plugins/org.eclipse.sirius.server.images/src/org/eclipse/sirius/server/images/internal/SiriusServerImagesFilter.java - sirius/org.eclipse.sirius - Git at Google

 /*******************************************************************************
  * Copyright (c) 2018 Obeo.
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *    Obeo - initial API and implementation
  *******************************************************************************/
 package org.eclipse.sirius.server.images.internal;

 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.URL;
 import java.net.URLConnection;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Optional;
 import java.util.stream.Stream;

 import javax.servlet.Filter;
 import javax.servlet.FilterChain;
 import javax.servlet.FilterConfig;
 import javax.servlet.ServletException;
 import javax.servlet.ServletRequest;
 import javax.servlet.ServletResponse;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;

 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.emf.edit.provider.ComposedAdapterFactory;
 import org.eclipse.emf.edit.provider.ComposedImage;
 import org.eclipse.emf.edit.provider.IItemLabelProvider;
 import org.eclipse.emf.edit.provider.ReflectiveItemProviderAdapterFactory;
 import org.eclipse.sirius.business.api.session.Session;
 import org.eclipse.sirius.server.images.api.ISiriusServerImagesConstants;
 import org.eclipse.sirius.services.common.api.SiriusServicesCommonOptionalUtils;
 import org.osgi.framework.Bundle;

 /**
  * Servlet filter used to provide support for images.
  *
  * @author sbegaudeau
  */
 public class SiriusServerImagesFilter implements Filter {

     /** The extension of jpg files. */
     private static final String JPG = "jpg"; //$NON-NLS-1$

     /** The extension of jpeg files. */
     private static final String JPEG = "jpeg"; //$NON-NLS-1$

     /** The jpeg mime type. */
     private static final String JPEG_MIME_TYPE = "image/jpeg"; //$NON-NLS-1$

     /** The extension of giffiles. */
     private static final String GIF = "gif"; //$NON-NLS-1$

     /** The gif mime type. */
     private static final String GIF_MIME_TYPE = "image/gif"; //$NON-NLS-1$

     /** The extension of bmp files. */
     private static final String BMP = "bmp"; //$NON-NLS-1$

     /** The bmp mime type. */
     private static final String BMP_MIME_TYPE = "image/bmp"; //$NON-NLS-1$

     /** The extension of pngfiles. */
     private static final String PNG = "png"; //$NON-NLS-1$

     /** The png mime type. */
     private static final String PNG_MIME_TYPE = "image/png"; //$NON-NLS-1$

     /** The extension of svg files. */
     private static final String SVG = "svg"; //$NON-NLS-1$

     /** The svg mime type. */
     private static final String SVG_MIME_TYPE = "image/svg+xml"; //$NON-NLS-1$

     @Override
     public void init(FilterConfig filterConfig) throws ServletException {
         // Do nothing
     }

     @Override
     public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
         if (request instanceof HttpServletRequest && response instanceof HttpServletResponse) {
             HttpServletRequest httpServletRequest = (HttpServletRequest) request;
             HttpServletResponse httpServletResponse = (HttpServletResponse) response;
             String requestURI = httpServletRequest.getRequestURI();
             if (this.isStaticImage(requestURI)) {
                 this.handleStaticImage(httpServletRequest, httpServletResponse, chain);
             } else if (this.isEObjectImage(httpServletRequest)) {
                 this.handleEObjectImage(httpServletRequest, httpServletResponse, chain);
             }
         }
     }

     /**
      * Indicates if the given request URI matches a static image path.
      *
      * @param requestURI
      *            The URI of the request
      * @return <code>true</code> if the given request URI matches an image path.
      */
     private boolean isStaticImage(String requestURI) {
         boolean isImagePath = requestURI.startsWith(ISiriusServerImagesConstants.IMAGES_PATH);

         boolean isImageExtension = requestURI.endsWith(JPG);
         isImageExtension = isImageExtension || requestURI.endsWith(JPEG);
         isImageExtension = isImageExtension || requestURI.endsWith(GIF);
         isImageExtension = isImageExtension || requestURI.endsWith(BMP);
         isImageExtension = isImageExtension || requestURI.endsWith(PNG);
         isImageExtension = isImageExtension || requestURI.endsWith(SVG);

         return isImagePath && isImageExtension;
     }

     /**
      * Returns the static image matching the given request.
      *
      * @param httpServletRequest
      *            The request
      * @param httpServletResponse
      *            The response
      * @param chain
      *            The filter chain
      * @throws ServletException
      *             In case of error
      * @throws IOException
      *             In case of error
      */
     private void handleStaticImage(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, FilterChain chain) throws ServletException, IOException {
         // requestURI = /images/projectname/path/to/a/folder/image.png
         String requestURI = httpServletRequest.getRequestURI();

