Package com.vaadin.flow.component.virtuallist

Class VirtualList<T>

  • Type Parameters:
    T - the type of the items supported by the list
    All Implemented Interfaces:
    com.vaadin.flow.component.AttachNotifier, com.vaadin.flow.component.BlurNotifier<VirtualList<T>>, com.vaadin.flow.component.DetachNotifier, com.vaadin.flow.component.Focusable<VirtualList<T>>, com.vaadin.flow.component.FocusNotifier<VirtualList<T>>, com.vaadin.flow.component.HasElement, com.vaadin.flow.component.HasEnabled, com.vaadin.flow.component.HasSize, com.vaadin.flow.component.HasStyle, com.vaadin.flow.data.binder.HasDataProvider<T>, com.vaadin.flow.data.binder.HasItems<T>, Serializable
    @Tag("vaadin-virtual-list")
@NpmPackage(value="@vaadin/polymer-legacy-adapter",version="23.6.1") @NpmPackage(value="@vaadin/virtual-list",version="23.6.1") @NpmPackage(value="@vaadin/vaadin-virtual-list",version="23.6.1")
@JsModule("@vaadin/polymer-legacy-adapter/style-modules.js") @JsModule("@vaadin/polymer-legacy-adapter/template-renderer.js") @JsModule("@vaadin/virtual-list/src/vaadin-virtual-list.js") @JsModule("./flow-component-renderer.js") @JsModule("./virtualListConnector.js")
public class VirtualList<T>
extends com.vaadin.flow.component.Component
implements com.vaadin.flow.data.binder.HasDataProvider<T>, com.vaadin.flow.component.HasStyle, com.vaadin.flow.component.HasSize, com.vaadin.flow.component.Focusable<VirtualList<T>>
    Virtual List allows you to render a long list of items inside a scrollable container without sacrificing performance. Each item is rendered on the fly as the user scrolls the list. To use the component, you need to assign it a set of data items and a renderer that is used for rendering each individual data item. The height of an item is determined by its content and can change dynamically.

    This component supports DataProviders to load data asynchronously and Renderers to render the markup for each item.

    Author:
    Vaadin Ltd.
    See Also:
    Serialized Form

    • Nested Class Summary

      • Nested classes/interfaces inherited from interface com.vaadin.flow.component.BlurNotifier

        com.vaadin.flow.component.BlurNotifier.BlurEvent<C extends com.vaadin.flow.component.Component>

      • Nested classes/interfaces inherited from interface com.vaadin.flow.component.FocusNotifier

        com.vaadin.flow.component.FocusNotifier.FocusEvent<C extends com.vaadin.flow.component.Component>

    • Constructor Summary

      Constructors 
      Constructor Description
      VirtualList()
      Creates an empty list.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      com.vaadin.flow.data.provider.DataCommunicator<T> getDataCommunicator()
      Returns the data communicator of this list.
      com.vaadin.flow.data.provider.DataProvider<T,​?> getDataProvider()
      Returns the data provider of this list.
      T getPlaceholderItem()
      Gets the placeholder item of this list, or null if none has been set.
      void onEnabledStateChanged​(boolean enabled)  
      void setDataProvider​(com.vaadin.flow.data.provider.DataProvider<T,​?> dataProvider)  
      void setPlaceholderItem​(T placeholderItem)
      Sets an item to be shown as placeholder in the list while the real data in being fetched from the server.
      void setRenderer​(Renderer<T> renderer)
      Sets a renderer for the items in the list.
      void setRenderer​(com.vaadin.flow.function.ValueProvider<T,​String> valueProvider)
      Sets a renderer for the items in the list, by using a ValueProvider.

