bundles/org.eclipse.e4.core.services/src/org/eclipse/e4/core/services/nls/BaseMessageRegistry.java - platform/eclipse.platform.runtime - Git at Google

 /*******************************************************************************
  * Copyright (c) 2014 Dirk Fauth and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *    Dirk Fauth <dirk.fauth@googlemail.com> - initial API and implementation
  *******************************************************************************/
 package org.eclipse.e4.core.services.nls;

 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.security.AccessController;
 import java.security.PrivilegedAction;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
 import java.util.Map.Entry;
 import javax.annotation.PreDestroy;
 import org.eclipse.e4.core.internal.services.ResourceBundleHelper;
 import org.osgi.service.log.LogService;

 /**
  * Using this MessageRegistry allows to register controls for attributes in a
  * Messages class. These controls will automatically get updated in case of
  * Locale changes.
  * <p>
  * When updating the dependencies from Java 7 to Java 8, this class can be
  * replaced by a more modern variant that makes use of functional interfaces and
  * method references as shown in the above linked blog post.
  * </p>
  *
  * <p>
  * To use the registry you need to implement a subclass of
  * <code>BaseMessageRegistry</code> that is typed to the messages class that it
  * is related to. The main thing to do is to override
  * <code>updateMessages(M)</code> while getting the messages instance injected.
  * </p>
  *
  * <pre>
  * &#064;Creatable
  * public class ExampleMessageRegistry
  * 		extends
  * 			BaseMessageRegistry&lt;ExampleMessages&gt; {
  *
  * 	&#064;Override
  * 	&#064;Inject
  * 	public void updateMessages(@Translation ExampleMessages messages) {
  * 		super.updateMessages(messages);
  * 	}
  * }
  * </pre>
  *
  * <p>
  * Note that the registry instance is annotated with &#064;Creatable so it is
  * created per requestor and is making use of DI.
  * </p>
  *
  * @param <M>
  *            the message class type
  * @since 2.0
  */
 public class BaseMessageRegistry<M> {

 	private M messages;

 	private final Map<MessageConsumer, MessageSupplier> bindings = new HashMap<>();

 	/**
 	 * Register a consumer and a function that is acting as the supplier of the translation value.
 	 * <p>
 	 * This method allows to register a binding using method references and lambdas if used in an
 	 * environment that already uses Java 8.
 	 * </p>
 	 *
 	 * <pre>
 	 * &#064;Inject
 	 * ExampleMessageRegistry registry;
 	 *
 	 * Label myFirstLabel = new Label(parent, SWT.WRAP);
 	 * registry.register(myFirstLabel::setText, (m) -&gt; m.firstLabelMessage);
 	 * </pre>
 	 *
 	 * @param consumer
 	 *            The consumer of the message.
 	 * @param function
 	 *            The function that supplies the message.
 	 */
 	public void register(MessageConsumer consumer, final MessageFunction<M> function) {
 		register(consumer, new MessageSupplier() {

 			@Override
 			public String get() {
 				return function.apply(messages);
 			}
 		});
 	}

 	/**
 	 * Register a binding for the given consumer and supplier.
 	 *
 	 * <p>
 	 * Unless you don't want to anonymously implement the consumer and supplier interfaces yourself,
 	 * use the register methods that take the Control instance and String(s) as parameters.
 	 * </p>
 	 *
 	 * @param consumer
 	 *            The consumer of the message.
 	 * @param supplier
 	 *            The supplier of the message.
 	 *
 	 * @see BaseMessageRegistry#register(Object, String, String)
 	 * @see BaseMessageRegistry#registerProperty(Object, String, String)
 	 */
 	public void register(MessageConsumer consumer, MessageSupplier supplier) {
 		//set the value to the control
 		consumer.accept(supplier.get());
 		//remember the control and the supplier
 		bindings.put(consumer, supplier);
 	}

 	/**
 	 * Binds a method of an object to a message. Doing this the specified method will be called on
 	 * the instance with the message String as parameter that is retrieved via message key out of
 	 * the local Messages instance.
 	 *
 	 * @param control
 	 *            The control for which a message binding should be created
 	 * @param method
 	 *            The method that should be bound. Methods that can be bound need to accept one
 	 *            String parameter.
 	 * @param messageKey
 	 *            The key of the message property that should be bound
 	 *
 	 * @see BaseMessageRegistry#registerProperty(Object, String, String)
 	 */
 	public void register(final Object control, final String method, final String messageKey) {
 		MessageConsumer consumer = createConsumer(control, method);
 		MessageSupplier supplier = createSupplier(messageKey);
 		//only register if consumer and supplier were created
 		if (consumer != null && supplier != null)
 			register(consumer, supplier);
 	}

