Merge branch 'master-MC1.7.10' of github.com:MightyPirates/OpenComputers into master-MC1.8

Conflicts:
	src/main/scala/li/cil/oc/common/item/Analyzer.scala
	src/main/scala/li/cil/oc/common/item/Debugger.scala
	src/main/scala/li/cil/oc/server/component/Agent.scala
	src/main/scala/li/cil/oc/server/component/DebugCard.scala
	src/main/scala/li/cil/oc/server/component/Transposer.scala
	src/main/scala/li/cil/oc/util/InventoryUtils.scala

src/main/resources/application.conf

@@ -465,8 +465,8 @@ opencomputers {
     # screens. This also controls how frequent distributors revalidate their
     # global state and secondary distributors, as well as how often the power
     # converter queries sources for energy (for now: only BuildCraft). If set
-    # to 1, this would query every tick. The default queries every 20 ticks,
+    # to 1, this would query every tick. The default queries every 10 ticks,
-    # or in other words once per second.
+    # or in other words twice per second.
     # Higher values mean more responsive power consumption, but slightly more
     # work per tick (shouldn't be that noticeable, though). Note that this
     # has no influence on the actual amount of energy required by computers

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

@@ -118,6 +118,7 @@ object EventHandler {
   @SubscribeEvent
   def playerLoggedIn(e: PlayerLoggedInEvent) {
     if (SideTracker.isServer) e.player match {
+      case _: FakePlayer => // Nope
       case player: EntityPlayerMP =>
         if (!LuaStateFactory.isAvailable) {
           player.addChatMessage(Localization.Chat.WarningLuaFallback)

src/main/scala/li/cil/oc/common/container/Player.scala

@@ -15,6 +15,7 @@ import net.minecraft.inventory.Slot
 import net.minecraft.item.ItemStack
 import net.minecraft.nbt.NBTBase
 import net.minecraft.nbt.NBTTagCompound
+import net.minecraftforge.common.util.FakePlayer
 
 import scala.collection.convert.WrapAsScala._
 
@@ -155,6 +156,7 @@ abstract class Player(val playerInventory: InventoryPlayer, val otherInventory:
       val nbt = new NBTTagCompound()
       detectCustomDataChanges(nbt)
       for (entry <- crafters) entry match {
+        case _: FakePlayer => // Nope
         case player: EntityPlayerMP => ServerPacketSender.sendContainerUpdate(this, nbt, player)
         case _ =>
       }

src/main/scala/li/cil/oc/common/entity/Drone.scala

@@ -465,8 +465,14 @@ class Drone(val world: World) extends Entity(world) with MachineHost with intern
 
   override def interactFirst(player: EntityPlayer) = {
     if (player.isSneaking) {
+      if (api.Items.get(player.getCurrentEquippedItem) == api.Items.get(Constants.ItemName.Wrench)) {
         kill()
       }
+      else if (!world.isRemote && !machine.isRunning) {
+        preparePowerUp()
+        start()
+      }
+    }
     else if (!world.isRemote) {
       player.openGui(OpenComputers, GuiType.Drone.id, world, getEntityId, 0, 0)
     }

src/main/scala/li/cil/oc/common/item/Analyzer.scala

@@ -16,6 +16,7 @@ import net.minecraft.entity.player.EntityPlayerMP
 import net.minecraft.item.ItemStack
 import net.minecraft.util.EnumFacing
 import net.minecraft.world.World
+import net.minecraftforge.common.util.FakePlayer
 import net.minecraftforge.event.entity.player.EntityInteractEvent
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent
 
@@ -59,6 +60,7 @@ object Analyzer {
 
   private def analyzeNodes(nodes: Array[Node], player: EntityPlayer) = if (nodes != null) for (node <- nodes if node != null) {
     player match {
+      case _: FakePlayer => // Nope
       case playerMP: EntityPlayerMP =>
         if (node != null) node.host match {
           case machine: Machine =>

src/main/scala/li/cil/oc/common/item/Debugger.scala

@@ -9,11 +9,13 @@ import net.minecraft.entity.player.EntityPlayer
 import net.minecraft.entity.player.EntityPlayerMP
 import net.minecraft.item.ItemStack
 import net.minecraft.util.EnumFacing
+import net.minecraftforge.common.util.FakePlayer
 
 class Debugger(val parent: Delegator) extends traits.Delegate {
   override def onItemUse(stack: ItemStack, player: EntityPlayer, position: BlockPosition, side: EnumFacing, hitX: Float, hitY: Float, hitZ: Float) = {
     val world = position.world.get
     player match {
+      case _: FakePlayer => false // Nope
       case realPlayer: EntityPlayerMP =>
         world.getTileEntity(position) match {
           case host: SidedEnvironment =>

src/main/scala/li/cil/oc/common/nanomachines/provider/DisintegrationProvider.scala