         // segments = ["", "images", "projectname", "path", "to", "a", "folder", "image.png"]
         String[] segments = requestURI.split("/"); //$NON-NLS-1$
         if (segments.length >= 4) {
             String bundleSymbolicName = segments[2];

             // imagePath = path/to/a/folder/image.png
             String imagePath = Arrays.stream(segments).skip(3).reduce("", (string1, string2) -> { //$NON-NLS-1$
                 return string1 + '/' + string2;
             });

             Optional<Bundle> optionalBundle = Optional.ofNullable(Platform.getBundle(bundleSymbolicName));
             Optional<URL> optionalImageUrl = optionalBundle.map(bundle -> bundle.getEntry(imagePath));
             if (optionalImageUrl.isPresent()) {
                 URL url = optionalImageUrl.get();
                 URLConnection connection = url.openConnection();

                 httpServletResponse.setContentLength(connection.getContentLength());
                 httpServletResponse.setContentType(this.getContentType(imagePath));
                 try (InputStream inputStream = connection.getInputStream(); OutputStream outputStream = httpServletResponse.getOutputStream();) {
                     this.copy(inputStream, outputStream);
                     outputStream.flush();
                 }
             } else {
                 chain.doFilter(httpServletRequest, httpServletResponse);
             }
         } else {
             chain.doFilter(httpServletRequest, httpServletResponse);
         }
     }

     /**
      * Returns the content type of the image at the given path.
      *
      * @param path
      *            The path of the image
      * @return The content type of the image
      */
     private String getContentType(String path) {
         String contentType = null;

         if (path.endsWith(JPG) || path.endsWith(JPEG)) {
             contentType = JPEG_MIME_TYPE;
         } else if (path.endsWith(GIF)) {
             contentType = GIF_MIME_TYPE;
         } else if (path.endsWith(BMP)) {
             contentType = BMP_MIME_TYPE;
         } else if (path.endsWith(PNG)) {
             contentType = PNG_MIME_TYPE;
         } else if (path.endsWith(SVG)) {
             contentType = SVG_MIME_TYPE;
         }

         return contentType;
     }

     /**
      * Copy the content of the given input stream to the given output stream.
      *
      * @param inputStream
      *            The input stream
      * @param outputStream
      *            The output stream
      * @return The size of the content transfered from the input stream to the output stream
      * @throws IOException
      *             In case of error
      */
     private long copy(InputStream inputStream, OutputStream outputStream) throws IOException {
         long byteRead = 0L;
         byte[] buffer = new byte[4096];
         int index;
         while ((index = inputStream.read(buffer)) > 0) {
             outputStream.write(buffer, 0, index);
             byteRead += index;
         }
         return byteRead;
     }

     /**
      * Indicates if the given request potentially matches the path of an EObject's image.
      *
      * @param httpServletRequest
      *            The HTTP request
      * @return <code>true</code> if the request matches an EObject's image path, <code>false</code> otherwise
      */
     private boolean isEObjectImage(HttpServletRequest httpServletRequest) {
         boolean isImagePath = httpServletRequest.getRequestURI().startsWith(ISiriusServerImagesConstants.IMAGES_PATH);
         boolean hasFragment = httpServletRequest.getParameterMap().containsKey(ISiriusServerImagesConstants.FRAGMENT);

         return isImagePath && hasFragment;
     }

     /**
      * Handles the retrieval of the image of the EObject matching the given request.
      *
      * @param httpServletRequest
      *            The request
      * @param httpServletResponse
      *            The response
      * @param chain
      *            The filter chain
      * @throws ServletException
      *             In case of error
      * @throws IOException
      *             In case of error
      */
     private void handleEObjectImage(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, FilterChain chain) throws ServletException, IOException {
         // requestURI = /images/projectname/path/to/a/folder/resource
         String requestURI = httpServletRequest.getRequestURI();

