/*
 * 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: IFSerializer.java 1814395 2017-11-06 11:56:26Z ssteiner $ */

package org.apache.fop.render.intermediate;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Paint;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.geom.AffineTransform;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Map;

import org.w3c.dom.Document;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;

import org.apache.xmlgraphics.image.loader.ImageManager;
import org.apache.xmlgraphics.image.loader.ImageSessionContext;
import org.apache.xmlgraphics.util.QName;
import org.apache.xmlgraphics.util.XMLizable;

import org.apache.fop.accessibility.StructureTreeEventHandler;
import org.apache.fop.fo.extensions.InternalElementMapping;
import org.apache.fop.fonts.FontInfo;
import org.apache.fop.render.DefaultRendererConfigurator;
import org.apache.fop.render.RenderingContext;
import org.apache.fop.render.intermediate.IFRendererConfig.IFRendererConfigParser;
import org.apache.fop.render.intermediate.IFStructureTreeBuilder.IFStructureTreeElement;
import org.apache.fop.render.intermediate.extensions.AbstractAction;
import org.apache.fop.render.intermediate.extensions.Bookmark;
import org.apache.fop.render.intermediate.extensions.BookmarkTree;
import org.apache.fop.render.intermediate.extensions.DocumentNavigationExtensionConstants;
import org.apache.fop.render.intermediate.extensions.Link;
import org.apache.fop.render.intermediate.extensions.NamedDestination;
import org.apache.fop.traits.BorderProps;
import org.apache.fop.traits.RuleStyle;
import org.apache.fop.util.ColorUtil;
import org.apache.fop.util.DOM2SAX;
import org.apache.fop.util.LanguageTags;
import org.apache.fop.util.XMLConstants;
import org.apache.fop.util.XMLUtil;


IFPainter implementation that serializes the intermediate format to XML.
/**
 * IFPainter implementation that serializes the intermediate format to XML.
 */
public class IFSerializer extends AbstractXMLWritingIFDocumentHandler
implements IFConstants, IFPainter, IFDocumentNavigationHandler {

    
Intermediate Format (IF) version, used to express an @version attribute
in the root element of the IF document, the initial value of which
is set to '2.0' to signify that something preceded it (but didn't
happen to be marked as such), and that this version is not necessarily
backwards compatible with the unmarked (<2.0) version.
/**
     * Intermediate Format (IF) version, used to express an @version attribute
     * in the root element of the IF document, the initial value of which
     * is set to '2.0' to signify that something preceded it (but didn't
     * happen to be marked as such), and that this version is not necessarily
     * backwards compatible with the unmarked (&lt;2.0) version.
     */
    public static final String VERSION = "2.0";

    private IFDocumentHandler mimicHandler;
    private int pageSequenceIndex; // used for accessibility

    
Holds the intermediate format state /** Holds the intermediate format state */
    private IFState state;

    private String currentID = "";

    private IFStructureTreeBuilder structureTreeBuilder;

    public IFSerializer(IFContext context) {
        super(context);
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    protected String getMainNamespace() {
        return NAMESPACE;
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public boolean supportsPagesOutOfOrder() {
        return false;
        //Theoretically supported but disabled to improve performance when
        //rendering the IF to the final format later on
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public String getMimeType() {
        return MIME_TYPE;
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public IFDocumentHandlerConfigurator getConfigurator() {
        if (this.mimicHandler != null) {
            return getMimickedDocumentHandler().getConfigurator();
        } else {
            return new DefaultRendererConfigurator(getUserAgent(), new IFRendererConfigParser());
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    public IFDocumentNavigationHandler getDocumentNavigationHandler() {
        return this;
    }

    
Tells this serializer to mimic the given document handler (mostly applies to the font set
that is used during layout).
Params:
targetHandler – the document handler to mimic/**
     * Tells this serializer to mimic the given document handler (mostly applies to the font set
     * that is used during layout).
     * @param targetHandler the document handler to mimic
     */
    public void mimicDocumentHandler(IFDocumentHandler targetHandler) {
        this.mimicHandler = targetHandler;
    }

