import com.vaadin.client.renderers.ClickableRenderer; //导入依赖的package包/类
@Override
protected void init() {
    super.init();

    expanderClickHandlerRegistration = getHierarchyRenderer()
            .addClickHandler(new ClickableRenderer.RendererClickHandler<JsonObject>() {
                @Override
                public void onClick(ClickableRenderer.RendererClickEvent<JsonObject> event) {
                    NavigationExtensionConnector navigation = getNavigationExtensionConnector();
                    if (navigation != null) {
                        navigation.toggleCollapse(getRowKey(event.getRow()));
                    }

                    event.stopPropagation();
                    event.preventDefault();
                }
            });

    replaceMemberFields();
}
 

import com.vaadin.client.renderers.ClickableRenderer; //导入依赖的package包/类
@Override
protected HandlerRegistration addClickHandler(ClickableRenderer.RendererClickHandler<JsonObject> handler) {
    return getRenderer().addClickHandler(handler);
}
 

import com.vaadin.client.renderers.ClickableRenderer; //导入依赖的package包/类
@Override
protected HandlerRegistration addClickHandler(ClickableRenderer.RendererClickHandler<JsonObject> jsonObjectRendererClickHandler) {
	return getRenderer().addClickHandler(jsonObjectRendererClickHandler);
}
 

import com.vaadin.client.renderers.ClickableRenderer; //导入依赖的package包/类
@Override
protected HandlerRegistration addClickHandler(
		ClickableRenderer.RendererClickHandler<JsonObject> handler) {
	return getRenderer().addClickHandler(handler);
}