uk.ac.starlink.table

Class EditableColumn

java.lang.Object

uk.ac.starlink.table.ColumnData

uk.ac.starlink.table.WrapperColumn

uk.ac.starlink.table.EditableColumn

public class EditableColumn
extends WrapperColumn

A column which can be initialised from a given existing column, but whose cells can be written to. Whether the initialisation is done by copying the whole lot and creating a new column or by just keeping track of the changed elements is unspecified and down to the implementation. Modifications to the cell data or the metadata of this column will not affect the data/metadata of the base column.

Author:

Mark Taylor (Starlink)

Constructor Summary

Constructors

Constructor and Description
EditableColumn(ColumnData base) Constructs a new EditableColumn based on an existing column.

Method Summary

Modifier and Type	Method and Description
boolean	isWritable() Returns true.
Object	readValue(long irow) Returns the value stored at a given row in this column.
void	storeValue(long irow, Object value) Stores a given value in a given row for this column.

Methods inherited from class uk.ac.starlink.table.WrapperColumn

getBaseColumn

Methods inherited from class uk.ac.starlink.table.ColumnData

getColumnInfo, setColumnInfo

Methods inherited from class java.lang.Object

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

Constructor Detail

EditableColumn

public EditableColumn(ColumnData base)

Constructs a new EditableColumn based on an existing column.

Method Detail

isWritable

public boolean isWritable()

Returns true.

Overrides:

isWritable in class WrapperColumn

Returns:

whether cells can be edited. They can.

readValue

public Object readValue(long irow)
                 throws IOException

Description copied from class: ColumnData

Returns the value stored at a given row in this column.

Overrides:

readValue in class WrapperColumn

Parameters:

irow - the row from which to retrieve the value

Returns:

the value stored at irow

Throws:

IOException - if there is some problem reading

storeValue

public void storeValue(long irow,
                       Object value)
                throws IOException

Description copied from class: ColumnData

Stores a given value in a given row for this column. Will only work if the isWritable method returns true. The implementation in the ColumnData class throws an UnsupportedOperationException.

Overrides:

storeValue in class WrapperColumn

Parameters:

irow - the row to store it in

value - the object to store

Throws:

IOException - if there is some problem writing