com.vaadin.ui

Class ComboBox<T>

java.lang.Object

com.vaadin.server.AbstractClientConnector

com.vaadin.ui.AbstractComponent

com.vaadin.ui.AbstractListing<T>

com.vaadin.ui.AbstractSingleSelect<T>

com.vaadin.ui.ComboBox<T>

Type Parameters:

T - item (bean) type in ComboBox

All Implemented Interfaces:

HasFilterableDataProvider<T,String>, HasItems<T>, HasValue<T>, ContextClickEvent.ContextClickNotifier, FieldEvents.BlurNotifier, FieldEvents.FocusNotifier, MethodEventSource, ClientConnector, Sizeable, Connector, Component, Component.Focusable, SingleSelect<T>, Serializable

public class ComboBox<T>
extends AbstractSingleSelect<T>
implements FieldEvents.BlurNotifier, FieldEvents.FocusNotifier, HasFilterableDataProvider<T,String>

A filtering dropdown single-select. Items are filtered based on user input. Supports the creation of new items when a handler is set by the user.

Author:

Vaadin Ltd

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	ComboBox.CaptionFilter Predicate to check ComboBox item captions against user typed strings.
protected static class	ComboBox.DeclarativeStyleGenerator<T> Item style generator class for declarative support.
static interface	ComboBox.FetchItemsCallback<T> A callback method for fetching items.
static interface	ComboBox.NewItemHandler Deprecated. Since 8.4 replaced by ComboBox.NewItemProvider.
static interface	ComboBox.NewItemProvider<T> Provider function that adds a new item based on user input when the new items allowed mode is active.

Nested classes/interfaces inherited from class com.vaadin.ui.AbstractListing

AbstractListing.AbstractListingExtension<T>

Nested classes/interfaces inherited from interface com.vaadin.ui.Component

Component.ErrorEvent, Component.Event, Component.Focusable, Component.Listener

Nested classes/interfaces inherited from interface com.vaadin.server.ClientConnector

ClientConnector.AttachEvent, ClientConnector.AttachListener, ClientConnector.ConnectorErrorEvent, ClientConnector.DetachEvent, ClientConnector.DetachListener

Nested classes/interfaces inherited from interface com.vaadin.server.Sizeable

Sizeable.Unit

Nested classes/interfaces inherited from interface com.vaadin.data.HasValue

HasValue.ValueChangeEvent<V>, HasValue.ValueChangeListener<V>

Field Summary

Fields inherited from class com.vaadin.ui.AbstractComponent

DESIGN_ATTR_PLAIN_TEXT

Fields inherited from interface com.vaadin.server.Sizeable

SIZE_UNDEFINED, UNITS_CM, UNITS_EM, UNITS_EX, UNITS_INCH, UNITS_MM, UNITS_PERCENTAGE, UNITS_PICAS, UNITS_PIXELS, UNITS_POINTS

Constructor Summary

Constructors

Modifier	Constructor and Description
	ComboBox() Constructs an empty combo box without a caption.
protected	ComboBox(DataCommunicator<T> dataCommunicator) Constructs and initializes an empty combo box.
	ComboBox(String caption) Constructs an empty combo box, whose content can be set with HasFilterableDataProvider.setDataProvider(DataProvider) or setItems(Collection).
	ComboBox(String caption, Collection<T> options) Constructs a combo box with a static in-memory data provider with the given options.