@@ -1,6 +1,5 @@
 package li.cil.oc.common.nanomachines.provider
 
-import li.cil.oc.Settings
 import li.cil.oc.Settings
 import li.cil.oc.api
 import li.cil.oc.api.nanomachines.DisableReason
@@ -14,6 +13,7 @@ import net.minecraft.entity.player.EntityPlayerMP
 import net.minecraft.item.ItemStack
 import net.minecraft.nbt.NBTTagCompound
 import net.minecraft.world.World
+import net.minecraftforge.common.util.FakePlayer
 import net.minecraftforge.event.ForgeEventFactory
 import net.minecraftforge.event.entity.player.PlayerInteractEvent.Action
 import net.minecraftforge.fml.common.eventhandler.Event
@@ -42,6 +42,7 @@ object DisintegrationProvider extends ScalaProvider("c4e7e3c2-8069-4fbb-b08e-74b
     override def update(): Unit = {
       val world = player.getEntityWorld
       if (!world.isRemote) player match {
+        case _: FakePlayer => // Nope
         case playerMP: EntityPlayerMP =>
           val now = world.getTotalWorldTime
 

src/main/scala/li/cil/oc/common/tileentity/Charger.scala

@@ -205,7 +205,7 @@ class Charger extends traits.Environment with traits.PowerAcceptor with traits.R
     }
 
     val players = world.getEntitiesWithinAABB(classOf[EntityPlayer], bounds).collect {
-      case player: EntityPlayer => new PlayerChargeable(player)
+      case player: EntityPlayer if api.Nanomachines.hasController(player) => new PlayerChargeable(player)
     }
 
     // Only update list when we have to, keeps pointless block updates to a minimum.

src/main/scala/li/cil/oc/common/tileentity/Hologram.scala

@@ -319,7 +319,7 @@ class Hologram(var tier: Int) extends traits.Environment with SidedEnvironment w
 
       result(true)
     }
-    else result(null, "not supported")
+    else result(Unit, "not supported")
   }
 
   @Callback(doc = """function(speed:number, x:number, y:number, z:number):boolean -- Set the rotation speed of the displayed hologram.""")
@@ -338,7 +338,7 @@ class Hologram(var tier: Int) extends traits.Environment with SidedEnvironment w
 
       result(true)
     }
-    else result(null, "not supported")
+    else result(Unit, "not supported")
   }
 
   private def checkCoordinates(args: Arguments, idxX: Int = 0, idxY: Int = 1, idxZ: Int = 2) = {

src/main/scala/li/cil/oc/common/tileentity/Printer.scala

@@ -152,7 +152,7 @@ class Printer extends traits.Environment with traits.Inventory with traits.Rotat
   @Callback(doc = """function(minX:number, minY:number, minZ:number, maxX:number, maxY:number, maxZ:number, texture:string[, state:boolean=false][,tint:number]) -- Adds a shape to the printers configuration, optionally specifying whether it is for the off or on state.""")
   def addShape(context: Context, args: Arguments): Array[Object] = {
     if (data.stateOff.size > Settings.get.maxPrintComplexity || data.stateOn.size > Settings.get.maxPrintComplexity) {
-      return result(null, "model too complex")
+      return result(Unit, "model too complex")
     }
     val minX = (args.checkInteger(0) max 0 min 16) / 16f
     val minY = (args.checkInteger(1) max 0 min 16) / 16f
@@ -193,7 +193,7 @@ class Printer extends traits.Environment with traits.Inventory with traits.Rotat
   @Callback(doc = """function([count:number]):boolean -- Commit and begin printing the current configuration.""")
   def commit(context: Context, args: Arguments): Array[Object] = {
     if (!canPrint) {
-      return result(null, "model invalid")
+      return result(Unit, "model invalid")
     }
     limit = (args.optDouble(0, 1) max 0 min Integer.MAX_VALUE).toInt
     isActive = limit > 0

src/main/scala/li/cil/oc/common/tileentity/Transposer.scala

@@ -4,7 +4,7 @@ import li.cil.oc.server.component
 import net.minecraft.nbt.NBTTagCompound
 
 class Transposer extends traits.Environment {
-  val transposer = new component.Transposer(this)
+  val transposer = new component.Transposer.Block(this)
 
   def node = transposer.node
 

src/main/scala/li/cil/oc/integration/appeng/PartEnvironmentBase.scala

@@ -1,7 +1,5 @@
 package li.cil.oc.integration.appeng
 
-import appeng.api.implementations.tiles.ISegmentedInventory
-import appeng.api.parts.IPartHost
 import li.cil.oc.api.internal.Database
 import li.cil.oc.api.machine.Arguments
 import li.cil.oc.api.machine.Context
@@ -9,7 +7,6 @@ import li.cil.oc.api.network.Component
 import li.cil.oc.api.network.ManagedEnvironment
 import li.cil.oc.util.ExtendedArguments._
 import li.cil.oc.util.ResultWrapper.result
-import net.minecraftforge.common.util.ForgeDirection
 
