1 /*

     2  * Portions Copyright 1999-2005 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(new Integer(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 }