Package com.mckoi.database

Class GTTableColumnsDataSource

java.lang.Object

com.mckoi.database.GTDataSource

com.mckoi.database.GTTableColumnsDataSource

All Implemented Interfaces:

MutableTableDataSource, TableDataSource

final class GTTableColumnsDataSource
extends GTDataSource

An implementation of MutableTableDataSource that presents information about the columns of all tables in all schema.

NOTE: This is not designed to be a long kept object. It must not last beyond the lifetime of a transaction.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) static DataTableDef	DEF_DATA_TABLE_DEF	The data table def that describes this table of data source.
private int	row_count	The number of rows in this table.
private Transaction	transaction	The transaction that is the view of this information.
private DataTableDef[]	visible_tables	The list of all DataTableDef visible to the transaction.

Constructor Summary

Constructors

Constructor	Description
GTTableColumnsDataSource(Transaction transaction)	Constructor.

Method Summary

Modifier and Type	Method	Description
void	dispose()	Disposes this table data source.
TObject	getCellContents(int column, int row)	Returns an object that represents the information in the given cell in the table.
DataTableDef	getDataTableDef()	Returns a DataTableDef object that defines the layout of the table that this data is in.
int	getRowCount()	Returns the number of rows in this data source.
GTTableColumnsDataSource	init()	Initialize the data source.

Methods inherited from class com.mckoi.database.GTDataSource

addRootLock, addRow, booleanColumn, columnValue, constraintIntegrityCheck, dateColumn, flushIndexChanges, getColumnScheme, getJournal, getSystem, numericColumn, removeRootLock, removeRow, rowEnumeration, stringColumn, updateRow

Methods inherited from class java.lang.Object

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

Field Detail

transaction

private Transaction transaction

The transaction that is the view of this information.

visible_tables

private DataTableDef[] visible_tables

The list of all DataTableDef visible to the transaction.

row_count

private int row_count

The number of rows in this table.

DEF_DATA_TABLE_DEF

static final DataTableDef DEF_DATA_TABLE_DEF

The data table def that describes this table of data source.

Constructor Detail

GTTableColumnsDataSource

public GTTableColumnsDataSource(Transaction transaction)

Constructor.

Method Detail

init

public GTTableColumnsDataSource init()

Initialize the data source.

getDataTableDef

public DataTableDef getDataTableDef()

Description copied from interface: TableDataSource

Returns a DataTableDef object that defines the layout of the table that this data is in.

This may return 'null' if there is no table definition.

Specified by:

getDataTableDef in interface TableDataSource

Specified by:

getDataTableDef in class GTDataSource

getRowCount

public int getRowCount()

Description copied from interface: TableDataSource

Returns the number of rows in this data source.

NOTE: Returns 'n' - getCellContents(column, row) is not necessarily valid for row = [0..n]. Use 'rowEnumerator' to generate an iterator for valid row values over this data source.

Specified by:

getRowCount in interface TableDataSource

Specified by:

getRowCount in class GTDataSource

getCellContents

public TObject getCellContents(int column,
                               int row)

Description copied from interface: TableDataSource

Returns an object that represents the information in the given cell in the table. This may be an expensive operation, so calls to it should be kept to a minimum. Note that the offset between two rows is not necessarily 1. Use 'rowEnumeration' to create a row iterator.

Specified by:

getCellContents in interface TableDataSource

Specified by:

getCellContents in class GTDataSource

dispose

public void dispose()

Description copied from interface: MutableTableDataSource

Disposes this table data source. After this method is called, most use of this object is undefined, except for the 'getCellContent' and 'compareCellContent' methods which are valid provided the source is under a root lock.

Specified by:

dispose in interface MutableTableDataSource

Overrides:

dispose in class GTDataSource