com.vaadin.flow.router.

Class EventUtil


  • public final class EventUtil
extends Object

    Event handling utilities.

    Since:

    1.0

    Author:

    Vaadin Ltd

    • 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

      • 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