Package com.vaadin.flow.dom

Class Node<N extends Node<N>>

  • Type Parameters:
    N - The narrowed type of the node
    All Implemented Interfaces:
    Serializable
    Direct Known Subclasses:
    Element, ShadowRoot
    public abstract class Node<N extends Node<N>>
extends Object
implements Serializable
    Represents a node in the DOM.

    Contains methods for updating and querying hierarchical structure.

    Since:
    1.0
    Author:
    Vaadin Ltd
    See Also:
    Serialized Form

    • Constructor Detail

      • Node

        protected Node​(StateNode node,
               ElementStateProvider stateProvider)
        Private constructor for initializing with an existing node and state provider.
        Parameters:
        node - the state node, not null
        stateProvider - the state provider, not null

    • Method Detail

      • getNode

        public StateNode getNode()
        Gets the node this element is connected to.

        This method is meant for internal use only.

        Returns:
        the node for this element

      • getStateProvider

        public ElementStateProvider getStateProvider()
        Gets the state provider for this element.

        This method is meant for internal use only.

        Returns:
        the state provider for this element

      • getChildCount

        public int getChildCount()
        Gets the number of child elements.
        Returns:
        the number of child elements

      • getChild

        public Element getChild​(int index)
        Returns the child element at the given position.
        Parameters:
        index - the index of the child element to return
        Returns:
        the child element

      • getChildren

        public Stream<Element> getChildren()
        Gets all the children of this element.
        Returns:
        a stream of children

      • appendChild

        public N appendChild​(Element... children)
        Adds the given children as the last children of this element.
        Parameters:
        children - the element(s) to add
        Returns:
        this element

      • appendChild

        public N appendChild​(Collection<Element> children)
        Adds the given children as the last children of this element.
        Parameters:
        children - the element(s) to add
        Returns:
        this element

      • appendVirtualChild

        public N appendVirtualChild​(Element... children)
        Appends the given children as the virtual children of the element.

        The virtual child is not really a child of the DOM element. The client-side counterpart is created in the memory, but it's not attached to the DOM tree. The resulting element is referenced via the server side Element in JS function call as usual.

        Parameters:
        children - the element(s) to add
        Returns:
        this element

      • appendVirtualChild

        public N appendVirtualChild​(Collection<Element> children)
        Appends the given children as the virtual children of the element.

        The virtual child is not really a child of the DOM element. The client-side counterpart is created in the memory, but it's not attached to the DOM tree. The resulting element is referenced via the server side Element in JS function call as usual.

        Parameters:
        children - the element(s) to add
        Returns:
        this element

      • removeVirtualChild

        public N removeVirtualChild​(Element... children)
        Removes the given children that have been attached as the virtual children of this element.

        The virtual child is not really a child of the DOM element. The client-side counterpart is created in the memory but it's not attached to the DOM tree. The resulting element is referenced via the server side Element in JS function call as usual. *

        Parameters:
        children - the element(s) to remove
        Returns:
        this element

      • removeVirtualChild

        public N removeVirtualChild​(Collection<Element> children)
        Removes the given children that have been attached as the virtual children of this element.

        The virtual child is not really a child of the DOM element. The client-side counterpart is created in the memory but it's not attached to the DOM tree. The resulting element is referenced via the server side Element in JS function call as usual. *

        Parameters:
        children - the element(s) to remove
        Returns:
        this element

      • isVirtualChild

        public boolean isVirtualChild()
        Gets whether this element is a virtual child of its parent.
        Returns:
        true if the element has a parent and the element is a virtual child of it, false otherwise.

      • insertChild

        public N insertChild​(int index,
                     Element... children)
        Inserts the given child element(s) at the given position.
        Parameters:
        index - the position at which to insert the new child
        children - the child element(s) to insert
        Returns:
        this element

      • insertChild

        public N insertChild​(int index,
                     Collection<Element> children)
        Inserts the given child element(s) at the given position.
        Parameters:
        index - the position at which to insert the new child
        children - the child element(s) to insert
        Returns:
        this element

      • indexOfChild

        public int indexOfChild​(Element child)
        Returns the index of the specified child in the children list, or -1 if this list does not contain the child.
        Parameters:
        child - the child element
        Returns:
        index of the child or -1 if it's not a child

      • setChild

        public N setChild​(int index,
                  Element child)
        Replaces the child at the given position with the given child element.
        Parameters:
        index - the position of the child element to replace
        child - the child element to insert
        Returns:
        this element

      • removeChild

        public N removeChild​(Element... children)
        Removes the given child element(s).
        Parameters:
        children - the child element(s) to remove
        Returns:
        this element

      • removeChild

        public N removeChild​(Collection<Element> children)
        Removes the given child element(s).
        Parameters:
        children - the child element(s) to remove
        Returns:
        this element

      • removeChild

        public N removeChild​(int index)
        Removes the child at the given index.
        Parameters:
        index - the index of the child to remove
        Returns:
        this element

      • removeAllChildren

        public N removeAllChildren()
        Removes all child elements, including elements only present at the client-side.
        Returns:
        this element

      • getParentNode

        public Node getParentNode()
        Gets the parent node.
        Returns:
        the parent node or null if this element does not have a parent

      • getSelf

        protected abstract N getSelf()
        Gets the narrow typed reference to this object.
        Returns:
        this object casted to its type

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Object

      • accept

        public N accept​(NodeVisitor visitor)
        Applies the visitor for the node.
        Parameters:
        visitor - the visitor to apply to the node
        Returns:
        this element

      • ensureChildHasParent

        protected void ensureChildHasParent​(Element child,
                                    boolean internalCheck)
        Ensures that the child has the correct parent.

        Default implementation doesn't do anything. Subclasses may override the method to implement their own behavior.

        Parameters:
        child - the element to check for its parent
        internalCheck - whether to use assertions or throw an exception on failure