Playerlist and Serverlist combos are properly updated. It is possible to send commands to servers.

src/Main.java

@@ -37,8 +37,8 @@ class Main {
                             try {
                                 String readText = collection.getServer().read();
                                 if (!readText.equals("")) {
-                                	//TODO: If the text contains joining or leaving message of player, update playerlist.
                                     collection.getServerConsole().output(readText);
+                                    updatePlayerList(readText, collection);
                                 }
                             } catch (IOException e) {
                                 e.printStackTrace();
@@ -60,4 +60,76 @@ class Main {
 			System.exit(1);
 		}
 	}
+
+	private static void updatePlayerList(String text, Collection collection) {
+	    try {
+            if (!collection.getServer().typeName().equals("Bungee")) { //Bungee servers are not to be treated as normal servers.
+                String joinedPlayer = stringBetween(text, "[Server thread/INFO]: ", " joined the game");
+                if (!joinedPlayer.equals("")) {
+                    if (!collection.getServer().hasPlayer(joinedPlayer)) {
+                        collection.getServer().addPlayer(joinedPlayer);
+                    }
+                } else {
+                    joinedPlayer = stringBetween(text, "UUID of player ", " is ");
+                    if (!joinedPlayer.equals("")) {
+                        if (!collection.getServer().hasPlayer(joinedPlayer)) {
+                            collection.getServer().addPlayer(joinedPlayer);
+                        }
+                    }
+                }
+                if (joinedPlayer.equals("")) {
+                    String leftPlayer = stringBetween(text, "INFO]: ", " lost connection");
+                    if (!leftPlayer.equals("")) {
+                        if (collection.getServer().hasPlayer(leftPlayer)) {
+                            collection.getServer().removePlayer(leftPlayer);
+                        }
+                    } else {
+                        leftPlayer = stringBetween(text, "[Server thread/INFO]: ", " left the game");
+                        if (!leftPlayer.equals("")) {
+                            if (collection.getServer().hasPlayer(leftPlayer)) {
+                                collection.getServer().removePlayer(leftPlayer);
+                            }
+                        }
+                    }
+                }
+            }
+        } catch (Exception e) {
+	        e.printStackTrace();
+        }
+        /*
+        If Not ($PlayersArray = "BUNGEE") Then
+		$NewDataLine = StringSplit($NewData, @CRLF, 1)
+		For $x = 0 To UBound($NewDataLine) - 1
+			$NewPlayer = _StringBetween($NewDataLine[$x], "[Server thread/INFO]: ", " joined the game", 1, True)
+			If Not IsArray($NewPlayer) Then $NewPlayer = _StringBetween($NewDataLine[$x], "UUID of player ", " is ", 1, True)
+			$LeftPlayer = _StringBetween($NewDataLine[$x], "INFO]: ", " lost connection", 1, True)
+			If Not IsArray($LeftPlayer) Then $LeftPlayer = _StringBetween($NewDataLine[$x], "[Server thread/INFO]: ", " left the game", 1, True)
+			If IsArray($NewPlayer) Then
+				If _ArraySearch($PlayersArray, StringReplace($NewPlayer[0], " ", "")) = -1 Then
+					_ArrayAdd($PlayersArray, StringReplace($NewPlayer[0], " ", ""))
+				EndIf
+			EndIf
+			If IsArray($LeftPlayer) Then
+				_ArrayDelete($PlayersArray, _ArraySearch($PlayersArray, $LeftPlayer[0]))
+			EndIf
+		Next
+	EndIf
+         */
+    }
+
+    /**
+     * Finds a substring between two substrings in a string.
+     *
+     * @param string The string containing the substrings
+     * @param start  The substring before the wanted substring
+     * @param end    The substring after the wanted substring
+     * @return The wanted substring.
+     */
+    private static String stringBetween(String string, String start, String end) throws StringIndexOutOfBoundsException {
+        int startPos = string.indexOf(start) + start.length();
+        if (string.indexOf(end, startPos) < startPos) {
+            return "";
+        }
+        return string.substring(startPos, string.indexOf(end, startPos));
+    }
 }

src/net/knarcraft/serverlauncher/profile/Profile.java

@@ -39,18 +39,20 @@ public class Profile {
     }
 
     public void addCollection(String name) {
-        if (!collectionExists(name)) {
+        if (!collectionExists(name) && !name.equals("") && !name.equals("All")) {
             collections.add(new Collection(name));
+            GUI.getGUI().updateSelectServers();
         } else {
-            JOptionPane.showMessageDialog(null, "A server name must my unique and not empty.", "Error", JOptionPane.ERROR_MESSAGE);
+            JOptionPane.showMessageDialog(null, "A server name must my unique and not empty or \"All\".", "Error", JOptionPane.ERROR_MESSAGE);
         }
     }
 
     public void removeCollection(int i) {
         this.collections.remove(i);
+        GUI.getGUI().updateSelectServers();
     }
 
-    private Collection getCollection(String name) {
+    public Collection getCollection(String name) {
         for (Collection collection : this.collections) {
             if (collection.getName().equals(name)) {
                 return collection;

src/net/knarcraft/serverlauncher/server/Server.java

@@ -50,15 +50,29 @@ public class Server {
 
     public void addPlayer(String name) {
         this.playerList.add(name);
+        GUI.getGUI().addPlayer(name);
     }
 
     public void removePlayer(String name) {
         for (int i = 0; i < playerList.size(); i++) {
             if (name.equals(playerList.get(i))) {
                 playerList.remove(i);
-                return;
             }
         }
+        GUI.getGUI().removePlayer(name);
+    }
+
+    public ArrayList<String> getPlayers() {
+        return this.playerList;
+    }
+
+    public boolean hasPlayer(String name) {
+        for (String player : this.playerList) {
+            if (player.equals(name)) {
+                return true;
+            }
+        }
+        return false;
     }
 