Method Summary

Modifier and Type	Method and Description
Registration	addBlurListener(FieldEvents.BlurListener listener) Adds a BlurListener to the Component which gets fired when a Field loses keyboard focus.
Registration	addFocusListener(FieldEvents.FocusListener listener) Adds a FocusListener to the Component which gets fired when a Field receives keyboard focus.
Registration	addValueChangeListener(HasValue.ValueChangeListener<T> listener) Adds a value change listener.
void	attach() Notifies the connector that it is connected to a VaadinSession (and therefore also to a UI).
void	detach() Notifies the connector that it is detached from its VaadinSession.
DataProvider<T,?>	getDataProvider() Returns the source of data items used by this listing.
String	getEmptySelectionCaption() Returns the empty selection caption.
ItemCaptionGenerator<T>	getItemCaptionGenerator() Gets the item caption generator that is used to produce the strings shown in the combo box for each item.
IconGenerator<T>	getItemIconGenerator() Gets the currently used item icon generator.
ComboBox.NewItemHandler	getNewItemHandler() Deprecated. Since 8.4 use getNewItemProvider() instead.
ComboBox.NewItemProvider<T>	getNewItemProvider() Returns the provider function that is called when the user enters a new item (not present in the data provider).
int	getPageLength() Returns the page length of the suggestion popup.
String	getPlaceholder() Gets the current placeholder text shown when the combo box would be empty.
String	getPopupWidth() Returns the suggestion pop-up's width as a CSS string.
protected ComboBoxState	getState() Returns the shared state bean with information to be sent from the server to the client.
protected ComboBoxState	getState(boolean markAsDirty) Returns the shared state for this connector.
StyleGenerator<T>	getStyleGenerator() Gets the currently used style generator that is used to generate CSS class names for items.
boolean	isEmptySelectionAllowed() Returns whether the user is allowed to select nothing in the combo box.
boolean	isScrollToSelectedItem() Returns true if the select should find the page with the selected item when opening the popup.
boolean	isTextInputAllowed() Returns true if the user can enter text into the field to either filter the selections or enter a new value if new item provider or handler is set (see setNewItemProvider(NewItemProvider) (recommended) and setNewItemHandler(NewItemHandler) (deprecated)).
protected T	readItem(org.jsoup.nodes.Element child, Set<T> selected, DesignContext context) Reads an Item from a design and inserts it into the data source.
protected void	readItems(org.jsoup.nodes.Element design, DesignContext context) Reads the data source items from the design.
void	setDataProvider(ComboBox.CaptionFilter captionFilter, ListDataProvider<T> listDataProvider) Sets a list data provider with an item caption filter as the data provider of this combo box.
void	setDataProvider(ComboBox.FetchItemsCallback<T> fetchItems, SerializableToIntFunction<String> sizeCallback) Sets a CallbackDataProvider using the given fetch items callback and a size callback.
<C> void	setDataProvider(DataProvider<T,C> dataProvider, SerializableFunction<String,C> filterConverter) Sets the data provider and filter converter for this listing.
void	setDataProvider(ListDataProvider<T> listDataProvider) Sets a list data provider as the data provider of this combo box.
void	setEmptySelectionAllowed(boolean emptySelectionAllowed) Sets whether the user is allowed to select nothing in the combo box.
void	setEmptySelectionCaption(String caption) Sets the empty selection caption.
void	setItemCaptionGenerator(ItemCaptionGenerator<T> itemCaptionGenerator) Sets the item caption generator that is used to produce the strings shown in the combo box for each item.
void	setItemIconGenerator(IconGenerator<T> itemIconGenerator) Sets the item icon generator that is used to produce custom icons for shown items.
void	setItems(Collection<T> items) Sets the data items of this component provided as a collection.
void	setItems(ComboBox.CaptionFilter captionFilter, Collection<T> items) Sets the data items of this listing and a simple string filter with which the item string and the text the user has input are compared.
void	setItems(ComboBox.CaptionFilter captionFilter, T... items) Sets the data items of this listing and a simple string filter with which the item string and the text the user has input are compared.
void	setItems(Stream<T> streamOfItems) Sets the data items of this listing provided as a stream.
void	setItems(T... items) Sets the data items of this listing.
void	setNewItemHandler(ComboBox.NewItemHandler newItemHandler) Deprecated. Since 8.4 use setNewItemProvider(NewItemProvider) instead.
void	setNewItemProvider(ComboBox.NewItemProvider<T> newItemProvider) Sets the provider function that is called when user types a new item.
void	setPageLength(int pageLength) Sets the page length for the suggestion popup.
void	setPlaceholder(String placeholder) Sets the placeholder string - a textual prompt that is displayed when the select would otherwise be empty, to prompt the user for input.
void	setPopupWidth(String width) Sets the suggestion pop-up's width as a CSS string.
void	setScrollToSelectedItem(boolean scrollToSelectedItem) Sets whether to scroll the selected item visible (directly open the page on which it is) when opening the combo box popup or not.
void	setStyleGenerator(StyleGenerator<T> itemStyleGenerator) Sets the style generator that is used to produce custom class names for items visible in the popup.
void	setTextInputAllowed(boolean textInputAllowed) Sets whether it is possible to input text into the field or whether the field area of the component is just used to show what is selected.
protected void	updateSelectedItemState(T value) This method updates the shared selection state of the AbstractSingleSelect.
protected org.jsoup.nodes.Element	writeItem(org.jsoup.nodes.Element design, T item, DesignContext context) Writes a data source Item to a design.