         // segments = ["", "images", "projectname", "path", "to", "a", "folder", "resource"]
         String[] segments = requestURI.split("/"); //$NON-NLS-1$
         if (segments.length >= 4) {
             String projectName = segments[2];

             // resourcePath = path/to/a/folder/resource
             String resourcePath = Arrays.stream(segments).skip(3).reduce("", (string1, string2) -> { //$NON-NLS-1$
                 return string1 + '/' + string2;
             });

             String eObjectFragment = httpServletRequest.getParameter(ISiriusServerImagesConstants.FRAGMENT);

             Optional<IProject> optionalProject = Optional.ofNullable(ResourcesPlugin.getWorkspace().getRoot().getProject(projectName));
             Optional<IFile> optionalFile = optionalProject.map(iProject -> iProject.getFile(new Path(resourcePath)));
             Optional<Session> optionalSession = optionalProject.flatMap(SiriusServicesCommonOptionalUtils::toSession);
             Optional<Resource> optionalResource = optionalFile.flatMap(iFile -> {
                 return optionalSession.flatMap(session -> SiriusServicesCommonOptionalUtils.toResource(session, iFile));
             });

             Optional<EObject> optionalEObject = optionalResource.map(resource -> resource.getEObject(eObjectFragment));
             Optional<Object> optionalImage = optionalEObject.flatMap(this::toImage);
             Optional<URL> optionalURL = optionalImage.flatMap(this::toURL);
             if (optionalURL.isPresent()) {
                 URL imageURL = optionalURL.get();
                 URLConnection connection = imageURL.openConnection();

                 httpServletResponse.setContentLength(connection.getContentLength());
                 httpServletResponse.setContentType(this.getContentType(imageURL.toString()));
                 try (InputStream inputStream = connection.getInputStream(); OutputStream outputStream = httpServletResponse.getOutputStream();) {
                     this.copy(inputStream, outputStream);
                     outputStream.flush();
                 }
             } else {
                 chain.doFilter(httpServletRequest, httpServletResponse);
             }
         } else {
             chain.doFilter(httpServletRequest, httpServletResponse);
         }
     }

     /**
      * Converts the given image object to an URL.
      *
      * @param object
      *            The image object
      * @return An optional containing an URL or an empty optional
      */
     private Optional<URL> toURL(Object object) {
         // @formatter:off
         Optional<URL> optionalURL = Optional.of(object)
                 .filter(URL.class::isInstance)
                 .map(URL.class::cast);

         if (!optionalURL.isPresent()) {
             optionalURL = Optional.of(object)
                     .filter(ComposedImage.class::isInstance)
                     .map(ComposedImage.class::cast)
                     .map(ComposedImage::getImages)
                     .map(Collection::stream)
                     .flatMap(Stream::findFirst)
                     .filter(URL.class::isInstance)
                     .map(URL.class::cast);
         }
         // @formatter:on
         return optionalURL;
     }

     /**
      * Retrieves the image for the given eObject or an empty optional if none could be found.
      *
      * @param eObject
      *            The eObject
      * @return An optional with the image for the given EObject
      */
     private Optional<Object> toImage(EObject eObject) {
         // @formatter:off
         ComposedAdapterFactory composedAdapterFactory = new ComposedAdapterFactory(ComposedAdapterFactory.Descriptor.Registry.INSTANCE);
         composedAdapterFactory.addAdapterFactory(new ReflectiveItemProviderAdapterFactory());

         return Optional.of(composedAdapterFactory.adapt(eObject, IItemLabelProvider.class))
                 .filter(IItemLabelProvider.class::isInstance)
                 .map(IItemLabelProvider.class::cast)
                 .map(labelProvider -> labelProvider.getImage(eObject));
         // @formatter:on
     }

