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:-
ILineTrackerExtension
since version 3.1 introducing the concept of rewrite sessions.
Clients may implement this interface or use the standard implementation
DefaultLineTracker
orConfigurableLineTracker
.
-
-
Method Summary
All Methods Instance Methods Abstract Methods 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 Detail
-
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. Returnsnull
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 rangelength
- 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 textlength
- the length of the replaced texttext
- 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
-
-