eu.interedition.text.util.Ranges.java Source code

Introduction

Here is the source code for eu.interedition.text.util.Ranges.java

Source

/*
 * #%L
 * Text: A text model with range-based markup via standoff annotations.
 * %%
 * Copyright (C) 2010 - 2011 The Interedition Development Group
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */
package eu.interedition.text.util;

import com.google.common.collect.Ordering;
import com.google.common.collect.Sets;
import eu.interedition.text.TextRange;
import eu.interedition.text.TextTarget;

import java.util.*;

public class Ranges {
    public static final Ordering<TextRange> START_ORDERING = Ordering.from(new Comparator<TextRange>() {

        public int compare(TextRange o1, TextRange o2) {
            final long result = o1.getStart() - o2.getStart();
            return (result < 0 ? -1 : (result > 0 ? 1 : 0));
        }
    });

    public static final Ordering<TextRange> END_ORDERING = Ordering.from(new Comparator<TextRange>() {

        public int compare(TextRange o1, TextRange o2) {
            final long result = o2.getEnd() - o1.getEnd();
            return (result < 0 ? -1 : (result > 0 ? 1 : 0));
        }
    });

    public static final Ordering<TextTarget> NATURAL_ORDERING = Ordering.natural();

    public static SortedSet<TextRange> compressAdjacent(SortedSet<TextRange> ranges) {
        final SortedSet<TextRange> compressed = Sets.newTreeSet();

        TextRange current = null;
        for (Iterator<TextRange> rangeIt = ranges.iterator(); rangeIt.hasNext();) {
            final TextRange range = rangeIt.next();
            if (current == null) {
                current = new TextRange(range);
            } else {
                if (current.getEnd() == range.getStart()) {
                    current = new TextRange(current.getStart(), range.getEnd());
                } else {
                    compressed.add(current);
                    current = new TextRange(range);
                }
            }
            if (!rangeIt.hasNext()) {
                compressed.add(current);
            }
        }

        return compressed;
    }

    public static SortedSet<TextRange> compress(SortedSet<TextRange> ranges) {
        final SortedSet<TextRange> compressed = Sets.newTreeSet();

        TextRange current = null;
        for (Iterator<TextRange> rangeIt = ranges.iterator(); rangeIt.hasNext();) {
            final TextRange range = rangeIt.next();
            if (current == null) {
                current = new TextRange(range);
            } else {
                if (current.getEnd() >= range.getStart()) {
                    current = new TextRange(current.getStart(), Math.max(current.getEnd(), range.getEnd()));
                } else {
                    compressed.add(current);
                    current = new TextRange(range);
                }
            }
            if (!rangeIt.hasNext()) {
                compressed.add(current);
            }
        }

        return compressed;
    }

    public static int length(SortedSet<TextTarget> ranges) {
        int length = 0;
        for (TextTarget r : ranges) {
            length += r.length();
        }
        return length;
    }

    public static List<TextRange> exclude(Iterable<TextRange> ranges, List<TextRange> excluded) {
        excluded = START_ORDERING.sortedCopy(excluded);

        final List<TextRange> result = START_ORDERING.sortedCopy(ranges);
        for (ListIterator<TextRange> it = result.listIterator(); it.hasNext();) {
            final TextRange r = it.next();
            it.remove();

            for (Iterator<TextRange> exIt = excluded.iterator(); exIt.hasNext();) {
                final TextRange ex = exIt.next();
                if (ex.precedes(r)) {
                    exIt.remove();
                } else if (r.precedes(ex)) {
                    continue;
                }
                for (TextRange remainder : r.substract(ex)) {
                    it.add(remainder);
                }

            }
        }
        return result;
    }
}