com.vaadin.flow.router

Class EventUtil

java.lang.Object

com.vaadin.flow.router.EventUtil

public final class EventUtil
extends Object

Event handling utilities.

Since:

1.0

Author:

Vaadin Ltd

Method Summary

Modifier and Type	Method and Description
static List<AfterNavigationObserver>	collectAfterNavigationObservers(UI ui) Collect all Components implementing AfterNavigationObserver that are found in the given UI.
static List<BeforeEnterObserver>	collectBeforeEnterObservers(Collection<? extends HasElement> oldChain, Collection<? extends HasElement> newChain) Collect before enter observer instances based on what will be attached when a new view chain is applied.
static List<BeforeEnterObserver>	collectBeforeEnterObserversFromChain(Collection<? extends HasElement> chain, Collection<? extends HasElement> childrenExclusions) Collect before enter observer instances based on what will be attached when a new view chain is applied.
static List<BeforeEnterObserver>	collectBeforeEnterObserversFromChainElement(HasElement element, Collection<? extends HasElement> childrenExclusions) Collect before enter observer instances in the element's hierarchy.
static List<BeforeLeaveObserver>	collectBeforeLeaveObservers(UI ui) Collect all Components implementing BeforeLeaveObserver connected to the given UI.
static List<LocaleChangeObserver>	collectLocaleChangeObservers(Element element) Collect all Components implementing LocaleChangeObserver connected to the given element tree.
static List<LocaleChangeObserver>	collectLocaleChangeObservers(List<HasElement> components) Collect all Components implementing LocaleChangeObserver connected to the tree of all given Components in list.
static <T> Stream<T>	getImplementingComponents(Stream<Element> elementStream, Class<T> type) Collect elements with Component implementing listener of type T.
static void	informLocaleChangeObservers(UI ui) Inform components connected to the given ui that implement LocaleChangeObserver about locale change.
static void	informLocaleChangeObservers(UI ui, List<HasElement> components) Inform components implementing LocaleChangeObserver about locale change.
static void	inspectHierarchy(Element node, Collection<Element> descendants, Predicate<Element> filter) Collect all children for given node as a Element stream.

Methods inherited from class java.lang.Object

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

Method Detail

collectBeforeEnterObservers

public static List<BeforeEnterObserver> collectBeforeEnterObservers(Collection<? extends HasElement> oldChain,
                                                                    Collection<? extends HasElement> newChain)

Collect before enter observer instances based on what will be attached when a new view chain is applied. Because components in the new chain might still have children that will yet be detached, the old chain is also needed in order to exclude anything that is only in the old chain but missing from the new chain.

Parameters:

oldChain - the view chain prior to the navigation

newChain - the view chain after the navigation

Returns:

list of found BeforeEnterObservers

collectBeforeEnterObserversFromChain

public static List<BeforeEnterObserver> collectBeforeEnterObserversFromChain(Collection<? extends HasElement> chain,
                                                                             Collection<? extends HasElement> childrenExclusions)

Collect before enter observer instances based on what will be attached when a new view chain is applied.

Parameters:

chain - the view chain after the navigation

childrenExclusions - any children of any element in the chain input that is found in this collection will be excluded from the result

Returns:

list of found BeforeEnterObservers in the chain tree.

collectBeforeEnterObserversFromChainElement

public static List<BeforeEnterObserver> collectBeforeEnterObserversFromChainElement(HasElement element,
                                                                                    Collection<? extends HasElement> childrenExclusions)

Collect before enter observer instances in the element's hierarchy.

Parameters:

element - an element

childrenExclusions - any children of the element input that is found in this collection will be excluded from the result

Returns:

list of found BeforeEnterObservers in the element hierarchy tree.

collectBeforeLeaveObservers

public static List<BeforeLeaveObserver> collectBeforeLeaveObservers(UI ui)

Collect all Components implementing BeforeLeaveObserver connected to the given UI.

Parameters:

ui - UI to search from

Returns:

navigation listeners

collectAfterNavigationObservers

public static List<AfterNavigationObserver> collectAfterNavigationObservers(UI ui)

Collect all Components implementing AfterNavigationObserver that are found in the given UI.

Parameters:

ui - UI to search from

Returns:

after navigation listeners

collectLocaleChangeObservers

public static List<LocaleChangeObserver> collectLocaleChangeObservers(Element element)

Collect all Components implementing LocaleChangeObserver connected to the given element tree.

Parameters:

element - element to search from

Returns:

navigation listeners

collectLocaleChangeObservers

public static List<LocaleChangeObserver> collectLocaleChangeObservers(List<HasElement> components)

Collect all Components implementing LocaleChangeObserver connected to the tree of all given Components in list.

Parameters:

components - components to search

Returns:

navigation listeners

informLocaleChangeObservers

public static void informLocaleChangeObservers(UI ui)

Inform components connected to the given ui that implement LocaleChangeObserver about locale change.

Parameters:

ui - UI for locale change

informLocaleChangeObservers

public static void informLocaleChangeObservers(UI ui,
                                               List<HasElement> components)

Inform components implementing LocaleChangeObserver about locale change.

Parameters:

ui - UI for locale change

components - components to search

getImplementingComponents

public static <T> Stream<T> getImplementingComponents(Stream<Element> elementStream,
                                                      Class<T> type)

Collect elements with Component implementing listener of type T.

Type Parameters:

T - type that is used in filtering

Parameters:

elementStream - collected elements

type - class type to filter by

Returns:

stream of components implementing T

inspectHierarchy

public static void inspectHierarchy(Element node,
                                    Collection<Element> descendants,
                                    Predicate<Element> filter)

Collect all children for given node as a Element stream.

Parameters:

node - start node to collect child elements from

descendants - a collector of descendants to fill

filter - predicate to check whether a given element and its descendants should be included