 	/**
 	 * Binds the setter of a property of an object to a message. Doing this the setter of the given
 	 * property will be called on the instance with the message String as parameter that is
 	 * retrieved via message key out of the local Messages instance.
 	 *
 	 * @param control
 	 *            The control for which a message binding should be created
 	 * @param property
 	 *            The property of the control which should be bound
 	 * @param messageKey
 	 *            The key of the message property that should be bound
 	 *
 	 * @see BaseMessageRegistry#register(Object, String, String)
 	 */
 	public void registerProperty(final Object control, final String property, final String messageKey) {
 		MessageConsumer consumer = createConsumer(control, "set" + Character.toUpperCase(property.charAt(0)) + property.substring(1));
 		MessageSupplier supplier = createSupplier(messageKey);
 		//only register if consumer and supplier were created
 		if (consumer != null && supplier != null)
 			register(consumer, supplier);
 	}

 	/**
 	 * This method performs the localization update for all bound objects.
 	 * <p>
 	 * Typically this method is overriden by a concrete implementation where the Messages instance
 	 * is injected via &#064;Inject and &#064;Translation.
 	 * </p>
 	 *
 	 * @param messages
 	 *            The new Messages instance that should be used to update the localization.
 	 */
 	public void updateMessages(M messages) {
 		//remember the current message instance
 		this.messages = messages;
 		//iterate over all registered consumer
 		for (Map.Entry<MessageConsumer, MessageSupplier> entry : bindings.entrySet()) {
 			entry.getKey().accept(entry.getValue().get());
 		}
 	}

 	/**
 	 *
 	 * @param control
 	 *            The control on which the created consumer should operate
 	 * @param method
 	 *            The method the created consumer should call to set the new
 	 *            value
 	 * @return A MessageConsumer that sets a value to the property of the given
 	 *         control, or {@code null} in case of any exception
 	 */
 	protected MessageConsumer createConsumer(final Object control, final String method) {

 		final LogService logService = ResourceBundleHelper.getLogService();

 		try {
 			final Method m = control.getClass().getMethod(method, String.class);
 			if (m != null) {
 				return new MessageConsumerImplementation(logService, m, control);
 			}
 		} catch (NoSuchMethodException e) {
 			if (logService != null)
 				logService.log(LogService.LOG_WARNING,
 						"The method '" + e.getMessage()
 								+ "' does not exist. Binding is not created!");
 		} catch (SecurityException e) {
 			if (logService != null)
 				logService.log(
 						LogService.LOG_WARNING,
 						"Error on accessing method '" + method + "' on class '"
 								+ control.getClass() + "' with error message '" + e.getMessage()
 								+ "'. Binding is not created!");
 		}

 		return null;
 	}

 	private final class MessageConsumerImplementation implements MessageConsumer {
 		private final LogService logService;
 		private final Method m;
 		private final Object control;

 		private MessageConsumerImplementation(LogService logService, Method m, Object control) {
 			this.logService = logService;
 			this.m = m;
 			this.control = control;
 		}

 		@Override
 		public void accept(final String value) {
 			try {
 				// ensure the method is accessible so the registry
 				// also works well with protected or package
 				// protected classes
 				if (System.getSecurityManager() == null) {
 					m.setAccessible(true);
 					m.invoke(control, value);
 				} else {
 					AccessController.doPrivileged(new PrivilegedAction<Object>() {

 						@Override
 						public Object run() {
 							m.setAccessible(true);
 							try {
 								m.invoke(control, value);
 							} catch (Exception e) {
 								// if anything fails on invoke we unregister the
 								// binding to avoid further issues e.g. this can
 								// happen in case of disposed SWT controls
 								bindings.remove(MessageConsumerImplementation.this);
 								if (logService != null)
 									logService.log(LogService.LOG_INFO,
 											"Error on invoke '" + m.getName() + "' on '" + control.getClass()
 													+ "' with error message '" + e.getMessage()
 													+ "'. Binding is removed.");
 							}
 							return null;
 						}