    
Returns the document handler that is being mimicked by this serializer.
Returns:
the mimicked document handler or null if no such document handler has been set/**
     * Returns the document handler that is being mimicked by this serializer.
     * @return the mimicked document handler or null if no such document handler has been set
     */
    public IFDocumentHandler getMimickedDocumentHandler() {
        return this.mimicHandler;
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public FontInfo getFontInfo() {
        if (this.mimicHandler != null) {
            return this.mimicHandler.getFontInfo();
        } else {
            return null;
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void setFontInfo(FontInfo fontInfo) {
        if (this.mimicHandler != null) {
            this.mimicHandler.setFontInfo(fontInfo);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void setDefaultFontInfo(FontInfo fontInfo) {
        if (this.mimicHandler != null) {
            this.mimicHandler.setDefaultFontInfo(fontInfo);
        }
    }

    @Override
    public StructureTreeEventHandler getStructureTreeEventHandler() {
        if (structureTreeBuilder == null) {
            structureTreeBuilder = new IFStructureTreeBuilder();
        }
        return structureTreeBuilder;
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    public void startDocument() throws IFException {
        super.startDocument();
        try {
            handler.startDocument();
            handler.startPrefixMapping("", NAMESPACE);
            handler.startPrefixMapping(XLINK_PREFIX, XLINK_NAMESPACE);
            handler.startPrefixMapping(DocumentNavigationExtensionConstants.PREFIX,
                    DocumentNavigationExtensionConstants.NAMESPACE);
            handler.startPrefixMapping(InternalElementMapping.STANDARD_PREFIX,
                    InternalElementMapping.URI);
            AttributesImpl atts = new AttributesImpl();
            addAttribute(atts, "version", VERSION);
            handler.startElement(EL_DOCUMENT, atts);
        } catch (SAXException e) {
            throw new IFException("SAX error in startDocument()", e);
        }
    }

    @Override
    public void setDocumentLocale(Locale locale) {
        AttributesImpl atts  = new AttributesImpl();
        atts.addAttribute(XML_NAMESPACE, "lang", "xml:lang", XMLUtil.CDATA,
                LanguageTags.toLanguageTag(locale));
        try {
            handler.startElement(EL_LOCALE, atts);
            handler.endElement(EL_LOCALE);
        } catch (SAXException e) {
            throw new RuntimeException("Unable to create the " + EL_LOCALE + " element.", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    public void startDocumentHeader() throws IFException {
        try {
            handler.startElement(EL_HEADER);
        } catch (SAXException e) {
            throw new IFException("SAX error in startDocumentHeader()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    public void endDocumentHeader() throws IFException {
        try {
            handler.endElement(EL_HEADER);
        } catch (SAXException e) {
            throw new IFException("SAX error in startDocumentHeader()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    public void startDocumentTrailer() throws IFException {
        try {
            handler.startElement(EL_TRAILER);
        } catch (SAXException e) {
            throw new IFException("SAX error in startDocumentTrailer()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    public void endDocumentTrailer() throws IFException {
        try {
            handler.endElement(EL_TRAILER);
        } catch (SAXException e) {
            throw new IFException("SAX error in endDocumentTrailer()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void endDocument() throws IFException {
        try {
            handler.endElement(EL_DOCUMENT);
            handler.endDocument();
            finishDocumentNavigation();
        } catch (SAXException e) {
            throw new IFException("SAX error in endDocument()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void startPageSequence(String id) throws IFException {
        try {
            AttributesImpl atts = new AttributesImpl();
            if (id != null) {
                atts.addAttribute(XML_NAMESPACE, "id", "xml:id", XMLUtil.CDATA, id);
            }
            Locale lang = getContext().getLanguage();
            if (lang != null) {
                atts.addAttribute(XML_NAMESPACE, "lang", "xml:lang", XMLUtil.CDATA,
                        LanguageTags.toLanguageTag(lang));
            }
            XMLUtil.addAttribute(atts, XMLConstants.XML_SPACE, "preserve");
            addForeignAttributes(atts);
            handler.startElement(EL_PAGE_SEQUENCE, atts);
            if (this.getUserAgent().isAccessibilityEnabled()) {
                assert (structureTreeBuilder != null);
                structureTreeBuilder.replayEventsForPageSequence(handler, pageSequenceIndex++);
            }
        } catch (SAXException e) {
            throw new IFException("SAX error in startPageSequence()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void endPageSequence() throws IFException {
        try {

