/**
 * Copyright (C) 2001-2017 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.DocumentEvent;
import javax.swing.text.BadLocationException;
import javax.swing.text.Element;
import javax.swing.text.PlainDocument;
import javax.swing.text.Segment;
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);
	}
}