 					});
 				}
 			} catch (Exception e) {
 				// if anything fails on invoke we unregister the binding to
 				// avoid further issues
 				// e.g. this can happen in case of disposed SWT controls
 				bindings.remove(this);
 				if (logService != null)
 					logService.log(LogService.LOG_INFO,
 							"Error on invoke '" + m.getName() + "' on '" + control.getClass() + "' with error message '"
 									+ e.getMessage() + "'. Binding is removed.");
 			}
 		}
 	}

 	/**
 	 *
 	 * @param messageKey
 	 *            The name of the field that should be accessed
 	 * @return A MessageSupplier that returns the message value for the given message key
 	 */
 	protected MessageSupplier createSupplier(final String messageKey) {
 		final LogService logService = ResourceBundleHelper.getLogService();
 		try {
 			final Field f = messages.getClass().getField(messageKey);
 			if (f != null) {
 				return new MessageSupplierImplementation(logService, f);
 			}
 		} catch (NoSuchFieldException e) {
 			if (logService != null)
 				logService.log(LogService.LOG_WARNING, "The class '" + this.messages.getClass().getName()
 						+ "' does not contain a field with name '" + e.getMessage() + "'. Binding is not created!");
 		} catch (SecurityException e) {
 			if (logService != null)
 				logService.log(LogService.LOG_WARNING,
 						"Error on accessing field '" + messageKey + "' on class '" + messages.getClass()
 								+ "' with error message '" + e.getMessage() + "'. Binding is not created!");
 		}
 		return null;
 	}

 	private final class MessageSupplierImplementation implements MessageSupplier {
 		private final LogService logService;
 		private final Field f;

 		private MessageSupplierImplementation(LogService logService, Field f) {
 			this.logService = logService;
 			this.f = f;
 		}

 		@Override
 		public String get() {
 			String message = null;
 			try {
 				message = (String) f.get(messages);
 			} catch (Exception e) {
 				// if anything fails on invoke we unregister the binding to
 				// avoid further issues
 				// e.g. this can happen in case of disposed SWT controls
 				Iterator<Entry<MessageConsumer, MessageSupplier>> iterator = bindings.entrySet().iterator();
 				iterator.forEachRemaining(entry -> {
 					if (entry.getValue() == MessageSupplierImplementation.this) {
 						iterator.remove();
 					}
 				});
 				if (logService != null)
 					logService.log(LogService.LOG_INFO,
 							"Error on invoke '" + f.getName() + "' on '" + messages.getClass()
 									+ "' with error message '" + e.getMessage() + "'. Binding is removed.");
 			}
 			return message;
 		}
 	}

 	@PreDestroy
 	void unregister() {
 		this.bindings.clear();
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2014 Dirk Fauth and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* Dirk Fauth <dirk.fauth@googlemail.com> - initial API and implementation
	*******************************************************************************/
	package org.eclipse.e4.core.services.nls;

	import java.lang.reflect.Field;
	import java.lang.reflect.Method;
	import java.security.AccessController;
	import java.security.PrivilegedAction;
	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.Map;
	import java.util.Map.Entry;
	import javax.annotation.PreDestroy;
	import org.eclipse.e4.core.internal.services.ResourceBundleHelper;
	import org.osgi.service.log.LogService;

	/**
	* Using this MessageRegistry allows to register controls for attributes in a
	* Messages class. These controls will automatically get updated in case of
	* Locale changes.
	* <p>
	* When updating the dependencies from Java 7 to Java 8, this class can be
	* replaced by a more modern variant that makes use of functional interfaces and
	* method references as shown in the above linked blog post.
	* </p>
	*
	* <p>
	* To use the registry you need to implement a subclass of
	* <code>BaseMessageRegistry</code> that is typed to the messages class that it
	* is related to. The main thing to do is to override
	* <code>updateMessages(M)</code> while getting the messages instance injected.
	* </p>
	*
	* <pre>
	* @Creatable
	* public class ExampleMessageRegistry
	* extends
	* BaseMessageRegistry<ExampleMessages> {
	*
	* @Override
	* @Inject
	* public void updateMessages(@Translation ExampleMessages messages) {
	* super.updateMessages(messages);
	* }
	* }
	* </pre>
	*
	* <p>
	* Note that the registry instance is annotated with @Creatable so it is
	* created per requestor and is making use of DI.
	* </p>
	*
	* @param <M>
	* the message class type
	* @since 2.0
	*/
	public class BaseMessageRegistry<M> {

	private M messages;

	private final Map<MessageConsumer, MessageSupplier> bindings = new HashMap<>();

