http://www.eclipse.org/platform: Text (Eclipse Foundation) 
Copyright (c) 2000, 2010 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation

/*******************************************************************************
 * Copyright (c) 2000, 2010 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jface.text;



Default document implementation. Uses a GapTextStore wrapped inside a CopyOnWriteTextStore as text store. 
 The used line tracker considers the following strings as line delimiters: "\n", "\r", "\r\n". In case of a text replacement across line delimiter boundaries and with different line delimiters, the line tracker might have to be repaired. Use isLineInformationRepairNeeded(int, int, String) before doing the text replace if you have the need to discover such a situation. 



The document is ready to use. It has a default position category for which a default position
updater is installed.




Performance: The implementation should perform reasonably well for typical source code documents. It is not designed for very large documents of a size of several megabytes. Space-saving implementations are initially used for both the text store and the line tracker; the first modification after a set incurs the cost to transform the document structures to efficiently handle updates. 


 See GapTextStore and TreeLineTracker for algorithmic behavior of the used
document structures.



See Also:
/**
 * Default document implementation. Uses a {@link org.eclipse.jface.text.GapTextStore} wrapped
 * inside a {@link org.eclipse.jface.text.CopyOnWriteTextStore} as text store.
 * <p>
 * The used line tracker considers the following strings as line delimiters: "\n", "\r", "\r\n". In
 * case of a text replacement across line delimiter boundaries and with different line delimiters,
 * the line tracker might have to be repaired. Use
 * {@link #isLineInformationRepairNeeded(int, int, String)} before doing the text replace if you
 * have the need to discover such a situation.
 * </p>
 * <p>
 * The document is ready to use. It has a default position category for which a default position
 * updater is installed.
 * </p>
 * <p>
 * <strong>Performance:</strong> The implementation should perform reasonably well for typical
 * source code documents. It is not designed for very large documents of a size of several
 * megabytes. Space-saving implementations are initially used for both the text store and the line
 * tracker; the first modification after a {@link #set(String) set} incurs the cost to transform the
 * document structures to efficiently handle updates.
 * </p>
 * <p>
 * See {@link GapTextStore} and <code>TreeLineTracker</code> for algorithmic behavior of the used
 * document structures.
 * </p>
 *
 * @see org.eclipse.jface.text.GapTextStore
 * @see org.eclipse.jface.text.CopyOnWriteTextStore
 */
public class Document extends AbstractDocument {
	
Creates a new empty document.

/**
	 * Creates a new empty document.
	 */
	public Document() {
		super();
		setTextStore(new CopyOnWriteTextStore(new GapTextStore()));
		setLineTracker(new DefaultLineTracker());
		completeInitialization();
	}

	
Creates a new document with the given initial content.

Params:
  • initialContent – the document's initial content
/**
	 * Creates a new document with the given initial content.
	 *
	 * @param initialContent the document's initial content
	 */
	public Document(String initialContent) {
		super();
		setTextStore(new CopyOnWriteTextStore(new GapTextStore()));
		setLineTracker(new DefaultLineTracker());
		getStore().set(initialContent);
		getTracker().set(initialContent);
		completeInitialization();
	}

	@Override
	public boolean isLineInformationRepairNeeded(int offset, int length, String text) throws BadLocationException {
		if ((0 > offset) || (0 > length) || (offset + length > getLength()))
			throw new BadLocationException();

		return isLineInformationRepairNeeded(text) || isLineInformationRepairNeeded(get(offset, length));
	}

	
Checks whether the line information needs to be repaired.

Params:
  • text – the text to check
Returns:true if the line information must be repaired
Since:3.4
/**
	 * Checks whether the line information needs to be repaired.
	 *
	 * @param text the text to check
	 * @return <code>true</code> if the line information must be repaired
	 * @since 3.4
	 */
	private boolean isLineInformationRepairNeeded(String text) {
		if (text == null)
			return false;

		int length= text.length();
		if (length == 0)
			return false;

		int rIndex= text.indexOf('\r');
		int nIndex= text.indexOf('\n');
		if (rIndex == -1 && nIndex == -1)
			return false;

		if (rIndex > 0 && rIndex < length-1 && nIndex > 1 && rIndex < length-2)
			return false;

		String defaultLD= null;
		try {
			defaultLD= getLineDelimiter(0);
		} catch (BadLocationException x) {
			return true;
		}

		if (defaultLD == null)
			return false;

		defaultLD= getDefaultLineDelimiter();

		if (defaultLD.length() == 1) {
			if (rIndex != -1 && !"\r".equals(defaultLD)) //$NON-NLS-1$
				return true;
			if (nIndex != -1 && !"\n".equals(defaultLD)) //$NON-NLS-1$
				return true;
		} else if (defaultLD.length() == 2)
			return rIndex == -1 || nIndex - rIndex != 1;

		return false;
	}

}