            handler.endElement(EL_PAGE_SEQUENCE);
        } catch (SAXException e) {
            throw new IFException("SAX error in endPageSequence()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void startPage(int index, String name, String pageMasterName, Dimension size)
            throws IFException {
        try {
            AttributesImpl atts = new AttributesImpl();
            addAttribute(atts, "index", Integer.toString(index));
            addAttribute(atts, "name", name);
            if (pageMasterName != null) {
                //fox:external-document doesn't have a page-master
                addAttribute(atts, "page-master-name", pageMasterName);
            }
            addAttribute(atts, "width", Integer.toString(size.width));
            addAttribute(atts, "height", Integer.toString(size.height));
            addForeignAttributes(atts);
            getContext().setPageIndex(index);
            handler.startElement(EL_PAGE, atts);
        } catch (SAXException e) {
            throw new IFException("SAX error in startPage()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    public void startPageHeader() throws IFException {
        try {
            handler.startElement(EL_PAGE_HEADER);
            if (this.getUserAgent().isAccessibilityEnabled()) {
                structureTreeBuilder.replayEventsForRetrievedMarkers(handler);
            }
        } catch (SAXException e) {
            throw new IFException("SAX error in startPageHeader()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    public void endPageHeader() throws IFException {
        try {
            handler.endElement(EL_PAGE_HEADER);
        } catch (SAXException e) {
            throw new IFException("SAX error in endPageHeader()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public IFPainter startPageContent() throws IFException {
        try {
            handler.startElement(EL_PAGE_CONTENT);
            this.state = IFState.create();
            return this;
        } catch (SAXException e) {
            throw new IFException("SAX error in startPageContent()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void endPageContent() throws IFException {
        try {
            this.state = null;
            currentID = "";
            handler.endElement(EL_PAGE_CONTENT);
        } catch (SAXException e) {
            throw new IFException("SAX error in endPageContent()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    public void startPageTrailer() throws IFException {
        try {
            handler.startElement(EL_PAGE_TRAILER);
        } catch (SAXException e) {
            throw new IFException("SAX error in startPageTrailer()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    @Override
    public void endPageTrailer() throws IFException {
        try {
            commitNavigation();
            handler.endElement(EL_PAGE_TRAILER);
        } catch (SAXException e) {
            throw new IFException("SAX error in endPageTrailer()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void endPage() throws IFException {
        try {
            handler.endElement(EL_PAGE);
            getContext().setPageIndex(-1);
        } catch (SAXException e) {
            throw new IFException("SAX error in endPage()", e);
        }
    }

    //---=== IFPainter ===---

    
{@inheritDoc} /** {@inheritDoc} */
    public void startViewport(AffineTransform transform, Dimension size, Rectangle clipRect)
            throws IFException {
        startViewport(IFUtil.toString(transform), size, clipRect);
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void startViewport(AffineTransform[] transforms, Dimension size, Rectangle clipRect)
            throws IFException {
        startViewport(IFUtil.toString(transforms), size, clipRect);
    }

    private void startViewport(String transform, Dimension size, Rectangle clipRect)
            throws IFException {
        try {
            AttributesImpl atts = new AttributesImpl();
            if (transform != null && transform.length() > 0) {
                addAttribute(atts, "transform", transform);
            }
            addAttribute(atts, "width", Integer.toString(size.width));
            addAttribute(atts, "height", Integer.toString(size.height));
            if (clipRect != null) {
                addAttribute(atts, "clip-rect", IFUtil.toString(clipRect));
            }
            handler.startElement(EL_VIEWPORT, atts);
        } catch (SAXException e) {
            throw new IFException("SAX error in startViewport()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void endViewport() throws IFException {
        try {
            handler.endElement(EL_VIEWPORT);
        } catch (SAXException e) {
            throw new IFException("SAX error in endViewport()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void startGroup(AffineTransform[] transforms, String layer) throws IFException {
        startGroup(IFUtil.toString(transforms), layer);
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void startGroup(AffineTransform transform, String layer) throws IFException {
        startGroup(IFUtil.toString(transform), layer);
    }

