Listening to message status changes, sending READ status updates

src/main/java/envoy/client/Chat.java

@@ -1,11 +1,14 @@
 package envoy.client;
 
+import java.io.IOException;
 import java.io.Serializable;
 
+import envoy.client.net.Client;
 import envoy.client.ui.list.ComponentListModel;
 import envoy.data.Message;
 import envoy.data.Message.MessageStatus;
 import envoy.data.User;
+import envoy.event.MessageStatusChangeEvent;
 
 /**
  * Represents a chat between two {@link User}s <br>
@@ -49,14 +52,25 @@ public class Chat implements Serializable {
 	 * {@code READ} starting from the bottom and stopping once a read message is
 	 * found.
 	 *
+	 * @param client the client instance used to notify the server about the message
+	 *               status changes
+	 * @throws IOException if a {@link MessageStatusChangeEvent} could not be
+	 *                     delivered to the server
 	 * @since Envoy v0.3-alpha
 	 */
-	public void read() {
-		for (int i = model.size() - 1; i >= 0; --i)
-			if (model.get(i).getSenderId() == recipient.getId()) {
-				if (model.get(i).getStatus() == MessageStatus.READ) break;
-				else model.get(i).setStatus(MessageStatus.READ);
+	public void read(Client client) throws IOException {
+		for (int i = model.size() - 1; i >= 0; --i) {
+			final Message m = model.get(i);
+			if (m.getSenderId() == recipient.getId()) {
+				if (m.getStatus() == MessageStatus.READ) break;
+				else {
+					m.setStatus(MessageStatus.READ);
+
+					// TODO: Cache events in offline mode
+					client.sendEvent(new MessageStatusChangeEvent(m));
+				}
 			}
+		}
 	}
 
 	/**

src/main/java/envoy/client/net/Client.java

@@ -13,7 +13,9 @@ import envoy.client.Config;
 import envoy.client.database.LocalDb;
 import envoy.client.util.EnvoyLog;
 import envoy.data.*;
+import envoy.event.Event;
 import envoy.event.IdGeneratorRequest;
+import envoy.event.MessageStatusChangeEvent;
 import envoy.util.SerializationUtils;
 
 /**
@@ -42,7 +44,7 @@ public class Client implements Closeable {
 
 	// Configuration and logging
 	private static final Config	config	= Config.getInstance();
-	private static final Logger logger = EnvoyLog.getLogger(Client.class.getSimpleName());
+	private static final Logger	logger	= EnvoyLog.getLogger(Client.class.getSimpleName());
 
 	/**
 	 * Enters the online mode by acquiring a user ID from the server. As a
@@ -103,19 +105,21 @@ public class Client implements Closeable {
 		// Relay cached unread messages
 		cache.setProcessor(receivedMessageProcessor);
 
-		// TODO: Status handling
+		// Process message status changes
+		receiver.registerProcessor(MessageStatusChangeEvent.class, new MessageStatusChangeEventProcessor());
 
 		// Process message ID generation
 		receiver.registerProcessor(IdGenerator.class, localDb::setIdGenerator);
 
-		// Request a generator if none is present
+		// Request a generator if none is present or the existing one is consumed
 		if (!localDb.hasIdGenerator() || !localDb.getIdGenerator().hasNext()) requestIdGenerator();
 
 		return cache;
 	}
 
 	/**
-	 * Sends a message to the server.
+	 * Sends a message to the server. The message's status will be incremented once
+	 * it was delivered successfully.
 	 *
 	 * @param message the message to send
 	 * @throws IOException if the message does not reach the server
@@ -126,6 +130,14 @@ public class Client implements Closeable {
 		message.nextStatus();
 	}
 
+	/**
+	 * Sends an event to the server.
+	 *
+	 * @param evt the event to send
+	 * @throws IOException if the event did not reach the server
+	 */
+	public void sendEvent(Event<?> evt) throws IOException { writeObject(evt); }
+
 	/**
 	 * Requests a new {@link IdGenerator} from the server.
 	 *

