java/java-impl/src/com/intellij/psi/filters/types/AssignableToFilter.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.filters.types;

import com.intellij.psi.*;
import com.intellij.psi.filters.ElementFilter;
import com.intellij.psi.filters.FilterUtil;
import com.intellij.psi.filters.InitializableFilter;
import com.intellij.psi.filters.OrFilter;
import com.intellij.psi.infos.CandidateInfo;

import java.util.ArrayList;
import java.util.List;

/**
 * Created by IntelliJ IDEA.
 * User: ik
 * Date: 28.01.2003
 * Time: 20:53:38
 * To change this template use Options | File Templates.
 */
public class AssignableToFilter implements InitializableFilter{
  private PsiType myType = null;
  private ElementFilter myFilter = null;

  public AssignableToFilter(PsiType type){
    myType = type;
  }

  public AssignableToFilter(){}

  @Override
  public void init(Object[] type){
    myFilter = new OrFilter();
    final List<ElementFilter> filters = new ArrayList<ElementFilter>();
    for (final Object o : type) {
      PsiType currentType = null;
      if (o instanceof PsiType) {
        currentType = (PsiType)o;
      }
      else if (o instanceof PsiClass) {
        final PsiClass psiClass = (PsiClass)o;
        currentType = JavaPsiFacade.getInstance(psiClass.getProject()).getElementFactory().createType(psiClass);
      }
      if (currentType != null) {
        filters.add(new AssignableToFilter(currentType));
      }
    }
    myFilter = new OrFilter(filters.toArray(new ElementFilter[filters.size()]));
  }

  @Override
  public boolean isClassAcceptable(Class hintClass){
    return true;
  }

  @Override
  public boolean isAcceptable(Object element, PsiElement context){
    if(myType != null){
      if(element == null) return false;
      if (element instanceof PsiType) return myType.isAssignableFrom((PsiType) element);
      PsiSubstitutor substitutor = null;
      if(element instanceof CandidateInfo){
        final CandidateInfo info = (CandidateInfo)element;
        substitutor = info.getSubstitutor();
        element = info.getElement();
      }

      PsiType typeByElement = FilterUtil.getTypeByElement((PsiElement)element, context);
      if(substitutor != null) typeByElement = substitutor.substitute(typeByElement);
      return typeByElement != null && typeByElement.isAssignableFrom(myType) && !typeByElement.equals(myType);
    }
    else if(myFilter != null){
      if(element == null) return false;
      return myFilter.isAcceptable(element, context);
    }
    else return false;
  }

  public String toString(){
    if(myType != null)
      return "assignable-to(" + myType + ")";
    else if(myFilter != null) return myFilter.toString();
    return "uninitialized-equals-filter";
  }
}