      • Methods inherited from class com.vaadin.flow.component.Component

        addListener, findAncestor, fireEvent, from, get, getChildren, getElement, getEventBus, getId, getListeners, getLocale, getParent, getTranslation, getTranslation, getTranslation, getTranslation, getTranslation, getTranslation, getUI, hasListener, isAttached, isTemplateMapped, isVisible, onAttach, onDetach, scrollIntoView, set, setElement, setId, setVisible

      • Methods inherited from interface com.vaadin.flow.component.AttachNotifier

        addAttachListener

      • Methods inherited from interface com.vaadin.flow.component.BlurNotifier

        addBlurListener

      • Methods inherited from interface com.vaadin.flow.component.DetachNotifier

        addDetachListener

      • Methods inherited from interface com.vaadin.flow.component.Focusable

        addFocusShortcut, blur, focus, getTabIndex, setTabIndex

      • Methods inherited from interface com.vaadin.flow.component.FocusNotifier

        addFocusListener

      • Methods inherited from interface com.vaadin.flow.data.binder.HasDataProvider

        setItems

      • Methods inherited from interface com.vaadin.flow.component.HasElement

        getElement

      • Methods inherited from interface com.vaadin.flow.component.HasEnabled

        isEnabled, setEnabled

      • Methods inherited from interface com.vaadin.flow.data.binder.HasItems

        setItems, setItems

      • Methods inherited from interface com.vaadin.flow.component.HasSize

        getHeight, getHeightUnit, getMaxHeight, getMaxWidth, getMinHeight, getMinWidth, getWidth, getWidthUnit, setHeight, setHeight, setHeightFull, setMaxHeight, setMaxHeight, setMaxWidth, setMaxWidth, setMinHeight, setMinHeight, setMinWidth, setMinWidth, setSizeFull, setSizeUndefined, setWidth, setWidth, setWidthFull

      • Methods inherited from interface com.vaadin.flow.component.HasStyle

        addClassName, addClassNames, getClassName, getClassNames, getStyle, hasClassName, removeClassName, removeClassNames, setClassName, setClassName

    • Constructor Detail

      • VirtualList

        public VirtualList()
        Creates an empty list.

    • Method Detail

      • setDataProvider

        public void setDataProvider​(com.vaadin.flow.data.provider.DataProvider<T,​?> dataProvider)
        Specified by:
        setDataProvider in interface com.vaadin.flow.data.binder.HasDataProvider<T>

      • getDataProvider

        public com.vaadin.flow.data.provider.DataProvider<T,​?> getDataProvider()
        Returns the data provider of this list.
        Returns:
        the data provider of this list, not null

      • getDataCommunicator

        public com.vaadin.flow.data.provider.DataCommunicator<T> getDataCommunicator()
        Returns the data communicator of this list.
        Returns:
        the data communicator, not null

      • setRenderer

        public void setRenderer​(com.vaadin.flow.function.ValueProvider<T,​String> valueProvider)
        Sets a renderer for the items in the list, by using a ValueProvider. The String returned by the provider is used to render each item.
        Parameters:
        valueProvider - a provider for the label string for each item in the list, not null

      • setRenderer

        public void setRenderer​(Renderer<T> renderer)
        Sets a renderer for the items in the list.

        When set, a same renderer is used for the placeholder item. See setPlaceholderItem(Object) for details.

        Parameters:
        renderer - a renderer for the items in the list, not null

      • setPlaceholderItem

        public void setPlaceholderItem​(T placeholderItem)
        Sets an item to be shown as placeholder in the list while the real data in being fetched from the server.

        Setting a placeholder item improves the user experience of the list while scrolling, since the placeholder uses the same renderer set with setRenderer(Renderer), maintaining the same height for placeholders and actual items.

        When no placeholder item is set (or when set to null), an empty placeholder element is created.

        Note: when using ComponentRenderers, the component used for the placeholder is statically stamped in the list. It can not be modified, nor receives any events.

        Parameters:
        placeholderItem - the item used as placeholder in the list, while the real data is being fetched from the server

      • getPlaceholderItem

        public T getPlaceholderItem()
        Gets the placeholder item of this list, or null if none has been set.
        Returns:
        the placeholder item

      • onEnabledStateChanged

        public void onEnabledStateChanged​(boolean enabled)
        Overrides:
        onEnabledStateChanged in class com.vaadin.flow.component.Component