     @Override
     public void destroy() {
         // Do nothing
     }

 }
	/*******************************************************************************
	* Copyright (c) 2018 Obeo.
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* Obeo - initial API and implementation
	*******************************************************************************/
	package org.eclipse.sirius.server.images.internal;

	import java.io.IOException;
	import java.io.InputStream;
	import java.io.OutputStream;
	import java.net.URL;
	import java.net.URLConnection;
	import java.util.Arrays;
	import java.util.Collection;
	import java.util.Optional;
	import java.util.stream.Stream;

	import javax.servlet.Filter;
	import javax.servlet.FilterChain;
	import javax.servlet.FilterConfig;
	import javax.servlet.ServletException;
	import javax.servlet.ServletRequest;
	import javax.servlet.ServletResponse;
	import javax.servlet.http.HttpServletRequest;
	import javax.servlet.http.HttpServletResponse;

	import org.eclipse.core.resources.IFile;
	import org.eclipse.core.resources.IProject;
	import org.eclipse.core.resources.ResourcesPlugin;
	import org.eclipse.core.runtime.Path;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.emf.ecore.EObject;
	import org.eclipse.emf.ecore.resource.Resource;
	import org.eclipse.emf.edit.provider.ComposedAdapterFactory;
	import org.eclipse.emf.edit.provider.ComposedImage;
	import org.eclipse.emf.edit.provider.IItemLabelProvider;
	import org.eclipse.emf.edit.provider.ReflectiveItemProviderAdapterFactory;
	import org.eclipse.sirius.business.api.session.Session;
	import org.eclipse.sirius.server.images.api.ISiriusServerImagesConstants;
	import org.eclipse.sirius.services.common.api.SiriusServicesCommonOptionalUtils;
	import org.osgi.framework.Bundle;

	/**
	* Servlet filter used to provide support for images.
	*
	* @author sbegaudeau
	*/
	public class SiriusServerImagesFilter implements Filter {

	/** The extension of jpg files. */
	private static final String JPG = "jpg"; //$NON-NLS-1$

	/** The extension of jpeg files. */
	private static final String JPEG = "jpeg"; //$NON-NLS-1$

	/** The jpeg mime type. */
	private static final String JPEG_MIME_TYPE = "image/jpeg"; //$NON-NLS-1$

	/** The extension of giffiles. */
	private static final String GIF = "gif"; //$NON-NLS-1$

	/** The gif mime type. */
	private static final String GIF_MIME_TYPE = "image/gif"; //$NON-NLS-1$

	/** The extension of bmp files. */
	private static final String BMP = "bmp"; //$NON-NLS-1$

	/** The bmp mime type. */
	private static final String BMP_MIME_TYPE = "image/bmp"; //$NON-NLS-1$

	/** The extension of pngfiles. */
	private static final String PNG = "png"; //$NON-NLS-1$

	/** The png mime type. */
	private static final String PNG_MIME_TYPE = "image/png"; //$NON-NLS-1$

	/** The extension of svg files. */
	private static final String SVG = "svg"; //$NON-NLS-1$

	/** The svg mime type. */
	private static final String SVG_MIME_TYPE = "image/svg+xml"; //$NON-NLS-1$

	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
	// Do nothing
	}

	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
	if (request instanceof HttpServletRequest && response instanceof HttpServletResponse) {
	HttpServletRequest httpServletRequest = (HttpServletRequest) request;
	HttpServletResponse httpServletResponse = (HttpServletResponse) response;
	String requestURI = httpServletRequest.getRequestURI();
	if (this.isStaticImage(requestURI)) {
	this.handleStaticImage(httpServletRequest, httpServletResponse, chain);
	} else if (this.isEObjectImage(httpServletRequest)) {
	this.handleEObjectImage(httpServletRequest, httpServletResponse, chain);
	}
	}
	}