     /**
@@ -122,6 +136,10 @@ public class Server {
         }
     }
 
+    public String typeName() {
+        return this.type.getName();
+    }
+
     /**
      * Sets the server's server version to a valid version, or ignores the request.
      *

src/net/knarcraft/serverlauncher/userinterface/GUI.java

@@ -42,7 +42,8 @@ public class GUI implements ActionListener {
     private JComboBox<String> profiles;
     private final JLabel lblStatuslabel = new JLabel("Servers are stopped");
     //Server controls
-    private JComboBox targetServer, targetPlayer;
+    private JComboBox<String> targetServer;
+    private JComboBox<String> targetPlayer;
     private JButton btnKick, btnBan, btnOp, btnDeop, btnCustomCommand, btnSaveserver, btnReload, btnServerConsoles;
     private JTextField customCommand;
     //Text
@@ -52,13 +53,13 @@ public class GUI implements ActionListener {
     private String downloadJarsText;
     private String aboutText;
 
+    private final ArrayList<String> globalPlayers;
+
 
     private JTabbedPane serversPane;
 
     private final ArrayList<ServerTab> serverTabs = new ArrayList<>();
 
-    //TODO: Update target server list with the list of servers when adding or removing a server.
-
     /**
      * Create the application window.
      */
@@ -66,6 +67,36 @@ public class GUI implements ActionListener {
         initialize();
         loadMessages();
         gui = this;
+        this.globalPlayers = new ArrayList<>();
+    }
+
+    public void addPlayer(String name) {
+        this.globalPlayers.add(name);
+        this.updatePlayers();
+    }
+
+    public void removePlayer(String name) {
+        for (int i = 0; i < this.globalPlayers.size(); i++) {
+            if (this.globalPlayers.get(i).equals(name)) {
+                this.globalPlayers.remove(i);
+            }
+        }
+        this.updatePlayers();
+    }
+
+    private void updatePlayers() {
+        String selectedServerValue;
+        Object selectedServer = targetServer.getSelectedItem();
+        if (selectedServer != null) {
+            targetPlayer.removeAllItems();
+            selectedServerValue = selectedServer.toString();
+            if (selectedServerValue.equals("All")) {
+                for (String player : this.globalPlayers) targetPlayer.addItem(player);
+            } else {
+                for (String player : this.currentProfile().getCollection(selectedServerValue).getServer().getPlayers())
+                    targetPlayer.addItem(player);
+            }
+        }
     }
 
     public void setStatus(String text) {
@@ -112,7 +143,6 @@ public class GUI implements ActionListener {
                 i = this.serverTabs.size();
             }
         }
-
     }
 
     private void initialize() {
@@ -274,11 +304,11 @@ public class GUI implements ActionListener {
         SpringLayout sl_panel_1 = new SpringLayout();
         controlServers.setLayout(sl_panel_1);
 
-        targetServer = new JComboBox();
+        targetServer = new JComboBox<>();
         sl_panel_1.putConstraint(SpringLayout.NORTH, targetServer, 10, SpringLayout.NORTH, controlServers);
         controlServers.add(targetServer);
 
-        targetPlayer = new JComboBox();
+        targetPlayer = new JComboBox<>();
         sl_panel_1.putConstraint(SpringLayout.NORTH, targetPlayer, 6, SpringLayout.SOUTH, targetServer);
         targetPlayer.setEditable(true);
         controlServers.add(targetPlayer);
@@ -334,6 +364,7 @@ public class GUI implements ActionListener {
         sl_panel_1.putConstraint(SpringLayout.EAST, btnCustomCommand, 0, SpringLayout.EAST, btnOp);
         controlServers.add(btnCustomCommand);
         btnCustomCommand.addActionListener(this);
+        frame.getRootPane().setDefaultButton(btnCustomCommand);
 
         customCommand = new JTextField();
         sl_panel_1.putConstraint(SpringLayout.WEST, customCommand, 10, SpringLayout.WEST, controlServers);
@@ -391,6 +422,14 @@ public class GUI implements ActionListener {
         serverTabs.add(serverTab);
     }
 
+    public void updateSelectServers() {
+        this.targetServer.removeAllItems();
+        this.targetServer.addItem("All");
+        for (Collection collection : currentProfile().getCollections()) {
+            this.targetServer.addItem(collection.getName());
+        }
+    }
+
     @Override
     public void actionPerformed(ActionEvent e) {
         String selectedServerValue = null, selectedPlayerValue = null;
@@ -459,7 +498,8 @@ public class GUI implements ActionListener {
             }
         } else if (e.getSource() == btnCustomCommand) {
             if (selectedServerValue != null) {
-                currentProfile().sendCommand(selectedServerValue, customCommand.getSelectedText());
+                currentProfile().sendCommand(selectedServerValue, customCommand.getText());
+                customCommand.setText("");
             }
         } else if (e.getSource() == btnSaveserver) {
             if (selectedServerValue != null) {