Prompt when passing priority if mana in your mana pool would be lost

forge-game/src/main/java/forge/game/mana/ManaPool.java

@@ -92,6 +92,28 @@ public class ManaPool implements Iterable<Mana> {
         }
     }
 
+    /**
+     * <p>
+     * willManaBeLostAtEndOfPhase.
+     * 
+     * @return - whether floating mana will be lost if the current phase ended right now
+     * </p>
+     */
+    public final boolean willManaBeLostAtEndOfPhase() {
+        if (floatingMana.isEmpty() ||
+                owner.getGame().getStaticEffects().getGlobalRuleChange(GlobalRuleChange.manapoolsDontEmpty) ||
+                owner.hasKeyword("Convert unused mana to Colorless")) {
+            return false;
+        }
+
+        if (owner.hasKeyword("Green mana doesn't empty from your mana pool as steps and phases end.") &&
+                getAmountOfColor(MagicColor.GREEN) == totalMana()) {
+            return false; //won't lose floating mana if all mana is green and green mana isn't going to be emptied
+        }
+
+        return true;
+    }
+
     /**
      * <p>
      * clearPool.
@@ -101,14 +123,14 @@ public class ManaPool implements Iterable<Mana> {
      */
     public final int clearPool(boolean isEndOfPhase) {
         // isEndOfPhase parameter: true = end of phase, false = mana drain effect
-        if (this.floatingMana.isEmpty()) { return 0; }
+        if (floatingMana.isEmpty()) { return 0; }
 
         if (isEndOfPhase && owner.getGame().getStaticEffects().getGlobalRuleChange(GlobalRuleChange.manapoolsDontEmpty)) {
             return 0;
         }
 
         int numRemoved = 0;
-        boolean keepGreenMana = isEndOfPhase && this.owner.hasKeyword("Green mana doesn't empty from your mana pool as steps and phases end.");
+        boolean keepGreenMana = isEndOfPhase && owner.hasKeyword("Green mana doesn't empty from your mana pool as steps and phases end.");
         boolean convertToColorless = owner.hasKeyword("Convert unused mana to Colorless");
 
         List<Byte> keys = Lists.newArrayList(floatingMana.keySet());
@@ -122,7 +144,7 @@ public class ManaPool implements Iterable<Mana> {
         for (Byte b : keys) {
             if (isEndOfPhase && !owner.getGame().getPhaseHandler().is(PhaseType.CLEANUP)) {
                 final List<Mana> pMana = new ArrayList<Mana>();
-                for (final Mana mana : this.floatingMana.get(b)) {
+                for (final Mana mana : floatingMana.get(b)) {
                     if (mana.getManaAbility()!= null && mana.getManaAbility().isPersistentMana()) {
                         pMana.add(mana);
                     }

forge-gui/src/main/java/forge/match/input/InputPassPriority.java

@@ -17,12 +17,18 @@
  */
 package forge.match.input;
 
+import forge.GuiBase;
+import forge.game.Game;
 import forge.game.card.Card;
 import forge.game.phase.PhaseType;
 import forge.game.player.Player;
 import forge.game.spellability.SpellAbility;
 import forge.match.MatchUtil;
+import forge.model.FModel;
+import forge.properties.ForgePreferences.FPref;
 import forge.util.ITriggerEvent;
+import forge.util.ThreadUtil;
+import forge.util.gui.SOptionPane;
 
 import java.util.List;
 
@@ -61,7 +67,12 @@ public class InputPassPriority extends InputSyncronizedBase {
     /** {@inheritDoc} */
     @Override
     protected final void onOk() {
-        stop();
+        passPriority(new Runnable() {
+            @Override
+            public void run() {
+                stop();
+            }
+        });
     }
 
     /** {@inheritDoc} */
@@ -69,11 +80,38 @@ public class InputPassPriority extends InputSyncronizedBase {
     protected final void onCancel() {
         if (!MatchUtil.undoLastAction()) { //undo if possible
             //otherwise end turn
-            player.getController().autoPassUntil(PhaseType.CLEANUP);
-            stop();
+            passPriority(new Runnable() {
+                @Override
+                public void run() {
+                    player.getController().autoPassUntil(PhaseType.CLEANUP);
+                    stop();
+                }
+            });
         }
     }
 
+    private void passPriority(final Runnable runnable) {
+        //if gui player has mana floating that will be lost if phase ended right now, prompt before passing priority
+        Game game = GuiBase.getInterface().getGame();
+        Player player = game.getPhaseHandler().getPriorityPlayer();
+        if (player != null && player.getManaPool().willManaBeLostAtEndOfPhase() && player.getLobbyPlayer() == GuiBase.getInterface().getGuiPlayer()) {
+            ThreadUtil.invokeInGameThread(new Runnable() { //must invoke in game thread so dialog can be shown on mobile game
+                @Override
+                public void run() {
+                    String message = "You have mana floating in your mana pool that will be lost if you pass priority now.";
+                    if (FModel.getPreferences().getPrefBoolean(FPref.UI_MANABURN)) {
+                        message += " You will take mana burn damage equal to the amount of floating mana.";
+                    }
+                    if (SOptionPane.showOptionDialog(message, "Mana Floating", SOptionPane.WARNING_ICON, new String[]{"OK", "Cancel"}) == 0) {
+                        runnable.run();
+                    }
+                }
+            });
+            return;
+        }
+        runnable.run(); //just pass priority immediately if no mana floating that would be lost
+    }
+
     public SpellAbility getChosenSa() { return chosenSa; }
 
     @Override