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- /*
- * 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.bidi;
-
- import java.util.Iterator;
- import java.util.List;
- import java.util.Vector;
-
- import org.apache.commons.logging.Log;
- import org.apache.commons.logging.LogFactory;
-
- import org.apache.fop.fo.CharIterator;
- import org.apache.fop.fo.FONode;
- import org.apache.fop.fo.FObj;
- import org.apache.fop.traits.Direction;
- import org.apache.fop.traits.WritingModeTraits;
- import org.apache.fop.traits.WritingModeTraitsGetter;
- import org.apache.fop.util.CharUtilities;
-
- // CSOFF: LineLengthCheck
-
- /**
- * The <code>DelimitedTextRange</code> class implements the "delimited text range" as described
- * by XML-FO 1.1 §5.8, which contains a flattened sequence of characters. Any FO that generates
- * block areas serves as a delimiter.
- *
- * <p>This work was originally authored by Glenn Adams (gadams@apache.org).</p>
- */
- public class DelimitedTextRange {
- private FONode fn; // node that generates this text range
- private StringBuffer buffer; // flattened character sequence of generating FO nodes
- private List intervals; // list of intervals over buffer of generating FO nodes
- /**
- * Primary constructor.
- * @param fn node that generates this text range
- */
- public DelimitedTextRange(FONode fn) {
- this.fn = fn;
- this.buffer = new StringBuffer();
- this.intervals = new Vector();
- }
- /**
- * Obtain node that generated this text range.
- * @return node that generated this text range
- */
- public FONode getNode() {
- return fn;
- }
- /**
- * Append interval using characters from character iterator IT.
- * @param it character iterator
- * @param fn node that generates interval being appended
- */
- public void append(CharIterator it, FONode fn) {
- if (it != null) {
- int s = buffer.length();
- int e = s;
- while (it.hasNext()) {
- char c = it.nextChar();
- buffer.append(c);
- e++;
- }
- intervals.add(new TextInterval(fn, s, e));
- }
- }
- /**
- * Append interval using character C.
- * @param c character
- * @param fn node that generates interval being appended
- */
- public void append(char c, FONode fn) {
- if (c != 0) {
- int s = buffer.length();
- int e = s + 1;
- buffer.append(c);
- intervals.add(new TextInterval(fn, s, e));
- }
- }
- /**
- * Determine if range is empty.
- * @return true if range is empty
- */
- public boolean isEmpty() {
- return buffer.length() == 0;
- }
- /**
- * Resolve bidirectional levels for this range.
- */
- public void resolve() {
- WritingModeTraitsGetter tg;
- if ((tg = WritingModeTraits.getWritingModeTraitsGetter(getNode())) != null) {
- resolve(tg.getInlineProgressionDirection());
- }
- }
- @Override
- public String toString() {
- StringBuffer sb = new StringBuffer("DR: " + fn.getLocalName() + " { <" + CharUtilities.toNCRefs(buffer.toString()) + ">");
- sb.append(", intervals <");
- boolean first = true;
- for (Iterator it = intervals.iterator(); it.hasNext(); ) {
- TextInterval ti = (TextInterval) it.next();
- if (first) {
- first = false;
- } else {
- sb.append(',');
- }
- sb.append(ti.toString());
- }
- sb.append("> }");
- return sb.toString();
- }
- private void resolve(Direction paragraphEmbeddingLevel) {
- int [] levels;
- if ((levels = UnicodeBidiAlgorithm.resolveLevels(buffer, paragraphEmbeddingLevel)) != null) {
- assignLevels(levels);
- assignBlockLevel(paragraphEmbeddingLevel);
- assignTextLevels();
- }
- }
- /**
- * <p>Assign resolved levels to all text intervals of this delimited text range.</p>
- * <p>Has a possible side effect of replacing the intervals array with a new array
- * containing new text intervals, such that each text interval is associated with
- * a single level run.</p>
- * @param levels array of levels each corresponding to each index of the delimited
- * text range
- */
- private void assignLevels(int[] levels) {
- Vector intervalsNew = new Vector(intervals.size());
- for (Iterator it = intervals.iterator(); it.hasNext(); ) {
- TextInterval ti = (TextInterval) it.next();
- intervalsNew.addAll(assignLevels(ti, levels));
- }
- if (!intervalsNew.equals(intervals)) {
- intervals = intervalsNew;
- }
- }
- /**
- * <p>Assign resolved levels to a specified text interval over this delimited text
- * range.</p>
- * <p>Returns a list of text intervals containing either (1) the single, input text
- * interval or (2) two or more new text intervals obtained from sub-dividing the input
- * text range into level runs, i.e., runs of text assigned to a single level.</p>
- * @param ti a text interval to which levels are to be assigned
- * @param levels array of levels each corresponding to each index of the delimited
- * text range
- * @return a list of text intervals as described above
- */
- private static final Log log = LogFactory.getLog(BidiResolver.class);
- private List assignLevels(TextInterval ti, int[] levels) {
- Vector tiv = new Vector();
- FONode fn = ti.getNode();
- int fnStart = ti.getStart(); // start of node's text in delimited text range
- for (int i = fnStart, n = ti.getEnd(); i < n; ) {
- int s = i; // inclusive start index of interval in delimited text range
- int e = s; // exclusive end index of interval in delimited text range
- int l = levels [ s ]; // current run level
- while (e < n) { // skip to end of run level or end of interval
- if (levels [ e ] != l) {
- break;
- } else {
- e++;
- }
- }
- if ((ti.getStart() == s) && (ti.getEnd() == e)) {
- ti.setLevel(l); // reuse interval, assigning it single level
- } else {
- ti = new TextInterval(fn, fnStart, s, e, l); // subdivide interval
- }
- if (log.isDebugEnabled()) {
- log.debug("AL(" + l + "): " + ti);
- }
- tiv.add(ti);
- i = e;
- }
- return tiv;
- }
- /**
- * <p>Assign resolved levels for each interval to source #PCDATA in the associated FOText.</p>
- */
- private void assignTextLevels() {
- for (Iterator it = intervals.iterator(); it.hasNext(); ) {
- TextInterval ti = (TextInterval) it.next();
- ti.assignTextLevels();
- }
- }
- private void assignBlockLevel(Direction paragraphEmbeddingLevel) {
- int defaultLevel = (paragraphEmbeddingLevel == Direction.RL) ? 1 : 0;
- for (Iterator it = intervals.iterator(); it.hasNext(); ) {
- TextInterval ti = (TextInterval) it.next();
- assignBlockLevel(ti.getNode(), defaultLevel);
- }
- }
- private void assignBlockLevel(FONode node, int defaultLevel) {
- for (FONode fn = node; fn != null; fn = fn.getParent()) {
- if (fn instanceof FObj) {
- FObj fo = (FObj) fn;
- if (fo.isBidiRangeBlockItem()) {
- if (fo.getBidiLevel() < 0) {
- fo.setBidiLevel(defaultLevel);
- }
- break;
- }
- }
- }
- }
- }
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