Methods inherited from class com.vaadin.ui.AbstractSingleSelect

addSelectionListener, getCustomAttributes, getSelectedItem, getValue, isReadOnly, isRequiredIndicatorVisible, isSelected, keyToItem, setReadOnly, setRequiredIndicatorVisible, setSelectedItem, setSelectedItem, setValue

Methods inherited from class com.vaadin.ui.AbstractListing

addDataGenerator, deserializeDeclarativeRepresentation, doReadDesign, doWriteDesign, focus, getDataCommunicator, getTabIndex, internalGetDataProvider, internalSetDataProvider, internalSetDataProvider, readDesign, readItem, removeDataGenerator, serializeDeclarativeRepresentation, setTabIndex, writeDesign, writeItems

Methods inherited from class com.vaadin.ui.AbstractComponent

addContextClickListener, addListener, addShortcutListener, addStyleName, beforeClientResponse, findAncestor, fireComponentErrorEvent, fireComponentEvent, getActionManager, getCaption, getComponentError, getData, getDebugId, getDescription, getErrorMessage, getHeight, getHeightUnits, getIcon, getId, getLocale, getParent, getPrimaryStyleName, getStyleName, getWidth, getWidthUnits, isCaptionAsHtml, isConnectorEnabled, isEnabled, isOrHasAncestor, isResponsive, isVisible, removeContextClickListener, removeListener, removeShortcutListener, removeStyleName, setCaption, setCaptionAsHtml, setComponentError, setData, setDebugId, setDescription, setDescription, setEnabled, setHeight, setHeight, setHeightFull, setHeightUndefined, setIcon, setId, setLocale, setParent, setPrimaryStyleName, setResponsive, setSizeFull, setSizeUndefined, setStyleName, setVisible, setWidth, setWidth, setWidthFull, setWidthUndefined

Methods inherited from class com.vaadin.server.AbstractClientConnector

addAttachListener, addDetachListener, addExtension, addListener, addListener, addListener, addListener, addListener, addListener, addMethodInvocationToQueue, createState, encodeState, equals, fireEvent, getAllChildrenIterable, getConnectorId, getErrorHandler, getExtensions, getListeners, getResource, getRpcManager, getRpcProxy, getSession, getStateType, getUI, handleConnectorRequest, hashCode, hasListeners, isAttached, isThis, markAsDirty, markAsDirtyRecursive, registerRpc, registerRpc, removeAttachListener, removeDetachListener, removeExtension, removeListener, removeListener, removeListener, removeListener, removeListener, requestRepaint, requestRepaintAll, retrievePendingRpcCalls, setErrorHandler, setResource, updateDiffstate

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.vaadin.data.HasFilterableDataProvider

setDataProvider

Methods inherited from interface com.vaadin.ui.Component

addListener, addStyleName, addStyleNames, getCaption, getDescription, getIcon, getId, getLocale, getParent, getPrimaryStyleName, getStyleName, getUI, isEnabled, isVisible, readDesign, removeListener, removeStyleName, removeStyleNames, setCaption, setEnabled, setIcon, setId, setParent, setPrimaryStyleName, setStyleName, setStyleName, setVisible, writeDesign

