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- /*
- * 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.BlockKnuthSequence;
- 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 BlockKnuthSequence();
- 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, 0);
- 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, int maxFlagCount) {
- super(align, alignLast, first, partOverflowRecovery, maxFlagCount);
- }
-
- 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;
- }
-
- }
-
- }
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