/*******************************************************************************
 * Copyright (c) 2006, 2008 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.text.undo.DocumentUndoEvent;

// import dwtx.text.undo.DocumentUndoManager; // packageimport
// import dwtx.text.undo.DocumentUndoManagerRegistry; // packageimport
// import dwtx.text.undo.IDocumentUndoListener; // packageimport
// import dwtx.text.undo.UndoMessages; // packageimport
// import dwtx.text.undo.IDocumentUndoManager; // packageimport


import dwt.dwthelper.utils;


import dwtx.core.runtime.Assert;
import dwtx.jface.text.IDocument;


/**
 * Describes document changes initiated by undo or redo.
 * <p>
 * Clients are not supposed to subclass or create instances of this class.
 * </p>
 *
 * @see IDocumentUndoManager
 * @see IDocumentUndoListener
 * @since 3.2
 * @noinstantiate This class is not intended to be instantiated by clients.
 * @noextend This class is not intended to be subclassed by clients.
 */
public class DocumentUndoEvent {

    /**
     * Indicates that the described document event is about to be
     * undone.
     */
    public static const int ABOUT_TO_UNDO= 1 << 0;

    /**
     * Indicates that the described document event is about to be
     * redone.
     */
    public static const int ABOUT_TO_REDO= 1 << 1;

    /**
     * Indicates that the described document event has been undone.
     */
    public static const int UNDONE= 1 << 2;

    /**
     * Indicates that the described document event has been redone.
     */
    public static const int REDONE= 1 << 3;

    /**
     * Indicates that the described document event is a compound undo
     * or redo event.
     */
    public static const int COMPOUND= 1 << 4;

    /** The changed document. */
    private IDocument fDocument;

    /** The document offset where the change begins. */
    private int fOffset;

    /** Text inserted into the document. */
    private String fText;

    /** Text replaced in the document. */
    private String fPreservedText;

    /** Bit mask of event types describing the event */
    private int fEventType;

    /** The source that triggered this event or <code>null</code> if unknown. */
    private Object fSource;

    /**
     * Creates a new document event.
     *
     * @param doc the changed document
     * @param offset the offset of the replaced text
     * @param text the substitution text
     * @param preservedText the replaced text
     * @param eventType a bit mask describing the type(s) of event
     * @param source the source that triggered this event or <code>null</code> if unknown
     */
    this(IDocument doc, int offset, String text, String preservedText, int eventType, Object source) {

        Assert.isNotNull(doc);
        Assert.isTrue(offset >= 0);

        fDocument= doc;
        fOffset= offset;
        fText= text;
        fPreservedText= preservedText;
        fEventType= eventType;
        fSource= source;
    }

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

    /**
     * Returns the offset of the change.
     *
     * @return the offset of the change
     */
    public int getOffset() {
        return fOffset;
    }

    /**
     * Returns the text that has been inserted.
     *
     * @return the text that has been inserted
     */
    public String getText() {
        return fText;
    }

    /**
     * Returns the text that has been replaced.
     *
     * @return the text that has been replaced
     */
    public String getPreservedText() {
        return fPreservedText;
    }

    /**
     * Returns the type of event that is occurring.
     *
     * @return the bit mask that indicates the type (or types) of the event
     */
    public int getEventType() {
        return fEventType;
    }

    /**
     * Returns the source that triggered this event.
     *
     * @return the source that triggered this event.
     */
    public Object getSource() {
        return fSource;
    }

    /**
     * Returns whether the change was a compound change or not.
     *
     * @return  <code>true</code> if the undo or redo change is a
     *          compound change, <code>false</code> if it is not
     */
    public bool isCompound() {
        return (fEventType & COMPOUND) !is 0;
    }
}