com.vaadin.flow.dom.Element.getComponent()方法的使用及代码示例

x33g5p2x  于2022-01-19 转载在 其他  
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本文整理了Java中com.vaadin.flow.dom.Element.getComponent()方法的一些代码示例，展示了Element.getComponent()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Element.getComponent()方法的具体详情如下：
包路径：com.vaadin.flow.dom.Element
类名称：Element
方法名：getComponent

Element.getComponent介绍

[英]Gets the component this element has been mapped to, if any.
[中]获取此元素已映射到的组件（如果有）。

代码示例

代码示例来源：origin: com.vaadin/flow-server

  1. /**
  2.  * Gets the innermost mapped component for the element.
  3.  * <p>
  4.  * This returns {@link Element#getComponent()} if something else than a
  5.  * {@link Composite} is mapped to the element. If a {@link Composite} is
  6.  * mapped to the element, finds the innermost content of the
  7.  * {@link Composite} chain.
  8.  *
  9.  * @param element
  10.  *            the element which is mapped to a component
  11.  * @return the innermost component mapped to the element
  12.  */
  13. public static Component getInnermostComponent(Element element) {
  14.   assert element.getComponent().isPresent();
  15.   Component component = element.getComponent().get();
  16.   if (component instanceof Composite) {
  17.     return ComponentUtil
  18.         .getInnermostComponent((Composite<?>) component);
  19.   }
  20.   return component;
  21. }

代码示例来源：origin: com.vaadin/vaadin-upload-flow

  1. private Component getComponentAtSlot(String slot) {
  2.   return getElement().getChildren()
  3.       .filter(child -> slot.equals(child.getAttribute("slot")))
  4.       .filter(child -> child.getComponent().isPresent())
  5.       .map(child -> child.getComponent().get()).findFirst()
  6.       .orElse(null);
  7. }

代码示例来源：origin: com.vaadin/flow-server

  1. /**
  2.  * Collect elements with Component implementing listener of type T.
  3.  *
  4.  * @param elementStream
  5.  *            collected elements
  6.  * @param type
  7.  *            class type to filter by
  8.  * @param <T>
  9.  *            type that is used in filtering
  10.  * @return stream of components implementing T
  11.  */
  12. public static <T> Stream<T> getImplementingComponents(
  13.     Stream<Element> elementStream, Class<T> type) {
  14.   return elementStream.flatMap(
  15.       o -> o.getComponent().map(Stream::of).orElseGet(Stream::empty))
  16.       .filter(component -> type
  17.           .isAssignableFrom(component.getClass()))
  18.       .map(component -> (T) component);
  19. }

代码示例来源：origin: com.vaadin/vaadin-text-field-flow

  1. /**
  2.    * Gets the first child component of the parent that is in the specified
  3.    * slot.
  4.    * 
  5.    * @param parent
  6.    *            the component to get child from, not {@code null}
  7.    * @param slot
  8.    *            the name of the slot inside the parent, not {@code null}
  9.    * @return a child component of the parent in the specified slot, or
  10.    *         {@code null} if none is found
  11.    */
  12.   public static Component getChildInSlot(HasElement parent, String slot) {
  13.     Optional<Element> element = getElementsInSlot(parent, slot).findFirst();
  14.     if (element.isPresent()) {
  15.       return element.get().getComponent().get();
  16.     }
  17.     return null;
  18.   }
  19. }

代码示例来源：origin: com.vaadin/vaadin-accordion-flow

  1. private static Optional<AccordionPanel> getOpenedPanel(Accordion accordion, Integer index) {
  2.   return index == null || index >= accordion.getChildren().count() ? Optional.empty() :
  3.       accordion.getElement().getChild(index).getComponent().map(AccordionPanel.class::cast);
  4. }

代码示例来源：origin: com.vaadin/flow-server

  1. /**
  2.  * Finds the first component by traversing upwards in the element hierarchy,
  3.  * starting from the given element.
  4.  *
  5.  * @param element
  6.  *            the element from which to begin the search
  7.  * @return optional of the component, empty if no component is found
  8.  */
  9. public static Optional<Component> findParentComponent(Element element) {
  10.   Element mappedElement = element;
  11.   while (mappedElement != null
  12.       && !mappedElement.getComponent().isPresent()) {
  13.     mappedElement = mappedElement.getParent();
  14.   }
  15.   if (mappedElement == null) {
  16.     return Optional.empty();
  17.   }
  18.   return Optional.of(getInnermostComponent(mappedElement));
  19. }

