feat: event-hand

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

@@ -0,0 +1,112 @@
+package ch.njol.skript.expressions;
+
+import ch.njol.skript.Skript;
+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.lang.Expression;
+import ch.njol.skript.lang.ExpressionType;
+import ch.njol.skript.lang.SkriptParser;
+import ch.njol.skript.lang.util.SimpleExpression;
+import ch.njol.skript.registrations.Classes;
+import ch.njol.skript.util.slot.EquipmentSlot;
+import ch.njol.util.Kleenean;
+import java.lang.reflect.Method;
+import java.util.WeakHashMap;
+import org.bukkit.entity.LivingEntity;
+import org.bukkit.event.Event;
+import org.bukkit.event.entity.EntityEvent;
+import org.bukkit.event.player.PlayerEvent;
+import org.jetbrains.annotations.Nullable;
+
+@Name("Hand")
+@Description({"Returns which hand player uses in some InteractEvents"})
+@Examples({
+	"on click:",
+	"    send \"%event-hand%\" to event-player",
+	"    if event-hand is off hand",
+	"        send \"It is off hand\" to event-player"
+})
+@Since("INSERT VERSION")
+public class ExprEvtHand extends SimpleExpression<EquipmentSlot> {
+	private static final WeakHashMap<Class<? extends Event>, Method> GET_HAND_METHODS = new WeakHashMap<>();
+
+	static {
+		Skript.registerExpression(ExprEvtHand.class, EquipmentSlot.class, ExpressionType.SIMPLE, "[event( |-)]hand");
+	}
+
+	@Override
+	public String toString(@Nullable Event e, boolean debug) {
+		if (e == null)
+			return "the hand";
+		return Classes.getDebugMessage(getSingle(e));
+	}
+
+	@Override
+	public boolean isSingle() {
+		return true;
+	}
+
+	@Override
+	public Class<? extends EquipmentSlot> getReturnType() {
+		return EquipmentSlot.class;
+	}
+
+	@Override
+	public boolean init(Expression<?>[] expressions, int matchedPattern, Kleenean isDelayed, SkriptParser.ParseResult parseResult) {
+		if (getParser().getCurrentEvents() == null) {
+			Skript.error("There is no 'event-hand' without a event");
+			return false;
+		}
+		for (Class<? extends Event> currentEvent : getParser().getCurrentEvents()) {
+			if (Skript.methodExists(currentEvent, "getHand")) {
+				try {
+					GET_HAND_METHODS.put(currentEvent, currentEvent.getDeclaredMethod("getHand"));  //Cache it when init
+					return true;
+				} catch (NoSuchMethodException ignored) {
+				}
+			}
+		}
+		Skript.error("There is no 'event-hand' in this event: " + getParser().getCurrentEventName());
+		return false;
+	}
+
+	@Override
+	protected @Nullable EquipmentSlot[] get(Event event) {
+		Method getHandMethod = GET_HAND_METHODS.get(event.getClass());
+		if (getHandMethod == null) {
+			try {
+				getHandMethod = event.getClass().getDeclaredMethod("getHand");
+				GET_HAND_METHODS.put(event.getClass(), getHandMethod);
+			} catch (NoSuchMethodException ignored) {
+				return null;  //If it is not cached, and cannot get the method, stop trigger
+			}
+		}
+
+
+		LivingEntity entity = null;
+		if (event instanceof EntityEvent) {
+			if (((EntityEvent) event).getEntity() instanceof LivingEntity) {
+				entity = (LivingEntity) ((EntityEvent) event).getEntity();
+			}
+		} else if (event instanceof PlayerEvent) {
+			entity = ((PlayerEvent) event).getPlayer();
+		}
+		if (entity == null || entity.getEquipment() == null) return null;
+
+
+		try {
+			org.bukkit.inventory.EquipmentSlot bkEquip = (org.bukkit.inventory.EquipmentSlot) getHandMethod.invoke(event);
+			return new EquipmentSlot[]{
+				new EquipmentSlot(entity.getEquipment(),
+					bkEquip == org.bukkit.inventory.EquipmentSlot.HAND
+						? EquipmentSlot.EquipSlot.TOOL
+						: EquipmentSlot.EquipSlot.OFF_HAND
+				)
+			};
+		} catch (ReflectiveOperationException ignored) {
+			return null;
+		}
+	}
+}