/*******************************************************************************
* Copyright (c) 2012-2015 Codenvy, S.A.
* 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:
* Codenvy, S.A. - initial API and implementation
*******************************************************************************/
package org.eclipse.che.ide.ext.java.jdt.text;
import org.eclipse.che.ide.api.editor.text.BadLocationException;
import org.eclipse.che.ide.api.editor.text.Region;
/**
* A line tracker maps character positions to line numbers and vice versa. Initially the line tracker is informed about its
* underlying text in order to initialize the mapping information. After that, the line tracker is informed about all changes of
* the underlying text allowing for incremental updates of the mapping information. It is the client's responsibility to actively
* inform the line tacker about text changes. For example, when using a line tracker in combination with a document the document
* controls the line tracker.
* <p/>
* Clients may implement this interface or use the standard implementation
* </p>
* {DefaultLineTracker} or {ConfigurableLineTracker}.
*/
public interface LineTracker {
/**
* Returns the strings this tracker considers as legal line delimiters.
*
* @return the legal line delimiters
*/
String[] getLegalLineDelimiters();
/**
* Returns the line delimiter of the specified line. Returns <code>null</code> if the line is not closed with a line delimiter.
*
* @param line
* the line whose line delimiter is queried
* @return the line's delimiter or <code>null</code> if line does not have a delimiter
* @throws BadLocationException
* if the line number is invalid in this tracker's line structure
*/
String getLineDelimiter(int line) throws BadLocationException;
/**
* Computes the number of lines in the given text.
*
* @param text
* the text whose number of lines should be computed
* @return the number of lines in the given text
*/
int computeNumberOfLines(String text);
/**
* Returns the number of lines.
* <p>
* Note that a document always has at least one line.
* </p>
*
* @return the number of lines in this tracker's line structure
*/
int getNumberOfLines();
/**
* Returns the number of lines which are occupied by a given text range.
*
* @param offset
* the offset of the specified text range
* @param length
* the length of the specified text range
* @return the number of lines occupied by the specified range
* @throws BadLocationException
* if specified range is unknown to this tracker
*/
int getNumberOfLines(int offset, int length) throws BadLocationException;
/**
* Returns the position of the first character of the specified line.
*
* @param line
* the line of interest
* @return offset of the first character of the line
* @throws BadLocationException
* if the line is unknown to this tracker
*/
int getLineOffset(int line) throws BadLocationException;
/**
* Returns length of the specified line including the line's delimiter.
*
* @param line
* the line of interest
* @return the length of the line
* @throws BadLocationException
* if line is unknown to this tracker
*/
int getLineLength(int line) throws BadLocationException;
/**
* Returns the line number the character at the given offset belongs to.
*
* @param offset
* the offset whose line number to be determined
* @return the number of the line the offset is on
* @throws BadLocationException
* if the offset is invalid in this tracker
*/
int getLineNumberOfOffset(int offset) throws BadLocationException;
/**
* Returns a line description of the line at the given offset. The description contains the start offset and the length of the
* line excluding the line's delimiter.
*
* @param offset
* the offset whose line should be described
* @return a region describing the line
* @throws BadLocationException
* if offset is invalid in this tracker
*/
Region getLineInformationOfOffset(int offset) throws BadLocationException;
/**
* Returns a line description of the given line. The description contains the start offset and the length of the line excluding
* the line's delimiter.
*
* @param line
* the line that should be described
* @return a region describing the line
* @throws BadLocationException
* if line is unknown to this tracker
*/
Region getLineInformation(int line) throws BadLocationException;
/**
* Informs the line tracker about the specified change in the tracked text.
*
* @param offset
* the offset of the replaced text
* @param length
* the length of the replaced text
* @param text
* the substitution text
* @throws BadLocationException
* if specified range is unknown to this tracker
*/
void replace(int offset, int length, String text) throws BadLocationException;
/**
* Sets the tracked text to the specified text.
*
* @param text
* the new tracked text
*/
void set(String text);
}