Methods inherited from interface com.vaadin.server.ClientConnector

addAttachListener, addDetachListener, beforeClientResponse, encodeState, getErrorHandler, getExtensions, getRpcManager, getStateType, handleConnectorRequest, isAttached, isConnectorEnabled, markAsDirty, markAsDirtyRecursive, removeAttachListener, removeDetachListener, removeExtension, requestRepaint, requestRepaintAll, retrievePendingRpcCalls, setErrorHandler

Methods inherited from interface com.vaadin.shared.Connector

getConnectorId

Methods inherited from interface com.vaadin.server.Sizeable

getHeight, getHeightUnits, getWidth, getWidthUnits, setHeight, setHeight, setHeightFull, setHeightUndefined, setSizeFull, setSizeUndefined, setWidth, setWidth, setWidthFull, setWidthUndefined

Methods inherited from interface com.vaadin.data.HasValue

clear, getDefaultValidator, getEmptyValue, getOptionalValue, isEmpty

Constructor Detail

ComboBox

public ComboBox()

Constructs an empty combo box without a caption. The content of the combo box can be set with HasFilterableDataProvider.setDataProvider(DataProvider) or setItems(Collection)

ComboBox

public ComboBox(String caption)

Constructs an empty combo box, whose content can be set with HasFilterableDataProvider.setDataProvider(DataProvider) or setItems(Collection).

Parameters:

caption - the caption to show in the containing layout, null for no caption

ComboBox

public ComboBox(String caption,
                Collection<T> options)

Constructs a combo box with a static in-memory data provider with the given options.

Parameters:

caption - the caption to show in the containing layout, null for no caption

options - collection of options, not null

ComboBox

protected ComboBox(DataCommunicator<T> dataCommunicator)

Constructs and initializes an empty combo box.

Parameters:

dataCommunicator - the data comnunicator to use with this ComboBox

Since:

8.5

Method Detail

setItems

public void setItems(Collection<T> items)

Sets the data items of this component provided as a collection.

The provided items are wrapped into a ListDataProvider and this instance is used as a data provider for the #setDataProvider(DataProvider) method. It means that the items collection can be accessed later on via ListDataProvider.getItems():

 
 HasDataProvider<String> listing = new CheckBoxGroup<>();
 listing.setItems(Arrays.asList("a","b"));
 ...

 Collection collection = ((ListDataProvider)listing.getDataProvider()).getItems();
 
 

The provided collection instance may be used as-is. Subsequent modification of the collection might cause inconsistent data to be shown in the component unless it is explicitly instructed to read the data again.

Filtering will use a case insensitive match to show all items where the filter text is a substring of the caption displayed for that item.

Specified by:

setItems in interface HasItems<T>

Parameters:

items - the data items to display, not null

setItems

public void setItems(Stream<T> streamOfItems)

Sets the data items of this listing provided as a stream.

This is just a shorthand for HasItems.setItems(Collection), that collects objects in the stream to a list. Thus, using this method, instead of its array and Collection variations, doesn't save any memory. If you have a large data set to bind, using a lazy data provider is recommended. See BackEndDataProvider for more info.

The provided items are wrapped into a ListDataProvider and this instance is used as a data provider for the #setDataProvider(DataProvider) method. It means that the items collection can be accessed later on via ListDataProvider.getItems():

 
 HasDataProvider<String> listing = new CheckBoxGroup<>();
 listing.setItems(Stream.of("a","b"));
 ...

 Collection collection = ((ListDataProvider<String>)listing.getDataProvider()).getItems();
 
 

Filtering will use a case insensitive match to show all items where the filter text is a substring of the caption displayed for that item.

Specified by:

setItems in interface HasItems<T>

Parameters:

streamOfItems - the stream of data items to display, not null

See Also:

HasItems.setItems(Collection)

setItems

public void setItems(T... items)

Sets the data items of this listing.

The provided items are wrapped into a ListDataProvider and this instance is used as a data provider for the #setDataProvider(DataProvider) method. It means that the items collection can be accessed later on via ListDataProvider.getItems():

 
 HasDataProvider listing = new CheckBoxGroup<>();
 listing.setItems("a","b");
 ...

