/*
* Weblounge: Web Content Management System
* Copyright (c) 2012 The Weblounge Team
* http://weblounge.o2it.ch
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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 ch.entwine.weblounge.preview.imagemagick;
import ch.entwine.weblounge.common.content.PreviewGenerator;
import ch.entwine.weblounge.common.content.image.ImagePreviewGenerator;
import org.im4java.core.ConvertCmd;
import org.im4java.core.IMOperation;
import org.osgi.framework.ServiceRegistration;
import org.osgi.service.component.ComponentContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Activator that will register the image preview generator depending on the
* availability of the <code>ImageMagick</code> binaries.
*/
public class ImageMagickActivator {
/** The logger */
private static final Logger logger = LoggerFactory.getLogger(ImageMagickActivator.class);
/** The page preview generator */
private ImageMagickPreviewGenerator previewGenerator = null;
/** The service reference */
private ServiceRegistration service = null;
/**
* Callback from the OSGi container on component activation.
*
* @param ctx
* the component context
*/
void activate(ComponentContext ctx) {
if (imageMagickAvailable()) {
logger.debug("Registering ImageMagick image preview generator");
String[] classes = new String[] {
PreviewGenerator.class.getName(),
ImagePreviewGenerator.class.getName() };
previewGenerator = new ImageMagickPreviewGenerator();
previewGenerator.activate(ctx);
service = ctx.getBundleContext().registerService(classes, previewGenerator, null);
logger.info("ImageMagick image preview generator registered");
} else {
logger.debug("Skipping registration of ImageMagick image preview generator");
}
}
/**
* Callback from the OSGi container on component inactivation.
*
* @param ctx
* the component context
*/
void deactivate(ComponentContext ctx) {
if (service == null)
return;
try {
logger.debug("Unregistering ImageMagick image preview generator");
previewGenerator.deactivate();
ctx.getBundleContext().ungetService(service.getReference());
} catch (Throwable t) {
// Never mind, seems like we are shutting down
} finally {
previewGenerator = null;
service = null;
}
}
/**
* Returns <code>true</code> if the <code>ImageMagick</code> library is
* available.
*
* @return <code>true</code> if the library is available
*/
private boolean imageMagickAvailable() {
try {
ConvertCmd cmd = new ConvertCmd();
IMOperation versionOp = new IMOperation();
versionOp.version();
cmd.run(versionOp);
logger.debug("ImageMagick detected and found to be working");
return true;
} catch (Throwable e) {
logger.info("ImageMagick not available: {}", e.getMessage());
return false;
}
}
}