Introduces toggle effect & expression

src/main/java/ch/njol/skript/classes/Changer.java

@@ -37,7 +37,7 @@
 public interface Changer<T> {
 
 	public static enum ChangeMode {
-		ADD, SET, REMOVE, REMOVE_ALL, DELETE, RESET;
+		ADD, SET, REMOVE, REMOVE_ALL, DELETE, RESET, TOGGLE;
 	}
 
 	/**

src/main/java/ch/njol/skript/classes/data/DefaultChangers.java

@@ -60,12 +60,9 @@ public Class<? extends Object>[] acceptChange(final ChangeMode mode) {
 					return CollectionUtils.array(PotionEffectType[].class, ItemType[].class, Inventory.class);
 				case REMOVE_ALL:
 					return CollectionUtils.array(PotionEffectType[].class, ItemType[].class);
-				case SET:
-				case RESET: // REMIND reset entity? (unshear, remove held item, reset weapon/armour, ...)
+				default: // REMIND reset entity? (unshear, remove held item, reset weapon/armour, ...)
 					return null;
 			}
-			assert false;
-			return null;
 		}
 
 		@Override
@@ -268,7 +265,7 @@ public void change(final Inventory[] invis, final @Nullable Object[] delta, fina
 							}
 						}
 						break;
-					case RESET:
+					default:
 						assert false;
 				}
 				InventoryHolder holder = invi.getHolder();
@@ -343,7 +340,7 @@ public void change(final Block[] blocks, final @Nullable Object[] delta, final C
 						}
 						state.update();
 						break;
-					case RESET:
+					default:
 						assert false;
 				}
 			}

src/main/java/ch/njol/skript/effects/EffChange.java

@@ -19,6 +19,7 @@
 package ch.njol.skript.effects;
 
 import java.util.Arrays;
+import java.util.List;
 import java.util.logging.Level;
 
 import org.bukkit.event.Event;
@@ -73,7 +74,10 @@
 		"delete {variable}",
 		"# reset:",
 		"reset walk speed of player",
-		"reset chunk at the targeted block"})
+		"reset chunk at the targeted block",
+		"# toggle:",
+		"toggle player's flight mode",
+		"toggle player's gravity"})
 @Since("1.0 (set, add, remove, delete), 2.0 (remove all)")
 public class EffChange extends Effect {
 	private static Patterns<ChangeMode> patterns = new Patterns<>(new Object[][] {
@@ -90,7 +94,9 @@ public class EffChange extends Effect {
 
 			{"(delete|clear) %~objects%", ChangeMode.DELETE},
 
-			{"reset %~objects%", ChangeMode.RESET}
+			{"reset %~objects%", ChangeMode.RESET},
+
+			{"toggle %~objects%", ChangeMode.TOGGLE}
 	});
 
 	static {
@@ -146,6 +152,10 @@ public boolean init(final Expression<?>[] exprs, final int matchedPattern, final
 				break;
 			case RESET:
 				changed = exprs[0];
+				break;
+			case TOGGLE:
+				changed = exprs[0];
+				break;
 		}
 
 		CountingLogHandler h = new CountingLogHandler(Level.SEVERE).start();
@@ -187,6 +197,9 @@ public boolean init(final Expression<?>[] exprs, final int matchedPattern, final
 						Skript.error(what + " can't be reset. It can however be deleted which might result in the desired effect.", ErrorQuality.SEMANTIC_ERROR);
 					else
 						Skript.error(what + " can't be reset", ErrorQuality.SEMANTIC_ERROR);
+					break;
+				case TOGGLE:
+					Skript.error(what + " can't be toggled", ErrorQuality.SEMANTIC_ERROR);
 			}
 			return false;
 		}
@@ -272,9 +285,9 @@ else if (mode == ChangeMode.SET)
 	protected void execute(Event e) {
 		Expression<?> changer = this.changer;
 		Object[] delta = changer == null ? null : changer.getArray(e);
+		List<ChangeMode> modes = List.of(ChangeMode.DELETE, ChangeMode.RESET, ChangeMode.TOGGLE);
 		delta = changer == null ? delta : changer.beforeChange(changed, delta);
-
-		if ((delta == null || delta.length == 0) && (mode != ChangeMode.DELETE && mode != ChangeMode.RESET)) {
+		if ((delta == null || delta.length == 0) && (!modes.contains(mode))) {
 			if (changed.acceptChange(ChangeMode.DELETE) != null)
 				changed.change(e, null, ChangeMode.DELETE);
 			return;
@@ -302,6 +315,8 @@ public String toString(final @Nullable Event e, final boolean debug) {
 				return "delete/clear " + changed.toString(e, debug);
 			case RESET:
 				return "reset " + changed.toString(e, debug);
+			case TOGGLE:
+				return "toggle " + changed.toString(e, debug);
 		}
 		assert false;
 		return "";

