/*******************************************************************************
 * Copyright (c) 2000, 2006 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
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module dwtx.jface.text.DocumentPartitioningChangedEvent;

import dwt.dwthelper.utils;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import dwtx.core.runtime.Assert;

/**
 * Event describing the change of document partitionings.
 *
 * @see dwtx.jface.text.IDocumentExtension3
 * @since 3.0
 */
public class DocumentPartitioningChangedEvent {

    /** The document whose partitionings changed */
    private final IDocument fDocument;
    /** The map of partitionings to changed regions. */
    private final Map fMap= new HashMap();


    /**
     * Creates a new document partitioning changed event for the given document.
     * Initially this event is empty, i.e. does not describe any change.
     *
     * @param document the changed document
     */
    public DocumentPartitioningChangedEvent(IDocument document) {
        fDocument= document;
    }

    /**
     * Returns the changed document.
     *
     * @return the changed document
     */
    public IDocument getDocument() {
        return fDocument;
    }

    /**
     * Returns the changed region of the given partitioning or <code>null</code>
     * if the given partitioning did not change.
     *
     * @param partitioning the partitioning
     * @return the changed region of the given partitioning or <code>null</code>
     */
    public IRegion getChangedRegion(String partitioning) {
        return (IRegion) fMap.get(partitioning);
    }

    /**
     * Returns the set of changed partitionings.
     *
     * @return the set of changed partitionings
     */
    public String[] getChangedPartitionings() {
        String[] partitionings= new String[fMap.size()];
        fMap.keySet().toArray(partitionings);
        return partitionings;
    }

    /**
     * Sets the specified range as changed region for the given partitioning.
     *
     * @param partitioning the partitioning
     * @param offset the region offset
     * @param length the region length
     */
    public void setPartitionChange(String partitioning, int offset, int length) {
        Assert.isNotNull(partitioning);
        fMap.put(partitioning, new Region(offset, length));
    }

    /**
     * Returns <code>true</code> if the set of changed partitionings is empty,
     * <code>false</code> otherwise.
     *
     * @return <code>true</code> if the set of changed partitionings is empty
     */
    public bool isEmpty() {
        return fMap.isEmpty();
    }

    /**
     * Returns the coverage of this event. This is the minimal region that
     * contains all changed regions of all changed partitionings.
     *
     * @return the coverage of this event
     */
    public IRegion getCoverage() {
        if (fMap.isEmpty())
            return new Region(0, 0);

        int offset= -1;
        int endOffset= -1;
        Iterator e= fMap.values().iterator();
        while (e.hasNext()) {
            IRegion r= (IRegion) e.next();

            if (offset < 0 || r.getOffset() < offset)
                offset= r.getOffset();

            int end= r.getOffset() + r.getLength();
            if (end > endOffset)
                endOffset= end;
        }

        return new Region(offset, endOffset - offset);
    }
}