[439] | 1 | // Module : $RCSfile: NodeIdentityRule.java,v $ |
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| 2 | // Version : $Revision: 0.0 $ $Author: patrick $ $Date: 19.02.2012 $ |
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| 3 | // Project : TaskTreeCreator |
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| 4 | // Creation : 2012 by patrick |
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| 5 | // Copyright : Patrick Harms, 2012 |
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[557] | 6 | |
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[439] | 7 | package de.ugoe.cs.quest.tasktrees.nodeequality; |
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| 8 | |
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[557] | 9 | import de.ugoe.cs.quest.tasktrees.treeifc.ISelection; |
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| 10 | import de.ugoe.cs.quest.tasktrees.treeifc.ITaskTreeNode; |
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[439] | 11 | |
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| 12 | /** |
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[557] | 13 | * <p> |
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| 14 | * this node comparison rule is capable of comparing selections. If both selections do not have |
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| 15 | * children, they are treated as lexically equal. If they have the same number of children other |
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| 16 | * than 0 and all these children are lexically equal, then the selections are lexically equal. |
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| 17 | * They are syntactically equal, if each child of both selections is syntactically equal to any |
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| 18 | * other child. The rule can not compare semantical equality if the nodes are not at least |
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| 19 | * syntactically equal and returns null, if it can not decide this. |
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| 20 | * </p> |
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[439] | 21 | * |
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| 22 | * @version $Revision: $ $Date: 19.02.2012$ |
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| 23 | * @author 2012, last modified by $Author: patrick$ |
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| 24 | */ |
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[557] | 25 | public class SelectionComparisonRule implements NodeComparisonRule { |
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[439] | 26 | |
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[557] | 27 | /** the rule manager for internally comparing task tree nodes */ |
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| 28 | private NodeEqualityRuleManager mRuleManager; |
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[439] | 29 | |
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[557] | 30 | /** |
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| 31 | * <p> |
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| 32 | * simple constructor to provide the rule with the node equality rule manager to be able |
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| 33 | * to perform comparisons of the children of provided task tree nodes |
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| 34 | * </p> |
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| 35 | * |
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| 36 | * @param ruleManager the rule manager for comparing task tree nodes |
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| 37 | */ |
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| 38 | SelectionComparisonRule(NodeEqualityRuleManager ruleManager) { |
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| 39 | super(); |
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| 40 | mRuleManager = ruleManager; |
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| 41 | } |
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[439] | 42 | |
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[557] | 43 | /* |
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| 44 | * (non-Javadoc) |
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| 45 | * |
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| 46 | * @see de.ugoe.cs.tasktree.nodeequality.NodeEqualityRule#apply(TaskTreeNode, TaskTreeNode) |
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| 47 | */ |
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| 48 | @Override |
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| 49 | public NodeEquality compare(ITaskTreeNode node1, ITaskTreeNode node2) { |
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| 50 | if ((!(node1 instanceof ISelection)) || (!(node2 instanceof ISelection))) { |
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| 51 | return null; |
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[439] | 52 | } |
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[557] | 53 | |
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| 54 | // if both sequences do not have children, they are equal although this doesn't make sense |
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| 55 | if ((node1.getChildren().size() == 0) && (node2.getChildren().size() == 0)) { |
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| 56 | return NodeEquality.LEXICALLY_EQUAL; |
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[439] | 57 | } |
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[557] | 58 | |
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| 59 | // Selections are syntactically equal, if they have children, which are all syntactically |
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| 60 | // equal. |
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| 61 | // They are lexically equals, if they have the same number and order of lexically equal |
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| 62 | // children |
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| 63 | boolean lexicallyEqual = node1.getChildren().size() == node2.getChildren().size(); |
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| 64 | |
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| 65 | for (int i = 0; i < node1.getChildren().size(); i++) { |
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| 66 | ITaskTreeNode child1 = node1.getChildren().get(i); |
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| 67 | boolean foundLexicallyEqualChild = false; |
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| 68 | |
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| 69 | for (int j = 0; j < node2.getChildren().size(); j++) { |
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| 70 | ITaskTreeNode child2 = node2.getChildren().get(j); |
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| 71 | |
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| 72 | NodeEquality nodeEquality = mRuleManager.applyRules(child1, child2); |
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| 73 | |
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| 74 | if (!nodeEquality.isAtLeast(NodeEquality.SYNTACTICALLY_EQUAL)) { |
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| 75 | return null; |
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| 76 | } |
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| 77 | else if (nodeEquality.isAtLeast(NodeEquality.LEXICALLY_EQUAL)) { |
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| 78 | foundLexicallyEqualChild = true; |
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| 79 | } |
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| 80 | } |
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| 81 | |
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| 82 | // if we compare two children at the same position and if they are lexically equal |
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| 83 | // then it can be further expected, that the selections are lexically equal |
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| 84 | lexicallyEqual &= foundLexicallyEqualChild; |
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| 85 | } |
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| 86 | |
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| 87 | if (lexicallyEqual) { |
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| 88 | return NodeEquality.LEXICALLY_EQUAL; |
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| 89 | } |
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| 90 | else { |
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| 91 | return NodeEquality.SYNTACTICALLY_EQUAL; |
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| 92 | } |
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[439] | 93 | } |
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| 94 | } |
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