HelpBlock.java 文件源码

/**
 * Constructor.
 */
public HelpBlock() {
    super(Document.get().createSpanElement());
    setStyleName(Styles.HELP_BLOCK);
    addHandler(new ChangeHandler() {
        @Override
        public void onChange(ChangeEvent event) {
            if (iconElement != null) {
                iconElement.removeFromParent();
            }
            if (error && iconType != null) {
                iconElement = createIconElement();
                getElement().insertFirst(iconElement);
            }
        }
    }, ChangeEvent.getType());
}