platform/lang-api/src/com/intellij/psi/PsiWalkingState.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;
  18
  19 import com.intellij.openapi.diagnostic.Logger;
  20 import org.jetbrains.annotations.NotNull;
  21
  22 /**
  23  * @author cdr
  24  */
  25 public abstract class PsiWalkingState extends WalkingState<PsiElement> {
  26   private static final Logger LOG = Logger.getInstance("#com.intellij.psi.PsiWalkingState");
  27   private final PsiElementVisitor myVisitor;
  28
  29   private static class PsiTreeGuide implements TreeGuide<PsiElement> {
  30     public PsiElement getNextSibling(@NotNull PsiElement element) {
  31       return element.getNextSibling();
  32     }
  33
  34     public PsiElement getPrevSibling(@NotNull PsiElement element) {
  35       return element.getPrevSibling();
  36     }
  37
  38     public PsiElement getFirstChild(@NotNull PsiElement element) {
  39       return element.getFirstChild();
  40     }
  41
  42     public PsiElement getParent(@NotNull PsiElement element) {
  43       return element.getParent();
  44     }
  45
  46     private static final PsiTreeGuide instance = new PsiTreeGuide();
  47   }
  48
  49   protected PsiWalkingState(PsiElementVisitor delegate) {
  50     super(PsiTreeGuide.instance);
  51     myVisitor = delegate;
  52   }
  53
  54   @Override
  55   public void visit(@NotNull PsiElement element) {
  56     element.accept(myVisitor);
  57   }
  58
  59   @Override
  60   public void elementStarted(@NotNull PsiElement element) {
  61     if (!startedWalking && element instanceof PsiCompiledElement) {
  62       // do not walk inside compiled PSI since getNextSibling() is too slow there
  63       LOG.error(element+"; Do not use walking visitor inside compiled PSI since getNextSibling() is too slow there");
  64     }
  65
  66     super.elementStarted(element);
  67   }
  68 }