src/main/java/ch/njol/skript/expressions/ExprAI.java

@@ -33,7 +33,7 @@
 @Name("Entity AI")
 @Description("Returns whether an entity has AI.")
 @Examples("set artificial intelligence of target entity to false")
-@Since("2.5")
+@Since("2.5, INSERT VERSION (toggle support)")
 public class ExprAI extends SimplePropertyExpression<LivingEntity, Boolean> {
 
 	static {
@@ -49,12 +49,23 @@ public Boolean convert(LivingEntity entity) {
 	@Nullable
 	@Override
 	public Class<?>[] acceptChange(Changer.ChangeMode mode) {
-		return mode == Changer.ChangeMode.SET ? CollectionUtils.array(Boolean.class) : null;
+		switch (mode) {
+			case SET:
+			case TOGGLE:
+				return CollectionUtils.array(Boolean.class);
+			default:
+				return null;
+		}
 	}
 
 	@Override
 	public void change(Event event, @Nullable Object[] delta, Changer.ChangeMode mode) {
 		if (delta == null || delta[0] == null) {
+			if (mode == Changer.ChangeMode.TOGGLE) {
+				for (LivingEntity entity : getExpr().getArray(event)) {
+					entity.setAI(!entity.hasAI());
+				}
+			}
 			return;
 		}
 		boolean value = (Boolean) delta[0];

src/main/java/ch/njol/skript/expressions/ExprEventCancelled.java

@@ -82,12 +82,11 @@ public Class<?>[] acceptChange(final ChangeMode mode) {
 			Skript.error("Can't cancel the event anymore after it has already passed");
 			return null;
 		}
-		if (mode == ChangeMode.SET || mode == ChangeMode.DELETE)
+		if (mode == ChangeMode.SET || mode == ChangeMode.DELETE | mode == ChangeMode.TOGGLE)
 			return CollectionUtils.array(Boolean.class);
 		return null;
 	}
 
-	@SuppressWarnings("incomplete-switch")
 	@Override
 	public void change(final Event e, final @Nullable Object[] delta, final ChangeMode mode) {
 		if (!(e instanceof Cancellable))
@@ -99,6 +98,11 @@ public void change(final Event e, final @Nullable Object[] delta, final ChangeMo
 			case SET:
 				assert delta != null;
 				((Cancellable) e).setCancelled((Boolean) delta[0]);
+				break;
+			case TOGGLE:
+				Cancellable cancellable = (Cancellable) e;
+				cancellable.setCancelled(!cancellable.isCancelled());
+				break;
 		}
 	}
 

src/main/java/ch/njol/skript/expressions/ExprFlightMode.java

@@ -18,21 +18,22 @@
  */
 package ch.njol.skript.expressions;
 
+import org.bukkit.entity.Player;
+import org.bukkit.event.Event;
+import org.eclipse.jdt.annotation.Nullable;
+
 import ch.njol.skript.classes.Changer;
 import ch.njol.skript.doc.Description;
 import ch.njol.skript.doc.Examples;
 import ch.njol.skript.doc.Name;
 import ch.njol.skript.doc.Since;
 import ch.njol.skript.expressions.base.SimplePropertyExpression;
 import ch.njol.util.coll.CollectionUtils;
-import org.bukkit.entity.Player;
-import org.bukkit.event.Event;
-import org.eclipse.jdt.annotation.Nullable;
 
 @Name("Flight Mode")
 @Description("Whether the player(s) are allowed to fly. Use <a href=effects.html#EffMakeFly>Make Fly</a> effect to force player(s) to fly.")
 @Examples({"set flight mode of player to true", "send \"%flying state of all players%\""})
-@Since("2.2-dev34")
+@Since("2.2-dev34, INSERT VERSION (toggle support)")
 public class ExprFlightMode extends SimplePropertyExpression<Player, Boolean> {
 