	/**
	* Register a consumer and a function that is acting as the supplier of the translation value.
	* <p>
	* This method allows to register a binding using method references and lambdas if used in an
	* environment that already uses Java 8.
	* </p>
	*
	* <pre>
	* @Inject
	* ExampleMessageRegistry registry;
	*
	* Label myFirstLabel = new Label(parent, SWT.WRAP);
	* registry.register(myFirstLabel::setText, (m) -> m.firstLabelMessage);
	* </pre>
	*
	* @param consumer
	* The consumer of the message.
	* @param function
	* The function that supplies the message.
	*/
	public void register(MessageConsumer consumer, final MessageFunction<M> function) {
	register(consumer, new MessageSupplier() {

	@Override
	public String get() {
	return function.apply(messages);
	}
	});
	}

	/**
	* Register a binding for the given consumer and supplier.
	*
	* <p>
	* Unless you don't want to anonymously implement the consumer and supplier interfaces yourself,
	* use the register methods that take the Control instance and String(s) as parameters.
	* </p>
	*
	* @param consumer
	* The consumer of the message.
	* @param supplier
	* The supplier of the message.
	*
	* @see BaseMessageRegistry#register(Object, String, String)
	* @see BaseMessageRegistry#registerProperty(Object, String, String)
	*/
	public void register(MessageConsumer consumer, MessageSupplier supplier) {
	//set the value to the control
	consumer.accept(supplier.get());
	//remember the control and the supplier
	bindings.put(consumer, supplier);
	}

	/**
	* Binds a method of an object to a message. Doing this the specified method will be called on
	* the instance with the message String as parameter that is retrieved via message key out of
	* the local Messages instance.
	*
	* @param control
	* The control for which a message binding should be created
	* @param method
	* The method that should be bound. Methods that can be bound need to accept one
	* String parameter.
	* @param messageKey
	* The key of the message property that should be bound
	*
	* @see BaseMessageRegistry#registerProperty(Object, String, String)
	*/
	public void register(final Object control, final String method, final String messageKey) {
	MessageConsumer consumer = createConsumer(control, method);
	MessageSupplier supplier = createSupplier(messageKey);
	//only register if consumer and supplier were created
	if (consumer != null && supplier != null)
	register(consumer, supplier);
	}

	/**
	* Binds the setter of a property of an object to a message. Doing this the setter of the given
	* property will be called on the instance with the message String as parameter that is
	* retrieved via message key out of the local Messages instance.
	*
	* @param control
	* The control for which a message binding should be created
	* @param property
	* The property of the control which should be bound
	* @param messageKey
	* The key of the message property that should be bound
	*
	* @see BaseMessageRegistry#register(Object, String, String)
	*/
	public void registerProperty(final Object control, final String property, final String messageKey) {
	MessageConsumer consumer = createConsumer(control, "set" + Character.toUpperCase(property.charAt(0)) + property.substring(1));
	MessageSupplier supplier = createSupplier(messageKey);
	//only register if consumer and supplier were created
	if (consumer != null && supplier != null)
	register(consumer, supplier);
	}

	/**
	* This method performs the localization update for all bound objects.
	* <p>
	* Typically this method is overriden by a concrete implementation where the Messages instance
	* is injected via @Inject and @Translation.
	* </p>
	*
	* @param messages
	* The new Messages instance that should be used to update the localization.
	*/
	public void updateMessages(M messages) {
	//remember the current message instance
	this.messages = messages;
	//iterate over all registered consumer
	for (Map.Entry<MessageConsumer, MessageSupplier> entry : bindings.entrySet()) {
	entry.getKey().accept(entry.getValue().get());
	}
	}