代码示例来源：origin: com.vaadin/flow-server

  1. /**
  2.  * Finds the first component instance in each {@link Element} subtree by
  3.  * traversing the {@link Element} tree starting from the given element.
  4.  *
  5.  * @param element
  6.  *            the element to start scanning from
  7.  * @param componentConsumer
  8.  *            a consumer which is called for each found component
  9.  */
  10. public static void findComponents(Element element,
  11.     Consumer<Component> componentConsumer) {
  12.   assert element != null;
  13.   assert componentConsumer != null;
  14.   Optional<Component> maybeComponent = element.getComponent();
  15.   if (maybeComponent.isPresent()) {
  16.     Component component = maybeComponent.get();
  17.     componentConsumer.accept(component);
  18.     return;
  19.   }
  20.   element.getChildren().forEach(childElement -> ComponentUtil
  21.       .findComponents(childElement, componentConsumer));
  22. }

代码示例来源：origin: com.vaadin/flow-server

  1. @SuppressWarnings("unchecked")
  2. private void injectTemplateElement(Element element, Field field) {
  3.   Class<?> fieldType = field.getType();
  4.   if (Component.class.isAssignableFrom(fieldType)) {
  5.     attachComponentIfUses(element);
  6.     Component component;
  7.     Optional<Component> wrappedComponent = element.getComponent();
  8.     if (wrappedComponent.isPresent()) {
  9.       component = wrappedComponent.get();
  10.     } else {
  11.       Class<? extends Component> componentType = (Class<? extends Component>) fieldType;
  12.       component = Component.from(element, componentType);
  13.     }
  14.     ReflectTools.setJavaFieldValue(template, field, component);
  15.   } else if (Element.class.isAssignableFrom(fieldType)) {
  16.     ReflectTools.setJavaFieldValue(template, field, element);
  17.   } else {
  18.     String msg = String.format(
  19.         "The field '%s' in '%s' has an @'%s' "
  20.             + "annotation but the field type '%s' "
  21.             + "does not extend neither '%s' nor '%s'",
  22.         field.getName(), templateClass.getName(),
  23.         Id.class.getSimpleName(), fieldType.getName(),
  24.         Component.class.getSimpleName(),
  25.         Element.class.getSimpleName());
  26.     throw new IllegalArgumentException(msg);
  27.   }
  28. }

代码示例来源：origin: com.vaadin/flow-server

  1. Optional<Component> currentComponent = element.getComponent();
  2. if (currentComponent.isPresent()) {

代码示例来源：origin: com.vaadin/flow-data

  1. /**
  2.    * Gets the index of the child element that represents the given item.
  3.    * 
  4.    * @param item
  5.    *            the item to look for
  6.    * @return the index of the child element that represents the item, or -1 if
  7.    *         the item is not found
  8.    */
  9.   default int getItemPosition(T item) {
  10.     if (item == null) {
  11.       return -1;
  12.     }
  13.     return IntStream.range(0, getElement().getChildCount()).filter(i -> {
  14.       Optional<Component> c = getElement().getChild(i).getComponent();
  15.       return c.isPresent() && c.get() instanceof ItemComponent
  16.           && item.equals(((ItemComponent<?>) c.get()).getItem());
  17.     }).findFirst().orElse(-1);
  18.   }
  19. }

代码示例来源：origin: com.vaadin/flow-server

  1. /**
  2.  * Sets the content for this composite and attaches it to the element.
  3.  * <p>
  4.  * This method must only be called once.
  5.  *
  6.  * @param content
  7.  *            the content for the composite
  8.  */
  9. private void setContent(T content) {
  10.   assert content.getElement().getComponent()
  11.       .isPresent() : "Composite should never be attached to an element which is not attached to a component";
  12.   assert this.content == null : "Content has already been initialized";
  13.   this.content = content;
  14.   Element element = content.getElement();
  15.   // Always replace the composite reference as this will be called from
  16.   // inside out, so the end result is that the element refers to the
  17.   // outermost composite in the probably rare case that multiple
  18.   // composites are nested
  19.   ElementUtil.setComponent(element, this);
  20. }

代码示例来源：origin: com.vaadin/flow-server

  1. /**
  2.  * Sets the enabled state of the element.
  3.  *
  4.  * @param enabled
  5.  *            the enabled state
  6.  * @return the element
  7.  */
  8. public Element setEnabled(final boolean enabled) {
  9.   getNode().setEnabled(enabled);
  10.   Optional<Component> componentOptional = getComponent();
  11.   if (componentOptional.isPresent()) {
  12.     Component component = componentOptional.get();
  13.     component.onEnabledStateChanged(enabled);
  14.     informChildrenOfStateChange(enabled, component);
  15.   }
  16.   return getSelf();
  17. }