 	static {
@@ -47,7 +48,7 @@ public Boolean convert(final Player player) {
 	@Override
 	@Nullable
 	public Class<?>[] acceptChange(Changer.ChangeMode mode) {
-		if (mode == Changer.ChangeMode.SET || mode == Changer.ChangeMode.RESET) {
+		if (mode == Changer.ChangeMode.SET || mode == Changer.ChangeMode.RESET || mode == Changer.ChangeMode.TOGGLE) {
 			return CollectionUtils.array(Boolean.class);
 		}
 		return null;
@@ -57,7 +58,11 @@ public Class<?>[] acceptChange(Changer.ChangeMode mode) {
 	public void change(Event event, @Nullable Object[] delta, Changer.ChangeMode mode) {
 		boolean state = mode != Changer.ChangeMode.RESET && delta != null && (boolean) delta[0];
 		for (Player player : getExpr().getArray(event)) {
-			player.setAllowFlight(state);
+			if (mode == Changer.ChangeMode.TOGGLE) {
+				player.setAllowFlight(!player.getAllowFlight());
+			} else {
+				player.setAllowFlight(state);
+			}
 		}
 	}
 

src/main/java/ch/njol/skript/expressions/ExprGlidingState.java

@@ -33,7 +33,7 @@
 @Name("Gliding State")
 @Description("Sets of gets gliding state of player. It allows you to set gliding state of entity even if they do not have an <a href=\"https://minecraft.gamepedia.com/Elytra\">Elytra</a> equipped.")
 @Examples({"set gliding of player to off"})
-@Since("2.2-dev21")
+@Since("2.2-dev21, INSERT VERSION (toggle support)")
 public class ExprGlidingState extends SimplePropertyExpression<LivingEntity, Boolean> {
 
 	static {
@@ -59,14 +59,19 @@ public Class<Boolean> getReturnType() {
 	@Override
 	@Nullable
 	public Class<?>[] acceptChange(final ChangeMode mode) {
-		if (mode == ChangeMode.SET || mode == ChangeMode.RESET)
+		if (mode == ChangeMode.SET || mode == ChangeMode.RESET || mode == ChangeMode.TOGGLE)
 			return new Class[] {Boolean.class};
 		return null;
 	}
 
 	@Override
 	public void change(final Event e, final @Nullable Object[] delta, final ChangeMode mode) throws UnsupportedOperationException {
-		for (final LivingEntity entity : getExpr().getArray(e))
-			entity.setGliding(delta == null ? false : (Boolean) delta[0]);
+		for (final LivingEntity entity : getExpr().getArray(e)) {
+			if (mode == ChangeMode.TOGGLE) {
+				entity.setGliding(!entity.isGliding());
+			} else {
+				entity.setGliding(delta == null ? false : (Boolean) delta[0]);
+			}
+		}
 	}
 }

src/main/java/ch/njol/skript/expressions/ExprGlowing.java

@@ -32,7 +32,7 @@
 @Name("Glowing")
 @Description("Indicates if targeted entity is glowing (new 1.9 effect) or not. Glowing entities can be seen through walls.")
 @Examples({"set glowing of player to true"})
-@Since("2.2-dev18")
+@Since("2.2-dev18, INSERT VERSION (toggle support)")
 public class ExprGlowing extends SimplePropertyExpression<Entity, Boolean> {
 
 	static {
@@ -64,7 +64,12 @@ public Class<?>[] acceptChange(final ChangeMode mode) {
 
 	@Override
 	public void change(final Event e, final @Nullable Object[] delta, final ChangeMode mode) throws UnsupportedOperationException {
-		for (final Entity entity : getExpr().getArray(e))
-			entity.setGlowing(delta == null ? false : (Boolean) delta[0]);
+		for (final Entity entity : getExpr().getArray(e)) {
+			if (mode == ChangeMode.TOGGLE) {
+				entity.setGlowing(!entity.isGlowing());
+			} else {
+				entity.setGlowing(delta == null ? false : (Boolean) delta[0]);
+			}
+		}
 	}
 }

src/main/java/ch/njol/skript/expressions/ExprGravity.java

@@ -33,7 +33,7 @@
 @Name("Gravity")
 @Description("If entity is affected by gravity or not, i.e. if it has Minecraft 1.10+ NoGravity flag.")
 @Examples({"set gravity of player off"})
-@Since("2.2-dev21")
+@Since("2.2-dev21, INSERT VERSION (toggle support)")
 public class ExprGravity extends SimplePropertyExpression<Entity, Boolean> {
 
 	static {
@@ -59,14 +59,20 @@ public Class<Boolean> getReturnType() {
 	@Override
 	@Nullable
 	public Class<?>[] acceptChange(final ChangeMode mode) {
-		if (mode == ChangeMode.SET || mode == ChangeMode.RESET)
+		if (mode == ChangeMode.SET || mode == ChangeMode.RESET || mode == ChangeMode.TOGGLE)
 			return new Class[] {Boolean.class};
 		return null;
 	}
 
