org.jfree.report
Interface DataRow

All Superinterfaces:
DataSet
All Known Implementing Classes:
ExpressionDataRow, FastGlobalView, GlobalView, ImportedVariablesDataRow, ParameterDataRow, ReportDataRow, StaticDataRow

public interface DataRow
extends DataSet

This is the base interface for all data access collectors. A data-row adds a certain order to the elements in the dataset. It also allows statefull comparisions and data attributes using DataFlags.

The data-row is an internal concept of JFreeReport. The report engine will be responsible for creating and maintaining these implementations. Authors of functions and expressions usually dont have to care where a datarow comes from or at which particular instance they are looking right now.

Note: Do not attempt to cache the datarow outside the core engine. This can have funny sideeffects and might trigger the end of the world.

Author:
Thomas Morgner

Method Summary
 java.lang.Object get(int col)
          Returns the value of the expression or column in the tablemodel using the given column number as index.
 java.lang.Object get(java.lang.String col)
          Returns the value of the function, expression or column using its specific name.
 int getColumnCount()
          Returns the number of columns, expressions and functions and marked ReportProperties in the report.
 java.lang.String getColumnName(int col)
          Returns the name of the column, expression or function.
 DataFlags getFlags(int col)
          Queries lowlevel meta-data for the current value of the specified column.
 DataFlags getFlags(java.lang.String col)
          Queries lowlevel meta-data for the current value of the specified column.
 

Method Detail

get

java.lang.Object get(int col)
                     throws DataSourceException
Returns the value of the expression or column in the tablemodel using the given column number as index. For functions and expressions, the getValue() method is called and for columns from the tablemodel the tablemodel method getValueAt(row, column) gets called.

Specified by:
get in interface DataSet
Parameters:
col - the item index.
Returns:
the value.
Throws:
java.lang.IllegalStateException - if the datarow detected a deadlock.
DataSourceException - if an error occured.

get

java.lang.Object get(java.lang.String col)
                     throws DataSourceException
Returns the value of the function, expression or column using its specific name. The given name is translated into a valid column number and the the column is queried. For functions and expressions, the getValue() method is called and for columns from the tablemodel the tablemodel method getValueAt(row, column) gets called.

Parameters:
col - the item index.
Returns:
the value.
Throws:
java.lang.IllegalStateException - if the datarow detected a deadlock.
DataSourceException - if an error occured.

getColumnName

java.lang.String getColumnName(int col)
                               throws DataSourceException
Returns the name of the column, expression or function. For columns from the tablemodel, the tablemodels getColumnName method is called. For functions, expressions and report properties the assigned name is returned.

Specified by:
getColumnName in interface DataSet
Parameters:
col - the item index.
Returns:
the name.
Throws:
DataSourceException - if an error occured.

getColumnCount

int getColumnCount()
                   throws DataSourceException
Returns the number of columns, expressions and functions and marked ReportProperties in the report.

Specified by:
getColumnCount in interface DataSet
Returns:
the item count.
Throws:
DataSourceException - if an error occured.

getFlags

DataFlags getFlags(java.lang.String col)
                   throws DataSourceException
Queries lowlevel meta-data for the current value of the specified column.

Parameters:
col - the colum for which to query the meta-data flags
Returns:
the dataflag collection for the value in the named column
Throws:
DataSourceException - if an error occured.

getFlags

DataFlags getFlags(int col)
                   throws DataSourceException
Queries lowlevel meta-data for the current value of the specified column.

Parameters:
col - the colum for which to query the meta-data flags
Returns:
the dataflag collection for the value in the specified column
Throws:
DataSourceException - if an error occured.