Might fix a memory leak.

src/main/scala/li/cil/oc/common/EventHandler.scala

@@ -21,6 +21,7 @@ import li.cil.oc.common.tileentity.Robot
 import li.cil.oc.common.tileentity.traits.power
 import li.cil.oc.integration.Mods
 import li.cil.oc.integration.util
+import li.cil.oc.server.component.Keyboard
 import li.cil.oc.server.{PacketSender => ServerPacketSender}
 import li.cil.oc.util._
 import net.minecraft.client.Minecraft
@@ -34,6 +35,7 @@ import net.minecraftforge.common.util.ForgeDirection
 import net.minecraftforge.event.world.BlockEvent
 import net.minecraftforge.event.world.WorldEvent
 
+import scala.collection.convert.WrapAsScala._
 import scala.collection.mutable
 import scala.concurrent.ExecutionContext.Implicits.global
 import scala.concurrent.Future
@@ -45,10 +47,14 @@ object EventHandler {
 
   private val runningRobots = mutable.Set.empty[Robot]
 
+  private val keyboards = java.util.Collections.newSetFromMap[Keyboard](new java.util.WeakHashMap[Keyboard, java.lang.Boolean])
+
   def onRobotStart(robot: Robot): Unit = runningRobots += robot
 
   def onRobotStopped(robot: Robot): Unit = runningRobots -= robot
 
+  def addKeyboard(keyboard: Keyboard): Unit = keyboards += keyboard
+
   def schedule(tileEntity: TileEntity) {
     if (SideTracker.isServer) pending.synchronized {
       pending += (() => Network.joinOrCreateNetwork(tileEntity))
@@ -186,6 +192,21 @@ object EventHandler {
     }
   }
 
+  @SubscribeEvent
+  def onPlayerRespawn(e: PlayerRespawnEvent) {
+    keyboards.foreach(_.releasePressedKeys(e.player))
+  }
+
+  @SubscribeEvent
+  def onPlayerChangedDimension(e: PlayerChangedDimensionEvent) {
+    keyboards.foreach(_.releasePressedKeys(e.player))
+  }
+
+  @SubscribeEvent
+  def onPlayerLogout(e: PlayerLoggedOutEvent) {
+    keyboards.foreach(_.releasePressedKeys(e.player))
+  }
+
   lazy val drone = api.Items.get("drone")
   lazy val eeprom = api.Items.get("eeprom")
   lazy val mcu = api.Items.get("microcontroller")

src/main/scala/li/cil/oc/server/component/Keyboard.scala

@@ -1,21 +1,14 @@
 package li.cil.oc.server.component
 
-import cpw.mods.fml.common.FMLCommonHandler
-import cpw.mods.fml.common.eventhandler.SubscribeEvent
-import cpw.mods.fml.common.gameevent.PlayerEvent.PlayerChangedDimensionEvent
-import cpw.mods.fml.common.gameevent.PlayerEvent.PlayerLoggedOutEvent
-import cpw.mods.fml.common.gameevent.PlayerEvent.PlayerRespawnEvent
 import li.cil.oc.Settings
 import li.cil.oc.api
 import li.cil.oc.api.Network
 import li.cil.oc.api.component.Keyboard.UsabilityChecker
 import li.cil.oc.api.driver.EnvironmentHost
 import li.cil.oc.api.network.Message
-import li.cil.oc.api.network.Node
 import li.cil.oc.api.network.Visibility
 import li.cil.oc.api.prefab
 import net.minecraft.entity.player.EntityPlayer
-import net.minecraftforge.event.world.WorldEvent
 
 import scala.collection.mutable
 
@@ -35,21 +28,6 @@ class Keyboard(val host: EnvironmentHost) extends prefab.ManagedEnvironment with
 
   // ----------------------------------------------------------------------- //
 
-  @SubscribeEvent
-  def onPlayerRespawn(e: PlayerRespawnEvent) {
-    releasePressedKeys(e.player)
-  }
-
-  @SubscribeEvent
-  def onPlayerChangedDimension(e: PlayerChangedDimensionEvent) {
-    releasePressedKeys(e.player)
-  }
-
-  @SubscribeEvent
-  def onPlayerLogout(e: PlayerLoggedOutEvent) {
-    releasePressedKeys(e.player)
-  }
-
   def releasePressedKeys(player: EntityPlayer) {
     pressedKeys.get(player) match {
       case Some(keys) => for ((code, char) <- keys) {
@@ -65,29 +43,8 @@ class Keyboard(val host: EnvironmentHost) extends prefab.ManagedEnvironment with
     pressedKeys.remove(player)
   }
 
-  @SubscribeEvent
-  def onWorldUnload(e: WorldEvent.Unload) {
-    try FMLCommonHandler.instance.bus.unregister(this) catch {
-      case ignore: Throwable =>
-    }
-  }
-
   // ----------------------------------------------------------------------- //
 
-  override def onConnect(node: Node) {
-    if (node == this.node) {
-      FMLCommonHandler.instance.bus.register(this)
-    }
-  }
-
-  override def onDisconnect(node: Node) {
-    if (node == this.node) {
-      try FMLCommonHandler.instance.bus.unregister(this) catch {
-        case ignore: Throwable =>
-      }
-    }
-  }
-
   override def onMessage(message: Message) = {
     message.data match {
       case Array(p: EntityPlayer, char: Character, code: Integer) if message.name == "keyboard.keyDown" =>