OEBCoverBackgroundReader.java

/*
 * Copyright (C) 2010-2011 Geometer Plus <contact@geometerplus.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

package org.geometerplus.fbreader.formats.oeb;

import org.geometerplus.zlibrary.core.constants.XMLNamespaces;
import org.geometerplus.zlibrary.core.constants.MimeTypes;
import org.geometerplus.zlibrary.core.filesystem.ZLFile;
import org.geometerplus.zlibrary.core.image.ZLFileImage;
import org.geometerplus.zlibrary.core.xml.*;

import org.geometerplus.fbreader.formats.util.MiscUtil;

class OEBCoverBackgroundReader extends ZLXMLReaderAdapter implements XMLNamespaces, MimeTypes {
	private class XHTMLImageFinder extends ZLXMLReaderAdapter {
		@Override
		public boolean processNamespaces() {
			return true;
		}

		@Override
		public boolean startElementHandler(String tag, ZLStringMap attributes) {
			tag = tag.toLowerCase();
			String href = null;
			if ("img".equals(tag)) {
				href = attributes.getValue("src");
			} else if ("image".equals(tag)) {
				href = getAttributeValue(attributes, XLink, "href");
			}

			if (href != null) {
				myImage = new ZLFileImage(
					MIME_IMAGE_AUTO,
					ZLFile.createFileByPath(myXHTMLPathPrefix + href)
				);
				return true;
			}

			return false;
		}
	}

	private ZLFileImage myImage;
	private String myPathPrefix;
	private String myXHTMLPathPrefix;
	private String myCoverXHTML;
	private boolean myReadGuide;

	public ZLFileImage readCover(ZLFile file) {
		myPathPrefix = MiscUtil.htmlDirectoryPrefix(file);
		myReadGuide = false;
		myImage = null;
		myCoverXHTML = null;
		read(file);
		if (myCoverXHTML != null) {
			final ZLFile coverFile = ZLFile.createFileByPath(myCoverXHTML);
			if (coverFile != null) {
				final String ext = coverFile.getExtension();
				if ("gif".equals(ext) || "jpg".equals(ext) || "jpeg".equals(ext)) {
					myImage = new ZLFileImage(MIME_IMAGE_AUTO, coverFile);
				} else {
					myXHTMLPathPrefix = MiscUtil.htmlDirectoryPrefix(coverFile);
					new XHTMLImageFinder().read(coverFile);
				}
			}
		}
		return myImage;
	}

	private static final String GUIDE = "guide";
	private static final String REFERENCE = "reference";
	private static final String COVER = "cover";
	private static final String COVER_IMAGE = "other.ms-coverimage-standard";

	@Override
	public boolean startElementHandler(String tag, ZLStringMap attributes) {
		tag = tag.toLowerCase().intern();
		if (GUIDE == tag) {
			myReadGuide = true;
		} else if (myReadGuide && REFERENCE == tag) {
			final String type = attributes.getValue("type");
			if (COVER == type) {
				final String href = attributes.getValue("href");
				if (href != null) {
					myCoverXHTML = myPathPrefix + MiscUtil.decodeHtmlReference(href);
					return true;
				}
			} else if (COVER_IMAGE == type) {
				final String href = attributes.getValue("href");
				if (href != null) {
					myImage = new ZLFileImage(
						MIME_IMAGE_AUTO,
						ZLFile.createFileByPath(myPathPrefix + MiscUtil.decodeHtmlReference(href))
					);
					return true;
				}
			}
		}
		return false;
	}

	@Override
	public boolean endElementHandler(String tag) {
		tag = tag.toLowerCase();
		if (GUIDE == tag) {
			myReadGuide = false;
			return true;
		}
		return false;
	}
}