Package com.vaadin.flow.component.shared

Class SelectionPreservationHandler<T>

java.lang.Object

com.vaadin.flow.component.shared.SelectionPreservationHandler<T>

All Implemented Interfaces:

Serializable

public abstract class SelectionPreservationHandler<T>
extends Object
implements Serializable

Abstract class that handles selection when DataProvider.refreshAll() is called.

Uses SelectionPreservationMode to switch between the selection preservation modes.

Author:

Vaadin Ltd.

See Also:

• SelectionPreservationMode
• Serialized Form

Constructor Summary

Constructors

Constructor	Description
SelectionPreservationHandler(SelectionPreservationMode selectionPreservationMode)	Constructor taking in the initial selection preservation mode.

Method Summary

Modifier and Type	Method	Description
final SelectionPreservationMode	getSelectionPreservationMode()	Gets the selection preservation mode.
final void	handleDataChange(DataChangeEvent<T> dataChangeEvent)	Handles data change based on the current selection preservation mode.
abstract void	onDiscard(DataChangeEvent<T> dataChangeEvent)	Clears selection when DataProvider.refreshAll() is called.
abstract void	onPreserveAll(DataChangeEvent<T> dataChangeEvent)	Preserves all selected items when DataProvider.refreshAll() is called.
abstract void	onPreserveExisting(DataChangeEvent<T> dataChangeEvent)	Preserves the selected items that still exist after DataProvider.refreshAll() is called.
final void	setSelectionPreservationMode(SelectionPreservationMode selectionPreservationMode)	Sets the selection preservation mode.

Methods inherited from class java.lang.Object

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

Constructor Details

SelectionPreservationHandler

public SelectionPreservationHandler(SelectionPreservationMode selectionPreservationMode)

Constructor taking in the initial selection preservation mode.

Parameters:

selectionPreservationMode - the selection preservation mode, not null

Method Details

setSelectionPreservationMode

public final void setSelectionPreservationMode(SelectionPreservationMode selectionPreservationMode)

Sets the selection preservation mode. Determines what happens with the selection when DataProvider.refreshAll() is called.

Parameters:

selectionPreservationMode - the selection preservation mode to switch to, not null

See Also:

• SelectionPreservationMode

getSelectionPreservationMode

public final SelectionPreservationMode getSelectionPreservationMode()

Gets the selection preservation mode.

Returns:

the selection preservation mode

See Also:

• setSelectionPreservationMode(SelectionPreservationMode)

handleDataChange

public final void handleDataChange(DataChangeEvent<T> dataChangeEvent)

Handles data change based on the current selection preservation mode.

Parameters:

dataChangeEvent - the data change event

See Also:

• setSelectionPreservationMode(SelectionPreservationMode)

onPreserveAll

public abstract void onPreserveAll(DataChangeEvent<T> dataChangeEvent)

Preserves all selected items when DataProvider.refreshAll() is called.

Parameters:

dataChangeEvent - the data change event

onPreserveExisting

public abstract void onPreserveExisting(DataChangeEvent<T> dataChangeEvent)

Preserves the selected items that still exist after DataProvider.refreshAll() is called.

Parameters:

dataChangeEvent - the data change event

onDiscard

public abstract void onDiscard(DataChangeEvent<T> dataChangeEvent)

Clears selection when DataProvider.refreshAll() is called.

Parameters:

dataChangeEvent - the data change event