Method Details

• addItemCountChangeListener

  public Registration addItemCountChangeListener(ComponentEventListener<ItemCountChangeEvent<?>> listener)

  Description copied from interface: DataView

  Add an item count change listener that is fired when the item count changes. This can happen for instance when filtering the items.

  Item count change listener is bound to the component and will be retained even if the data changes by setting of a new items or DataProvider to component.

  NOTE: when the component supports lazy loading (implements HasLazyDataView) and a count callback has not been provided, an estimate of the item count is used and increased until the actual count has been reached. When the estimate is used, the event is fired with the ItemCountChangeEvent.isItemCountEstimated() returning true.

  Specified by:

  addItemCountChangeListener in interface DataView<T>

  Parameters:

  listener - item count change listener to register

  Returns:

  registration for removing the listener

• getSupportedDataProviderType

  protected abstract Class<?> getSupportedDataProviderType()

  Returns supported DataProvider type for this DataView.

  Returns:

  supported data provider type

• verifyDataProviderType

  protected final void verifyDataProviderType(Class<?> dataProviderType)

  Verifies an obtained DataProvider type is appropriate for current Data View type.

  Parameters:

  dataProviderType - data provider type to be verified

  Throws:

  IllegalStateException - if data provider type is incompatible with data view type

• verifyDataProviderType

  protected final void verifyDataProviderType(DataProvider<T,?> dataProvider)

  Verifies an obtained DataProvider type is appropriate for current Data View type. If the data provider is a wrapper, then the wrapped data provider is verified too.

  Parameters:

  dataProvider - data provider to be verified

  Throws:

  IllegalStateException - if data provider type is incompatible with data view type

• getItemIndex

  public Optional<Integer> getItemIndex(T item)

  Description copied from interface: DataView

  Gets the index of the given item from the data available to the component. Data is filtered and sorted the same way as in the component.

  Specified by:

  getItemIndex in interface DataView<T>

  Parameters:

  item - item to get index for

  Returns:

  index of the item or empty optional if the item is not found

• getItems

  public Stream<T> getItems()

  Description copied from interface: DataView

  Get the full data available to the component. Data is filtered and sorted the same way as in the component.

  Consumers of the returned stream are responsible for closing it when all the stream operations are done to ensure that any resources feeding the stream are properly released. Failure to close the stream might lead to resource leaks.

  It is strongly recommended to use a try-with-resources block to automatically close the stream after its terminal operation has been executed. Below is an example of how to properly use and close the stream:

  
   try (Stream<T> stream = dataView.getItems()) {
       stream.forEach(System.out::println); // Example terminal operation
   }
   

  Specified by:

  getItems in interface DataView<T>

  Returns:

  filtered and sorted data set

• refreshItem

  public void refreshItem(T item)

  Description copied from interface: DataView

  Notifies the component that the item has been updated and thus should be refreshed.

  For this to work properly, the item must either implement Object.equals(Object) and Object.hashCode() to consider both the old and the new item instances to be equal, or alternatively use the DataView.setIdentifierProvider(IdentifierProvider) to set an appropriate item's identifier.

  This method delegates the update to DataProvider.refreshItem(Object).

  Specified by:

  refreshItem in interface DataView<T>

  Parameters:

  item - item containing updated state

  See Also:

  • DataView.setIdentifierProvider(IdentifierProvider)

• refreshAll

  public void refreshAll()

  Description copied from interface: DataView

  Notifies the component that all the items should be refreshed.

  Specified by:

  refreshAll in interface DataView<T>

• setIdentifierProvider

  public void setIdentifierProvider(IdentifierProvider<T> identifierProvider)

  Description copied from interface: DataView

  Sets an identifier provider, which returns an identifier for the given item. The identifier is used for comparing the equality of items. Usage example: dataView.setIdentifiedProvider(Item::getId);.

  Specified by:

  setIdentifierProvider in interface DataView<T>

  Parameters:

  identifierProvider - function that returns the non-null identifier for a given item

• getIdentifierProvider

  protected IdentifierProvider<T> getIdentifierProvider()

• addIdentifierProviderChangeListener

  public Registration addIdentifierProviderChangeListener(ComponentEventListener<IdentifierProviderChangeEvent<T,?>> listener)

  Add an identifier provider change listener that is fired when a custom identifier provider is set with setIdentifierProvider(IdentifierProvider).

  Can be used by components to get notified that a new identifier provider has been set through the data view.

  Parameters:

  listener - identifier provider change listener to register

  Returns:

  registration for removing the listener

• equals

  protected boolean equals(T item, T compareTo)

• getItemIndex

  protected int getItemIndex(T item, Stream<T> stream)

  Gets item index from the given stream.

  Parameters:

  item - the item to get index for

  stream - the stream to get index from

  Returns:

  the index of the item in the stream, or -1 if not found