GrMethodComparator.java

/*
 * Copyright 2000-2015 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 org.jetbrains.plugins.groovy.lang.resolve;

import com.intellij.openapi.extensions.ExtensionPointName;
import com.intellij.psi.PsiElement;
import com.intellij.psi.PsiMethod;
import com.intellij.psi.PsiType;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.plugins.groovy.lang.psi.api.statements.typedef.members.GrGdkMethod;
import org.jetbrains.plugins.groovy.lang.psi.impl.GroovyMethodResult;

/**
 * @author Max Medvedev
 */
public abstract class GrMethodComparator {

  public static final ExtensionPointName<GrMethodComparator> EP_NAME = ExtensionPointName.create("org.intellij.groovy.methodComparator");

  public interface Context {

    @Nullable
    PsiType[] getArgumentTypes();

    @Nullable
    PsiType[] getTypeArguments();

    @Nullable
    PsiType getThisType();

    @NotNull
    PsiElement getPlace();

    boolean isConstructor();
  }

  public abstract Boolean dominated(@NotNull GroovyMethodResult result1,
                                    @NotNull GroovyMethodResult result2,
                                    @NotNull Context context);

  /**
   * @return method1 has more general parameter types than method2
   */
  @NotNull
  public static Boolean checkDominated(@NotNull GroovyMethodResult result1,
                                       @NotNull GroovyMethodResult result2,
                                       @NotNull Context context) {
    for (GrMethodComparator comparator : EP_NAME.getExtensions()) {
      Boolean result = comparator.dominated(result1, result2, context);
      if (result != null) {
        return result;
      }
    }
    return true;
  }

  /**
   * @return <ul>
   * <li>1 if second is more preferable</li>
   * <li>0 if methods are equal</li>
   * <li>-1 if first is more preferable</li>
   * </ul>
   */
  public static int compareMethods(@NotNull GroovyMethodResult result1, @NotNull GroovyMethodResult result2, @NotNull Context context) {
    final PsiMethod method1 = result1.getElement();
    final PsiMethod method2 = result2.getElement();

    if (!method1.getName().equals(method2.getName())) return 0;

    boolean firstIsPreferable = checkDominated(result2, result1, context);
    boolean secondIsPreferable = checkDominated(result1, result2, context);

    if (secondIsPreferable) {
      if (firstIsPreferable) {
        if (method2 instanceof GrGdkMethod && !(method1 instanceof GrGdkMethod)) {
          return -1;
        }
      }
      return 1;
    }

    if (firstIsPreferable) {
      return -1;
    }

    return 0;
  }
}