Various API issues

[EMFCompare2.git] / plugins / org.eclipse.emf.compare.edit / src / org / eclipse / emf / compare / provider / spec / MatchResourceItemProviderSpec.java

/*******************************************************************************
 * Copyright (c) 2012, 2013 Obeo.
 * 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:
 *     Obeo - initial API and implementation
 *******************************************************************************/
package org.eclipse.emf.compare.provider.spec;

import static com.google.common.base.Predicates.not;

import com.google.common.base.Predicate;

import org.eclipse.emf.common.notify.AdapterFactory;
import org.eclipse.emf.compare.Comparison;
import org.eclipse.emf.compare.MatchResource;
import org.eclipse.emf.compare.ResourceAttachmentChange;
import org.eclipse.emf.compare.provider.IItemDescriptionProvider;
import org.eclipse.emf.compare.provider.IItemStyledLabelProvider;
import org.eclipse.emf.compare.provider.MatchResourceItemProvider;
import org.eclipse.emf.compare.provider.utils.ComposedStyledString;
import org.eclipse.emf.compare.provider.utils.IStyledString;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.edit.provider.AdapterFactoryItemDelegator;

/**
 * Specialized {@link MatchResourceItemProvider} returning nice output for {@link #getText(Object)} and
 * {@link #getImage(Object)}.
 * 
 * @author <a href="mailto:mikael.barbero@obeo.fr">Mikael Barbero</a>
 */
public class MatchResourceItemProviderSpec extends MatchResourceItemProvider implements IItemStyledLabelProvider, IItemDescriptionProvider {

        /** The item delegator for matched resources. */
        private final AdapterFactoryItemDelegator itemDelegator;

        /**
         * Constructor calling super {@link #MatchResourceItemProviderSpec(AdapterFactory)}.
         * 
         * @param adapterFactory
         *            the adapter factory
         */
        public MatchResourceItemProviderSpec(AdapterFactory adapterFactory) {
                super(adapterFactory);
                itemDelegator = new AdapterFactoryItemDelegator(getRootAdapterFactory());
        }

        /**
         * Predicate to check if the URI of the current attachment change is equal to one (at least) of the URIs
         * of the resources matched by the given <code>MatchResource</code>.
         * 
         * @param matchResource
         *            The match resource.
         * @return The predicate.
         */
        private static Predicate<ResourceAttachmentChange> uriEqualToOneAtLeast(final MatchResource matchResource) {
                return new Predicate<ResourceAttachmentChange>() {
                        public boolean apply(ResourceAttachmentChange difference) {
                                final String diffResourceURI = difference.getResourceURI();
                                return diffResourceURI != null
                                                && (diffResourceURI.equals(matchResource.getLeftURI())
                                                                || diffResourceURI.equals(matchResource.getRightURI()) || diffResourceURI
                                                                        .equals(matchResource.getOriginURI()));
                        }
                };
        }

        /**
         * Predicate to check if the URI of the current attachment change is different from all the URIs of the
         * resources matched by the given <code>MatchResource</code>.
         * 
         * @param matchResource
         *            The match resource.
         * @return The predicate.
         * @since 3.0
         */
        public static final Predicate<ResourceAttachmentChange> uriDifferentFromAll(
                        final MatchResource matchResource) {
                return not(uriEqualToOneAtLeast(matchResource));
        }

        /**
         * {@inheritDoc}
         * 
         * @see org.eclipse.emf.compare.provider.MatchResourceItemProvider#getText(java.lang.Object)
         */
        @Override
        public String getText(Object object) {
                final MatchResource matchResource = (MatchResource)object;
                final String leftURI = matchResource.getLeftURI();
                final String rightURI = matchResource.getRightURI();

                final String commonBase = getCommonBase(leftURI, rightURI);

                String text = ""; //$NON-NLS-1$
                if (leftURI != null) {
                        text += leftURI.substring(commonBase.length());
                }
                text += " <-> "; //$NON-NLS-1$
                if (rightURI != null) {
                        text += rightURI.substring(commonBase.length());
                }
                if (matchResource.eContainer() instanceof Comparison
                                && ((Comparison)matchResource.eContainer()).isThreeWay()) {
                        final String originURI = matchResource.getOriginURI();
                        if (originURI != null) {
                                text += " (" + originURI.substring(commonBase.length()) + ")"; //$NON-NLS-1$ //$NON-NLS-2$
                        }
                }
                return text;
        }

        /**
         * {@inheritDoc}
         * 
         * @see org.eclipse.emf.compare.provider.MatchResourceItemProvider#getImage(java.lang.Object)
         */
        @Override
        public Object getImage(Object object) {
                final MatchResource matchResource = (MatchResource)object;
                Resource resource = matchResource.getLeft();
                Object image = null;
                if (resource == null) {
                        resource = matchResource.getRight();
                        if (resource == null) {
                                resource = matchResource.getOrigin();
                        }
                }

                if (resource != null) {
                        image = itemDelegator.getImage(resource);
                        if (image == null) {
                                image = super.getImage(object);
                        }
                } else {
                        image = super.getImage(object);
                }
                return image;
        }

        /**
         * Returns the longest common starting substring of the two given strings.
         * 
         * @param left
         *            First of the two strings for which we need the common starting substring.
         * @param right
         *            Second of the two strings for which we need the common starting substring.
         * @return The longest common starting substring of the two given strings.
         */
        public String getCommonBase(String left, String right) {
                if (left == null || right == null) {
                        return ""; //$NON-NLS-1$
                }

                final char[] leftChars = left.toCharArray();
                final char[] rightChars = right.toCharArray();

                final StringBuilder buffer = new StringBuilder();
                StringBuilder fragmentBuffer = new StringBuilder();
                for (int i = 0; i < Math.min(leftChars.length, rightChars.length); i++) {
                        if (leftChars[i] == rightChars[i]) {
                                fragmentBuffer.append(leftChars[i]);

                                if (leftChars[i] == '\\' || leftChars[i] == '/') {
                                        buffer.append(fragmentBuffer);
                                        fragmentBuffer = new StringBuilder();
                                }
                        } else {
                                break;
                        }
                }

                return buffer.toString();
        }

        /* Missing override : only for EMF 2.10 and later. Do not tag. */
        /**
         * {@inheritDoc}
         * 
         * @see org.eclipse.emf.compare.provider.IItemStyledLabelProvider#getStyledText(java.lang.Object)
         */
        public IStyledString.IComposedStyledString getStyledText(Object object) {
                return new ComposedStyledString(getText(object));
        }

        /**
         * {@inheritDoc}
         * 
         * @see org.eclipse.emf.compare.provider.IItemDescriptionProvider#getDescription(java.lang.Object)
         */
        public String getDescription(Object object) {
                return getText(object);
        }
}