org.jboss.elemento.LazyElement Maven / Gradle / Ivy
/*
* Copyright 2015-2016 Red Hat, Inc, and individual contributors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jboss.elemento;
import elemental2.dom.HTMLElement;
/**
* Convenience class to support lazy element creation. The bulk of a LazyElement is not instantiated until {@link
* #element()} is called.
*/
public abstract class LazyElement implements IsElement {
private E element;
/**
* Creates and returns the element on demand by calling {@link #createElement()} or just returns the previously
* created element.
*/
@Override
public E element() {
if (element == null) {
element = createElement();
}
return element;
}
/**
* Create the element contained within the {@link LazyElement}.
*
* @return the lazy element
*/
protected abstract E createElement();
/** @return whether the element has already been created. */
protected boolean initialized() {
return element != null;
}
}