	/**
	*
	* @param control
	* The control on which the created consumer should operate
	* @param method
	* The method the created consumer should call to set the new
	* value
	* @return A MessageConsumer that sets a value to the property of the given
	* control, or {@code null} in case of any exception
	*/
	protected MessageConsumer createConsumer(final Object control, final String method) {

	final LogService logService = ResourceBundleHelper.getLogService();

	try {
	final Method m = control.getClass().getMethod(method, String.class);
	if (m != null) {
	return new MessageConsumerImplementation(logService, m, control);
	}
	} catch (NoSuchMethodException e) {
	if (logService != null)
	logService.log(LogService.LOG_WARNING,
	"The method '" + e.getMessage()
	+ "' does not exist. Binding is not created!");
	} catch (SecurityException e) {
	if (logService != null)
	logService.log(
	LogService.LOG_WARNING,
	"Error on accessing method '" + method + "' on class '"
	+ control.getClass() + "' with error message '" + e.getMessage()
	+ "'. Binding is not created!");
	}

	return null;
	}

	private final class MessageConsumerImplementation implements MessageConsumer {
	private final LogService logService;
	private final Method m;
	private final Object control;

	private MessageConsumerImplementation(LogService logService, Method m, Object control) {
	this.logService = logService;
	this.m = m;
	this.control = control;
	}

	@Override
	public void accept(final String value) {
	try {
	// ensure the method is accessible so the registry
	// also works well with protected or package
	// protected classes
	if (System.getSecurityManager() == null) {
	m.setAccessible(true);
	m.invoke(control, value);
	} else {
	AccessController.doPrivileged(new PrivilegedAction<Object>() {

	@Override
	public Object run() {
	m.setAccessible(true);
	try {
	m.invoke(control, value);
	} catch (Exception e) {
	// if anything fails on invoke we unregister the
	// binding to avoid further issues e.g. this can
	// happen in case of disposed SWT controls
	bindings.remove(MessageConsumerImplementation.this);
	if (logService != null)
	logService.log(LogService.LOG_INFO,
	"Error on invoke '" + m.getName() + "' on '" + control.getClass()
	+ "' with error message '" + e.getMessage()
	+ "'. Binding is removed.");
	}
	return null;
	}

	});
	}
	} catch (Exception e) {
	// if anything fails on invoke we unregister the binding to
	// avoid further issues
	// e.g. this can happen in case of disposed SWT controls
	bindings.remove(this);
	if (logService != null)
	logService.log(LogService.LOG_INFO,
	"Error on invoke '" + m.getName() + "' on '" + control.getClass() + "' with error message '"
	+ e.getMessage() + "'. Binding is removed.");
	}
	}
	}

	/**
	*
	* @param messageKey
	* The name of the field that should be accessed
	* @return A MessageSupplier that returns the message value for the given message key
	*/
	protected MessageSupplier createSupplier(final String messageKey) {
	final LogService logService = ResourceBundleHelper.getLogService();
	try {
	final Field f = messages.getClass().getField(messageKey);
	if (f != null) {
	return new MessageSupplierImplementation(logService, f);
	}
	} catch (NoSuchFieldException e) {
	if (logService != null)
	logService.log(LogService.LOG_WARNING, "The class '" + this.messages.getClass().getName()
	+ "' does not contain a field with name '" + e.getMessage() + "'. Binding is not created!");
	} catch (SecurityException e) {
	if (logService != null)
	logService.log(LogService.LOG_WARNING,
	"Error on accessing field '" + messageKey + "' on class '" + messages.getClass()
	+ "' with error message '" + e.getMessage() + "'. Binding is not created!");
	}
	return null;
	}

	private final class MessageSupplierImplementation implements MessageSupplier {
	private final LogService logService;
	private final Field f;

	private MessageSupplierImplementation(LogService logService, Field f) {
	this.logService = logService;
	this.f = f;
	}

	@Override
	public String get() {
	String message = null;
	try {
	message = (String) f.get(messages);
	} catch (Exception e) {
	// if anything fails on invoke we unregister the binding to
	// avoid further issues
	// e.g. this can happen in case of disposed SWT controls
	Iterator<Entry<MessageConsumer, MessageSupplier>> iterator = bindings.entrySet().iterator();
	iterator.forEachRemaining(entry -> {
	if (entry.getValue() == MessageSupplierImplementation.this) {
	iterator.remove();
	}
	});
	if (logService != null)
	logService.log(LogService.LOG_INFO,
	"Error on invoke '" + f.getName() + "' on '" + messages.getClass()
	+ "' with error message '" + e.getMessage() + "'. Binding is removed.");
	}
	return message;
	}
	}

	@PreDestroy
	void unregister() {
	this.bindings.clear();
	}
	}