Home | History | Annotate | Download | only in layout 
      1 //  2016 and later: Unicode, Inc. and others.
      2 // License & terms of use: http://www.unicode.org/copyright.html#License
      3 /*
      4  *******************************************************************************
      5  * Copyright (C) 1998-2007, International Business Machines Corporation and    *
      6  * others. All Rights Reserved.                                                *
      7  *******************************************************************************
      8  *
      9  * Created on Dec 3, 2003
     10  *
     11  *******************************************************************************
     12  */
     13 package com.ibm.icu.dev.tool.layout;
     14 
     15 import java.util.Vector;
     16 
     17 import com.ibm.icu.impl.Utility;
     18 
     19 public class LigatureTreeWalker extends TreeWalker implements LookupSubtable
     20 {
     21     protected int[] componentChars;
     22     protected int componentCount;
     23     protected int lastFirstComponent;
     24 
     25     protected Vector ligatureSets;
     26     protected Vector ligatureSet;
     27 
     28     public LigatureTreeWalker()
     29     {
     30         componentChars = new int[30];
     31         componentCount = 0;
     32         lastFirstComponent = -1;
     33         ligatureSet = null;
     34         ligatureSets = new Vector();
     35     }
     36 
     37     public void down(int ch)
     38     {
     39         componentChars[componentCount] = ch;
     40         componentCount += 1;
     41     }
     42 
     43     public void up()
     44     {
     45         if (componentCount > 0) {
     46             componentCount -= 1;
     47         }
     48     }
     49 
     50     public void ligature(int lig)
     51     {
     52         int firstComponent = componentChars[0];
     53 
     54         if (lastFirstComponent != firstComponent) {
     55             if (ligatureSet != null) {
     56                 ligatureSets.addElement(ligatureSet);
     57             }
     58 
     59             ligatureSet = new Vector();
     60             lastFirstComponent = firstComponent;
     61         }
     62 
     63         ligatureSet.addElement(new LigatureEntry(lig, componentChars, componentCount));
     64     }
     65 
     66     public void done()
     67     {
     68         if (ligatureSet != null) {
     69             ligatureSets.addElement(ligatureSet);
     70         }
     71     }
     72     protected int firstComponentChar(int ligatureSetIndex)
     73     {
     74         Vector aLigatureSet = (Vector) ligatureSets.elementAt(ligatureSetIndex);
     75         LigatureEntry firstEntry = (LigatureEntry) aLigatureSet.elementAt(0);
     76 
     77         return firstEntry.getComponentChar(0);
     78     }
     79 
     80     protected void writeCoverageTable(OpenTypeTableWriter writer)
     81     {
     82         int ligatureSetCount = ligatureSets.size();
     83 
     84         writer.writeData(1);
     85         writer.writeData(ligatureSetCount);
     86 
     87         for (int set = 0; set < ligatureSetCount; set += 1) {
     88             writer.writeData(firstComponentChar(set));
     89         }
     90     }
     91 
     92     public void writeLookupSubtable(OpenTypeTableWriter writer)
     93     {
     94         int coverageOffset, ligatureSetOffset, ligatureTableOffset;
     95         int ligatureSubstitutionBase = writer.getOutputIndex();
     96         int ligatureSetCount = ligatureSets.size();
     97 
     98         //System.out.println("Writing " + tableName + "...");
     99 
    100         writer.writeData(1);   // substFormat
    101 
    102         coverageOffset = writer.getOutputIndex();
    103         writer.writeData(0);   // coverageTableOffset (will fix later)
    104 
    105         writer.writeData(ligatureSetCount);
    106 
    107         ligatureSetOffset = writer.getOutputIndex();
    108         for (int set = 0; set < ligatureSetCount; set += 1) {
    109             writer.writeData(0);  // ligatureSet offset - will fix later
    110         }
    111 
    112         for (int set = 0; set < ligatureSetCount; set += 1) {
    113             System.out.print(Utility.hex(firstComponentChar(set), 6) + ": ");
    114 
    115             Vector aLigatureSet = (Vector) ligatureSets.elementAt(set);
    116             int ligatureCount = aLigatureSet.size();
    117             int ligatureSetAddress = writer.getOutputIndex();
    118 
    119             System.out.println(ligatureCount + " ligatures.");
    120 
    121             writer.fixOffset(ligatureSetOffset++, ligatureSubstitutionBase);
    122             writer.writeData(ligatureCount);
    123 
    124             ligatureTableOffset = writer.getOutputIndex();
    125             for (int lig = 0; lig < ligatureCount; lig += 1) {
    126                 writer.writeData(0);  // ligatureTableOffset (will fix later)
    127             }
    128 
    129             for (int lig = 0; lig < ligatureCount; lig += 1) {
    130                 LigatureEntry entry = (LigatureEntry) aLigatureSet.elementAt(lig);
    131                 int compCount = entry.getComponentCount();
    132 
    133                 writer.fixOffset(ligatureTableOffset++, ligatureSetAddress);
    134                 writer.writeData(entry.getLigature());
    135                 writer.writeData(compCount);
    136 
    137                 for (int comp = 1; comp < compCount; comp += 1) {
    138                     writer.writeData(entry.getComponentChar(comp));
    139                 }
    140             }
    141         }
    142 
    143         writer.fixOffset(coverageOffset, ligatureSubstitutionBase);
    144         writeCoverageTable(writer);
    145     }
    146 }
    147