ModifierChanged.java

/*
 * Copyright 2014 Lukas Krejci
 *
 * 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.revapi.java.checks.common;

import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import javax.lang.model.element.Modifier;

import org.revapi.Difference;
import org.revapi.java.spi.CheckBase;
import org.revapi.java.spi.Code;
import org.revapi.java.spi.JavaModelElement;

/**
 * @author Lukas Krejci
 * @since 0.1
 */
public abstract class ModifierChanged extends CheckBase {
    private final boolean added;
    private final Code code;
    private final Modifier modifier;

    protected ModifierChanged(boolean added, Code code, Modifier modifier) {
        this.added = added;
        this.code = code;
        this.modifier = modifier;
    }

    protected final void doVisit(JavaModelElement oldElement, JavaModelElement newElement) {
        if (oldElement == null || newElement == null) {
            return;
        }

        if (isBothPrivate(oldElement, newElement)) {
            return;
        }

        boolean oldHas = oldElement.getDeclaringElement().getModifiers().contains(modifier);
        boolean newHas = newElement.getDeclaringElement().getModifiers().contains(modifier);

        if ((added && !oldHas && newHas) || (!added && oldHas && !newHas)) {
            pushActive(oldElement, newElement);
        }
    }

    @Override
    protected List<Difference> doEnd() {
        ActiveElements<JavaModelElement> elements = popIfActive();
        if (elements == null) {
            return null;
        }

        return Collections.singletonList(createDifference(code, Code.attachmentsFor(elements.oldElement, elements.newElement,
                "oldModifiers", stringify(elements.oldElement.getDeclaringElement().getModifiers()),
                "newModifiers", stringify(elements.newElement.getDeclaringElement().getModifiers()))));
    }

    //ordered according to http://cr.openjdk.java.net/~alundblad/styleguide/index-v6.html
    public static String stringify(Set<Modifier> modifiers) {
        return modifiers.stream()
                .sorted(Comparator.comparingInt(ModifierChanged::score))
                .map(m -> m.name().toLowerCase())
                .collect(Collectors.joining(" "));
    }

    private static int score(Modifier mod) {
        //public
        //private
        //protected
        //abstract
        //static
        //final
        //transient
        //volatile
        //default
        //synchronized
        //native
        //strictfp

        switch (mod) {
            case PUBLIC: return 0;
            case PRIVATE: return 1;
            case PROTECTED: return 2;
            case ABSTRACT: return 3;
            case STATIC: return 4;
            case FINAL: return 5;
            case TRANSIENT: return 6;
            case VOLATILE: return 7;
            case DEFAULT: return 8;
            case SYNCHRONIZED: return 9;
            case NATIVE: return 10;
            case STRICTFP: return 11;
            default:
                return 12;
        }
    }
}