org.eclipse.scada.vi.ui.draw2d.loader.XMISymbolLoader.java Source code

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Here is the source code for org.eclipse.scada.vi.ui.draw2d.loader.XMISymbolLoader.java

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/*******************************************************************************
 * Copyright (c) 2011, 2016 TH4 SYSTEMS GmbH and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     TH4 SYSTEMS GmbH - initial API and implementation
 *     Jens Reimann - additional work
 *     IBH SYSTEMS GmbH - minor cleanups
 *******************************************************************************/
package org.eclipse.scada.vi.ui.draw2d.loader;

import java.net.URL;
import java.nio.charset.StandardCharsets;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
import org.eclipse.emf.ecore.util.EcoreUtil;
import org.eclipse.emf.ecore.xmi.impl.XMIResourceFactoryImpl;
import org.eclipse.scada.vi.model.Symbol;
import org.eclipse.scada.vi.model.VisualInterfacePackage;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.io.Resources;

public class XMISymbolLoader implements SymbolLoader {
    private final static Logger logger = LoggerFactory.getLogger(XMISymbolLoader.class);

    private static final XMIResourceFactoryImpl FACTORY_INSTANCE = new XMIResourceFactoryImpl();

    private final URI uri;

    private Symbol symbol;

    public XMISymbolLoader(final String uri) {
        this(URI.createURI(uri));
    }

    public XMISymbolLoader(final URI uri) {
        this.uri = uri;
    }

    @Override
    public String getSourceName() {
        return this.uri.toString();
    }

    @Override
    public Symbol loadSymbol() throws Exception {
        if (this.symbol == null) {
            load();
            if (this.symbol == null) {
                throw new IllegalStateException(String.format("Resource '%s' did not contain a symbol", this.uri));
            }
        }
        return this.symbol;
    }

    @Override
    public String resolveUri(final String uri) {
        final String result = URI.createURI(uri).resolve(this.uri).toString();
        logger.debug("Resolved URI: {} -> {}", uri, result); //$NON-NLS-1$
        return result;
    }

    @Override
    public String loadStringResource(final String url) throws Exception {
        final String target = resolveUri(url);
        logger.debug("Loading resource from: {}", target); //$NON-NLS-1$
        return Resources.toString(new URL(target), StandardCharsets.UTF_8);
    }

    protected void load() throws Exception {
        // register model
        VisualInterfacePackage.eINSTANCE.eClass();

        this.symbol = null;

        final ResourceSet resourceSet = new ResourceSetImpl();

        // set resource factory to XMI on extension map
        resourceSet.getResourceFactoryRegistry().getExtensionToFactoryMap().put("vi", FACTORY_INSTANCE); //$NON-NLS-1$

        final Resource resource = resourceSet.getResource(this.uri, true);

        this.symbol = (Symbol) EcoreUtil.getObjectByType(resource.getContents(),
                VisualInterfacePackage.Literals.SYMBOL);
    }
}