org.eclipse.equinox.internal.p2.ui.viewers.MetadataRepositoryElementComparator.java Source code

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Here is the source code for org.eclipse.equinox.internal.p2.ui.viewers.MetadataRepositoryElementComparator.java

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/*******************************************************************************
 *  Copyright (c) 2000, 2009 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.equinox.internal.p2.ui.viewers;

import org.eclipse.core.runtime.URIUtil;
import org.eclipse.equinox.internal.p2.ui.model.MetadataRepositoryElement;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerComparator;

/**
 * 
 * @since 3.5
 */
public class MetadataRepositoryElementComparator extends ViewerComparator {
    private int key;
    private static final String ENABLED = "XX"; //$NON-NLS-1$  // Value doesn't matter, just that it's not BLANK
    private static final String BLANK = ""; //$NON-NLS-1$
    private static final int ASCENDING = 1;
    private static final int DESCENDING = -1;
    private int primaryKeyDirection = ASCENDING;

    public MetadataRepositoryElementComparator(int sortKey) {
        this.key = sortKey;
    }

    public int compare(Viewer viewer, Object obj1, Object obj2) {
        MetadataRepositoryElement repo1 = obj1 instanceof MetadataRepositoryElement
                ? (MetadataRepositoryElement) obj1
                : null;
        MetadataRepositoryElement repo2 = obj2 instanceof MetadataRepositoryElement
                ? (MetadataRepositoryElement) obj2
                : null;
        if (repo1 == null || repo2 == null)
            // If these are not both metadata repository elements, use the super class comparator.
            return super.compare(viewer, obj1, obj2);
        int result = compare(repo1, repo2, key, primaryKeyDirection);
        if (result == 0) {
            int secondaryKey = getSecondaryKeyFor(key);
            if (secondaryKey < 0)
                return result;
            result = compare(repo1, repo2, secondaryKey, ASCENDING);
            if (result == 0)
                result = compare(repo1, repo2, getSecondaryKeyFor(secondaryKey), ASCENDING);
        }
        return result;
    }

    int compare(MetadataRepositoryElement repo1, MetadataRepositoryElement repo2, int sortKey, int direction) {
        String key1, key2;
        if (sortKey == RepositoryDetailsLabelProvider.COL_NAME) {
            // Compare the repo names
            key1 = repo1.getName();
            key2 = repo2.getName();
        } else if (sortKey == RepositoryDetailsLabelProvider.COL_LOCATION) {
            key1 = URIUtil.toUnencodedString(repo1.getLocation());
            key2 = URIUtil.toUnencodedString(repo2.getLocation());
        } else { // COL_ENABLEMENT
            key1 = repo1.isEnabled() ? ENABLED : BLANK;
            key2 = repo2.isEnabled() ? ENABLED : BLANK;
        }
        // If the key is blank (no location, or disabled)..it should appear last
        if (key1.length() == 0 && key2.length() > 0)
            return direction;
        if (key1.length() > 0 && key2.length() == 0)
            return direction * -1;
        return key1.compareToIgnoreCase(key2) * direction;
    }

    private int getSecondaryKeyFor(int primaryKey) {
        // This is the important one - if sorting by enablement, sort by location, since
        // not all repos have a name
        if (primaryKey == RepositoryDetailsLabelProvider.COL_ENABLEMENT)
            return RepositoryDetailsLabelProvider.COL_LOCATION;
        if (primaryKey == RepositoryDetailsLabelProvider.COL_NAME)
            return RepositoryDetailsLabelProvider.COL_LOCATION;
        // unlikely to have duplicate locations requiring a secondary key
        if (primaryKey == RepositoryDetailsLabelProvider.COL_LOCATION)
            return RepositoryDetailsLabelProvider.COL_NAME;
        return -1;
    }

    public void sortAscending() {
        primaryKeyDirection = ASCENDING;
    }

    public void sortDescending() {
        primaryKeyDirection = DESCENDING;
    }

    public boolean isAscending() {
        return primaryKeyDirection == ASCENDING;
    }

    public void setSortKey(int key) {
        this.key = key;
    }

    public int getSortKey() {
        return key;
    }

}