/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2014 by RapidMiner and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapidminer.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.gui.tools.syntax;
/*
 * SyntaxDocument.java - Document that can be tokenized
 * Copyright (C) 1999 Slava Pestov
 *
 * You may use and modify this package for any purpose. Redistribution is
 * permitted, in both source and binary form, provided that this notice
 * remains intact in all source distributions of this package.
 */

import javax.swing.event.*;
import javax.swing.text.*;
import javax.swing.undo.UndoableEdit;

/**
 * A document implementation that can be tokenized by the syntax highlighting system.
 * 
 * @author Slava Pestov, Ingo Mierswa
 */
public class SyntaxDocument extends PlainDocument {

	private static final long serialVersionUID = 5959684700222385821L;

	/**
	 * Returns the token marker that is to be used to split lines of this document up into tokens. May return null if this document is not to be colorized.
	 */
	public TokenMarker getTokenMarker() {
		return tokenMarker;
	}

	/**
	 * Sets the token marker that is to be used to split lines of this document up into tokens. May throw an exception if this is not supported for this type of document.
	 * 
	 * @param tm
	 *            The new token marker
	 */
	public void setTokenMarker(TokenMarker tm) {
		tokenMarker = tm;
		if (tm == null)
			return;
		tokenMarker.insertLines(0, getDefaultRootElement().getElementCount());
		tokenizeLines();
	}

	/**
	 * Reparses the document, by passing all lines to the token marker. This should be called after the document is first loaded.
	 */
	public void tokenizeLines() {
		tokenizeLines(0, getDefaultRootElement().getElementCount());
	}

	/**
	 * Reparses the document, by passing the specified lines to the token marker. This should be called after a large quantity of text is first inserted.
	 * 
	 * @param start
	 *            The first line to parse
	 * @param len
	 *            The number of lines, after the first one to parse
	 */
	public void tokenizeLines(int start, int len) {
		if (tokenMarker == null || !tokenMarker.supportsMultilineTokens())
			return;

		Segment lineSegment = new Segment();
		Element map = getDefaultRootElement();

		len += start;

		try {
			for (int i = start; i < len; i++) {
				Element lineElement = map.getElement(i);
				int lineStart = lineElement.getStartOffset();
				getText(lineStart, lineElement.getEndOffset() - lineStart - 1, lineSegment);
				tokenMarker.markTokens(lineSegment, i);
			}
		} catch (BadLocationException bl) {
			bl.printStackTrace();
		}
	}

	/**
	 * Starts a compound edit that can be undone in one operation. Subclasses that implement undo should override this method; this class has no undo functionality so this method is empty.
	 */
	public void beginCompoundEdit() {
	}

	/**
	 * Ends a compound edit that can be undone in one operation. Subclasses that implement undo should override this method; this class has no undo functionality so this method is empty.
	 */
	public void endCompoundEdit() {
	}

	/**
	 * Adds an undoable edit to this document's undo list. The edit should be ignored if something is currently being undone.
	 * 
	 * @param edit
	 *            The undoable edit
	 * 
	 * @since jEdit 2.2pre1
	 */
	public void addUndoableEdit(UndoableEdit edit) {
	}

	// protected members
	protected transient TokenMarker tokenMarker;

	/**
	 * We overwrite this method to update the token marker state immediately so that any event listeners get a consistent token marker.
	 */
	@Override
	protected void fireInsertUpdate(DocumentEvent evt) {
		if (tokenMarker != null) {
			DocumentEvent.ElementChange ch = evt.getChange(getDefaultRootElement());
			if (ch != null) {
				tokenMarker.insertLines(ch.getIndex() + 1, ch.getChildrenAdded().length - ch.getChildrenRemoved().length);
			}
		}

		super.fireInsertUpdate(evt);
	}

	/**
	 * We overwrite this method to update the token marker state immediately so that any event listeners get a consistent token marker.
	 */
	@Override
	protected void fireRemoveUpdate(DocumentEvent evt) {
		if (tokenMarker != null) {
			DocumentEvent.ElementChange ch = evt.getChange(getDefaultRootElement());
			if (ch != null) {
				tokenMarker.deleteLines(ch.getIndex() + 1, ch.getChildrenRemoved().length - ch.getChildrenAdded().length);
			}
		}

		super.fireRemoveUpdate(evt);
	}
}