代码示例来源：origin: com.vaadin/flow-server

  1. /**
  2.  * Gets the parent component of this component.
  3.  * <p>
  4.  * A component can only have one parent.
  5.  *
  6.  * @return an optional parent component, or an empty optional if the
  7.  *         component is not attached to a parent
  8.  */
  9. public Optional<Component> getParent() {
  10.   // If "this" is a component inside a Composite, iterate from the
  11.   // Composite downwards
  12.   Optional<Component> mappedComponent = getElement().getComponent();
  13.   if (!mappedComponent.isPresent()) {
  14.     throw new IllegalStateException(
  15.         "You cannot use getParent() on a wrapped component. Use Component.wrapAndMap to include the component in the hierarchy");
  16.   }
  17.   if (isInsideComposite(mappedComponent.get())) {
  18.     Component parent = ComponentUtil.getParentUsingComposite(
  19.         (Composite<?>) mappedComponent.get(), this);
  20.     return Optional.of(parent);
  21.   }
  22.   // Find the parent component based on the first parent element which is
  23.   // mapped to a component
  24.   return ComponentUtil.findParentComponent(getElement().getParent());
  25. }

代码示例来源：origin: com.vaadin/flow-server

  1. /**
  2.  * Gets the child components of this component.
  3.  * <p>
  4.  * The default implementation finds child components by traversing each
  5.  * child {@link Element} tree.
  6.  * <p>
  7.  * If the component is injected to a PolymerTemplate using the
  8.  * <code>@Id</code> annotation the getChildren method will only return
  9.  * children added from the server side and will not return any children
  10.  * declared in the template file.
  11.  *
  12.  * @see Id
  13.  *
  14.  * @return the child components of this component
  15.  */
  16. public Stream<Component> getChildren() {
  17.   // This should not ever be called for a Composite as it will return
  18.   // wrong results
  19.   assert !(this instanceof Composite);
  20.   if (!getElement().getComponent().isPresent()) {
  21.     throw new IllegalStateException(
  22.         "You cannot use getChildren() on a wrapped component. Use Component.wrapAndMap to include the component in the hierarchy");
  23.   }
  24.   Builder<Component> childComponents = Stream.builder();
  25.   getElement().getChildren().forEach(childElement -> ComponentUtil
  26.       .findComponents(childElement, childComponents::add));
  27.   return childComponents.build();
  28. }

代码示例来源：origin: com.vaadin/vaadin-app-layout-flow

  1. @Override
  2. public void showRouterLayoutContent(HasElement content) {
  3.   Component component = content.getElement().getComponent().get();
  4.   String target = null;
  5.   if (component instanceof RouteNotFoundError) {
  6.     getAppLayoutMenu().selectMenuItem(null);
  7.   } else {
  8.     target = UI.getCurrent().getRouter()
  9.         .getUrl(component.getClass());
  10.     getAppLayoutMenu().getMenuItemTargetingRoute(target)
  11.         .ifPresent(item -> getAppLayoutMenu().selectMenuItem(item, false));
  12.   }
  13.   beforeNavigate(target, content);
  14.   getAppLayout().setContent(content.getElement());
  15.   afterNavigate(target, content);
  16. }

代码示例来源：origin: com.vaadin/flow-server

  1. private void informChildrenOfStateChange(boolean enabled,
  2.     Component component) {
  3.   component.getChildren().forEach(child -> {
  4.     child.onEnabledStateChanged(
  5.         enabled ? child.getElement().isEnabled() : false);
  6.     informChildrenOfStateChange(enabled, child);
  7.   });
  8.   if (component.getElement().getNode()
  9.       .hasFeature(VirtualChildrenList.class)) {
  10.     component.getElement().getNode()
  11.         .getFeatureIfInitialized(VirtualChildrenList.class)
  12.         .ifPresent(list -> {
  13.           final Consumer<Component> stateChangeInformer = virtual -> {
  14.             virtual.onEnabledStateChanged(enabled
  15.                 ? virtual.getElement().isEnabled() : false);
  16.             informChildrenOfStateChange(enabled, virtual);
  17.           };
  18.           final Consumer<StateNode> childNodeConsumer = childNode -> Element
  19.               .get(childNode).getComponent()
  20.               .ifPresent(stateChangeInformer);
  21.           list.forEachChild(childNodeConsumer);
  22.         });
  23.   }
  24. }

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