 Collection collection = ((ListDataProvider)listing.getDataProvider()).getItems();
 
 

Filtering will use a case insensitive match to show all items where the filter text is a substring of the caption displayed for that item.

Specified by:

setItems in interface HasItems<T>

Parameters:

items - the data items to display

See Also:

HasItems.setItems(Collection)

setDataProvider

public void setDataProvider(ListDataProvider<T> listDataProvider)

Sets a list data provider as the data provider of this combo box. Filtering will use a case insensitive match to show all items where the filter text is a substring of the caption displayed for that item.

Note that this is a shorthand that calls HasFilterableDataProvider.setDataProvider(DataProvider) with a wrapper of the provided list data provider. This means that getDataProvider() will return the wrapper instead of the original list data provider.

Parameters:

listDataProvider - the list data provider to use, not null

Since:

8.0

setItems

public void setItems(ComboBox.CaptionFilter captionFilter,
                     Collection<T> items)

Sets the data items of this listing and a simple string filter with which the item string and the text the user has input are compared.

Note that unlike setItems(Collection), no automatic case conversion is performed before the comparison.

Parameters:

captionFilter - filter to check if an item is shown when user typed some text into the ComboBox

items - the data items to display

Since:

8.0

setDataProvider

public void setDataProvider(ComboBox.CaptionFilter captionFilter,
                            ListDataProvider<T> listDataProvider)

Sets a list data provider with an item caption filter as the data provider of this combo box. The caption filter is used to compare the displayed caption of each item to the filter text entered by the user.

Parameters:

captionFilter - filter to check if an item is shown when user typed some text into the ComboBox

listDataProvider - the list data provider to use, not null

Since:

8.0

setItems

public void setItems(ComboBox.CaptionFilter captionFilter,
                     T... items)

Sets the data items of this listing and a simple string filter with which the item string and the text the user has input are compared.

Note that unlike setItems(Collection), no automatic case conversion is performed before the comparison.

Parameters:

captionFilter - filter to check if an item is shown when user typed some text into the ComboBox

items - the data items to display

Since:

8.0

getPlaceholder

public String getPlaceholder()

Gets the current placeholder text shown when the combo box would be empty.

Returns:

the current placeholder string, or null if not enabled

Since:

8.0

See Also:

setPlaceholder(String)

setPlaceholder

public void setPlaceholder(String placeholder)

Sets the placeholder string - a textual prompt that is displayed when the select would otherwise be empty, to prompt the user for input.

Parameters:

placeholder - the desired placeholder, or null to disable

Since:

8.0

setTextInputAllowed

public void setTextInputAllowed(boolean textInputAllowed)

Sets whether it is possible to input text into the field or whether the field area of the component is just used to show what is selected. By disabling text input, the comboBox will work in the same way as a NativeSelect

Parameters:

textInputAllowed - true to allow entering text, false to just show the current selection

See Also:

isTextInputAllowed()

isTextInputAllowed

public boolean isTextInputAllowed()

Returns true if the user can enter text into the field to either filter the selections or enter a new value if new item provider or handler is set (see setNewItemProvider(NewItemProvider) (recommended) and setNewItemHandler(NewItemHandler) (deprecated)). If text input is disabled, the comboBox will work in the same way as a NativeSelect

Returns:

true if text input is allowed

addBlurListener

public Registration addBlurListener(FieldEvents.BlurListener listener)

Description copied from interface: FieldEvents.BlurNotifier

Adds a BlurListener to the Component which gets fired when a Field loses keyboard focus.

Specified by:

addBlurListener in interface FieldEvents.BlurNotifier

Parameters:

listener - the blur listener to add, not null

Returns:

a registration object for removing the listener

See Also:

FieldEvents.BlurListener, Registration

addFocusListener

public Registration addFocusListener(FieldEvents.FocusListener listener)

Description copied from interface: FieldEvents.FocusNotifier

Adds a FocusListener to the Component which gets fired when a Field receives keyboard focus.

