Add support for thunderclap event to Java client

src/games/stendhal/client/events/GenericEvent.java

@@ -20,6 +20,7 @@
 
 import games.stendhal.client.entity.Entity;
 import games.stendhal.client.events.generic.SubEvent;
+import games.stendhal.client.events.generic.ThunderclapEvent;
 
 
 /**
@@ -31,7 +32,9 @@ public class GenericEvent extends Event<Entity> {
 
 	/** Registered sub-events. */
 	private static Map<String, Class<? extends SubEvent>> registry = new HashMap<String,
-			Class<? extends SubEvent>>();
+			Class<? extends SubEvent>>() {{
+		put("thunderclap", ThunderclapEvent.class);
+	}};
 
 
 	@Override

src/games/stendhal/client/events/generic/ThunderclapEvent.java

@@ -0,0 +1,121 @@
+/***************************************************************************
+ *                    Copyright © 2024 - Faiumoni e. V.                    *
+ ***************************************************************************
+ ***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+package games.stendhal.client.events.generic;
+
+import java.awt.AlphaComposite;
+import java.awt.Color;
+import java.awt.Composite;
+import java.awt.Graphics2D;
+import java.util.Timer;
+import java.util.TimerTask;
+
+import games.stendhal.client.ClientSingletonRepository;
+import games.stendhal.client.GameScreen;
+import games.stendhal.client.GameScreen.SceneCompleteRunnable;
+import games.stendhal.client.entity.Entity;
+import games.stendhal.client.sound.ConfiguredSounds;
+import games.stendhal.client.sprite.Sprite;
+import games.stendhal.client.sprite.SpriteStore;
+import games.stendhal.common.constants.SoundID;
+import games.stendhal.common.constants.SoundLayer;
+
+
+/**
+ * Creates a thunder and lightning effect.
+ */
+public class ThunderclapEvent extends SubEvent {
+
+	/** Thunder image. */
+	private static final Sprite image = SpriteStore.get().getSprite("data/maps/effect/lightning.png");
+
+	/** Determines if screen should flash white. */
+	private final boolean flash;
+	/** Determines if lightning bolt should be drawn. */
+	private final boolean lightning;
+	/** Time that event execution began. */
+	private long startTime;
+
+	/** Width of viewport for drawing flash. */
+	private int width;
+	/** Height of viewport for drawing flash. */
+	private int height;
+
+
+	/**
+	 * Creates a new thunderclap event.
+	 *
+	 * @param flags
+	 *   List of enabled flags.
+	 */
+	public ThunderclapEvent(final String[] flags) {
+		super(flags);
+		flash = !flagEnabled("no-flash");
+		lightning = !flagEnabled("no-lightning");
+		startTime = 0;
+
+		final GameScreen screen = GameScreen.get();
+		width = screen.getWidth();
+		height = screen.getHeight();
+	}
+
+	@Override
+	public void execute(final Entity entity) {
+		startTime = System.currentTimeMillis();
+		// thunder sound
+		ClientSingletonRepository.getSound().playLocalizedEffect(ConfiguredSounds.get(
+				SoundID.THUNDERCLAP), (int) entity.getX(), (int) entity.getY(), SoundLayer.FIGHTING_NOISE);
+		if (flash || lightning) {
+			final GameScreen viewport = GameScreen.get();
+			viewport.onSceneComplete = new SceneCompleteRunnable() {
+				@Override
+				public void run(final Graphics2D ctx, final int offsetX, final int offsetY) {
+					drawLightning(ctx, offsetX, offsetY);
+				}
+			};
+			new Timer().schedule(new TimerTask() {
+				@Override
+				public void run() {
+					viewport.onSceneComplete = null;
+				}
+			}, 300L);
+		}
+	}
+
+	/**
+	 * Draws a lightning effect on the viewport.
+	 *
+	 * @param ctx
+	 *   Viewport drawing canvas.
+	 * @param offsetX
+	 *   Canvas horizontal offset.
+	 * @param offsetY
+	 *   Canvas vertical offset.
+	 */
+	private void drawLightning(final Graphics2D ctx, final int offsetX, final int offsetY) {
+		final int timeDiff = (int) (System.currentTimeMillis() - startTime);
+		if (flash) {
+			final Composite savedComposite = ctx.getComposite();
+			if (timeDiff <= 100 || timeDiff > 200) {
+				ctx.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f));
+			} else {
+				ctx.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.75f));
+			}
+			ctx.setColor(Color.WHITE);
+			ctx.fillRect(offsetX, offsetY, width, height);
+			// restore composite info to make lightning opaque
+			ctx.setComposite(savedComposite);
+		}
+		if (lightning) {
+			image.draw(ctx, offsetX, offsetY);
+		}
+	}
+}

src/games/stendhal/client/sound/ConfiguredSounds.java

@@ -1,5 +1,5 @@
 /***************************************************************************
- *                     Copyright © 2020 - Arianne                          *
+ *                     Copyright © 2020-2024 - Arianne                     *
  ***************************************************************************
  ***************************************************************************
  *                                                                         *
@@ -26,6 +26,7 @@ public class ConfiguredSounds {
 		put(SoundID.COMMERCE, "coins-01");
 		put(SoundID.COMMERCE2, "cha-ching");
 		put(SoundID.HEAL, "heal-01");
+		put(SoundID.THUNDERCLAP, "event/thunderclap");
 	}};