    private void startGroup(String transform, String layer) throws IFException {
        try {
            AttributesImpl atts = new AttributesImpl();
            if (transform != null && transform.length() > 0) {
                addAttribute(atts, "transform", transform);
            }
            if (layer != null && layer.length() > 0) {
                addAttribute(atts, "layer", layer);
            }
            handler.startElement(EL_GROUP, atts);
        } catch (SAXException e) {
            throw new IFException("SAX error in startGroup()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void endGroup() throws IFException {
        try {
            handler.endElement(EL_GROUP);
        } catch (SAXException e) {
            throw new IFException("SAX error in endGroup()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void drawImage(String uri, Rectangle rect) throws IFException {
        try {
            addID();
            AttributesImpl atts = new AttributesImpl();
            addAttribute(atts, XLINK_HREF, uri);
            addAttribute(atts, "x", Integer.toString(rect.x));
            addAttribute(atts, "y", Integer.toString(rect.y));
            addAttribute(atts, "width", Integer.toString(rect.width));
            addAttribute(atts, "height", Integer.toString(rect.height));
            addForeignAttributes(atts);
            addStructureReference(atts);
            handler.element(EL_IMAGE, atts);
        } catch (SAXException e) {
            throw new IFException("SAX error in startGroup()", e);
        } finally {
            ImageSessionContext session = getUserAgent().getImageSessionContext();
            ImageManager imageManager = getUserAgent().getImageManager();
            imageManager.closeImage(uri, session);
        }
    }

    private void addForeignAttributes(AttributesImpl atts) throws SAXException {
        Map foreignAttributes = getContext().getForeignAttributes();
        if (!foreignAttributes.isEmpty()) {
            for (Object o : foreignAttributes.entrySet()) {
                Map.Entry entry = (Map.Entry) o;
                addAttribute(atts, (QName) entry.getKey(), entry.getValue().toString());
            }
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void drawImage(Document doc, Rectangle rect) throws IFException {
        try {
            addID();
            AttributesImpl atts = new AttributesImpl();
            addAttribute(atts, "x", Integer.toString(rect.x));
            addAttribute(atts, "y", Integer.toString(rect.y));
            addAttribute(atts, "width", Integer.toString(rect.width));
            addAttribute(atts, "height", Integer.toString(rect.height));
            addForeignAttributes(atts);
            addStructureReference(atts);
            handler.startElement(EL_IMAGE, atts);
            new DOM2SAX(handler).writeDocument(doc, true);
            handler.endElement(EL_IMAGE);
        } catch (SAXException e) {
            throw new IFException("SAX error in startGroup()", e);
        }
    }

    private static String toString(Paint paint) {
        if (paint instanceof Color) {
            return ColorUtil.colorToString((Color)paint);
        } else {
            throw new UnsupportedOperationException("Paint not supported: " + paint);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void clipRect(Rectangle rect) throws IFException {
        try {
            AttributesImpl atts = new AttributesImpl();
            addAttribute(atts, "x", Integer.toString(rect.x));
            addAttribute(atts, "y", Integer.toString(rect.y));
            addAttribute(atts, "width", Integer.toString(rect.width));
            addAttribute(atts, "height", Integer.toString(rect.height));
            handler.element(EL_CLIP_RECT, atts);
        } catch (SAXException e) {
            throw new IFException("SAX error in clipRect()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void clipBackground(Rectangle rect, BorderProps bpsBefore, BorderProps bpsAfter,
            BorderProps bpsStart, BorderProps bpsEnd) throws IFException {
        try {
            AttributesImpl atts = new AttributesImpl();
            addAttribute(atts, "x", Integer.toString(rect.x));
            addAttribute(atts, "y", Integer.toString(rect.y));
            addAttribute(atts, "width", Integer.toString(rect.width));
            addAttribute(atts, "height", Integer.toString(rect.height));
            if (hasRoundedCorners(bpsBefore, bpsAfter, bpsStart, bpsEnd)) {

                if (bpsBefore != null) {
                    addAttribute(atts, "top", bpsBefore.toString());
                }
                if (bpsAfter != null) {
                    addAttribute(atts, "bottom", bpsAfter.toString());
                }
                if (bpsStart != null) {
                    addAttribute(atts, "left", bpsStart.toString());
                }
                if (bpsEnd != null) {
                    addAttribute(atts, "right", bpsEnd.toString());
                }
            }
            handler.element(EL_CLIP_RECT, atts);
        } catch (SAXException e) {
            throw new IFException("SAX error in clipRect()", e);
        }
    }


