platform/lang-impl/src/com/intellij/codeInsight/completion/impl/BetterPrefixMatcher.java

/*
 * Copyright 2000-2013 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.codeInsight.completion.impl;

import com.intellij.codeInsight.completion.CompletionResult;
import com.intellij.codeInsight.completion.PrefixMatcher;
import org.jetbrains.annotations.NotNull;

import java.util.LinkedHashSet;

/**
 * @author peter
 */
public class BetterPrefixMatcher extends PrefixMatcher {
  private final PrefixMatcher myOriginal;
  private final int myMinMatchingDegree;

  public BetterPrefixMatcher(PrefixMatcher original, int minMatchingDegree) {
    super(original.getPrefix());
    myOriginal = original;
    myMinMatchingDegree = minMatchingDegree;
  }
  
  public static int getBestMatchingDegree(LinkedHashSet<CompletionResult> plainResults) {
    int bestMatchingDegree = Integer.MIN_VALUE;
    for (CompletionResult cr : plainResults) {
      bestMatchingDegree = Math.max(bestMatchingDegree, RealPrefixMatchingWeigher
        .getBestMatchingDegree(cr.getLookupElement(), cr.getPrefixMatcher()));
    }
    return bestMatchingDegree;
  }

  @Override
  public boolean prefixMatches(@NotNull String name) {
    if (!myOriginal.prefixMatches(name) || !myOriginal.isStartMatch(name)) {
      return false;
    }
    return myOriginal.matchingDegree(name) >= myMinMatchingDegree;
  }

  @Override
  public boolean isStartMatch(String name) {
    return myOriginal.isStartMatch(name);
  }

  @Override
  public int matchingDegree(String string) {
    return myOriginal.matchingDegree(string);
  }

  @NotNull
  @Override
  public PrefixMatcher cloneWithPrefix(@NotNull String prefix) {
    return new BetterPrefixMatcher(myOriginal.cloneWithPrefix(prefix), myMinMatchingDegree);
  }
}