/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You 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.sun.org.apache.bcel.internal.classfile;

import java.io.DataInput;

import java.io.IOException;

import com.sun.org.apache.bcel.internal.Const;

import com.sun.org.apache.bcel.internal.generic.Type;

import com.sun.org.apache.bcel.internal.util.BCELComparator;

/**

 * This class represents the field info structure, i.e., the representation

 * for a variable in the class. See JVM specification for details.

 *

 */

public final class Field extends FieldOrMethod {

    private static BCELComparator bcelComparator = new BCELComparator() {

        @Override

        public boolean equals( final Object o1, final Object o2 ) {

            final Field THIS = (Field) o1;

            final Field THAT = (Field) o2;

        }

        @Override

        public int hashCode( final Object o ) {

            final Field THIS = (Field) o;

            return THIS.getSignature().hashCode() ^ THIS.getName().hashCode();

        }

    };

    /**

     * Initialize from another object. Note that both objects use the same

     * references (shallow copy). Use clone() for a physical copy.

     */

    public Field(final Field c) {

        super(c);

    }

    /**

     * Construct object from file stream.

     * @param file Input stream

     */

    Field(final DataInput file, final ConstantPool constant_pool) throws IOException,

            ClassFormatException {

        super(file, constant_pool);

    }

    /**

     * @param access_flags Access rights of field

     * @param name_index Points to field name in constant pool

     * @param signature_index Points to encoded signature

     * @param attributes Collection of attributes

     * @param constant_pool Array of constants

     */

    public Field(final int access_flags, final int name_index, final int signature_index, final Attribute[] attributes,

            final ConstantPool constant_pool) {

        super(access_flags, name_index, signature_index, attributes, constant_pool);

    }

    /**

     * Called by objects that are traversing the nodes of the tree implicitely

     * defined by the contents of a Java class. I.e., the hierarchy of methods,

     * fields, attributes, etc. spawns a tree of objects.

     *

     * @param v Visitor object

     */

    @Override

    public void accept( final Visitor v ) {

        v.visitField(this);

    }

    /**

     * @return constant value associated with this field (may be null)

     */

    public final ConstantValue getConstantValue() {

        for (final Attribute attribute : super.getAttributes()) {

            if (attribute.getTag() == Const.ATTR_CONSTANT_VALUE) {

                return (ConstantValue) attribute;

            }

        }

        return null;

    }

    /**

     * Return string representation close to declaration format,

     * `public static final short MAX = 100', e.g..

     *

     * @return String representation of field, including the signature.

     */

    @Override

    public final String toString() {

        String name;

        String signature;

        String access; // Short cuts to constant pool

        // Get names from constant pool

        access = Utility.accessToString(super.getAccessFlags());

        access = access.isEmpty() ? "" : (access + " ");

        signature = Utility.signatureToString(getSignature());

        name = getName();

        final StringBuilder buf = new StringBuilder(64); // CHECKSTYLE IGNORE MagicNumber

        buf.append(access).append(signature).append(" ").append(name);

        final ConstantValue cv = getConstantValue();

        if (cv != null) {

            buf.append(" = ").append(cv);

        }

        for (final Attribute attribute : super.getAttributes()) {

            if (!(attribute instanceof ConstantValue)) {

                buf.append(" [").append(attribute).append("]");

            }

        }

        return buf.toString();

    }

    /**

     * @return deep copy of this field

     */

    public final Field copy( final ConstantPool _constant_pool ) {

        return (Field) copy_(_constant_pool);

    }

    /**

     * @return type of field

     */

    public Type getType() {

        return Type.getReturnType(getSignature());

    }

    /**

     * @return Comparison strategy object

     */

    public static BCELComparator getComparator() {

        return bcelComparator;

    }

    /**

     * @param comparator Comparison strategy object

     */

    public static void setComparator( final BCELComparator comparator ) {

        bcelComparator = comparator;

    }

    /**

     * Return value as defined by given BCELComparator strategy.

     * By default two Field objects are said to be equal when

     * their names and signatures are equal.

     *

     * @see java.lang.Object#equals(java.lang.Object)

     */

    @Override

    public boolean equals( final Object obj ) {

        return bcelComparator.equals(this, obj);

    }

    /**

     * Return value as defined by given BCELComparator strategy.

     * By default return the hashcode of the field's name XOR signature.

     *

     * @see java.lang.Object#hashCode()

     */

    @Override

    public int hashCode() {

        return bcelComparator.hashCode(this);

    }

}