Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /* $Id$ */ package org.apache.fop.complexscripts.scripts; import java.util.Arrays; import java.util.HashMap; import java.util.Map; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.fop.complexscripts.bidi.BidiClass; import org.apache.fop.complexscripts.bidi.BidiConstants; import org.apache.fop.complexscripts.fonts.GlyphDefinitionTable; import org.apache.fop.complexscripts.util.GlyphContextTester; import org.apache.fop.complexscripts.util.GlyphSequence; import org.apache.fop.complexscripts.util.ScriptContextTester; // CSOFF: AvoidNestedBlocksCheck // CSOFF: NoWhitespaceAfterCheck // CSOFF: InnerAssignmentCheck // CSOFF: SimplifyBooleanReturnCheck // CSOFF: LineLengthCheck /** * <p>The <code>ArabicScriptProcessor</code> class implements a script processor for * performing glyph substitution and positioning operations on content associated with the Arabic script.</p> * * <p>This work was originally authored by Glenn Adams (gadams@apache.org).</p> */ public class ArabicScriptProcessor extends DefaultScriptProcessor { /** logging instance */ private static final Log log = LogFactory.getLog(ArabicScriptProcessor.class); // CSOK: ConstantNameCheck /** features to use for substitutions */ private static final String[] gsubFeatures = // CSOK: ConstantNameCheck { "calt", // contextual alternates "ccmp", // glyph composition/decomposition "fina", // final (terminal) forms "init", // initial forms "isol", // isolated formas "liga", // standard ligatures "medi", // medial forms "rlig" // required ligatures }; /** features to use for positioning */ private static final String[] gposFeatures = // CSOK: ConstantNameCheck { "curs", // cursive positioning "kern", // kerning "mark", // mark to base or ligature positioning "mkmk" // mark to mark positioning }; private static class SubstitutionScriptContextTester implements ScriptContextTester { private static Map/*<String,GlyphContextTester>*/ testerMap = new HashMap/*<String,GlyphContextTester>*/(); static { testerMap.put("fina", new GlyphContextTester() { public boolean test(String script, String language, String feature, GlyphSequence gs, int index, int flags) { return inFinalContext(script, language, feature, gs, index, flags); } }); testerMap.put("init", new GlyphContextTester() { public boolean test(String script, String language, String feature, GlyphSequence gs, int index, int flags) { return inInitialContext(script, language, feature, gs, index, flags); } }); testerMap.put("isol", new GlyphContextTester() { public boolean test(String script, String language, String feature, GlyphSequence gs, int index, int flags) { return inIsolateContext(script, language, feature, gs, index, flags); } }); testerMap.put("liga", new GlyphContextTester() { public boolean test(String script, String language, String feature, GlyphSequence gs, int index, int flags) { return inLigatureContext(script, language, feature, gs, index, flags); } }); testerMap.put("medi", new GlyphContextTester() { public boolean test(String script, String language, String feature, GlyphSequence gs, int index, int flags) { return inMedialContext(script, language, feature, gs, index, flags); } }); } public GlyphContextTester getTester(String feature) { return (GlyphContextTester) testerMap.get(feature); } } private static class PositioningScriptContextTester implements ScriptContextTester { private static Map/*<String,GlyphContextTester>*/ testerMap = new HashMap/*<String,GlyphContextTester>*/(); public GlyphContextTester getTester(String feature) { return (GlyphContextTester) testerMap.get(feature); } } private final ScriptContextTester subContextTester; private final ScriptContextTester posContextTester; ArabicScriptProcessor(String script) { super(script); this.subContextTester = new SubstitutionScriptContextTester(); this.posContextTester = new PositioningScriptContextTester(); } /** {@inheritDoc} */ public String[] getSubstitutionFeatures() { return gsubFeatures; } /** {@inheritDoc} */ public ScriptContextTester getSubstitutionContextTester() { return subContextTester; } /** {@inheritDoc} */ public String[] getPositioningFeatures() { return gposFeatures; } /** {@inheritDoc} */ public ScriptContextTester getPositioningContextTester() { return