platform/core-impl/src/com/intellij/psi/impl/source/resolve/reference/impl/CachingReference.java

/*
 * Copyright 2000-2009 JetBrains s.r.o.
 *
 * 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.
 */
package com.intellij.psi.impl.source.resolve.reference.impl;

import com.intellij.psi.ElementManipulator;
import com.intellij.psi.ElementManipulators;
import com.intellij.psi.PsiElement;
import com.intellij.psi.PsiReference;
import com.intellij.psi.impl.source.resolve.ResolveCache;
import com.intellij.util.IncorrectOperationException;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;

/**
 * @author peter
 */
public abstract class CachingReference implements PsiReference {
  @Override
  public PsiElement resolve(){
    return ResolveCache.getInstance(getElement().getProject()).resolveWithCaching(this, MyResolver.INSTANCE, false, false);
  }

  @Nullable
  public abstract PsiElement resolveInner();

  @Override
  public boolean isReferenceTo(final PsiElement element) {
    return getElement().getManager().areElementsEquivalent(resolve(), element);
  }

  @Override
  public boolean isSoft(){
    return false;
  }

  @NotNull
  public static <T extends PsiElement> ElementManipulator<T> getManipulator(T currentElement){
    ElementManipulator<T> manipulator = ElementManipulators.getManipulator(currentElement);
    if (manipulator == null) {
      throw new IncorrectOperationException("Manipulator for this element is not defined: " + currentElement + "; " + currentElement.getClass());
    }
    return manipulator;
  }

  private static class MyResolver implements ResolveCache.Resolver {
    private static final MyResolver INSTANCE = new MyResolver();
    @Override
    @Nullable
    public PsiElement resolve(@NotNull PsiReference ref, boolean incompleteCode) {
      return ((CachingReference)ref).resolveInner();
    }
  }
  
}