/*
* Copyright 2000-2011 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.lookup;
import com.intellij.openapi.util.Pair;
import com.intellij.util.Function;
import com.intellij.util.ProcessingContext;
import com.intellij.util.SmartList;
import com.intellij.util.containers.ContainerUtil;
import com.intellij.util.containers.FlatteningIterator;
import org.jetbrains.annotations.NotNull;
import org.jetbrains.annotations.Nullable;
import java.util.*;
/**
* @author peter
*/
public abstract class ComparingClassifier<T> extends Classifier<T> {
private final boolean myNegated;
protected ComparingClassifier(Classifier<T> next, String name, boolean negated) {
super(next, name);
myNegated = negated;
}
@Nullable
public abstract Comparable getWeight(T t, ProcessingContext context);
@NotNull
@Override
public Iterable<T> classify(@NotNull final Iterable<T> source, @NotNull final ProcessingContext context) {
List<T> nulls = null;
TreeMap<Comparable, List<T>> map = new TreeMap<Comparable, List<T>>();
for (T t : source) {
final Comparable weight = getWeight(t, context);
if (weight == null) {
if (nulls == null) nulls = new SmartList<T>();
nulls.add(t);
} else {
List<T> list = map.get(weight);
if (list == null) {
map.put(weight, list = new SmartList<T>());
}
list.add(t);
}
}
final List<List<T>> values = new ArrayList<List<T>>();
values.addAll(myNegated ? map.descendingMap().values() : map.values());
ContainerUtil.addIfNotNull(values, nulls);
return new Iterable<T>() {
@Override
public Iterator<T> iterator() {
return new FlatteningIterator<List<T>, T>(values.iterator()) {
@Override
protected Iterator<T> createValueIterator(List<T> group) {
return myNext.classify(group, context).iterator();
}
};
}
};
}
@NotNull
@Override
public List<Pair<T, Object>> getSortingWeights(@NotNull Iterable<T> items, @NotNull final ProcessingContext context) {
return ContainerUtil.map(items, new Function<T, Pair<T, Object>>() {
@Override
public Pair<T, Object> fun(T t) {
return new Pair<T, Object>(t, getWeight(t, context));
}
});
}
}