Implement basic scoreboard support.

src/com/garbagemule/MobArena/ArenaImpl.java

@@ -102,6 +102,9 @@ public class ArenaImpl implements Arena
     private TimeStrategy timeStrategy;
     private AutoStartTimer autoStartTimer;
     
+    // Scoreboards
+    private ScoreboardManager scoreboard;
+    
     /**
      * Primary constructor. Requires a name and a world.
      */
@@ -166,6 +169,9 @@ public class ArenaImpl implements Arena
         String timeString = settings.getString("player-time-in-arena", "world");
         Time time = Enums.getEnumFromString(Time.class, timeString);
         this.timeStrategy = (time != null ? new TimeStrategyLocked(time) : new TimeStrategyNull());
+        
+        // Scoreboards
+        this.scoreboard = new ScoreboardManager(this);
     }
     
     
@@ -364,6 +370,10 @@ public class ArenaImpl implements Arena
         return limitManager;
     }
     
+    @Override
+    public ScoreboardManager getScoreboard() {
+        return scoreboard;
+    }
     
     
     
@@ -407,6 +417,9 @@ public class ArenaImpl implements Arena
             return false;
         }
         
+        // Initialize scoreboards
+        scoreboard.initialize();
+        
         // Teleport players, give full health, initialize map
         for (Player p : arenaPlayers) {
             // TODO figure out how people die in lobby and get sent to spectator area early
@@ -425,6 +438,8 @@ public class ArenaImpl implements Arena
             p.setFoodLevel(20);
             assignClassPermissions(p);
             arenaPlayerMap.get(p).resetStats();
+            
+            scoreboard.addPlayer(p);
         }
         
         // Start spawning monsters (must happen before 'running = true;')
@@ -882,6 +897,8 @@ public class ArenaImpl implements Arena
         arenaPlayers.remove(p);
         lobbyPlayers.remove(p);
         arenaPlayerMap.remove(p);
+        
+        scoreboard.removePlayer(p);
     }
     
     private void setHealth(Player p, int health) {

src/com/garbagemule/MobArena/ArenaListener.java

@@ -435,6 +435,7 @@ public class ArenaListener
                 ArenaPlayerStatistics stats = ap.getStats();
                 if (stats != null) {
                     ap.getStats().inc("kills");
+                    arena.getScoreboard().addKill((Player) damager);
                 }
             }
         }

src/com/garbagemule/MobArena/MASpawnThread.java

@@ -128,6 +128,8 @@ public class MASpawnThread implements Runnable
 
         w.announce(arena, wave);
         
+        arena.getScoreboard().updateWave(wave);
+        
         // Set the players' level to the wave number
         if (wavesAsLevel) {
             for (Player p : arena.getPlayersInArena()) {

src/com/garbagemule/MobArena/ScoreboardManager.java

@@ -0,0 +1,92 @@
+package com.garbagemule.MobArena;
+
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.scoreboard.DisplaySlot;
+import org.bukkit.scoreboard.Objective;
+import org.bukkit.scoreboard.Score;
+import org.bukkit.scoreboard.Scoreboard;
+
+import com.garbagemule.MobArena.framework.Arena;
+
+public class ScoreboardManager {
+    private Arena arena;
+    private Scoreboard scoreboard;
+    private Objective kills;
+    
+    /**
+     * Create a new scoreboard for the given arena.
+     * @param arena an arena
+     */
+    ScoreboardManager(Arena arena) {
+        this.arena = arena;
+        scoreboard = Bukkit.getScoreboardManager().getNewScoreboard();
+    }
+    
+    /**
+     * Add a player to the scoreboard by setting the player's scoreboard
+     * and giving him an initial to-be-reset non-zero score.
+     * @param player a player
+     */
+    void addPlayer(Player player) {
+        /* Set the player's scoreboard and give them an initial non-zero
+         * score. This is necessary due to either Minecraft or Bukkit
+         * not wanting to show non-zero scores initially. */
+        player.setScoreboard(scoreboard);
+        kills.getScore(player).setScore(8);
+    }
+    
+    /**
+     * Remove a player from the scoreboard by setting the player's scoreboard
+     * to the main server scoreboard.
+     * @param player a player
+     */
+    void removePlayer(Player player) {
+        player.setScoreboard(Bukkit.getScoreboardManager().getMainScoreboard());
+    }
+
+    /**
+     * Add a kill to the player's score. Called when a player kills a mob.
+     * @param player a player
+     */
+    void addKill(Player player) {
+        Score score = kills.getScore(player);
+        score.setScore(score.getScore() + 1);
+    }
+    
+    /**
+     * Update the scoreboard to display the given wave number.
+     * @param wave a wave number
+     */
+    void updateWave(int wave) {
+        kills.setDisplayName("§aMobArena Kills     §bWave " + wave);
+    }
+    
+    /**
+     * Initialize the scoreboard by resetting the kills objective and
+     * setting all player scores to 0.
+     */
+    void initialize() {
+        /* Initialization involves first unregistering the kill counter if
+         * it was already registered, and then setting it back up.
+         * It is necessary to delay the reset of the player scores, and the
+         * reset is necessary because of non-zero crappiness. */
+        resetKills();
+        arena.scheduleTask(new Runnable() {
+            public void run() {
+                for (Player p : arena.getPlayersInArena()) {
+                    kills.getScore(p).setScore(0);
+                }
+            }
+        }, 1);
+    }
+    
+    private void resetKills() {
+        if (kills != null) {
+            kills.unregister();
+        }
+        kills = scoreboard.registerNewObjective("kills", "ma-kills");
+        kills.setDisplaySlot(DisplaySlot.SIDEBAR);
+        updateWave(0);
+    }
+}

src/com/garbagemule/MobArena/framework/Arena.java

@@ -18,6 +18,7 @@ import com.garbagemule.MobArena.MASpawnThread;
 import com.garbagemule.MobArena.MobArena;
 import com.garbagemule.MobArena.MonsterManager;
 import com.garbagemule.MobArena.RewardManager;
+import com.garbagemule.MobArena.ScoreboardManager;
 import com.garbagemule.MobArena.leaderboards.Leaderboard;
 import com.garbagemule.MobArena.region.ArenaRegion;
 import com.garbagemule.MobArena.repairable.Repairable;
@@ -104,6 +105,8 @@ public interface Arena
 
     public void revivePlayer(Player p);
     
+    public ScoreboardManager getScoreboard();
+