Package org.eclipse.nebula.widgets.nattable.formula

Class FormulaDataProvider

java.lang.Object

org.eclipse.nebula.widgets.nattable.formula.FormulaDataProvider

All Implemented Interfaces:

IDataProvider

Direct Known Subclasses:

FormulaRowDataProvider

public class FormulaDataProvider
extends Object
implements IDataProvider

IDataProvider that is able to evaluate formulas. It wraps around a IDataProvider and checks if the requested value is a formula (starts with '='). Otherwise the value of the wrapped IDataProvider is returned.

Since:

1.4

See Also:

FormulaParser

Field Summary

Fields

Modifier and Type	Field	Description
protected FormulaErrorReporter	errorReporter
protected boolean	formulaEvaluationEnabled
protected FormulaParser	formulaParser
protected IDataProvider	underlyingDataProvider

Constructor Summary

Constructors

Constructor	Description
FormulaDataProvider(IDataProvider underlyingDataProvider)
FormulaDataProvider(IDataProvider underlyingDataProvider, FormulaParser parser)	This constructor supports the specification of a FormulaParser to customize parsing.

Method Summary

Modifier and Type	Method	Description
void	configureCaching(ILayer layer)	Configure the caching behavior of this FormulaDataProvider.
int	getColumnCount()
Object	getDataValue(int columnIndex, int rowIndex)	Gets the value at the given column and row index.
FormulaErrorReporter	getErrorReporter()
FormulaParser	getFormulaParser()
Object	getNativeDataValue(int columnIndex, int rowIndex)	Returns the data value out of the underlying IDataProvider without checking and performing formula evaluation.
Collection<String>	getRegisteredFunctions()
int	getRowCount()
protected IDataProvider	getUnderlyingDataProvider()
protected Object	processFormula(String formula, int columnIndex, int rowIndex)	Process the given formula String by using the internal FormulaParser.
void	registerFunction(String functionName, Class<? extends AbstractFunction> value)	Register a new function that can be evaluated.
void	setDataValue(int columnIndex, int rowIndex, Object newValue)	Sets the value at the given column and row index.
void	setErrorReporter(FormulaErrorReporter errorReporter)
void	setFormulaCachingEnabled(boolean enabled)	Enable/Disable formula result caching.
void	setFormulaEvaluationEnabled(boolean enabled)	Enable/Disable formula evaluation.

Methods inherited from class java.lang.Object

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

Field Detail

underlyingDataProvider

protected IDataProvider underlyingDataProvider

formulaParser

protected FormulaParser formulaParser

errorReporter

protected FormulaErrorReporter errorReporter

formulaEvaluationEnabled

protected boolean formulaEvaluationEnabled

Constructor Detail

FormulaDataProvider

public FormulaDataProvider(IDataProvider underlyingDataProvider)

Parameters:

underlyingDataProvider - The IDataProvider that should be wrapped.

FormulaDataProvider

public FormulaDataProvider(IDataProvider underlyingDataProvider,
                           FormulaParser parser)

This constructor supports the specification of a FormulaParser to customize parsing.

Parameters:

underlyingDataProvider - The IDataProvider that should be wrapped.

parser - The FormulaParser that should be used for formula parsing.

Method Detail

getDataValue

public Object getDataValue(int columnIndex,
                           int rowIndex)

Description copied from interface: IDataProvider

Gets the value at the given column and row index.

Specified by:

getDataValue in interface IDataProvider

Parameters:

columnIndex - The column index of the cell whose value is requested.

rowIndex - The row index of the cell whose value is requested.

Returns:

The data value associated with the specified cell coordintates.

processFormula

protected Object processFormula(String formula,
                                int columnIndex,
                                int rowIndex)

Process the given formula String by using the internal FormulaParser.

Parameters:

formula - The formula to process.

columnIndex - The column index of the cell that contains the formula. Needed for error handling.

rowIndex - The row index of the cell that contains the formula. Needed for error handling.

Returns:

The result of the processed formula or an error markup in case an error occurred on processing.

configureCaching

public void configureCaching(ILayer layer)

Configure the caching behavior of this FormulaDataProvider.

Parameters:

layer - The ILayer to which the internal CalculatedValueCache is connected to. Typically the DataLayer to which this FormulaDataProvider is set. If this value is null formula result caching can not be enabled because the CalculatedValueCache needs to operate on an ILayer.

getNativeDataValue

public Object getNativeDataValue(int columnIndex,
                                 int rowIndex)

Returns the data value out of the underlying IDataProvider without checking and performing formula evaluation. Needed in order to edit formulas in a NatTable or outside the NatTable.

Parameters:

columnIndex - The column index of the requested value.

rowIndex - The row index of the requested value.

Returns:

The value of the underlying IDataProvider without formula evaluation.

setDataValue

public void setDataValue(int columnIndex,
                         int rowIndex,
                         Object newValue)

Description copied from interface: IDataProvider

Sets the value at the given column and row index. Optional operation. Should throw UnsupportedOperationException if this operation is not supported.

Specified by:

setDataValue in interface IDataProvider

Parameters:

columnIndex - The column index of the cell whose value should be changed.

rowIndex - The row index of the cell whose value should be changed.

newValue - The new value that should be set.

getColumnCount

public int getColumnCount()

Specified by:

getColumnCount in interface IDataProvider

Returns:

The number of columns this IDataProvider handles.

getRowCount

public int getRowCount()

Specified by:

getRowCount in interface IDataProvider

Returns:

The number of rows this IDataProvider handles.

getUnderlyingDataProvider

protected IDataProvider getUnderlyingDataProvider()

Returns:

The underlying IDataProvider.

setFormulaEvaluationEnabled

public void setFormulaEvaluationEnabled(boolean enabled)

Enable/Disable formula evaluation.

Parameters:

enabled - true to enable formula evaluation, false to disable it.

setFormulaCachingEnabled

public void setFormulaCachingEnabled(boolean enabled)

Enable/Disable formula result caching. Enabling the formula result caching means that the parsing and calculation of formulas is performed in a background thread. The result is cached to reduce processing time, so the rendering is performed faster. Disabling the formula result caching means that parsing and calculation of formulas is performed always in the current thread which might lead to slower rendering.

Parameters:

enabled - true to enable formula result caching and background processing of parsing and calculation, false to disable it.

See Also:

configureCaching(ILayer)

registerFunction

public void registerFunction(String functionName,
                             Class<? extends AbstractFunction> value)

Register a new function that can be evaluated.

Parameters:

functionName - The name of the function that is used in a formula

value - The type of AbstractFunction that should be used when evaluation a formula that contains the given function.

getRegisteredFunctions

public Collection<String> getRegisteredFunctions()

Returns:

The names of the registered functions that are evaluated by this FormulaDataProvider.

getFormulaParser

public FormulaParser getFormulaParser()

Returns:

The FormulaParser that is used by this FormulaDataProvider to parse function strings.

getErrorReporter

public FormulaErrorReporter getErrorReporter()

Returns:

The FormulaErrorReporter that is used to report formula errors to the user.

setErrorReporter

public void setErrorReporter(FormulaErrorReporter errorReporter)

Parameters:

errorReporter - The FormulaErrorReporter that should be used to report formula errors to the user.