source: default/trunk/de.ugoe.cs.swe.bnftools.ebnf.ui/src/de/ugoe/cs/swe/bnftools/visitor/EbnfVisitor.java @ 12

package de.ugoe.cs.swe.bnftools.visitor;

import java.util.Stack;

import org.eclipse.emf.ecore.EObject;

import de.ugoe.cs.swe.bnftools.ebnf.Atom;
import de.ugoe.cs.swe.bnftools.ebnf.DefinitionList;
import de.ugoe.cs.swe.bnftools.ebnf.EtsiBnf;
import de.ugoe.cs.swe.bnftools.ebnf.ExtRule;
import de.ugoe.cs.swe.bnftools.ebnf.GlobalCombinator;
import de.ugoe.cs.swe.bnftools.ebnf.GroupedSequence;
import de.ugoe.cs.swe.bnftools.ebnf.HookCombinator;
import de.ugoe.cs.swe.bnftools.ebnf.Import;
import de.ugoe.cs.swe.bnftools.ebnf.MergeRule;
import de.ugoe.cs.swe.bnftools.ebnf.OptionalSequence;
import de.ugoe.cs.swe.bnftools.ebnf.RepeatedSequence;
import de.ugoe.cs.swe.bnftools.ebnf.Rule;
import de.ugoe.cs.swe.bnftools.ebnf.RuleCombinator;
import de.ugoe.cs.swe.bnftools.ebnf.RuleReference;
import de.ugoe.cs.swe.bnftools.ebnf.SectionHeading;
import de.ugoe.cs.swe.bnftools.ebnf.SingleDefinition;
import de.ugoe.cs.swe.bnftools.ebnf.StringRule;
import de.ugoe.cs.swe.bnftools.ebnf.Term;

public abstract class EbnfVisitor {
        
        protected EObject rootNode = null;
        protected Stack<Boolean> lastElementStack = new Stack<Boolean>();
        
        public EbnfVisitor() {
        }

        public EbnfVisitor(EObject rootNode) {
                this.rootNode = rootNode;
        }

        public void accept() {
                if (rootNode != null)
                        accept(rootNode);
        }

        public void accept(EObject node) {
                dispatcherBefore(node);
                acceptInner(node);
                dispatcherAfter(node);
        }

        private void acceptInner(EObject node) {
                Boolean lastElement = false;
                if (node.eContents().size() == 0)
                        lastElement = true;
                lastElementStack.push(lastElement);             
                for (int i=0; i < node.eContents().size(); i++) {
                        EObject currentNode = (EObject) node.eContents().get(i);
                        if (i == node.eContents().size()-1) {
                                lastElement = true;
                                lastElementStack.pop();
                                lastElementStack.push(lastElement);
                        }
                        dispatcherBefore(currentNode);
                        acceptInner(currentNode);
                        dispatcherAfter(currentNode);
                }
                lastElementStack.pop();
        }
        
        protected boolean isLastElement() {
                return lastElementStack.peek();
        }
        
        protected void dispatcherBefore(EObject node) {
                // ugly, but no time to find a prettier solution
                if (node instanceof EtsiBnf) {
                        visitBefore((EtsiBnf) node);
                } else if (node instanceof Atom) {
                        visitBefore((Atom) node);
                } else if (node instanceof DefinitionList) {
                        visitBefore((DefinitionList) node);
                } else if (node instanceof ExtRule) {
                        visitBefore((ExtRule) node);
                } else if (node instanceof GlobalCombinator) {
                        visitBefore((GlobalCombinator) node);
                } else if (node instanceof GroupedSequence) {
                        visitBefore((GroupedSequence) node);
                } else if (node instanceof HookCombinator) {
                        visitBefore((HookCombinator) node);
                } else if (node instanceof Import) {
                        visitBefore((Import) node);
                } else if (node instanceof MergeRule) {
                        visitBefore((MergeRule) node);
                } else if (node instanceof OptionalSequence) {
                        visitBefore((OptionalSequence) node);
                } else if (node instanceof RepeatedSequence) {
                        visitBefore((RepeatedSequence) node);
                } else if (node instanceof Rule) {
                        visitBefore((Rule) node);
                } else if (node instanceof RuleCombinator) {
                        visitBefore((RuleCombinator) node);
                } else if (node instanceof RuleReference) {
                        visitBefore((RuleReference) node);
                } else if (node instanceof SectionHeading) {
                        visitBefore((SectionHeading) node);
                } else if (node instanceof SingleDefinition) {
                        visitBefore((SingleDefinition) node);
                } else if (node instanceof StringRule) {
                        visitBefore((StringRule) node);
                } else if (node instanceof Term) {
                        visitBefore((Term) node);
                }
        }
        
