Feature/players listed

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

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+package ch.njol.skript.expressions;
+
+import java.util.Arrays;
+
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.event.Event;
+import org.jetbrains.annotations.Nullable;
+
+import ch.njol.skript.Skript;
+import ch.njol.skript.classes.Changer.ChangeMode;
+import ch.njol.skript.doc.Description;
+import ch.njol.skript.doc.Examples;
+import ch.njol.skript.doc.Keywords;
+import ch.njol.skript.doc.Name;
+import ch.njol.skript.doc.RequiredPlugins;
+import ch.njol.skript.doc.Since;
+import ch.njol.skript.expressions.base.PropertyExpression;
+import ch.njol.skript.lang.Expression;
+import ch.njol.skript.lang.SkriptParser.ParseResult;
+import ch.njol.util.Kleenean;
+import ch.njol.util.coll.CollectionUtils;
+
+@Name("Tablisted Players")
+@Description({
+	"The displayed players in the tablist for selected players.",
+	"Delete changer will remove all the online players.",
+	"Reset changer will reset the tablist to a default state viewing all the players again."
+})
+@Examples("tablist players of player")
+@RequiredPlugins("Paper 1.20.1+")
+@Since("INSERT VERSION")
+@Keywords("tablist")
+public class ExprListedPlayers extends PropertyExpression<Player, Player> {
+
+	static {
+		if (Skript.methodExists(Player.class, "isListed", Player.class)) {
+			registerDefault(ExprListedPlayers.class, Player.class, "[the] (tablist[ed]|listed) players", "players");
+		}
+	}
+
+	@Override
+	@SuppressWarnings("unchecked")
+	public boolean init(Expression<?>[] expressions, int matchedPattern, Kleenean isDelayed, ParseResult parseResult) {
+		setExpr((Expression<Player>) expressions[0]);
+		return true;
+	}
+
+	@Override
+	protected Player[] get(Event event, Player[] source) {
+		return Arrays.stream(source)
+				.flatMap(viewer -> Bukkit.getOnlinePlayers().stream().filter(viewer::isListed))
+				.toArray(Player[]::new);
+	}
+
+	@Override
+	public Class<?>[] acceptChange(ChangeMode mode) {
+		return CollectionUtils.array(Player[].class);
+	}
+
+	@Override
+	public void change(Event event, Object @Nullable [] delta, ChangeMode mode) {
+		Player[] recipients = (Player[]) delta;
+		Player[] viewers = getExpr().getArray(event);
+		switch (mode) {
+			case DELETE:
+				recipients = Bukkit.getOnlinePlayers().toArray(Player[]::new);
+				// $fallthrough
+			case REMOVE:
+				for (Player viewer : viewers) {
+					for (Player player : recipients) {
+						viewer.unlistPlayer(player);
+					}
+				}
+				break;
+			case SET:
+				for (Player viewer : viewers) {
+					for (Player player : Bukkit.getOnlinePlayers()) {
+						if (Arrays.stream(recipients).noneMatch(recipient -> recipient.equals(player))) {
+							// If the player is not in the recipients, unlist them
+							viewer.unlistPlayer(player);
+						}
+					}
+				}
+				// $fallthrough
+			case ADD:
+				assert recipients != null;
+				for (Player viewer : viewers) {
+					for (Player player : recipients) {
+						if (viewer.canSee(player)) {
+							viewer.listPlayer(player);
+						}
+					}
+				}
+				break;
+			case RESET:
+				for (Player viewer : viewers) {
+					for (Player player : Bukkit.getOnlinePlayers()) {
+						if (!viewer.isListed(player) && viewer.canSee(player)) {
+							viewer.listPlayer(player);
+						}
+					}
+				}
+				break;
+			default:
+				break;
+		}
+	}
+
+	@Override
+	public boolean isSingle() {
+		return false;
+	}
+
+	@Override
+	public Class<? extends Player> getReturnType() {
+		return Player.class;
+	}
+
+	@Override
+	public String toString(@Nullable Event event, boolean debug) {
+		return "tablisted players of " + getExpr().toString(event, debug);
+	}
+
+}