Allow pausing a Princess-only game

megamek/i18n/megamek/client/messages.properties

@@ -1972,6 +1972,10 @@ KeyBinds.cmdNames.undoSingleStep=Undo Single Step
 KeyBinds.cmdDesc.undoSingleStep=Undo single step in movement phase
 KeyBinds.cmdNames.extendTurnTimer=Activates Turn Timer Extension
 KeyBinds.cmdDesc.extendTurnTimer=When Turn Timer gets to 2 seconds left, reset timer.
+KeyBinds.cmdNames.pause=Pause the Game
+KeyBinds.cmdDesc.pause=Pauses the game. Works only when only Princess players with active units remain.
+KeyBinds.cmdNames.unpause=Unpause the Game
+KeyBinds.cmdDesc.unpause=Unpauses the game
 
 #Key Bindings Overlay
 KeyBindingsDisplay.fixedBinds=Toggle Unit Display and Minimap: Mouse Button 4\nZoom: Mouse Wheel\nTurn / Torso twist: Shift + Left-Click\nLine of Sight tool: Ctrl + Left-Click (two hexes)\nRuler tool: Alt + Left-Click (two hexes)

megamek/mmconf/defaultKeyBinds.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <KeyBindings xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:noNamespaceSchemaLocation="keyBindingSchema.xsd">
+             xsi:noNamespaceSchemaLocation="keyBindingSchema.xsd">
     <KeyBind>
         <command>scrollN</command> <!-- W -->
         <keyCode>87</keyCode>
@@ -78,6 +78,20 @@
         <isRepeatable>false</isRepeatable>
     </KeyBind>
 
+    <KeyBind>
+        <command>pause</command> <!-- Ctrl+Shift-P -->
+        <keyCode>80</keyCode>
+        <modifier>192</modifier>
+        <isRepeatable>false</isRepeatable>
+    </KeyBind>
+
+    <KeyBind>
+        <command>unpause</command> <!-- Ctrl+Alt-P -->
+        <keyCode>80</keyCode>
+        <modifier>640</modifier>
+        <isRepeatable>false</isRepeatable>
+    </KeyBind>
+
     <KeyBind>
         <command>nextWeapon</command> <!-- Down -->
         <keyCode>40</keyCode>

megamek/src/megamek/client/AbstractClient.java

@@ -235,6 +235,16 @@ public synchronized void sendDone(boolean done) {
         flushConn();
     }
 
+    public void sendPause() {
+        send(new Packet(PacketCommand.PAUSE));
+        flushConn();
+    }
+
+    public void sendUnpause() {
+        send(new Packet(PacketCommand.UNPAUSE));
+        flushConn();
+    }
+
     /**
      * Receives player information from the message packet.
      *

megamek/src/megamek/client/ui/swing/StatusBarPhaseDisplay.java

@@ -45,6 +45,7 @@
 import javax.swing.ToolTipManager;
 import javax.swing.border.EmptyBorder;
 
+import megamek.client.AbstractClient;
 import megamek.client.ui.GBC;
 import megamek.client.ui.Messages;
 import megamek.client.ui.swing.util.KeyBindReceiver;
@@ -157,8 +158,25 @@ public void actionPerformed(ActionEvent e) {
         KeyBindParser.addPreferenceChangeListener(this);
 
         MegaMekGUI.getKeyDispatcher().registerCommandAction(KeyCommandBind.EXTEND_TURN_TIMER, this, this::extendTimer);
+        MegaMekGUI.getKeyDispatcher().registerCommandAction(KeyCommandBind.PAUSE.cmd, this::pauseGameWhenOnlyBotUnitsRemain);
+        MegaMekGUI.getKeyDispatcher().registerCommandAction(KeyCommandBind.UNPAUSE.cmd,
+            () -> ((AbstractClient) clientgui.getClient()).sendUnpause());
     }
 
