/*
* Copyright 2016 the original author or authors.
*
* 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.gradle.internal.reflect;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Sets;
import org.gradle.internal.Cast;
import java.util.ArrayDeque;
import java.util.Collection;
import java.util.Queue;
import java.util.Set;
public class Types {
private static final Collection<Class<?>> OBJECT_TYPE = ImmutableList.<Class<?>>of(Object.class);
/**
* Visits all types in a type hierarchy in breadth-first order, super-classes first and then implemented interfaces.
*
* @param clazz the type of whose type hierarchy to visit.
* @param visitor the visitor to call for each type in the hierarchy.
*/
public static <T> void walkTypeHierarchy(Class<T> clazz, TypeVisitor<? extends T> visitor) {
walkTypeHierarchy(clazz, OBJECT_TYPE, visitor);
}
/**
* Visits all types in a type hierarchy in breadth-first order, super-classes first and then implemented interfaces.
*
* @param clazz the type of whose type hierarchy to visit.
* @param excludedTypes the types not to walk when encountered in the hierarchy.
* @param visitor the visitor to call for each type in the hierarchy.
*/
public static <T> void walkTypeHierarchy(Class<T> clazz, Collection<Class<?>> excludedTypes, TypeVisitor<? extends T> visitor) {
Set<Class<?>> seenInterfaces = Sets.newHashSet();
Queue<Class<? super T>> queue = new ArrayDeque<Class<? super T>>();
queue.add(clazz);
Class<? super T> type;
while ((type = queue.poll()) != null) {
if (excludedTypes.contains(type)) {
continue;
}
visitor.visitType(type);
Class<? super T> superclass = type.getSuperclass();
if (superclass != null) {
queue.add(superclass);
}
for (Class<?> iface : type.getInterfaces()) {
if (seenInterfaces.add(iface)) {
queue.add(Cast.<Class<? super T>>uncheckedCast(iface));
}
}
}
}
public interface TypeVisitor<T> {
void visitType(Class<? super T> type);
}
}