Package 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

      • 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