 	@Override
 	public void change(final Event e, final @Nullable Object[] delta, final ChangeMode mode) throws UnsupportedOperationException {
-		for (final Entity entity : getExpr().getArray(e))
-			entity.setGravity(delta == null ? true : (Boolean) delta[0]);
+		for (final Entity entity : getExpr().getArray(e)) {
+			if (mode == ChangeMode.TOGGLE) {
+				entity.setGravity(!entity.hasGravity());
+			} else {
+				entity.setGravity(delta == null ? true : (Boolean) delta[0]);
+			}
+		}
+
 	}
 }

src/main/java/ch/njol/skript/expressions/ExprRelationalVariable.java

@@ -135,7 +135,7 @@ public T[] get(Event e) {
 	@Override
 	@Nullable
 	public Class<?>[] acceptChange(ChangeMode mode) {
-		if (mode == ChangeMode.RESET)
+		if (mode == ChangeMode.RESET || mode == ChangeMode.TOGGLE)
 			return null;
 		for (Expression<?> expr : variables.getExpressions()) {
 			if (!((Variable<?>) expr).isList()) { // It's a single variable

src/main/java/ch/njol/skript/expressions/ExprSaturation.java

@@ -40,7 +40,7 @@
 @Name("Saturation")
 @Description("The saturation of a player. If used in a player event, it can be omitted and will default to event-player.")
 @Examples("set saturation of player to 20")
-@Since("2.2-Fixes-v10, 2.2-dev35 (fully modifiable)")
+@Since("2.2-Fixes-v10, 2.2-dev35 (fully modifiable), INSERT VERSION (toggle support)")
 public class ExprSaturation extends PropertyExpression<Player, Number> {
 
 	static {
@@ -98,6 +98,10 @@ public void change(Event e, @Nullable Object[] delta, Changer.ChangeMode mode) {
 				for (Player player : getExpr().getArray(e))
 					player.setSaturation(0);
 				break;
+			case TOGGLE:
+				for (Player player : getExpr().getArray(e))
+					player.setSaturation(player.getSaturation() == 100 ? 0 : 100);
+				break;
 		}
 	}
 

src/main/java/ch/njol/skript/expressions/ExprWhitelist.java

@@ -45,7 +45,7 @@
 @Examples({"set whitelist to false",
 	"add all players to whitelist",
 	"reset the whitelist"})
-@Since("2.5.2")
+@Since("2.5.2, INSERT VERSION (toggle support)")
 public class ExprWhitelist extends SimpleExpression<OfflinePlayer> {
 
 	static {
@@ -68,35 +68,37 @@ protected OfflinePlayer[] get(Event e) {
 	public Class<?>[] acceptChange(ChangeMode mode) {
 		if (mode == ChangeMode.ADD || mode == ChangeMode.REMOVE)
 			return CollectionUtils.array(OfflinePlayer[].class);
-		else if (mode == ChangeMode.SET || mode == ChangeMode.RESET)
+		else if (mode == ChangeMode.SET || mode == ChangeMode.RESET || mode == ChangeMode.TOGGLE)
 			return CollectionUtils.array(Boolean.class);
 		else
 			return null;
 	}
 
 	@Override
 	public void change(Event e, @Nullable Object[] delta, ChangeMode mode) {
+		if (delta == null) return;
 		switch (mode) {
 			case SET:
-				if (delta != null)
-					Bukkit.setWhitelist((Boolean) delta[0]);
+				Bukkit.setWhitelist((Boolean) delta[0]);
 				break;
 			case ADD:
-				if (delta != null) {
-					for (Object p : delta)
-						((OfflinePlayer) p).setWhitelisted(true);
-				}
+				for (Object p : delta)
+					((OfflinePlayer) p).setWhitelisted(true);
 				break;
 			case REMOVE:
-				if (delta != null) {
-					for (Object p : delta)
-						((OfflinePlayer) p).setWhitelisted(false);
-				}
+				for (Object p : delta)
+					((OfflinePlayer) p).setWhitelisted(false);
 				break;
 			case RESET:
 				for (OfflinePlayer p : Bukkit.getWhitelistedPlayers())
 					p.setWhitelisted(false);
 				break;
+			case TOGGLE:
+				for (Object p : delta) {
+					OfflinePlayer player = (OfflinePlayer) p;
+					player.setWhitelisted(!player.isWhitelisted());
+				}
+				break;
 			default:
 				assert false;
 		}