Java 类com.vaadin.server.BootstrapListener 实例源码

@Override
public void serviceInit(ServiceInitEvent event) {
    ValoDependencyFilter dependencyFilter = new ValoDependencyFilter();
    if (dependencyFilter.hasValoWebJar()) {
        event.addDependencyFilter(dependencyFilter);
    }

    VaadinServletService service = (VaadinServletService) event.getSource();

    WebApplicationContext applicationContext = WebApplicationContextUtils
            .findWebApplicationContext(
                    service.getServlet().getServletContext());

    String apiKey = applicationContext.getEnvironment()
            .getProperty("map.apikey");
    if (apiKey == null) {
        throw new RuntimeException(
                "Configure a map.apikey in your application.properties");
    }

    event.addBootstrapListener(new BootstrapListener() {
        @Override
        public void modifyBootstrapPage(BootstrapPageResponse response) {
            Element head = response.getDocument().head();
            head.appendElement("meta").attr("name", "viewport")
                    .attr("content", "width=device-width, initial-scale=1");

            // Flow sets element properties too late for google-map to get
            // the right API key. As a temporary workaround, we put our key
            // in the map's prototype instead.
            head.appendElement("script").html("window.mapApiKey = '"
                    + apiKey + "';\n"
                    + "customElements.whenDefined('google-map').then(function() {customElements.get('google-map').prototype.apiKey = window.mapApiKey})");

            head.appendElement("link").attr("rel", "import").attr("href",
                    response.getUriResolver().resolveVaadinUri(
                            "frontend://bower_components/vaadin-valo-theme/typography.html"));
            head.appendElement("link").attr("rel", "import").attr("href",
                    response.getUriResolver().resolveVaadinUri(
                            "frontend://bower_components/vaadin-valo-theme/color.html"));

            head.appendElement("custom-style").appendElement("style")
                    .attr("include", "valo-typography valo-colors");
        }
    });
}