All Zeros Sidebar in Paper 1.18.2 (1.8 Compatible)

SidebarPlugin.kt

package me.nathanfranke.sidebarplugin

import net.kyori.adventure.text.Component
import net.kyori.adventure.text.format.NamedTextColor
import net.kyori.adventure.text.serializer.legacy.LegacyComponentSerializer
import org.bukkit.ChatColor
import org.bukkit.entity.Player
import org.bukkit.event.EventHandler
import org.bukkit.event.Listener
import org.bukkit.event.player.PlayerJoinEvent
import org.bukkit.plugin.java.JavaPlugin
import org.bukkit.scoreboard.DisplaySlot
import org.bukkit.scoreboard.Objective

private val objectiveEntries = mutableMapOf<Objective, Set<String>>()

fun Player.updateSidebar(title: Component, items: List<Component>) {
	// Create the sidebar objective if it does not exist.
	val objective = scoreboard.getObjective(DisplaySlot.SIDEBAR) ?: run {
		scoreboard.registerNewObjective("@sidebar", "dummy", null).apply {
			displaySlot = DisplaySlot.SIDEBAR
		}
	}
	objective.displayName(title)

	// Prefix all scoreboard prefixes with this text to ensure they are ordered properly.
	val orderedLetters = ('a'..'z').toList()
	fun getOrderedPrefix(index: Int) = "\u00A7${orderedLetters[index]}\u00A7r"

	// Keep track of added objective scores, so they can be removed later.
	val entries = mutableSetOf<String>()

	for ((i, item) in items.withIndex()) {
		// Legacy players (pre-1.13) can only have 42 characters per line (14 prefix, 12 entry, 16 suffix).
		if (protocolVersion < 393) {
			val prefixLength = 14 // Maximum of 16, with 2 characters reserved for the team color (used internally).
			val entryLength = 12  // Maximum of 16, with 4 characters reserved for the ordering prefix.
			val suffixLength = 16 // Maximum of 16.

			// Convert item text into legacy text.
			var text = LegacyComponentSerializer.legacySection().serialize(item)

			// Separate as much text as possible into the prefix.
			val (prefix, prefixRemaining) = run {
				for (n in Integer.min(text.length, prefixLength) downTo 0) {
					val prefix = text.substring(0, n)
					if (prefix.endsWith(ChatColor.COLOR_CHAR)) {
						continue
					}
					val lastColors = ChatColor.getLastColors(prefix)
					val remaining = text.substring(n)
					return@run Pair(prefix, lastColors + remaining)
				}
				throw IllegalStateException()
			}
			text = prefixRemaining

			// Separate as much text as possible into the suffix.
			val (suffix, suffixRemaining) = run {
				for (n in Integer.min(text.length, suffixLength) downTo 0) {
					val suffix = text.substring(text.length - n)
					val remaining = text.substring(0, text.length - n)
					if (remaining.endsWith(ChatColor.COLOR_CHAR) && !suffix.startsWith(ChatColor.COLOR_CHAR)) {
						continue
					}
					val lastColors = ChatColor.getLastColors(remaining)
					if (lastColors.length + suffix.length > suffixLength) {
						continue
					}
					return@run Pair(lastColors + suffix, remaining)
				}
				throw IllegalStateException()
			}
			text = suffixRemaining

			// Ensure remaining text (entry) is not too long.
			if (text.length > entryLength) {
				text = text.substring(0, entryLength)
			}

			// Prepend the entry with the ordering prefix.
			val entry = getOrderedPrefix(i) + text

			// Create the entry team if it does not exist.
			val team = scoreboard.getTeam("@sidebar$i") ?: run {
				scoreboard.registerNewTeam("@sidebar$i")
			}
			team.addEntry(entry)
			team.prefix(LegacyComponentSerializer.legacySection().deserialize(prefix))
			team.suffix(LegacyComponentSerializer.legacySection().deserialize(suffix))
			objective.getScore(entry).score = 0
			entries.add(entry)
		} else {
			val entry = getOrderedPrefix(i)
			val team = scoreboard.getTeam("@sidebar$i") ?: run {
				scoreboard.registerNewTeam("@sidebar$i")
			}
			team.addEntry(entry)
			team.prefix(item)
			objective.getScore(entry).score = 0
			entries.add(entry)
		}
	}

	// Remove obsolete entries.
	for (entry in objectiveEntries[objective] ?: setOf()) {
		if (entry !in entries) {
			objective.getScore(entry).resetScore()
		}
	}

	objectiveEntries[objective] = entries
}

@Suppress("UNUSED")
class SidebarPlugin : JavaPlugin(), Listener {
	override fun onEnable() {
		server.scheduler.scheduleSyncRepeatingTask(
			this,
			{
				for (p in server.onlinePlayers) {
					val lines = (Math.random() * 10).toInt() + 1
					p.updateSidebar(
						Component.text("Lines: ").append(Component.text(lines)),
						(1..lines).map { i ->
							Component.text("Line #").append(Component.text(i)).color(NamedTextColor.NAMES.values().random())
						},
					)
				}
			},
			0, 20,
		)

		server.pluginManager.registerEvents(this, this)
	}

	@EventHandler
	fun onPlayerJoin(event: PlayerJoinEvent) {
		event.player.scoreboard = server.scoreboardManager.newScoreboard
	}
}