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
or
ConfigurableLineTracker
.-
Method Summary
Modifier and TypeMethodDescriptionint
computeNumberOfLines
(String text) Computes the number of lines in the given text.String[]
Returns the strings this tracker considers as legal line delimiters.getLineDelimiter
(int line) Returns the line delimiter of the specified line.getLineInformation
(int line) Returns a line description of the given line.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
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
Informs the line tracker about the specified change in the tracked text.void
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
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
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
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
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
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
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
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
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
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
Sets the tracked text to the specified text.- Parameters:
text
- the new tracked text
-