Specified by:

addFocusListener in interface FieldEvents.FocusNotifier

Parameters:

listener - the focus listener to add, not null

Returns:

a registration object for removing the listener

See Also:

FieldEvents.FocusListener, Registration

getPageLength

public int getPageLength()

Returns the page length of the suggestion popup.

Returns:

the pageLength

getPopupWidth

public String getPopupWidth()

Returns the suggestion pop-up's width as a CSS string. By default this width is set to "100%".

Returns:

explicitly set popup width as CSS size string or null if not set

Since:

7.7

See Also:

setPopupWidth(java.lang.String)

setPageLength

public void setPageLength(int pageLength)

Sets the page length for the suggestion popup. Setting the page length to 0 will disable suggestion popup paging (all items visible).

Parameters:

pageLength - the pageLength to set

isEmptySelectionAllowed

public boolean isEmptySelectionAllowed()

Returns whether the user is allowed to select nothing in the combo box.

Returns:

true if empty selection is allowed, false otherwise

Since:

8.0

setEmptySelectionAllowed

public void setEmptySelectionAllowed(boolean emptySelectionAllowed)

Sets whether the user is allowed to select nothing in the combo box. When true, a special empty item is shown to the user.

Parameters:

emptySelectionAllowed - true to allow not selecting anything, false to require selection

Since:

8.0

getEmptySelectionCaption

public String getEmptySelectionCaption()

Returns the empty selection caption.

The empty string "" is the default empty selection caption.

Returns:

the empty selection caption, not null

Since:

8.0

See Also:

setEmptySelectionAllowed(boolean), isEmptySelectionAllowed(), setEmptySelectionCaption(String), AbstractSingleSelect.isSelected(Object)

setEmptySelectionCaption

public void setEmptySelectionCaption(String caption)

Sets the empty selection caption.

The empty string "" is the default empty selection caption.

If empty selection is allowed via the setEmptySelectionAllowed(boolean) method (it is by default) then the empty item will be shown with the given caption.

Parameters:

caption - the caption to set, not null

Since:

8.0

See Also:

AbstractSingleSelect.isSelected(Object)

setPopupWidth

public void setPopupWidth(String width)

Sets the suggestion pop-up's width as a CSS string. By using relative units (e.g. "50%") it's possible to set the popup's width relative to the ComboBox itself.

By default this width is set to "100%" so that the pop-up's width is equal to the width of the combobox. By setting width to null the pop-up's width will automatically expand beyond 100% relative width to fit the content of all displayed items.

Parameters:

width - the width

Since:

7.7

See Also:

getPopupWidth()

setScrollToSelectedItem

public void setScrollToSelectedItem(boolean scrollToSelectedItem)

Sets whether to scroll the selected item visible (directly open the page on which it is) when opening the combo box popup or not.

This requires finding the index of the item, which can be expensive in many large lazy loading containers.

Parameters:

scrollToSelectedItem - true to find the page with the selected item when opening the selection popup

isScrollToSelectedItem

public boolean isScrollToSelectedItem()

Returns true if the select should find the page with the selected item when opening the popup.

Returns:

true if the page with the selected item will be shown when opening the popup

See Also:

setScrollToSelectedItem(boolean)

getItemCaptionGenerator

public ItemCaptionGenerator<T> getItemCaptionGenerator()

Description copied from class: AbstractListing

Gets the item caption generator that is used to produce the strings shown in the combo box for each item.

Overrides:

getItemCaptionGenerator in class AbstractListing<T>

Returns:

the item caption generator used, not null

setItemCaptionGenerator

public void setItemCaptionGenerator(ItemCaptionGenerator<T> itemCaptionGenerator)

Description copied from class: AbstractListing

Sets the item caption generator that is used to produce the strings shown in the combo box for each item. By default, String.valueOf(Object) is used.

Overrides:

setItemCaptionGenerator in class AbstractListing<T>

Parameters:

itemCaptionGenerator - the item caption provider to use, not null

setStyleGenerator

public void setStyleGenerator(StyleGenerator<T> itemStyleGenerator)

Sets the style generator that is used to produce custom class names for items visible in the popup. The CSS class name that will be added to the item is v-filterselect-item-[style name]. Returning null from the generator results in no custom style name being set.