    
{@inheritDoc} /** {@inheritDoc} */
    public void fillRect(Rectangle rect, Paint fill) throws IFException {
        if (fill == null) {
            return;
        }
        try {
            AttributesImpl atts = new AttributesImpl();
            addAttribute(atts, "x", Integer.toString(rect.x));
            addAttribute(atts, "y", Integer.toString(rect.y));
            addAttribute(atts, "width", Integer.toString(rect.width));
            addAttribute(atts, "height", Integer.toString(rect.height));
            addAttribute(atts, "fill", toString(fill));
            handler.element(EL_RECT, atts);
        } catch (SAXException e) {
            throw new IFException("SAX error in fillRect()", e);
        }
    }

    //TODO create a class representing all borders should exist
    //with query methods like this
    private boolean hasRoundedCorners(BorderProps bpsBefore, BorderProps bpsAfter,
            BorderProps bpsStart, BorderProps bpsEnd) {
        boolean rtn = false;

        if (bpsBefore != null && bpsBefore.getRadiusStart() > 0
                && bpsStart != null && bpsStart.getRadiusStart() > 0) {
            rtn = true;
        }

        if (bpsBefore != null && bpsBefore.getRadiusEnd() > 0
                && bpsEnd != null && bpsEnd.getRadiusStart() > 0) {
            rtn = true;
        }

        if (bpsEnd != null && bpsEnd.getRadiusEnd() > 0
                && bpsAfter != null && bpsAfter.getRadiusEnd() > 0) {
            rtn = true;
        }

        if (bpsAfter != null && bpsAfter.getRadiusStart() > 0
                && bpsStart != null && bpsStart.getRadiusEnd() > 0) {
            rtn = true;
        }

        return rtn;
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void drawBorderRect(Rectangle rect, BorderProps top, BorderProps bottom,
            BorderProps left, BorderProps right, Color innerBackgroundColor) throws IFException {
        if (top == null && bottom == null && left == null && right == null) {
            return;
        }
        try {
            AttributesImpl atts = new AttributesImpl();
            addAttribute(atts, "x", Integer.toString(rect.x));
            addAttribute(atts, "y", Integer.toString(rect.y));
            addAttribute(atts, "width", Integer.toString(rect.width));
            addAttribute(atts, "height", Integer.toString(rect.height));
            if (top != null) {
                addAttribute(atts, "top", top.toString());
            }
            if (bottom != null) {
                addAttribute(atts, "bottom", bottom.toString());
            }
            if (left != null) {
                addAttribute(atts, "left", left.toString());
            }
            if (right != null) {
                addAttribute(atts, "right", right.toString());
            }

            if (innerBackgroundColor != null) {
                addAttribute(atts, "inner-background-color",
                        ColorUtil.colorToString(innerBackgroundColor));
            }

