Package org.eclipse.jface.text

Interface ILineTracker

All Known Implementing Classes:
AbstractLineTracker, ConfigurableLineTracker, DefaultLineTracker
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 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.

In order to provide backward compatibility for clients of ILineTracker, extension interfaces are used to provide a means of evolution. The following extension interfaces exist:

Clients may implement this interface or use the standard implementation

DefaultLineTrackeror ConfigurableLineTracker.

  • Method Summary

    Modifier and Type
    Method
    Description
    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 Details

    • getLegalLineDelimiters

      String[] getLegalLineDelimiters()
      Returns the strings this tracker considers as legal line delimiters.
      Returns:
      the legal line delimiters

    • getLineDelimiter

      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

      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

      int getNumberOfLines()
      Returns the number of lines.

      Note that a document always has at least one line.

      Returns:
      the number of lines in this tracker's line structure

    • getNumberOfLines

      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

      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

      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

      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

      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

      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

      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

      void set(String text)
      Sets the tracked text to the specified text.
      Parameters:
      text - the new tracked text