/*******************************************************************************
 * 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.contentassist.IContextInformationValidator;

import dwt.dwthelper.utils;

import dwtx.jface.text.ITextViewer;


/**
 * A context information validator is used to determine if
 * a displayed context information is still valid or should
 * be dismissed.
 * <p>
 * The interface can be implemented by clients.
 * </p>
 *
 * @see IContextInformationPresenter
 */
public interface IContextInformationValidator {

    /**
     * Installs this validator for the given context information.
     *
     * @param info the context information which this validator should check
     * @param viewer the text viewer on which the information is presented
     * @param offset the document offset for which the information has been computed
     */
    void install(IContextInformation info, ITextViewer viewer, int offset);

    /**
     * Returns whether the information this validator is installed on is still valid
     * at the given document position.
     *
     * @param offset the current offset within the document
     * @return <code>true</code> if the information also valid at the given document position
     */
    bool isContextInformationValid(int offset);
}