platform/lang-impl/src/com/intellij/psi/impl/source/tree/RecursiveTreeElementWalkingVisitor.java

   1 /*
   2  * Copyright 2000-2009 JetBrains s.r.o.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 package com.intellij.psi.impl.source.tree;
  18
  19 import com.intellij.lang.ASTNode;
  20 import com.intellij.psi.WalkingState;
  21 import org.jetbrains.annotations.NotNull;
  22
  23 public abstract class RecursiveTreeElementWalkingVisitor extends TreeElementVisitor{
  24   private final boolean myDoTransform;
  25
  26   protected RecursiveTreeElementWalkingVisitor() {
  27     this(true);
  28   }
  29
  30   protected RecursiveTreeElementWalkingVisitor(boolean doTransform) {
  31     myDoTransform = doTransform;
  32   }
  33
  34   private static class ASTTreeGuide implements WalkingState.TreeGuide<ASTNode> {
  35     public ASTNode getNextSibling(@NotNull ASTNode element) {
  36       return element.getTreeNext();
  37     }
  38
  39     public ASTNode getPrevSibling(@NotNull ASTNode element) {
  40       return element.getTreePrev();
  41     }
  42
  43     public ASTNode getFirstChild(@NotNull ASTNode element) {
  44       return element.getFirstChildNode();
  45     }
  46
  47     public ASTNode getParent(@NotNull ASTNode element) {
  48       return element.getTreeParent();
  49     }
  50
  51     private static final ASTTreeGuide instance = new ASTTreeGuide();
  52   }
  53
  54   private final WalkingState<ASTNode> myWalkingState = new WalkingState<ASTNode>(ASTTreeGuide.instance) {
  55     @Override
  56     public void elementFinished(@NotNull ASTNode element) {
  57
  58     }
  59
  60     @Override
  61     public void visit(@NotNull ASTNode element) {
  62       ((TreeElement)element).acceptTree(RecursiveTreeElementWalkingVisitor.this);
  63     }
  64   };
  65
  66   @Override
  67   public void visitLeaf(LeafElement leaf) {
  68     visitNode(leaf);
  69   }
  70
  71   @Override
  72   public void visitComposite(CompositeElement composite) {
  73     visitNode(composite);
  74   }
  75
  76   protected void visitNode(TreeElement element){
  77     if (myDoTransform || !TreeUtil.isCollapsedChameleon(element)) {
  78       myWalkingState.elementStarted(element);
  79     }
  80   }
  81 }