FXMLComponentInterceptor.java

/*
 * Copyright (C) 2013,2014 The Cat Hive Developers.
 *
 * 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 com.cathive.fx.cdi;

import java.io.IOException;
import java.util.concurrent.CountDownLatch;

import com.cathive.fx.inject.core.FXMLComponent;

import javafx.application.Platform;
import javafx.fxml.FXMLLoader;

import javax.interceptor.AroundConstruct;
import javax.interceptor.Interceptor;
import javax.interceptor.InvocationContext;

/**
 * This factory is responsible for the production of CDI-aware FXML-based custom components that
 * have been annotated as such using the {@link com.cathive.fx.inject.core.FXMLComponent @FXMLComponent} annotation.
 *
 * @author Benjamin P. Jung
 */
@SuppressWarnings("UnusedDeclaration")
@FXMLComponent
@Interceptor
class FXMLComponentInterceptor {

    @AroundConstruct
    public void createCdiFXMLComponent(final InvocationContext invocationContext) throws Exception {

        // Performs c-tor invocation. Afterwards "invocationContext.getTarget()" will no longer return "null".
        invocationContext.proceed();

        // Fetches the newly created annotated object and it's class.
        final Object target = invocationContext.getTarget();
        final Class<?> targetClass = target.getClass();

        final FXMLComponent annotation = targetClass.getAnnotation(FXMLComponent.class);
        if (annotation == null) {
            throw new IllegalStateException(String.format("No @FXMLComponent annotation could be retrieved from class %s.", targetClass.getName()));
        }
        final FXMLLoader fxmlLoader = new CdiFXMLLoader();
        CdiFXMLLoaderFactory.initializeFXMLLoader(
                fxmlLoader,
                targetClass,
                annotation.location(),
                annotation.resources(),
                annotation.charset());
        fxmlLoader.setRoot(target);
        fxmlLoader.setController(target);

        // We now have to perform the actual loading of the FXML document.
        // ... we have to make sure that this happens on the right (thus: FX application) thread, though!
        if (Platform.isFxApplicationThread()) {
            fxmlLoader.load();
        } else {
            final CountDownLatch latch = new CountDownLatch(1);
            Platform.runLater(() -> {
                try {
                    final Object loaded = fxmlLoader.load();
                    latch.countDown();
                } catch (final IOException e) {
                    throw new IllegalStateException("Loading of FXML file failed.", e);
                }
            });
            latch.await();
        }

    }

}