        protected void dispatcherAfter(EObject node) {
                // ugly, but no time to find a prettier solution
                if (node instanceof EtsiBnf) {
                        visitAfter((EtsiBnf) node);
                } else if (node instanceof Atom) {
                        visitAfter((Atom) node);
                } else if (node instanceof DefinitionList) {
                        visitAfter((DefinitionList) node);
                } else if (node instanceof ExtRule) {
                        visitAfter((ExtRule) node);
                } else if (node instanceof GlobalCombinator) {
                        visitAfter((GlobalCombinator) node);
                } else if (node instanceof GroupedSequence) {
                        visitAfter((GroupedSequence) node);
                } else if (node instanceof HookCombinator) {
                        visitAfter((HookCombinator) node);
                } else if (node instanceof Import) {
                        visitAfter((Import) node);
                } else if (node instanceof MergeRule) {
                        visitAfter((MergeRule) node);
                } else if (node instanceof OptionalSequence) {
                        visitAfter((OptionalSequence) node);
                } else if (node instanceof RepeatedSequence) {
                        visitAfter((RepeatedSequence) node);
                } else if (node instanceof Rule) {
                        visitAfter((Rule) node);
                } else if (node instanceof RuleCombinator) {
                        visitAfter((RuleCombinator) node);
                } else if (node instanceof RuleReference) {
                        visitAfter((RuleReference) node);
                } else if (node instanceof SectionHeading) {
                        visitAfter((SectionHeading) node);
                } else if (node instanceof SingleDefinition) {
                        visitAfter((SingleDefinition) node);
                } else if (node instanceof StringRule) {
                        visitAfter((StringRule) node);
                } else if (node instanceof Term) {
                        visitAfter((Term) node);
                }
        }

        protected void visitBefore(EtsiBnf node) {
        }

        protected void visitAfter(EtsiBnf node) {
        }

        protected void visitBefore(Atom node) {
        }

        protected void visitAfter(Atom node) {
        }

        protected void visitBefore(Term node) {
        }

        protected void visitAfter(Term node) {
        }

        protected void visitBefore(DefinitionList node) {
        }

        protected void visitAfter(DefinitionList node) {
        }

        protected void visitBefore(ExtRule node) {
        }

        protected void visitAfter(ExtRule node) {
        }

        protected void visitBefore(GlobalCombinator node) {
        }

        protected void visitAfter(GlobalCombinator node) {
        }

        protected void visitBefore(GroupedSequence node) {
        }

        protected void visitAfter(GroupedSequence node) {
        }

        protected void visitBefore(HookCombinator node) {
        }

        protected void visitAfter(HookCombinator node) {
        }

        protected void visitBefore(Import node) {
        }

        protected void visitAfter(Import node) {
        }

        protected void visitBefore(MergeRule node) {
        }

        protected void visitAfter(MergeRule node) {
        }

        protected void visitBefore(OptionalSequence node) {
        }

        protected void visitAfter(OptionalSequence node) {
        }

        protected void visitBefore(RepeatedSequence node) {
        }

        protected void visitAfter(RepeatedSequence node) {
        }

        protected void visitBefore(Rule node) {
        }

        protected void visitAfter(Rule node) {
        }

        protected void visitBefore(RuleCombinator node) {
        }

        protected void visitAfter(RuleCombinator node) {
        }

        protected void visitBefore(RuleReference node) {
        }

        protected void visitAfter(RuleReference node) {
        }

        protected void visitBefore(SectionHeading node) {
        }

        protected void visitAfter(SectionHeading node) {
        }

        protected void visitBefore(SingleDefinition node) {
        }

        protected void visitAfter(SingleDefinition node) {
        }

        protected void visitBefore(StringRule node) {
        }

        protected void visitAfter(StringRule node) {
        }
        
}