            handler.element(EL_BORDER_RECT, atts);
        } catch (SAXException e) {
            throw new IFException("SAX error in drawBorderRect()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void drawLine(Point start, Point end, int width, Color color, RuleStyle style)
            throws IFException {
        try {
            addID();
            AttributesImpl atts = new AttributesImpl();
            addAttribute(atts, "x1", Integer.toString(start.x));
            addAttribute(atts, "y1", Integer.toString(start.y));
            addAttribute(atts, "x2", Integer.toString(end.x));
            addAttribute(atts, "y2", Integer.toString(end.y));
            addAttribute(atts, "stroke-width", Integer.toString(width));
            addAttribute(atts, "color", ColorUtil.colorToString(color));
            addAttribute(atts, "style", style.getName());
            handler.element(EL_LINE, atts);
        } catch (SAXException e) {
            throw new IFException("SAX error in drawLine()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void drawText(int x, int y, int letterSpacing, int wordSpacing,
            int[][] dp, String text) throws IFException {
        try {
            addID();
            AttributesImpl atts = new AttributesImpl();
            addAttribute(atts, "x", Integer.toString(x));
            addAttribute(atts, "y", Integer.toString(y));
            if (letterSpacing != 0) {
                addAttribute(atts, "letter-spacing", Integer.toString(letterSpacing));
            }
            if (wordSpacing != 0) {
                addAttribute(atts, "word-spacing", Integer.toString(wordSpacing));
            }
            if (dp != null) {
                if (IFUtil.isDPIdentity(dp)) {
                    // don't add dx or dp attribute
                } else if (IFUtil.isDPOnlyDX(dp)) {
                    // add dx attribute only
                    int[] dx = IFUtil.convertDPToDX(dp);
                    addAttribute(atts, "dx", IFUtil.toString(dx));
                } else {
                    // add dp attribute only
                    addAttribute(atts, "dp", XMLUtil.encodePositionAdjustments(dp));
                }
            }
            addStructureReference(atts);
            if (getContext().isHyphenated()) {
                addAttribute(atts, "hyphenated", "true");
            }
            handler.startElement(EL_TEXT, atts);
            char[] chars = text.toCharArray();
            handler.characters(chars, 0, chars.length);
            handler.endElement(EL_TEXT);
        } catch (SAXException e) {
            throw new IFException("SAX error in setFont()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void setFont(String family, String style, Integer weight, String variant, Integer size,
            Color color) throws IFException {
        try {
            AttributesImpl atts = new AttributesImpl();
            boolean changed;
            if (family != null) {
                changed = !family.equals(state.getFontFamily());
                if (changed) {
                    state.setFontFamily(family);
                    addAttribute(atts, "family", family);
                }
            }
            if (style != null) {
                changed = !style.equals(state.getFontStyle());
                if (changed) {
                    state.setFontStyle(style);
                    addAttribute(atts, "style", style);
                }
            }
            if (weight != null) {
                changed = (weight != state.getFontWeight());
                if (changed) {
                    state.setFontWeight(weight);
                    addAttribute(atts, "weight", weight.toString());
                }
            }
            if (variant != null) {
                changed = !variant.equals(state.getFontVariant());
                if (changed) {
                    state.setFontVariant(variant);
                    addAttribute(atts, "variant", variant);
                }
            }
            if (size != null) {
                changed = (size != state.getFontSize());
                if (changed) {
                    state.setFontSize(size);
                    addAttribute(atts, "size", size.toString());
                }
            }
            if (color != null) {
                changed = !org.apache.xmlgraphics.java2d.color.ColorUtil.isSameColor(
                        color, state.getTextColor());
                if (changed) {
                    state.setTextColor(color);
                    addAttribute(atts, "color", toString(color));
                }
            }
            if (atts.getLength() > 0) {
                handler.element(EL_FONT, atts);
            }
        } catch (SAXException e) {
            throw new IFException("SAX error in setFont()", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void handleExtensionObject(Object extension) throws IFException {
        if (extension instanceof XMLizable) {
            try {
                ((XMLizable)extension).toSAX(this.handler);
            } catch (SAXException e) {
                throw new IFException("SAX error while handling extension object", e);
            }
        } else {
            throw new UnsupportedOperationException(
                    "Extension must implement XMLizable: "
                            + extension + " (" + extension.getClass().getName() + ")");
        }
    }

    
Throws:
IllegalStateException – unless overridden
Returns:
a new rendering context/**
     * @return a new rendering context
     * @throws IllegalStateException unless overridden
     */
    protected RenderingContext createRenderingContext() throws IllegalStateException {
        throw new IllegalStateException("Should never be called!");
    }

    private void addAttribute(AttributesImpl atts,
            org.apache.xmlgraphics.util.QName attribute, String value) throws SAXException {
        handler.startPrefixMapping(attribute.getPrefix(), attribute.getNamespaceURI());
        XMLUtil.addAttribute(atts, attribute, value);
    }

    private void addAttribute(AttributesImpl atts, String localName, String value) {
        XMLUtil.addAttribute(atts, localName, value);
    }

    private void addStructureReference(AttributesImpl atts) {
        IFStructureTreeElement structureTreeElement
                = (IFStructureTreeElement) getContext().getStructureTreeElement();
        if (structureTreeElement != null) {
            addStructRefAttribute(atts, structureTreeElement.getId());
        }
    }

    private void addStructRefAttribute(AttributesImpl atts, String id) {
        atts.addAttribute(InternalElementMapping.URI,
                InternalElementMapping.STRUCT_REF,
                InternalElementMapping.STANDARD_PREFIX + ":" + InternalElementMapping.STRUCT_REF,
                XMLConstants.CDATA,
                id);
    }

    private void addID() throws SAXException {
        String id = getContext().getID();
        if (!currentID.equals(id)) {
            AttributesImpl atts = new AttributesImpl();
            addAttribute(atts, "name", id);
            handler.startElement(EL_ID, atts);
            handler.endElement(EL_ID);
            currentID = id;
        }
    }

    private Map incompleteActions = new java.util.HashMap();
    private List completeActions = new java.util.LinkedList();

    private void noteAction(AbstractAction action) {
        if (action == null) {
            throw new NullPointerException("action must not be null");
        }
        if (!action.isComplete()) {
            assert action.hasID();
            incompleteActions.put(action.getID(), action);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void renderNamedDestination(NamedDestination destination) throws IFException {
        noteAction(destination.getAction());

