Fix fighter images not switching to jets on tech.

game-app/game-core/src/main/java/games/strategy/engine/data/GameDataEvent.java

@@ -1,12 +1,14 @@
 package games.strategy.engine.data;
 
 import games.strategy.engine.data.changefactory.ObjectPropertyChange;
+import games.strategy.triplea.Constants;
 import java.util.Optional;
 
 /** Enum that represents various possible game data change events. */
 public enum GameDataEvent {
   UNIT_MOVED,
-  GAME_STEP_CHANGED;
+  GAME_STEP_CHANGED,
+  TECH_ATTACHMENT_CHANGED;
 
   /**
    * Converts a 'Change' object to a 'GameDataEvent' object, returns empty if the change object does
@@ -16,6 +18,12 @@ static Optional<GameDataEvent> lookupEvent(final Change change) {
     if (hasMoveChange(change)) {
       return Optional.of(UNIT_MOVED);
     }
+    if (change instanceof ChangeAttachmentChange) {
+      ChangeAttachmentChange attachmentChange = (ChangeAttachmentChange) change;
+      if (attachmentChange.getAttachmentName().equals(Constants.TECH_ATTACHMENT_NAME)) {
+        return Optional.of(TECH_ATTACHMENT_CHANGED);
+      }
+    }
     return Optional.empty();
   }
 

game-app/game-core/src/main/java/games/strategy/triplea/image/UnitImageFactory.java

@@ -25,7 +25,9 @@
 import java.io.IOException;
 import java.net.URL;
 import java.nio.file.Files;
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import javax.imageio.ImageIO;
@@ -60,6 +62,7 @@ public class UnitImageFactory {
   private final Map<String, ImageIcon> icons = new HashMap<>();
   // Temporary colorized image files used for URLs for html views (e.g. unit stats table).
   private final Map<ImageKey, URL> colorizedTempFiles = new HashMap<>();
+  private final List<File> tempFiles = new ArrayList<>();
   // Scaling factor for unit images
   private final double scaleFactor;
   private final ResourceLoader resourceLoader;
@@ -76,6 +79,18 @@ public UnitImageFactory(
     this.mapData = mapData;
   }
 
+  public void clearCache() {
+    images.clear();
+    icons.clear();
+    deleteTempFiles();
+    colorizedTempFiles.clear();
+  }
+
+  public void deleteTempFiles() {
+    tempFiles.forEach(File::delete);
+    tempFiles.clear();
+  }
+
   @Value
   @Builder
   public static class ImageKey {
@@ -283,6 +298,7 @@ public Optional<URL> getPossiblyTransformedImageUrl(final ImageKey imageKey) {
                 File file = Files.createTempFile(key.getFullName(), ".png").toFile();
                 // Delete the file on exit.
                 file.deleteOnExit();
+                tempFiles.add(file);
                 ImageIO.write(bufferedImage, "PNG", file);
                 return file.toURI().toURL();
               } catch (IOException e) {

game-app/game-core/src/main/java/games/strategy/triplea/ui/TechResultsDisplay.java

@@ -69,25 +69,17 @@ class TechResultsDisplay extends JPanel {
     final JPanel dice = new JPanel();
     dice.setLayout(new BoxLayout(dice, BoxLayout.X_AXIS));
     final int remainder = msg.getRemainder();
+    final var diceFactory = uiContext.getDiceImageFactory();
     for (int i = 0; i < msg.getRolls().length; i++) {
       // add 1 since dice are 0 based
       final int roll = msg.getRolls()[i] + 1;
-      final JLabel die;
+      final Die.DieType dieType;
       if (remainder > 0) {
-        die =
-            new JLabel(
-                uiContext
-                    .getDiceImageFactory()
-                    .getDieIcon(roll, roll <= remainder ? Die.DieType.HIT : Die.DieType.MISS));
+        dieType = (roll <= remainder) ? Die.DieType.HIT : Die.DieType.MISS;
       } else {
-        die =
-            new JLabel(
-                uiContext
-                    .getDiceImageFactory()
-                    .getDieIcon(
-                        roll, roll == data.getDiceSides() ? Die.DieType.HIT : Die.DieType.MISS));
+        dieType = (roll == data.getDiceSides()) ? Die.DieType.HIT : Die.DieType.MISS;
       }
-      dice.add(die);
+      dice.add(new JLabel(diceFactory.getDieIcon(roll, dieType)));
       dice.add(Box.createHorizontalStrut(2));
       dice.setMaximumSize(new Dimension(200, (int) dice.getMaximumSize().getHeight()));
     }

game-app/game-core/src/main/java/games/strategy/triplea/ui/UiContext.java

@@ -179,6 +179,7 @@ public void shutDown() {
       }
       activeToDeactivate.clear();
       windowsToCloseOnShutdown.clear();
+      unitImageFactory.deleteTempFiles();
     }
     StackTraceReportModel.setCurrentMapName(null);
     resourceLoader.close();

game-app/game-headed/src/main/java/games/strategy/triplea/ui/TripleAFrame.java

@@ -441,10 +441,17 @@ protected void paintComponent(final Graphics g) {
     // force a data change event to update the UI for edit mode
     dataChangeListener.gameDataChanged(ChangeFactory.EMPTY_CHANGE);
     data.addDataChangeListener(dataChangeListener);
-    game.getData().addGameDataEventListener(GameDataEvent.GAME_STEP_CHANGED, this::updateStep);
+    data.addGameDataEventListener(GameDataEvent.GAME_STEP_CHANGED, this::updateStep);
+    // Clear cached unit images when getting standard tech like jet power.
+    data.addGameDataEventListener(
+        GameDataEvent.TECH_ATTACHMENT_CHANGED, this::clearCachedUnitImages);
     uiContext.addShutdownWindow(this);
   }
 
+  private void clearCachedUnitImages() {
+    uiContext.getUnitImageFactory().clearCache();
+  }
+
   /**
    * Constructs a new instance of a TripleAFrame, but executes required IO-Operations off the EDT.
    */