From 74ba8e86e4e718f0b11b6b91fb464cd2e7d18e14 Mon Sep 17 00:00:00 2001 From: Jeremias Maerki Date: Wed, 5 Oct 2005 18:04:59 +0000 Subject: [PATCH] Test case for showing a problem with the Knuth algorithm. git-svn-id: https://svn.apache.org/repos/asf/xmlgraphics/fop/trunk@295059 13f79535-47bb-0310-9956-ffa450edef68 --- .../apache/fop/KnuthAlgorithmTestCase.java | 142 ++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 test/java/org/apache/fop/KnuthAlgorithmTestCase.java diff --git a/test/java/org/apache/fop/KnuthAlgorithmTestCase.java b/test/java/org/apache/fop/KnuthAlgorithmTestCase.java new file mode 100644 index 000000000..4a7047a75 --- /dev/null +++ b/test/java/org/apache/fop/KnuthAlgorithmTestCase.java @@ -0,0 +1,142 @@ +/* + * Copyright 2005 The Apache Software Foundation. + * + * Licensed 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; + +import java.util.List; + +import org.apache.fop.layoutmgr.BreakingAlgorithm; +import org.apache.fop.layoutmgr.ElementListObserver; +import org.apache.fop.layoutmgr.KnuthBox; +import org.apache.fop.layoutmgr.KnuthGlue; +import org.apache.fop.layoutmgr.KnuthPenalty; +import org.apache.fop.layoutmgr.KnuthSequence; + +import junit.framework.TestCase; + +/** + * Tests the Knuth algorithm implementation. + */ +public class KnuthAlgorithmTestCase extends TestCase { + + /** @see junit.framework.TestCase#setUp() */ + protected void setUp() throws Exception { + super.setUp(); + DebugHelper.registerStandardElementListObservers(); + } + + private KnuthSequence getKnuthSequence1() { + KnuthSequence seq = new KnuthSequence(); + for (int i = 0; i < 5; i++) { + seq.add(new KnuthBox(0, null, true)); + seq.add(new KnuthPenalty(0, KnuthPenalty.INFINITE, false, null, true)); + seq.add(new KnuthGlue(5000, 0, 0, null, true)); + seq.add(new KnuthBox(10000, null, false)); + if (i < 4) { + seq.add(new KnuthPenalty(0, 0, false, null, false)); + seq.add(new KnuthGlue(-5000, 0, 0, null, true)); + } + } + + seq.add(new KnuthPenalty(0, KnuthPenalty.INFINITE, false, null, false)); + seq.add(new KnuthGlue(0, Integer.MAX_VALUE, 0, null, false)); + seq.add(new KnuthPenalty(0, -KnuthPenalty.INFINITE, false, null, false)); + ElementListObserver.observe(seq, "test", null); + return seq; + } + + /** + * Tests a special condition where a negative-length glue occurs directly after a break + * possibility. + * @throws Exception if an error occurs + */ + public void test1() throws Exception { + MyBreakingAlgorithm algo = new MyBreakingAlgorithm(0, 0, true, true); + algo.setConstantLineWidth(30000); + KnuthSequence seq = getKnuthSequence1(); + algo.findBreakingPoints(seq, 1, true, BreakingAlgorithm.ALL_BREAKS); + Part[] parts = algo.getParts(); + assertEquals("Sequence must produce 3 parts", 3, parts.length); + assertEquals(5000, parts[0].difference); + assertEquals(5000, parts[1].difference); + } + + private class Part { + private int difference; + private double ratio; + private int position; + } + + private class MyBreakingAlgorithm extends BreakingAlgorithm { + + private List parts = new java.util.ArrayList(); + + public MyBreakingAlgorithm(int align, int alignLast, boolean first, + boolean partOverflowRecovery) { + super(align, alignLast, first, partOverflowRecovery); + } + + public Part[] getParts() { + return (Part[])parts.toArray(new Part[parts.size()]); + } + + public void updateData1(int total, double demerits) { + //nop + } + + public void updateData2(KnuthNode bestActiveNode, KnuthSequence sequence, int total) { + int difference = bestActiveNode.difference; + // it is always allowed to adjust space, so the ratio must be set regardless of + // the value of the property display-align; the ratio must be <= 1 + double ratio = bestActiveNode.adjustRatio; + if (ratio < 0) { + // page break with a negative difference: + // spaces always have enough shrink + difference = 0; + } else if (ratio <= 1 && bestActiveNode.line < total) { + // not-last page break with a positive difference smaller than the available + // stretch: spaces can stretch to fill the whole difference + difference = 0; + } else if (ratio > 1) { + // not-last page with a positive difference greater than the available stretch + // spaces can stretch to fill the difference only partially + ratio = 1; + difference -= bestActiveNode.availableStretch; + } else { + // last page with a positive difference: + // spaces do not need to stretch + ratio = 0; + } + + // add nodes at the beginning of the list, as they are found + // backwards, from the last one to the first one + Part part = new Part(); + part.difference = difference; + part.ratio = ratio; + part.position = bestActiveNode.position; + parts.add(0, part); + } + + protected int filterActiveNodes() { + //nop + return 0; + } + + } + +} -- 2.39.5