org.eclipse.jface.text
Interface ILineTracker

All Known Implementing Classes:

AbstractLineTracker

public interface ILineTracker

A line tracker maps character positions to line numbers and vice versa. Initially the line tracker is informed about its underlying text which 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.

Clients may implement this interface or use the standard implementation DefaultLineTracker.

Method Summary

int	computeNumberOfLines(String text) Computes the number of lines in the given text.
String[]	getLegalLineDelimiters() Returns the strings this tracker considers as legal line delimiters.
String	getLineDelimiter(int line) Returns the line delimiter of the specified line.
IRegion	getLineInformation(int line) Returns a line description of the given line.
IRegion	getLineInformationOfOffset(int offset) Returns a line description of the line at the given offset.
int	getLineLength(int line) Returns length of the specified line including the line's delimiter.
int	getLineNumberOfOffset(int offset) Returns the line number the character at the given offset belongs to.
int	getLineOffset(int line) Returns the position of the first character of the specified line.
int	getNumberOfLines() Returns the number of lines.
int	getNumberOfLines(int offset, int length) Returns the number of lines which are occupied by a given text range.
void	replace(int offset, int length, String text) Informs the line tracker about the specified change in the tracked text.
void	set(String text) Sets the tracked text to the specified text.

Method Detail

getLegalLineDelimiters

public String[] getLegalLineDelimiters()

Returns the strings this tracker considers as legal line delimiters.

Returns:

the legal line delimiters

getLineDelimiter

public String getLineDelimiter(int line)
                        throws BadLocationException

Returns the line delimiter of the specified line. Returns null if the line is not closed with a line delimiter.

Parameters:

line - the line whose line delimiter is queried

Returns:

the line's delimiter or null if line does not have a delimiter

Throws:

BadLocationException - if the line number is invalid in this tracker's line structure

computeNumberOfLines

public int computeNumberOfLines(String text)

Computes the number of lines in the given text.

Parameters:

text - the text whose number of lines should be computed

Returns:

the number of lines in the given text

getNumberOfLines

public int getNumberOfLines()

Returns the number of lines.

Returns:

the number of lines in this tracker's line structure

getNumberOfLines

public int getNumberOfLines(int offset,
                            int length)
                     throws BadLocationException

Returns the number of lines which are occupied by a given text range.

Parameters:

offset - the offset of the specified text range

length - the length of the specified text range

Returns:

the number of lines occupied by the specified range

Throws:

BadLocationException - if specified range is unknown to this tracker

getLineOffset

public int getLineOffset(int line)
                  throws BadLocationException

Returns the position of the first character of the specified line.

Parameters:

line - the line of interest

Returns:

offset of the first character of the line

Throws:

BadLocationException - if the line is unknown to this tracker

getLineLength

public int getLineLength(int line)
                  throws BadLocationException

Returns length of the specified line including the line's delimiter.

Parameters:

line - the line of interest

Returns:

the length of the line

Throws:

BadLocationException - if line is unknown to this tracker

getLineNumberOfOffset

public int getLineNumberOfOffset(int offset)
                          throws BadLocationException

Returns the line number the character at the given offset belongs to.

Parameters:

offset - the offset whose line number to be determined

Returns:

the number of the line the offset is on

Throws:

BadLocationException - if the offset is invalid in this tracker

getLineInformationOfOffset

public IRegion getLineInformationOfOffset(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.

Parameters:

offset - the offset whose line should be described

Returns:

a region describing the line

Throws:

BadLocationException - if offset is invalid in this tracker

getLineInformation

public IRegion getLineInformation(int line)
                           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.

Parameters:

line - the line that should be described

Returns:

a region describing the line

Throws:

BadLocationException - if line is unknown to this tracker

replace

public void replace(int offset,
                    int length,
                    String text)
             throws BadLocationException

Informs the line tracker about the specified change in the tracked text.

Parameters:

offset - the offset of the replaced text

length - the length of the replaced text

text - the substitution text

Throws:

BadLocationException - if specified range is unknown to this tracker

set

public void set(String text)

Sets the tracked text to the specified text.

Parameters:

text - the new tracked text