/*
 * 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.
 */

/* $Id$ */

package org.apache.fop.fo.properties;

import org.apache.fop.datatypes.CompoundDatatype;
import org.apache.fop.fo.FObj;
import org.apache.fop.fo.PropertyList;
import org.apache.fop.fo.expr.PropertyException;

/**
 * Superclass for properties wrapping a LengthPair value
 */
public class LengthPairProperty extends Property implements CompoundDatatype {
    private Property ipd;
    private Property bpd;

    /**
     * Inner class for creating instances of LengthPairProperty
     */
    public static class Maker extends CompoundPropertyMaker {

        /**
         * @param propId name of property for which this Maker should be created
         */
        public Maker(int propId) {
            super(propId);
        }

        /**
         * Create a new empty instance of LengthPairProperty.
         * @return the new instance.
         */
        public Property makeNewProperty() {
            return new LengthPairProperty();
        }

        /**
         * {@inheritDoc}
         */
        public Property convertProperty(Property p, PropertyList propertyList, FObj fo)
            throws PropertyException {
            if (p instanceof LengthPairProperty) {
                return p;
            }
            return super.convertProperty(p, propertyList, fo);
        }
    }

    /**
     * Creates a new LengthPairProperty with empty values.
     */
    public LengthPairProperty() {
        super();
    }

    /**
     * Creates a new LengthPairProperty.
     * @param ipd inline-progression-dimension
     * @param bpd block-progression-dimension
     */
    public LengthPairProperty(Property ipd, Property bpd) {
        this();
        this.ipd = ipd;
        this.bpd = bpd;
    }

    /**
     * Creates a new LengthPairProperty which sets both bpd and ipd to the
     * same value.
     * @param len length for both dimensions
     */
    public LengthPairProperty(Property len) {
        this(len, len);
    }

    /**
     * {@inheritDoc}
     */
    public void setComponent(int cmpId, Property cmpnValue,
                             boolean bIsDefault) {
        if (cmpId == CP_BLOCK_PROGRESSION_DIRECTION) {
            bpd = cmpnValue;
        } else if (cmpId == CP_INLINE_PROGRESSION_DIRECTION) {
            ipd = cmpnValue;
        }
    }

    /**
     * {@inheritDoc}
     */
    public Property getComponent(int cmpId) {
        if (cmpId == CP_BLOCK_PROGRESSION_DIRECTION) {
            return getBPD();
        } else if (cmpId == CP_INLINE_PROGRESSION_DIRECTION) {
            return getIPD();
        } else {
            return null;    // SHOULDN'T HAPPEN
        }
    }

    /**
     * @return Property holding the ipd length
     */
    public Property getIPD() {
        return this.ipd;
    }

    /**
     * @return Property holding the bpd length
     */
    public Property getBPD() {
        return this.bpd;
    }

    /** {@inheritDoc} */
    public String toString() {
        return "LengthPair["
            + "ipd:" + getIPD().getObject()
            + ", bpd:" + getBPD().getObject() + "]";
    }

    /**
     * @return this.lengthPair
     */
    public LengthPairProperty getLengthPair() {
        return this;
    }

    /**
     * @return this.lengthPair cast as an Object
     */
    public Object getObject() {
        return this;
    }

}