+    private void pauseGameWhenOnlyBotUnitsRemain() {
+        if (isIgnoringEvents() || !isVisible()) {
+            return;
+        }
+        IGame game = getClientgui().getClient().getGame();
+        List<Player> nonBots = game.getPlayersList().stream().filter(p -> !p.isBot()).toList();
+        boolean liveUnitsRemaining = nonBots.stream().anyMatch(p -> game.getEntitiesOwnedBy(p) > 0);
+        if (liveUnitsRemaining) {
+            clientgui.getClient().sendChat("Pausing the game only works when only bot units remain.");
+        } else {
+            clientgui.getClient().sendChat("Requesting game pause.");
+            ((AbstractClient) clientgui.getClient()).sendPause();
+        }
+    }
 
     /** Returns the list of buttons that should be displayed. */
     protected abstract List<MegaMekButton> getButtonList();

megamek/src/megamek/client/ui/swing/util/KeyCommandBind.java

@@ -90,6 +90,8 @@ public enum KeyCommandBind {
     TOGGLE_CONVERSIONMODE("toggleConversion", VK_M),
     PREV_MODE("prevMode", VK_KP_DOWN),
     NEXT_MODE("nextMode", VK_KP_UP),
+    PAUSE("pause", VK_P, CTRL_DOWN_MASK | SHIFT_DOWN_MASK),
+    UNPAUSE("unpause", VK_P, CTRL_DOWN_MASK | ALT_DOWN_MASK),
 
     // --------- The following binds are used by the CommonMenuBar:
     // Toggles isometric view on/off
@@ -218,4 +220,4 @@ public static String getDesc(KeyCommandBind k) {
         String key = getKeyText(k.key);
         return (mod.isEmpty() ? "" : mod + "+") + key;
     }
-}
+}

megamek/src/megamek/common/net/enums/PacketCommand.java

@@ -44,6 +44,10 @@ public enum PacketCommand {
     /** A packet setting a Client's ready status (S -> C) or updating the Server on the Client's status (C -> S). */
     PLAYER_READY,
 
+    /** A packet telling the server to pause / unpause packet handling (to interrupt a Princess-only game) */
+    PAUSE,
+    UNPAUSE,
+
     CHAT,
     ENTITY_ADD,
     ENTITY_REMOVE,

megamek/src/megamek/server/Server.java

@@ -209,6 +209,10 @@ public void run() {
     private static final String WARGAMES_RESPONSE = "Let's play global thermonuclear war.";
 
     private final ConnectionListener connectionListener = new ConnectionListener() {
+
+        private boolean isPaused = false;
+        private final List<ReceivedPacket> pausedWaitingList = new ArrayList<>();
+
         /**
          * Called when it is sensed that a connection has terminated.
          */
@@ -252,11 +256,34 @@ public void packetReceived(PacketReceivedEvent e) {
                     // Some packets should be handled immediately
                     handle(rp.getConnectionId(), rp.getPacket());
                     break;
-                default:
+                case PAUSE:
+                    if (!isPaused) {
+                        logger.info("Pause packet received - pausing packet handling");
+                        sendServerChat("Game is paused.");
+                    }
+                    isPaused = true;
+                    break;
+                case UNPAUSE:
+                    if (isPaused) {
+                        logger.info("Unpause packet received - resuming packet handling");
+                        sendServerChat("Game is resumed.");
+                    }
+                    isPaused = false;
                     synchronized (packetQueue) {
-                        packetQueue.add(rp);
+                        packetQueue.addAll(pausedWaitingList);
                         packetQueue.notifyAll();
                     }
+                    pausedWaitingList.clear();
+                    break;
+                default:
+                    if (isPaused) {
+                        pausedWaitingList.add(rp);
+                    } else {
+                        synchronized (packetQueue) {
+                            packetQueue.add(rp);
+                            packetQueue.notifyAll();
+                        }
+                    }
                     break;
             }
         }