/*******************************************************************************
 * Copyright (c) 2000, 2005 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.source.ICharacterPairMatcher;

import dwt.dwthelper.utils;

import dwtx.jface.text.IDocument;
import dwtx.jface.text.IRegion;

/**
 * A character pair matcher finds to a character at a certain document offset
 * the matching peer character. It is the matchers responsibility to define the
 * concepts of "matching" and "peer". The matching process starts at a given
 * offset. Starting of this offset, the matcher chooses a character close to
 * this offset. The anchor defines whether the chosen character is left or right
 * of the initial offset. The matcher then searches for the matching peer
 * character of the chosen character and if it finds one, delivers the minimal
 * region of the document that contains both characters.
 *
 * @since 2.1
 */
public interface ICharacterPairMatcher {

    /**
     * Indicates the anchor value "right".
     */
    int RIGHT= 0;
    /**
     * Indicates the anchor value "left".
     */
    int LEFT= 1;


    /**
     * Disposes this pair matcher.
     */
    void dispose();

    /**
     * Clears this pair matcher. I.e. the matcher throws away all state it might
     * remember and prepares itself for a new call of the <code>match</code>
     * method.
     */
    void clear();

    /**
     * Starting at the given offset, the matcher chooses a character close to this offset.
     * The matcher then searches for the matching peer character of the chosen character
     * and if it finds one, returns the minimal region of the document that contains both characters.
     * It returns <code>null</code> if there is no peer character.
     *
     * @param iDocument the document to work on
     * @param i the start offset
     * @return the minimal region containing the peer characters
     */
    IRegion match(IDocument iDocument, int i);

    /**
     * Returns the anchor for the region of the matching peer characters. The anchor
     * says whether the character that has been chosen to search for its peer character
     * has been left or right of the initial offset.
     *
     * @return <code>RIGHT</code> or <code>LEFT</code>
     */
    int getAnchor();
}