	/**
	* Indicates if the given request URI matches a static image path.
	*
	* @param requestURI
	* The URI of the request
	* @return <code>true</code> if the given request URI matches an image path.
	*/
	private boolean isStaticImage(String requestURI) {
	boolean isImagePath = requestURI.startsWith(ISiriusServerImagesConstants.IMAGES_PATH);

	boolean isImageExtension = requestURI.endsWith(JPG);
	isImageExtension = isImageExtension \|\| requestURI.endsWith(JPEG);
	isImageExtension = isImageExtension \|\| requestURI.endsWith(GIF);
	isImageExtension = isImageExtension \|\| requestURI.endsWith(BMP);
	isImageExtension = isImageExtension \|\| requestURI.endsWith(PNG);
	isImageExtension = isImageExtension \|\| requestURI.endsWith(SVG);

	return isImagePath && isImageExtension;
	}

	/**
	* Returns the static image matching the given request.
	*
	* @param httpServletRequest
	* The request
	* @param httpServletResponse
	* The response
	* @param chain
	* The filter chain
	* @throws ServletException
	* In case of error
	* @throws IOException
	* In case of error
	*/
	private void handleStaticImage(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, FilterChain chain) throws ServletException, IOException {
	// requestURI = /images/projectname/path/to/a/folder/image.png
	String requestURI = httpServletRequest.getRequestURI();

	// segments = ["", "images", "projectname", "path", "to", "a", "folder", "image.png"]
	String[] segments = requestURI.split("/"); //$NON-NLS-1$
	if (segments.length >= 4) {
	String bundleSymbolicName = segments[2];

	// imagePath = path/to/a/folder/image.png
	String imagePath = Arrays.stream(segments).skip(3).reduce("", (string1, string2) -> { //$NON-NLS-1$
	return string1 + '/' + string2;
	});

	Optional<Bundle> optionalBundle = Optional.ofNullable(Platform.getBundle(bundleSymbolicName));
	Optional<URL> optionalImageUrl = optionalBundle.map(bundle -> bundle.getEntry(imagePath));
	if (optionalImageUrl.isPresent()) {
	URL url = optionalImageUrl.get();
	URLConnection connection = url.openConnection();

	httpServletResponse.setContentLength(connection.getContentLength());
	httpServletResponse.setContentType(this.getContentType(imagePath));
	try (InputStream inputStream = connection.getInputStream(); OutputStream outputStream = httpServletResponse.getOutputStream();) {
	this.copy(inputStream, outputStream);
	outputStream.flush();
	}
	} else {
	chain.doFilter(httpServletRequest, httpServletResponse);
	}
	} else {
	chain.doFilter(httpServletRequest, httpServletResponse);
	}
	}

	/**
	* Returns the content type of the image at the given path.
	*
	* @param path
	* The path of the image
	* @return The content type of the image
	*/
	private String getContentType(String path) {
	String contentType = null;

	if (path.endsWith(JPG) \|\| path.endsWith(JPEG)) {
	contentType = JPEG_MIME_TYPE;
	} else if (path.endsWith(GIF)) {
	contentType = GIF_MIME_TYPE;
	} else if (path.endsWith(BMP)) {
	contentType = BMP_MIME_TYPE;
	} else if (path.endsWith(PNG)) {
	contentType = PNG_MIME_TYPE;
	} else if (path.endsWith(SVG)) {
	contentType = SVG_MIME_TYPE;
	}

	return contentType;
	}

	/**
	* Copy the content of the given input stream to the given output stream.
	*
	* @param inputStream
	* The input stream
	* @param outputStream
	* The output stream
	* @return The size of the content transfered from the input stream to the output stream
	* @throws IOException
	* In case of error
	*/
	private long copy(InputStream inputStream, OutputStream outputStream) throws IOException {
	long byteRead = 0L;
	byte[] buffer = new byte[4096];
	int index;
	while ((index = inputStream.read(buffer)) > 0) {
	outputStream.write(buffer, 0, index);
	byteRead += index;
	}
	return byteRead;
	}

	/**
	* Indicates if the given request potentially matches the path of an EObject's image.
	*
	* @param httpServletRequest
	* The HTTP request
	* @return <code>true</code> if the request matches an EObject's image path, <code>false</code> otherwise
	*/
	private boolean isEObjectImage(HttpServletRequest httpServletRequest) {
	boolean isImagePath = httpServletRequest.getRequestURI().startsWith(ISiriusServerImagesConstants.IMAGES_PATH);
	boolean hasFragment = httpServletRequest.getParameterMap().containsKey(ISiriusServerImagesConstants.FRAGMENT);

	return isImagePath && hasFragment;
	}

	/**
	* Handles the retrieval of the image of the EObject matching the given request.
	*
	* @param httpServletRequest
	* The request
	* @param httpServletResponse
	* The response
	* @param chain
	* The filter chain
	* @throws ServletException
	* In case of error
	* @throws IOException
	* In case of error
	*/
	private void handleEObjectImage(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, FilterChain chain) throws ServletException, IOException {
	// requestURI = /images/projectname/path/to/a/folder/resource
	String requestURI = httpServletRequest.getRequestURI();

