fop/src/java/org/apache/fop/fo/properties/FontShorthandProperty.java

/*
 * Copyright 2006 The Apache Software Foundation.
 * 
 * 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.
 */

/* $Id$ */

package org.apache.fop.fo.properties;

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;

/**
 * Property subclass for the font shorthand
 */
public class FontShorthandProperty extends ListProperty {

    /**
     * Inner class for creating instances of FontShorthandProperty
     */
    public static class Maker extends PropertyMaker {

        private static final int[] PROP_IDS = {
            Constants.PR_FONT_SIZE, Constants.PR_FONT_FAMILY,
            Constants.PR_LINE_HEIGHT, Constants.PR_FONT_STYLE,
            Constants.PR_FONT_VARIANT, Constants.PR_FONT_WEIGHT
        };
        
        /**
         * @param propId ID of the property for which Maker should be created
         */
        public Maker(int propId) {
            super(propId);
        }
        
        /**
         * @see PropertyMaker#make(PropertyList, String, FObj)
         */
        public Property make(PropertyList propertyList, 
                String value, FObj fo) throws PropertyException {
            
            FontShorthandProperty newProp = new FontShorthandProperty();
            newProp.setSpecifiedValue(value);
            
            String specVal = value;
            Property prop = null;
            if ("inherit".equals(specVal)) {
                for (int i = PROP_IDS.length; --i >= 0;) {
                    prop = propertyList.getFromParent(PROP_IDS[i]);
                    newProp.addProperty(prop, i);
                }
            } else {
                /* initialize list with nulls */
                for (int pos = 6; --pos >= 0;) {
                    newProp.addProperty(null, pos);
                }
                prop = checkEnumValues(specVal);
                if (prop == null) {
                    /* not an enum:
                     * value should consist at least of font-size and font-family
                     * separated by a space
                     * mind the possible spaces from quoted font-family names
                     */
                    int spaceIndex = value.indexOf(' ');
                    int quoteIndex = (value.indexOf('\'') == -1)
                        ? value.indexOf('\"') : value.indexOf('\'');
                    if (spaceIndex == -1 
                            || (quoteIndex != -1 && spaceIndex > quoteIndex)) {
                        /* no spaces or first space appears after the first
                         * single/double quote, so malformed value string
                         */
                        throw new PropertyException("Invalid property value: "
                                + "font=\"" + value + "\"");                        
                    } 
                    PropertyMaker m = null;
                    int fromIndex = spaceIndex + 1;
                    int toIndex = specVal.length();
                    /* at least one space that appears before the first
                     * single/double quote, so extract the individual properties
                     */
                    boolean fontFamilyParsed = false;
                    int commaIndex = value.indexOf(',');
                    while (!fontFamilyParsed) {
                        /* value contains a (list of) possibly quoted 
                         * font-family name(s) 
                         */
                        if (commaIndex == -1) {
                            /* no list, just a single name 
                             * (or first name in the list)
                             */
                            m = FObj.getPropertyMakerFor(PROP_IDS[1]);
                            prop = m.make(propertyList, specVal.substring(fromIndex), fo);
                            newProp.addProperty(prop, 1);
                            fontFamilyParsed = true;                            
                        } else {
                            if (quoteIndex != -1 && quoteIndex < commaIndex) {
                                /* a quoted font-family name as first name
                                 * in the comma-separated list
                                 * fromIndex = index of the first quote
                                 */
                                fromIndex = quoteIndex;
                            } else {
                                fromIndex = value.lastIndexOf(' ', commaIndex) + 1;
                            }
                            commaIndex = -1;
                        }
                    }
                    toIndex = fromIndex - 1;
                    fromIndex = value.lastIndexOf(' ', toIndex - 1) + 1;
                    value = specVal.substring(fromIndex, toIndex);
                    int slashIndex = value.indexOf('/');
                    String fontSize = value.substring(0, 
                            (slashIndex == -1) ? value.length() : slashIndex);
                    m = FObj.getPropertyMakerFor(PROP_IDS[0]);
                    prop = m.make(propertyList, fontSize, fo);
                    /* need to make sure subsequent call to LineHeightPropertyMaker.make()
                     * doesn't generate the default font-size property...
                     */
                    propertyList.putExplicit(PROP_IDS[0], prop);
                    newProp.addProperty(prop, 0);
                    if (slashIndex != -1) {
                        /* line-height */
                        String lineHeight = value.substring(slashIndex + 1);
                        m = FObj.getPropertyMakerFor(PROP_IDS[2]);
                        prop = m.make(propertyList, lineHeight, fo);
                        newProp.addProperty(prop, 2);
                    }
                    if (fromIndex != 0) {
                        toIndex = fromIndex - 1;
                        value = specVal.substring(0, toIndex);
                        fromIndex = 0;
                        spaceIndex = value.indexOf(' ');
                        do {
                            toIndex = (spaceIndex == -1) ? value.length() : spaceIndex;
                            String val = value.substring(fromIndex, toIndex);
                            for (int i = 6; --i >= 3;) {
                                if (newProp.list.get(i) == null) {
                                    /* not set */
                                    m = FObj.getPropertyMakerFor(PROP_IDS[i]);
                                    val = m.checkValueKeywords(val);
                                    prop = m.checkEnumValues(val);
                                    if (prop != null) {
                                        newProp.addProperty(prop, i);
                                    }
                                }
                            }
                            fromIndex = toIndex + 1;
                            spaceIndex = value.indexOf(' ', fromIndex);
                        } while (toIndex != value.length());
                    }
                } else {
                    //TODO: implement enum values
                    log.warn("Enum values other than \"inherit\""
                            + " not yet supported for the font shorthand.");
                    return null;
                }
            }
            if (newProp.list.get(0) == null || newProp.list.get(1) == null) {
                throw new PropertyException("Invalid property value: "
                        + "font-size and font-family are required for the font shorthand"
                        + "\nfont=" + value);
            }
            return newProp;
        }

    }
    
    private void addProperty(Property prop, int pos) {
        while (list.size() < (pos + 1)) {
            list.add(null);
        }
        list.set(pos, prop);
    }
}