        AttributesImpl atts = new AttributesImpl();
        atts.addAttribute("", "name", "name", XMLConstants.CDATA, destination.getName());
        try {
            handler.startElement(DocumentNavigationExtensionConstants.NAMED_DESTINATION, atts);
            serializeXMLizable(destination.getAction());
            handler.endElement(DocumentNavigationExtensionConstants.NAMED_DESTINATION);
        } catch (SAXException e) {
            throw new IFException("SAX error serializing named destination", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void renderBookmarkTree(BookmarkTree tree) throws IFException {
        AttributesImpl atts = new AttributesImpl();
        try {
            handler.startElement(DocumentNavigationExtensionConstants.BOOKMARK_TREE, atts);
            for (Object o : tree.getBookmarks()) {
                Bookmark b = (Bookmark) o;
                if (b.getAction() != null) {
                    serializeBookmark(b);
                }
            }
            handler.endElement(DocumentNavigationExtensionConstants.BOOKMARK_TREE);
        } catch (SAXException e) {
            throw new IFException("SAX error serializing bookmark tree", e);
        }
    }

    private void serializeBookmark(Bookmark bookmark) throws SAXException, IFException {
        noteAction(bookmark.getAction());

        AttributesImpl atts = new AttributesImpl();
        atts.addAttribute("", "title", "title", XMLUtil.CDATA, bookmark.getTitle());
        atts.addAttribute("", "starting-state", "starting-state",
                XMLUtil.CDATA, bookmark.isShown() ? "show" : "hide");
        handler.startElement(DocumentNavigationExtensionConstants.BOOKMARK, atts);
        serializeXMLizable(bookmark.getAction());
        for (Object o : bookmark.getChildBookmarks()) {
            Bookmark b = (Bookmark) o;
            if (b.getAction() != null) {
                serializeBookmark(b);
            }
        }
        handler.endElement(DocumentNavigationExtensionConstants.BOOKMARK);
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void renderLink(Link link) throws IFException {
        noteAction(link.getAction());

        AttributesImpl atts = new AttributesImpl();
        atts.addAttribute("", "rect", "rect",
                XMLConstants.CDATA, IFUtil.toString(link.getTargetRect()));
        if (getUserAgent().isAccessibilityEnabled()) {
            addStructRefAttribute(atts,
                    ((IFStructureTreeElement) link.getAction().getStructureTreeElement()).getId());
        }
        try {
            handler.startElement(DocumentNavigationExtensionConstants.LINK, atts);
            serializeXMLizable(link.getAction());
            handler.endElement(DocumentNavigationExtensionConstants.LINK);
        } catch (SAXException e) {
            throw new IFException("SAX error serializing link", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public void addResolvedAction(AbstractAction action) throws IFException {
        assert action.isComplete();
        assert action.hasID();
        AbstractAction noted = (AbstractAction)incompleteActions.remove(action.getID());
        if (noted != null) {
            completeActions.add(action);
        } else {
            //ignore as it was already complete when it was first used.
        }
    }

    public int getPageIndex() {
        return -1;
    }

    private void commitNavigation() throws IFException {
        Iterator iter = this.completeActions.iterator();
        while (iter.hasNext()) {
            AbstractAction action = (AbstractAction)iter.next();
            iter.remove();
            serializeXMLizable(action);
        }
        assert this.completeActions.size() == 0;
    }

    private void finishDocumentNavigation() {
        assert this.incompleteActions.size() == 0 : "Still holding incomplete actions!";
    }

    private void serializeXMLizable(XMLizable object) throws IFException {
        try {
            object.toSAX(handler);
        } catch (SAXException e) {
            throw new IFException("SAX error serializing object", e);
        }
    }

    
{@inheritDoc} /** {@inheritDoc} */
    public boolean isBackgroundRequired(BorderProps bpsTop, BorderProps bpsBottom,
            BorderProps bpsLeft, BorderProps bpsRight) {
        return true;
    }
}