src/main/java/envoy/client/net/MessageStatusChangeEventProcessor.java

@@ -0,0 +1,38 @@
+package envoy.client.net;
+
+import java.util.function.Consumer;
+import java.util.logging.Logger;
+
+import envoy.client.util.EnvoyLog;
+import envoy.data.Message.MessageStatus;
+import envoy.event.EventBus;
+import envoy.event.MessageStatusChangeEvent;
+
+/**
+ * Project: <strong>envoy-client</strong><br>
+ * File: <strong>MessageStatusChangeEventProcessor.java</strong><br>
+ * Created: <strong>4 Feb 2020</strong><br>
+ *
+ * @author Kai S. K. Engelbart
+ * @since Envoy v0.3-alpha
+ */
+public class MessageStatusChangeEventProcessor implements Consumer<MessageStatusChangeEvent> {
+
+	private static final Logger logger = EnvoyLog.getLogger(MessageStatusChangeEventProcessor.class.getSimpleName());
+
+	/**
+	 * Dispatches a {@link MessageStatusChangeEvent} if the status is
+	 * {@code RECEIVED} or {@code READ}.
+	 *
+	 * @param evt the status change event
+	 * @since Envoy v0.3-alpha
+	 */
+	@Override
+	public void accept(MessageStatusChangeEvent evt) {
+		if (evt.get().ordinal() <= MessageStatus.RECEIVED.ordinal()) logger.info("Received invalid message status change " + evt);
+		else {
+			logger.info("Received " + evt.toString());
+			EventBus.getInstance().dispatch(evt);
+		}
+	}
+}

src/main/java/envoy/client/ui/ChatWindow.java

@@ -3,6 +3,7 @@ package envoy.client.ui;
 import java.awt.*;
 import java.awt.event.KeyAdapter;
 import java.awt.event.KeyEvent;
+import java.io.IOException;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 
@@ -19,9 +20,11 @@ import envoy.client.ui.list.ComponentList;
 import envoy.client.ui.settings.SettingsScreen;
 import envoy.client.util.EnvoyLog;
 import envoy.data.Message;
+import envoy.data.Message.MessageStatus;
 import envoy.data.MessageBuilder;
 import envoy.data.User;
 import envoy.event.EventBus;
+import envoy.event.MessageStatusChangeEvent;
 
 /**
  * Project: <strong>envoy-client</strong><br>
@@ -173,7 +176,12 @@ public class ChatWindow extends JFrame {
 				currentChat = localDb.getChats().stream().filter(chat -> chat.getRecipient().getId() == user.getId()).findFirst().get();
 
 				// Read current Chat
-				currentChat.read();
+				try {
+					currentChat.read(client);
+				} catch (IOException e) {
+					e.printStackTrace();
+					logger.log(Level.WARNING, "Could notify server about message status change", e);
+				}
 
 				// Set chat title
 				textPane.setText(currentChat.getRecipient().getName());
@@ -213,6 +221,26 @@ public class ChatWindow extends JFrame {
 			repaint();
 		});
 
+		// Listen to message status changes
+		EventBus.getInstance().register(MessageStatusChangeEvent.class, (evt) -> {
+			final long			id		= ((MessageStatusChangeEvent) evt).getId();
+			final MessageStatus	status	= (MessageStatus) evt.get();
+
+			for (Chat c : localDb.getChats())
+				for (Message m : c.getModel())
+					if (m.getId() == id) {
+
+						// Update message status
+						m.setStatus(status);
+
+						// Update model and scroll down if current chat
+						if (c == currentChat) {
+							messageList.setModel(currentChat.getModel());
+							scrollPane.setChatOpened(true);
+						}
+					}
+		});
+
 		revalidate();
 	}
 
@@ -286,10 +314,7 @@ public class ChatWindow extends JFrame {
 			if (!localDb.getIdGenerator().hasNext()) client.requestIdGenerator();
 
 		} catch (Exception e) {
-			JOptionPane.showMessageDialog(this,
-					"Error sending message:\n" + e.toString(),
-					"Message sending error",
-					JOptionPane.ERROR_MESSAGE);
+			JOptionPane.showMessageDialog(this, "Error sending message:\n" + e.toString(), "Message sending error", JOptionPane.ERROR_MESSAGE);
 			e.printStackTrace();
 		}
 	}
@@ -320,9 +345,7 @@ public class ChatWindow extends JFrame {
 	 * @param client the {@link Client} used to send and receive messages
 	 * @since Envoy v0.2-alpha
 	 */
-	public void setClient(Client client) {
-		this.client = client;
-	}
+	public void setClient(Client client) { this.client = client; }
 
 	/**
 	 * Sets the {@link LocalDb} used by this {@link ChatWindow}. After