	// segments = ["", "images", "projectname", "path", "to", "a", "folder", "resource"]
	String[] segments = requestURI.split("/"); //$NON-NLS-1$
	if (segments.length >= 4) {
	String projectName = segments[2];

	// resourcePath = path/to/a/folder/resource
	String resourcePath = Arrays.stream(segments).skip(3).reduce("", (string1, string2) -> { //$NON-NLS-1$
	return string1 + '/' + string2;
	});

	String eObjectFragment = httpServletRequest.getParameter(ISiriusServerImagesConstants.FRAGMENT);

	Optional<IProject> optionalProject = Optional.ofNullable(ResourcesPlugin.getWorkspace().getRoot().getProject(projectName));
	Optional<IFile> optionalFile = optionalProject.map(iProject -> iProject.getFile(new Path(resourcePath)));
	Optional<Session> optionalSession = optionalProject.flatMap(SiriusServicesCommonOptionalUtils::toSession);
	Optional<Resource> optionalResource = optionalFile.flatMap(iFile -> {
	return optionalSession.flatMap(session -> SiriusServicesCommonOptionalUtils.toResource(session, iFile));
	});

	Optional<EObject> optionalEObject = optionalResource.map(resource -> resource.getEObject(eObjectFragment));
	Optional<Object> optionalImage = optionalEObject.flatMap(this::toImage);
	Optional<URL> optionalURL = optionalImage.flatMap(this::toURL);
	if (optionalURL.isPresent()) {
	URL imageURL = optionalURL.get();
	URLConnection connection = imageURL.openConnection();

	httpServletResponse.setContentLength(connection.getContentLength());
	httpServletResponse.setContentType(this.getContentType(imageURL.toString()));
	try (InputStream inputStream = connection.getInputStream(); OutputStream outputStream = httpServletResponse.getOutputStream();) {
	this.copy(inputStream, outputStream);
	outputStream.flush();
	}
	} else {
	chain.doFilter(httpServletRequest, httpServletResponse);
	}
	} else {
	chain.doFilter(httpServletRequest, httpServletResponse);
	}
	}

	/**
	* Converts the given image object to an URL.
	*
	* @param object
	* The image object
	* @return An optional containing an URL or an empty optional
	*/
	private Optional<URL> toURL(Object object) {
	// @formatter:off
	Optional<URL> optionalURL = Optional.of(object)
	.filter(URL.class::isInstance)
	.map(URL.class::cast);

	if (!optionalURL.isPresent()) {
	optionalURL = Optional.of(object)
	.filter(ComposedImage.class::isInstance)
	.map(ComposedImage.class::cast)
	.map(ComposedImage::getImages)
	.map(Collection::stream)
	.flatMap(Stream::findFirst)
	.filter(URL.class::isInstance)
	.map(URL.class::cast);
	}
	// @formatter:on
	return optionalURL;
	}

	/**
	* Retrieves the image for the given eObject or an empty optional if none could be found.
	*
	* @param eObject
	* The eObject
	* @return An optional with the image for the given EObject
	*/
	private Optional<Object> toImage(EObject eObject) {
	// @formatter:off
	ComposedAdapterFactory composedAdapterFactory = new ComposedAdapterFactory(ComposedAdapterFactory.Descriptor.Registry.INSTANCE);
	composedAdapterFactory.addAdapterFactory(new ReflectiveItemProviderAdapterFactory());

	return Optional.of(composedAdapterFactory.adapt(eObject, IItemLabelProvider.class))
	.filter(IItemLabelProvider.class::isInstance)
	.map(IItemLabelProvider.class::cast)
	.map(labelProvider -> labelProvider.getImage(eObject));
	// @formatter:on
	}

	@Override
	public void destroy() {
	// Do nothing
	}

	}