posContextTester; } /** {@inheritDoc} */ @Override public GlyphSequence reorderCombiningMarks(GlyphDefinitionTable gdef, GlyphSequence gs, int[][] gpa, String script, String language) { // a side effect of BIDI reordering is to order combining marks before their base, so we need to override the default here to // prevent double reordering return gs; } private static boolean inFinalContext(String script, String language, String feature, GlyphSequence gs, int index, int flags) { GlyphSequence.CharAssociation a = gs.getAssociation(index); int[] ca = gs.getCharacterArray(false); int nc = gs.getCharacterCount(); if (nc == 0) { return false; } else { int s = a.getStart(); int e = a.getEnd(); if (!hasFinalPrecedingContext(ca, nc, s, e)) { return false; } else if (forcesFinalThisContext(ca, nc, s, e)) { return true; } else if (!hasFinalFollowingContext(ca, nc, s, e)) { return false; } else { return true; } } } private static boolean inInitialContext(String script, String language, String feature, GlyphSequence gs, int index, int flags) { GlyphSequence.CharAssociation a = gs.getAssociation(index); int[] ca = gs.getCharacterArray(false); int nc = gs.getCharacterCount(); if (nc == 0) { return false; } else { int s = a.getStart(); int e = a.getEnd(); if (!hasInitialPrecedingContext(ca, nc, s, e)) { return false; } else if (!hasInitialFollowingContext(ca, nc, s, e)) { return false; } else { return true; } } } private static boolean inIsolateContext(String script, String language, String feature, GlyphSequence gs, int index, int flags) { GlyphSequence.CharAssociation a = gs.getAssociation(index); int nc = gs.getCharacterCount(); if (nc == 0) { return false; } else if ((a.getStart() == 0) && (a.getEnd() == nc)) { return true; } else { return false; } } private static boolean inLigatureContext(String script, String language, String feature, GlyphSequence gs, int index, int flags) { GlyphSequence.CharAssociation a = gs.getAssociation(index); int[] ca = gs.getCharacterArray(false); int nc = gs.getCharacterCount(); if (nc == 0) { return false; } else { int s = a.getStart(); int e = a.getEnd(); if (!hasLigaturePrecedingContext(ca, nc, s, e)) { return false; } else if (!hasLigatureFollowingContext(ca, nc, s, e)) { return false; } else { return true; } } } private static boolean inMedialContext(String script, String language, String feature, GlyphSequence gs, int index, int flags) { GlyphSequence.CharAssociation a = gs.getAssociation(index); int[] ca = gs.getCharacterArray(false); int nc = gs.getCharacterCount(); if (nc == 0) { return false; } else { int s = a.getStart(); int e = a.getEnd(); if (!hasMedialPrecedingContext(ca, nc, s, e)) { return false; } else if (!hasMedialThisContext(ca, nc, s, e)) { return false; } else if (!hasMedialFollowingContext(ca, nc, s, e)) { return false; } else { return true; } } } private static boolean hasFinalPrecedingContext(int[] ca, int nc, int s, int e) { int chp = 0; int clp = 0; for (int i = s; i > 0; i--) { int k = i - 1; if ((k >= 0) && (k < nc)) { chp = ca[k]; clp = BidiClass.getBidiClass(chp); if (clp != BidiConstants.NSM) { break; } } } if (clp != BidiConstants.AL) { return false; } else if (hasIsolateInitial(chp)) { return false; } else { return true; } } private static boolean forcesFinalThisContext(int[] ca, int nc, int s, int e) { int chl = 0; int cll = 0; for (int i = 0, n = e - s; i < n; i++) { int k = n - i - 1; int j = s + k; if ((j >= 0) && (j < nc)) { chl = ca[j]; cll = BidiClass.getBidiClass(chl); if (cll != BidiConstants.NSM) { break; } } } if (cll != BidiConstants.AL) { return false; } if (hasIsolateInitial(chl)) { return true; } else { return false; } } private static boolean hasFinalFollowingContext(int[] ca, int nc, int s, int e) { int chf = 0; int clf = 0; for (int i = e, n = nc; i < n; i++) { chf = ca[i]; clf = BidiClass.getBidiClass(chf); if (clf != BidiConstants.NSM) { break; } } if (clf != BidiConstants.AL) { return true; } else if (hasIsolateFinal(chf)) { return true; } else { return false; } } private static boolean hasInitialPrecedingContext(int[] ca, int nc, int s, int e) { int chp = 0; int clp = 0; for (int i = s; i > 0; i--) { int k = i - 1; if ((k >= 0) && (k < nc)) { chp = ca[k]; clp = BidiClass.getBidiClass(chp); if (clp != BidiConstants.NSM) { break; } } } if (clp != BidiConstants.AL) { return true; } else if (hasIsolateInitial(chp)) { return true; } else { return false; } } private static boolean hasInitialFollowingContext(int[] ca, int nc, int s, int e) { int chf = 0; int clf = 0; for (int i = e, n = nc; i < n; i++) { chf = ca[i]; clf = BidiClass.getBidiClass(chf); if (clf != BidiConstants.NSM) { break; } } if (clf != BidiConstants.AL) { return false; } else if (hasIsolateFinal(chf)) { return false; } else { return true; } } private static boolean hasMedialPrecedingContext(int[] ca, int nc, int s, int e) { int chp = 0; int clp = 0; for (int i = s; i > 0; i--) { int k = i - 1; if ((k >= 0) && (k < nc)) { chp = ca[k]; clp = BidiClass.getBidiClass(chp); if (clp != BidiConstants.NSM) { break; } } } if (clp != BidiConstants.AL) { return false; } else if (hasIsolateInitial(chp)) { return false; } else { return true; } } private static boolean hasMedialThisContext(int[] ca, int nc, int s, int e) { int chf = 0; // first non-NSM char in [s,e) int clf = 0; for (int i = 0, n = e - s; i < n; i++) { int k = s + i; if ((k >= 0) && (k < nc)) { chf = ca[s + i]; clf = BidiClass.getBidiClass(chf); if (clf != BidiConstants.NSM) { break; } } } if (clf != BidiConstants.AL) { return false; } int chl = 0; // last non-NSM char in [s,e) int cll = 0; for (int i = 0, n = e - s; i < n; i++) { int k = n - i - 1; int j = s + k; if ((j >= 0) && (j < nc)) { chl = ca[j]; cll = BidiClass.getBidiClass(chl); if (cll != BidiConstants.NSM) { break; } } } if (cll != BidiConstants.AL) { return false; } if (hasIsolateFinal(chf)) { return false; } else if (hasIsolateInitial(chl)) { return false; } else { return true; } } private static boolean hasMedialFollowingContext(int[] ca, int nc, int s, int e) { int chf = 0; int clf = 0; for (int i = e, n = nc; i < n; i++) { chf = ca[i]; clf = BidiClass.getBidiClass(chf); if (clf != BidiConstants.NSM) { break; } } if (clf != BidiConstants.AL) { return false; } else if (hasIsolateFinal(chf)) { return false; } else { return true; } } private static boolean hasLigaturePrecedingContext(int[] ca, int nc, int s, int e) { return true; } private static boolean hasLigatureFollowingContext(int[] ca, int nc, int s, int e) { int chf = 0; int clf = 0; for (int i = e, n = nc; i < n; i++) { chf = ca[i]; clf = BidiClass.getBidiClass(chf); if (clf != BidiConstants.NSM) { break; } } if (clf == BidiConstants.AL) { return true; } else { return false; } } /** * Ordered array of Unicode scalars designating those Arabic (Script) Letters * which exhibit an isolated form in word initial position. */ private static int[] isolatedInitials = { 0x0621, // HAMZA 0x0622, // ALEF WITH MADDA ABOVE 0x0623, // ALEF WITH HAMZA ABOVE 0x0624, // WAW WITH HAMZA ABOVE 0x0625, // ALEF WITH HAMZA BELOWW 0x0627, // ALEF 0x062F, // DAL 0x0630, // THAL 0x0631, // REH 0x0632, // ZAIN 0x0648, // WAW 0x0671, // ALEF WASLA 0x0672, // ALEF WITH WAVY HAMZA ABOVE 0x0673, // ALEF WITH WAVY HAMZA BELOW 0x0675, // HIGH HAMZA ALEF 0x0676, // HIGH HAMZA WAW 0x0677, // U WITH HAMZA ABOVE 0x0688, // DDAL 0x0689, // DAL WITH RING 0x068A, // DAL WITH DOT BELOW 0x068B, // DAL WITH DOT BELOW AND SMALL TAH 0x068C, // DAHAL 0x068D, // DDAHAL 0x068E, // DUL 0x068F, // DUL WITH THREE DOTS ABOVE DOWNWARDS 0x0690, // DUL WITH FOUR DOTS ABOVE 0x0691, // RREH 0x0692, // REH WITH SMALL V 0x0693, // REH WITH RING 0x0694, // REH WITH DOT BELOW 0x0695, // REH WITH SMALL V BELOW 0x0696, // REH WITH DOT BELOW AND DOT ABOVE 0x0697, // REH WITH TWO DOTS ABOVE 0x0698, // JEH 0x0699, // REH WITH FOUR DOTS ABOVE 0x06C4, // WAW WITH RING 0x06C5, // KIRGHIZ OE 0x06C6, // OE 0x06C7, // U 0x06C8, // YU 0x06C9, // KIRGHIZ YU 0x06CA, // WAW WITH TWO DOTS ABOVE 0x06CB, // VE 0x06CF, // WAW WITH DOT ABOVE 0x06EE, // DAL WITH INVERTED V 0x06EF // REH WITH INVERTED V }; private static boolean hasIsolateInitial(int ch) { return Arrays.binarySearch(isolatedInitials, ch) >= 0; } /** * Ordered array of Unicode scalars designating those Arabic (Script) Letters * which exhibit an isolated form in word final position. */ private static int[] isolatedFinals = { 0x0621 // HAMZA }; private static boolean hasIsolateFinal(int ch) { return Arrays.binarySearch(isolatedFinals, ch) >= 0; } }