Parameters:

itemStyleGenerator - the item style generator to set, not null

Throws:

NullPointerException - if itemStyleGenerator is null

Since:

8.0

See Also:

StyleGenerator

getStyleGenerator

public StyleGenerator<T> getStyleGenerator()

Gets the currently used style generator that is used to generate CSS class names for items. The default item style provider returns null for all items, resulting in no custom item class names being set.

Returns:

the currently used item style generator, not null

Since:

8.0

See Also:

StyleGenerator, setStyleGenerator(StyleGenerator)

setItemIconGenerator

public void setItemIconGenerator(IconGenerator<T> itemIconGenerator)

Description copied from class: AbstractListing

Sets the item icon generator that is used to produce custom icons for shown items. The generator can return null for items with no icon.

Implementations that support item icons make this method public.

Overrides:

setItemIconGenerator in class AbstractListing<T>

Parameters:

itemIconGenerator - the item icon generator to set, not null

See Also:

IconGenerator

getItemIconGenerator

public IconGenerator<T> getItemIconGenerator()

Description copied from class: AbstractListing

Gets the currently used item icon generator. The default item icon provider returns null for all items, resulting in no icons being used.

Implementations that support item icons make this method public.

Overrides:

getItemIconGenerator in class AbstractListing<T>

Returns:

the currently used item icon generator, not null

See Also:

IconGenerator, AbstractListing.setItemIconGenerator(IconGenerator)

setNewItemHandler

@Deprecated
public void setNewItemHandler(ComboBox.NewItemHandler newItemHandler)

Deprecated. Since 8.4 use setNewItemProvider(NewItemProvider) instead.

Sets the handler that is called when user types a new item. The creation of new items is allowed when a new item handler has been set. If new item provider is also set, the new item handler is ignored.

Parameters:

newItemHandler - handler called for new items, null to only permit the selection of existing items, all options ignored if new item provider is set

Since:

8.0

setNewItemProvider

public void setNewItemProvider(ComboBox.NewItemProvider<T> newItemProvider)

Sets the provider function that is called when user types a new item. The creation of new items is allowed when a new item provider has been set. If a deprecated new item handler is also set it is ignored in favor of new item provider.

Parameters:

newItemProvider - provider function that is called for new items, null to only permit the selection of existing items or to use a deprecated new item handler if set

Since:

8.4

getNewItemHandler

@Deprecated
public ComboBox.NewItemHandler getNewItemHandler()

Deprecated. Since 8.4 use getNewItemProvider() instead.

Returns the handler called when the user enters a new item (not present in the data provider).

Returns:

new item handler or null if none specified

getNewItemProvider

public ComboBox.NewItemProvider<T> getNewItemProvider()

Returns the provider function that is called when the user enters a new item (not present in the data provider).

Returns:

new item provider or null if none specified

Since:

8.4

addValueChangeListener

public Registration addValueChangeListener(HasValue.ValueChangeListener<T> listener)

Description copied from interface: HasValue

Adds a value change listener. The listener is called when the value of this HasValue is changed either by the user or programmatically.

Specified by:

addValueChangeListener in interface HasValue<T>

Overrides:

addValueChangeListener in class AbstractSingleSelect<T>

Parameters:

listener - the value change listener, not null

Returns:

a registration for the listener

getState

protected ComboBoxState getState()

Description copied from class: AbstractComponent

Returns the shared state bean with information to be sent from the server to the client. Subclasses should override this method and set any relevant fields of the state returned by super.getState().

Overrides:

getState in class AbstractSingleSelect<T>

Returns:

updated component shared state

getState

protected ComboBoxState getState(boolean markAsDirty)

Description copied from class: AbstractClientConnector

Returns the shared state for this connector.

Overrides:

getState in class AbstractSingleSelect<T>

Parameters:

markAsDirty - true if the connector should automatically be marked dirty, false otherwise

Returns:

The shared state for this connector. Never null.

