org.eclipse.jface.text
Class AbstractLineTracker

java.lang.Object
  org.eclipse.jface.text.AbstractLineTracker

All Implemented Interfaces:

ILineTracker

Direct Known Subclasses:

ConfigurableLineTracker, DefaultLineTracker

public abstract class AbstractLineTracker

extends Object

implements ILineTracker

Abstract implementation of ILineTracker. It lets the definition of line delimiters to subclasses. Assuming that '\n' is the only line delimiter, this abstract implementation defines the following line scheme:

• "" -> [0,0]
• "a" -> [0,1]
• "\n" -> [0,1], [1,0]
• "a\n" -> [0,2], [2,0]
• "a\nb" -> [0,2], [2,1]
• "a\nbc\n" -> [0,2], [2,3], [5,0]

This class must be subclassed.

Nested Class Summary

protected static class

AbstractLineTracker.DelimiterInfo Combines the information of the occurrence of a line delimiter.

Constructor Summary

protected

AbstractLineTracker() Creates a new line tracker.

Method Summary

int	computeNumberOfLines(String text) Computes the number of lines in the given text.
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 position) 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 position) 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 position, int length) Returns the number of lines which are occupied by a given text range.
protected abstract AbstractLineTracker.DelimiterInfo	nextDelimiterInfo(String text, int offset) Returns the information about the first delimiter found in the given text starting at the given offset.
void	replace(int position, 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.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.eclipse.jface.text.ILineTracker

getLegalLineDelimiters

Constructor Detail

AbstractLineTracker

protected AbstractLineTracker()

Creates a new line tracker.

Method Detail

getLineLength

public int getLineLength(int line)
                  throws BadLocationException

Description copied from interface: ILineTracker

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

Specified by:

getLineLength in interface ILineTracker

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 position)
                          throws BadLocationException

Description copied from interface: ILineTracker

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

Specified by:

getLineNumberOfOffset in interface ILineTracker

Parameters:

position - 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 position)
                                   throws BadLocationException

Description copied from interface: ILineTracker

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.

Specified by:

getLineInformationOfOffset in interface ILineTracker

Parameters:

position - 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

Description copied from interface: ILineTracker

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.

Specified by:

getLineInformation in interface ILineTracker

Parameters:

line - the line that should be described

Returns:

a region describing the line

Throws:

BadLocationException - if line is unknown to this tracker

getLineOffset

public int getLineOffset(int line)
                  throws BadLocationException

Description copied from interface: ILineTracker

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

Specified by:

getLineOffset in interface ILineTracker

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

getNumberOfLines

public int getNumberOfLines()

Description copied from interface: ILineTracker

Returns the number of lines.

Specified by:

getNumberOfLines in interface ILineTracker

Returns:

the number of lines in this tracker's line structure

getNumberOfLines

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

Description copied from interface: ILineTracker

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

Specified by:

getNumberOfLines in interface ILineTracker

Parameters:

position - 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

computeNumberOfLines

public int computeNumberOfLines(String text)

Description copied from interface: ILineTracker

Computes the number of lines in the given text.

Specified by:

computeNumberOfLines in interface ILineTracker

Parameters:

text - the text whose number of lines should be computed

Returns:

the number of lines in the given text

nextDelimiterInfo

protected abstract AbstractLineTracker.DelimiterInfo nextDelimiterInfo(String text,
                                                                       int offset)

Returns the information about the first delimiter found in the given text starting at the given offset.

Parameters:

text - the text to be searched

offset - the offset in the given text

Returns:

the information of the first found delimiter or null

replace

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

Description copied from interface: ILineTracker

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

Specified by:

replace in interface ILineTracker

Parameters:

position - 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)

Description copied from interface: ILineTracker

Sets the tracked text to the specified text.

Specified by:

set in interface ILineTracker

Parameters:

text - the new tracked text

getLineDelimiter

public String getLineDelimiter(int line)
                        throws BadLocationException

Description copied from interface: ILineTracker

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

Specified by:

getLineDelimiter in interface ILineTracker

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