oracle.javatools.editor

Interface RowMap

public interface RowMap

A RowMap is an interface for accessing the row structure information of a BasicEditorPane. This allows clients to determine the row that an offset is on, the starting and ending offset of a specific row, and the total number of rows in the BasicEditorPane. This interface is somewhat analogous to the LineMap interface for a TextBuffer, except that it applies to a visible "row" of the editor view, instead of a "line" in the buffer model.

Client Usage Notes:

• The mapping between a view "row" and a buffer "line" is not guaranteed to be one-on-one. If the editor has line wrapping enabled, then a single buffer "line" may span multiple view "rows". If the editor has code folding enabled, then a multiple buffer "lines" may span a single view "row. An editor may have line wrapping and code folding both enabled.

• All row numbers accessed through this interface are 0-based (as are all offsets.) This includes row numbers returned by the RowMap as well as specified by the client. For example, if there are 5 rows in the view, the rows will be numbered 0 through 4, while getRowCount() will return 5 rows.

• Following the conventions in the String class, start offsets returned from getRowStartOffset(int) are inclusive, while end offsets returned from getRowEndOffset(int) are exclusive.

  For example, if the first row of the view contains "abcd" followed followed by a newline (\n), then the start offset of the row will be 0, while the row offset will be 5. Note that the last character of a row may not necessarily be a line terminator, since buffer "lines" may span multiple view "rows".

• When mapping from an offset to a row using getRowFromOffset(int), the offset given has a forward bias. In the above example, offset 5 occurs between the newline (\n) of row 0 and the first character of row 1. Since the bias is to the right, getRowFromOffset( 5 ) will return row 1, not 0.

• Since the RowMap tracks the underlying editor view, it will be modified when the view receives notification that the text buffer has been modified. To ensure data consistency, clients must be sure to acquire at least a read lock on the underlying buffer while accessing the RowMap. This is just a documented policy, and is not enforced programmatically in order to not affect performance.

• For clients that listen separately to the text buffer for changes, should not assume that the editor view has already been notified of the same changes, since no guarantee is provided for notification order.

See Also:

LineMap, BasicEditorPane

Method Summary

Modifier and Type	Method and Description
BasicEditorPane	getEditorPane() Fetches the underlying BasicEditorPane that this row map applies to.
int	getRowCount() Fetches the number of rows in the view of this BasicEditorPane.
int	getRowEndOffset(int row) Given a specified row in the editor view, returns the offset from the beginning of a TextBuffer that the row ends at.
int	getRowFromOffset(int offset) Given an offset from the beginning of the underlying TextBuffer (data model), fetches the row number containing that offset using a Forward bias.
int	getRowStartLine(int row) Given a specified row in the editor view, returns the TextBuffer line which contains the starting offset (Forward bias) of the row.
int	getRowStartOffset(int row) Given a specified row in the editor view, returns the offset from the beginning of the TextBuffer (data model) for the start of the row.

Method Detail

getEditorPane

BasicEditorPane getEditorPane()

Fetches the underlying BasicEditorPane that this row map applies to.

Returns:

the editor pane

getRowCount

int getRowCount()

Fetches the number of rows in the view of this BasicEditorPane. For example, a 5-row editor view has rows 0 through 4.

Returns:

number of rows in the editor view

getRowFromOffset

int getRowFromOffset(int offset)

Given an offset from the beginning of the underlying TextBuffer (data model), fetches the row number containing that offset using a Forward bias. This means if row A starts with offset B, and previous row A-1 ends with offset B, getRowFromOffset(B) will return row A.

Returns:

the row containing an offset

getRowStartOffset

int getRowStartOffset(int row)

Given a specified row in the editor view, returns the offset from the beginning of the TextBuffer (data model) for the start of the row.

Parameters:

row - a row in the editor view

Returns:

the starting offset of the specified row

getRowEndOffset

int getRowEndOffset(int row)

Given a specified row in the editor view, returns the offset from the beginning of a TextBuffer that the row ends at.

Parameters:

row - a row in the editor view

Returns:

the ending offset of the specified row

getRowStartLine

int getRowStartLine(int row)

Given a specified row in the editor view, returns the TextBuffer line which contains the starting offset (Forward bias) of the row.

Parameters:

row - a row in the editor view

Returns:

the line containing the start of the specified row