplay(cp)) {
151 return supplementaryIndices[i]+2;
152 }
153 }
154 return 1;
155 }
156
157 /**
158 * Return an index for the given character. The index identifies a
159 * font family to getFont(), and has no other inherent meaning.
160 * @param c the character to map
161 * @return a value for consumption by getFont()
162 * @see #getFont
163 */
164 public int getFontIndex(char c) {
165
166 int blockIndex = c>>SHIFT;
167 int[] block = blocks[blockIndex];
168 if (block == null) {
169 block = new int[BLOCKSIZE];
170 blocks[blockIndex] = block;
171 }
172
173 int index = c & MASK;
174 if (block[index] == 0) {
175 block[index] = getIndexFor(c);
176 }
177 return block[index];
178 }
179
180 public int getFontIndex(int cp) {
181 if (cp < 0x10000) {
182 return getFontIndex((char)cp);
183 }
184 return getIndexFor(cp);
185 }
186
187 /**
188 * Determines the font index for the code point at the current position in the
189 * iterator, then advances the iterator to the first code point that has
190 * a different index or until the iterator is DONE, and returns the font index.
191 * @param iter a code point iterator, this will be advanced past any code
192 * points that have the same font index
193 * @return the font index for the initial code point found, or 1 if the iterator
194 * was empty.
195 */
196 public int nextFontRunIndex(CodePointIterator iter) {
197 int cp = iter.next();
198 int fontIndex = 1;
199 if (cp != CodePointIterator.DONE) {
200 fontIndex = getFontIndex(cp);
201
202 while ((cp = iter.next()) != CodePointIterator.DONE) {
203 if (getFontIndex(cp) != fontIndex) {
204 iter.prev();
205 break;
206 }
207 }
208 }
209 return fontIndex;
210 }
211
212 /**
213 * Return a Font from a given font index with properties
214 * from attributes. The font index, which should have been produced
215 * by getFontIndex(), determines a font family. The size and style
216 * of the Font reflect the properties in attributes. Any Font or
217 * font family specifications in attributes are ignored, on the
218 * assumption that clients have already handled them.
219 * @param index an index from getFontIndex() which determines the
220 * font family
221 * @param attributes a Map from which the size and style of the Font
222 * are determined. The default size is 12 and the default style
223 * is Font.PLAIN
224 * @see #getFontIndex
225 */
226 public Font getFont(int index,
227 Map<? extends AttributedCharacterIterator.Attribute, ?> attributes) {
228 Font font = defaultFont;
229
230 if (index >= 2) {
231 font = allFonts[index-2];
232 }
233
234 return font.deriveFont(attributes);
235 }
236
237 private static FontResolver INSTANCE;
238
239 /**
240 * Return a shared instance of FontResolver.
241 */
242 public static FontResolver getInstance() {
243 if (INSTANCE == null) {
244 INSTANCE = new FontResolver();
245 }
246 return INSTANCE;
247 }
248 }