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 * 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: LineHeightPropertyMaker.java 985537 2010-08-14 17:17:00Z jeremias $ */

package org.apache.fop.fo.properties;

import org.apache.fop.datatypes.Length;
import org.apache.fop.datatypes.LengthBase;
import org.apache.fop.datatypes.Numeric;
import org.apache.fop.fo.Constants;
import org.apache.fop.fo.FObj;
import org.apache.fop.fo.PropertyList;
import org.apache.fop.fo.expr.PropertyException;

A maker which calculates the line-height property.
This property maker is special because line-height inherits the specified
value, instead of the computed value.
So when a line-height is create based on an attribute, the specified value
is stored in the property and in compute() the stored specified value of
the nearest specified is used to recalculate the line-height.
/**
 * A maker which calculates the line-height property.
 * This property maker is special because line-height inherits the specified
 * value, instead of the computed value.
 * So when a line-height is create based on an attribute, the specified value
 * is stored in the property and in compute() the stored specified value of
 * the nearest specified is used to recalculate the line-height.
 */

public class LineHeightPropertyMaker extends SpaceProperty.Maker {
    
Create a maker for line-height.
Params:
propId – the is for linehight./**
     * Create a maker for line-height.
     * @param propId the is for linehight.
     */
    public LineHeightPropertyMaker(int propId) {
        super(propId);
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    public Property make(PropertyList propertyList, String value, FObj fo)
            throws PropertyException {
        /* if value was specified as a number/length/percentage then
         * conditionality and precedence components are overridden
         */
        Property p = super.make(propertyList, value, fo);
        p.getSpace().setConditionality(
                EnumProperty.getInstance(Constants.EN_RETAIN, "RETAIN"), true);
        p.getSpace().setPrecedence(
                EnumProperty.getInstance(Constants.EN_FORCE, "FORCE"), true);
        return p;
    }

    
Recalculate the line-height value based on the nearest specified
value.
{@inheritDoc}
/**
     * Recalculate the line-height value based on the nearest specified
     * value.
     * {@inheritDoc}
     */
    protected Property compute(PropertyList propertyList) throws PropertyException {
        // recalculate based on last specified value
        // Climb up propertylist and find last spec'd value
        Property specProp = propertyList.getNearestSpecified(propId);
        if (specProp != null) {
            String specVal = specProp.getSpecifiedValue();
            if (specVal != null) {
                return make(propertyList, specVal,
                            propertyList.getParentFObj());
            }
        }
        return null;
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    public Property convertProperty(Property p,
            PropertyList propertyList,
            FObj fo) throws PropertyException {
        Numeric numval = p.getNumeric();
        if (numval != null && numval.getDimension() == 0) {
            if (getPercentBase(propertyList) instanceof LengthBase) {
                Length base = ((LengthBase)getPercentBase(propertyList)).getBaseLength();
                if (base != null && base.isAbsolute()) {
                    p = FixedLength.getInstance(
                            numval.getNumericValue() * base.getNumericValue());
                } else {
                    p = new PercentLength(
                            numval.getNumericValue(), getPercentBase(propertyList));
                }
            }
            Property spaceProp = super.convertProperty(p, propertyList, fo);
            spaceProp.setSpecifiedValue(String.valueOf(numval.getNumericValue()));
            return spaceProp;
        }
        return super.convertProperty(p, propertyList, fo);
    }
}