See Also:

AbstractClientConnector.getState()

updateSelectedItemState

protected void updateSelectedItemState(T value)

Description copied from class: AbstractSingleSelect

This method updates the shared selection state of the AbstractSingleSelect.

Overrides:

updateSelectedItemState in class AbstractSingleSelect<T>

Parameters:

value - the value that is selected; may be null

attach

public void attach()

Description copied from interface: ClientConnector

Notifies the connector that it is connected to a VaadinSession (and therefore also to a UI).

The caller of this method is Connector#setParent(ClientConnector) if the parent is itself already attached to the session. If not, the parent will call the ClientConnector.attach() for all its children when it is attached to the session. This method is always called before the connector's data is sent to the client-side for the first time.

The attachment logic is implemented in AbstractClientConnector.

Specified by:

attach in interface ClientConnector

Specified by:

attach in interface Component

Overrides:

attach in class AbstractComponent

detach

public void detach()

Description copied from class: AbstractClientConnector

Notifies the connector that it is detached from its VaadinSession.

The caller of this method is #setParent(ClientConnector) if the parent is in the session. When the parent is detached from the session it is its responsibility to call ClientConnector.detach() for each of its children.

The AbstractClientConnector.getSession() and AbstractClientConnector.getUI() methods might return null after this method is called.

Specified by:

detach in interface ClientConnector

Overrides:

detach in class AbstractComponent

writeItem

protected org.jsoup.nodes.Element writeItem(org.jsoup.nodes.Element design,
                                            T item,
                                            DesignContext context)

Description copied from class: AbstractListing

Writes a data source Item to a design. Hierarchical select components should override this method to recursively write any child items as well.

Overrides:

writeItem in class AbstractSingleSelect<T>

Parameters:

design - the element into which to insert the item

item - the item to write

context - the DesignContext instance used in writing

Returns:

a JSOUP element representing the item

readItems

protected void readItems(org.jsoup.nodes.Element design,
                         DesignContext context)

Description copied from class: AbstractListing

Reads the data source items from the design.

Overrides:

readItems in class AbstractSingleSelect<T>

Parameters:

design - The element to obtain the state from

context - The DesignContext instance used for parsing the design

readItem

protected T readItem(org.jsoup.nodes.Element child,
                     Set<T> selected,
                     DesignContext context)

Description copied from class: AbstractSingleSelect

Reads an Item from a design and inserts it into the data source. Hierarchical select components should override this method to recursively recursively read any child items as well.

Overrides:

readItem in class AbstractSingleSelect<T>

Parameters:

child - a child element representing the item

selected - A set accumulating selected items. If the item that is read is marked as selected, its item id should be added to this set.

context - the DesignContext instance used in parsing

Returns:

the item id of the new item

getDataProvider

public DataProvider<T,?> getDataProvider()

Description copied from interface: HasItems

Returns the source of data items used by this listing.

Specified by:

getDataProvider in interface HasItems<T>

Returns:

the data provider, not null

setDataProvider

public <C> void setDataProvider(DataProvider<T,C> dataProvider,
                                SerializableFunction<String,C> filterConverter)

Description copied from interface: HasFilterableDataProvider

Sets the data provider and filter converter for this listing. The data provider is queried for displayed items as needed.

Specified by:

setDataProvider in interface HasFilterableDataProvider<T,String>

Parameters:

dataProvider - the data provider, not null

filterConverter - a function that converts filter values produced by this listing into filter values expected by the provided data provider, not null

setDataProvider

public void setDataProvider(ComboBox.FetchItemsCallback<T> fetchItems,
                            SerializableToIntFunction<String> sizeCallback)

Sets a CallbackDataProvider using the given fetch items callback and a size callback.

This method is a shorthand for making a CallbackDataProvider that handles a partial Query object.

Parameters:

fetchItems - a callback for fetching items

sizeCallback - a callback for getting the count of items

See Also:

CallbackDataProvider, HasFilterableDataProvider.setDataProvider(DataProvider)