org.eclipse.nebula.widgets.nattable.filterrow.combobox

Class FilterRowComboBoxDataProvider<T>

java.lang.Object

org.eclipse.nebula.widgets.nattable.filterrow.combobox.FilterRowComboBoxDataProvider<T>

Type Parameters:

T - The type of the objects shown within the NatTable. Needed to access the data columnwise.

All Implemented Interfaces:

IComboBoxDataProvider, ILayerListener

public class FilterRowComboBoxDataProvider<T>
extends Object
implements IComboBoxDataProvider, ILayerListener

IComboBoxDataProvider that provides items for a combobox in the filter row. These items are calculated dynamically based on the content contained in the column it is connected to.

On creating this IComboBoxDataProvider, the possible values for all columns will be calculated taking the whole data provided by the body IDataProvider into account. Therefore you shouldn't use this one if you show huge datasets at once.

As the values are cached in here, this IComboBoxDataProvider registers itself as ILayerListener to the body DataLayer. If values are updated or rows get added/deleted, it will update the cache accordingly.

Author:

Dirk Fauth

Constructor Summary

Constructors

Constructor and Description
FilterRowComboBoxDataProvider(ILayer bodyLayer, Collection<T> baseCollection, IColumnAccessor<T> columnAccessor)

Method Summary

Methods

Modifier and Type	Method and Description
void	addCacheUpdateListener(IFilterRowComboUpdateListener listener) Adds the given listener to the list of listeners for value cache updates.
protected FilterRowComboUpdateEvent	buildUpdateEvent(int columnIndex, List<?> cacheBefore, List<?> cacheAfter) Creates a FilterRowComboUpdateEvent for the given column index.
protected void	buildValueCache() Builds the local value cache for all columns.
protected List<?>	collectValues(int columnIndex) Iterates over all rows of the local body IDataProvider and collects the unique values for the given column index.
protected void	fireCacheUpdateEvent(FilterRowComboUpdateEvent event) Fire the given event to all registered listeners.
Collection<Integer>	getCachedColumnIndexes() This method returns the column indexes of the columns for which values was cached.
List<?>	getValues(int columnIndex, int rowIndex) Will determine the values for the cell at the specified position.
void	handleLayerEvent(ILayerEvent event) Handle an event notification from an ILayer
void	removeCacheUdpateListener(IFilterRowComboUpdateListener listener) Removes the given listener from the list of listeners for value cache updates.

Methods inherited from class java.lang.Object

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

Constructor Detail

FilterRowComboBoxDataProvider

public FilterRowComboBoxDataProvider(ILayer bodyLayer,
                             Collection<T> baseCollection,
                             IColumnAccessor<T> columnAccessor)

Parameters:

bodyLayer - A layer in the body region. Usually the DataLayer or a layer that is responsible for list event handling. Needed to register ourself as listener for data changes.

baseCollection - The base collection used to collect the unique values from. This need to be a collection that is not filtered, otherwise after modifications the content of the filter row combo boxes will only contain the current visible (not filtered) elements.

columnAccessor - The IColumnAccessor to be able to read the values out of the base collection objects.

Method Detail

getValues

public List<?> getValues(int columnIndex,
                int rowIndex)

Description copied from interface: IComboBoxDataProvider

Will determine the values for the cell at the specified position. It will return a list with canonical values. The registered IDisplayConverter will handle the conversion to display values when the ComboBoxCellEditor is filled with the selectable items. There is no need to convert within this method.

Specified by:

getValues in interface IComboBoxDataProvider

Parameters:

columnIndex - The column index of the cell whose ComboBoxCellEditor should be filled.

rowIndex - The row index of the cell whose ComboBoxCellEditor should be filled.

Returns:

List of values that should be used to fill the values of the ComboBoxCellEditor

buildValueCache

protected void buildValueCache()

Builds the local value cache for all columns.

getCachedColumnIndexes

public Collection<Integer> getCachedColumnIndexes()

This method returns the column indexes of the columns for which values was cached. Usually it will return all column indexes that are available in the table.

Returns:

The column indexes of the columns for which values was cached.

collectValues

protected List<?> collectValues(int columnIndex)

Iterates over all rows of the local body IDataProvider and collects the unique values for the given column index.

Parameters:

columnIndex - The column index for which the values should be collected

Returns:

List of all unique values that are contained in the body IDataProvider for the given column.

handleLayerEvent

public void handleLayerEvent(ILayerEvent event)

Description copied from interface: ILayerListener

Handle an event notification from an ILayer

Specified by:

handleLayerEvent in interface ILayerListener

Parameters:

event - the event

buildUpdateEvent

protected FilterRowComboUpdateEvent buildUpdateEvent(int columnIndex,
                                         List<?> cacheBefore,
                                         List<?> cacheAfter)

Creates a FilterRowComboUpdateEvent for the given column index. Calculates the diffs of the value cache for that column based on the given lists.

Parameters:

columnIndex - The column index for which the value cache was updated.

cacheBefore - The value cache for the column before the change. Needed to determine which values where removed by the update.

cacheAfter - The value cache for the column after the change. Needed to determine which values where added by the update.

Returns:

Event to tell about value cache updates for the given column.

fireCacheUpdateEvent

protected void fireCacheUpdateEvent(FilterRowComboUpdateEvent event)

Fire the given event to all registered listeners.

Parameters:

event - The event to handle.

addCacheUpdateListener

public void addCacheUpdateListener(IFilterRowComboUpdateListener listener)

Adds the given listener to the list of listeners for value cache updates.

Parameters:

listener - The listener to add.

removeCacheUdpateListener

public void removeCacheUdpateListener(IFilterRowComboUpdateListener listener)

Removes the given listener from the list of listeners for value cache updates.

Parameters:

listener - The listener to remove.