 import scala.reflect.ClassTag
 
@@ -25,7 +22,7 @@ trait PartEnvironmentBase extends ManagedEnvironment {
         val slot = args.optSlot(config, 1, 0)
         val stack = config.getStackInSlot(slot)
         result(stack)
-      case _ => result(null, "no matching part")
+      case _ => result(Unit, "no matching part")
     }
   }
 

src/main/scala/li/cil/oc/integration/dsu/DriverDeepStorageUnit.scala

@@ -11,7 +11,6 @@ import li.cil.oc.integration.ManagedTileEntityEnvironment
 import li.cil.oc.util.ResultWrapper._
 import net.minecraft.item.ItemStack
 import net.minecraft.world.World
-import powercrystals.minefactoryreloaded.api.IDeepStorageUnit
 
 object DriverDeepStorageUnit extends DriverTileEntity with EnvironmentAware {
   override def getTileEntityClass: Class[_] = classOf[IDeepStorageUnit]
@@ -31,7 +30,7 @@ object DriverDeepStorageUnit extends DriverTileEntity with EnvironmentAware {
     @Callback(doc = "function():int -- Get the maximum number of stored items.")
     def getStoredItemType(context: Context, args: Arguments): Array[AnyRef] = {
       if (Settings.get.allowItemStackInspection) result(tileEntity.getStoredItemType)
-      else result(null, "not enabled in config")
+      else result(Unit, "not enabled in config")
     }
   }
 

src/main/scala/li/cil/oc/integration/opencomputers/DriverTransposer.scala

@@ -0,0 +1,21 @@
+package li.cil.oc.integration.opencomputers
+
+import li.cil.oc.Constants
+import li.cil.oc.api
+import li.cil.oc.api.driver.EnvironmentAware
+import li.cil.oc.api.driver.EnvironmentHost
+import li.cil.oc.api.driver.item.HostAware
+import li.cil.oc.common.Slot
+import li.cil.oc.server.component
+import net.minecraft.item.ItemStack
+
+object DriverTransposer extends Item with HostAware with EnvironmentAware {
+  override def worksWith(stack: ItemStack) = isOneOf(stack,
+    api.Items.get(Constants.BlockName.Transposer))
+
+  override def createEnvironment(stack: ItemStack, host: EnvironmentHost) = new component.Transposer.Upgrade(host)
+
+  override def slot(stack: ItemStack) = Slot.Upgrade
+
+  override def providedEnvironment(stack: ItemStack) = classOf[component.Transposer.Upgrade]
+}

src/main/scala/li/cil/oc/integration/opencomputers/ModOpenComputers.scala

@@ -105,7 +105,6 @@ object ModOpenComputers extends ModProxy {
     api.Driver.add(DriverDebugCard)
     api.Driver.add(DriverEEPROM)
     api.Driver.add(DriverFileSystem)
-    api.Driver.add(DriverGeolyzer)
     api.Driver.add(DriverGraphicsCard)
     api.Driver.add(DriverInternetCard)
     api.Driver.add(DriverLinkedCard)
@@ -114,7 +113,6 @@ object ModOpenComputers extends ModProxy {
     api.Driver.add(DriverNetworkCard)
     api.Driver.add(DriverKeyboard)
     api.Driver.add(DriverRedstoneCard)
-    api.Driver.add(DriverScreen)
     api.Driver.add(DriverTablet)
     api.Driver.add(DriverWirelessNetworkCard)
 
@@ -122,6 +120,10 @@ object ModOpenComputers extends ModProxy {
     api.Driver.add(DriverContainerFloppy)
     api.Driver.add(DriverContainerUpgrade)
 
+    api.Driver.add(DriverGeolyzer)
+    api.Driver.add(DriverScreen)
+    api.Driver.add(DriverTransposer)
+
     api.Driver.add(DriverUpgradeAngel)
     api.Driver.add(DriverUpgradeBattery)
     api.Driver.add(DriverUpgradeChunkloader)
@@ -145,6 +147,7 @@ object ModOpenComputers extends ModProxy {
       Constants.BlockName.Geolyzer,
       Constants.BlockName.Keyboard,
       Constants.BlockName.ScreenTier1,
+      Constants.BlockName.Transposer,
       Constants.ItemName.AngelUpgrade,
       Constants.ItemName.BatteryUpgradeTier1,
       Constants.ItemName.BatteryUpgradeTier2,
@@ -163,27 +166,28 @@ object ModOpenComputers extends ModProxy {
       Constants.ItemName.TractorBeamUpgrade,
       Constants.ItemName.LeashUpgrade)
     blacklistHost(classOf[internal.Drone],
+      Constants.BlockName.Keyboard,
+      Constants.BlockName.ScreenTier1,
+      Constants.BlockName.Transposer,
       Constants.ItemName.APUTier1,
       Constants.ItemName.APUTier2,
       Constants.ItemName.GraphicsCardTier1,
       Constants.ItemName.GraphicsCardTier2,
       Constants.ItemName.GraphicsCardTier3,
-      Constants.BlockName.Keyboard,
       Constants.ItemName.NetworkCard,
       Constants.ItemName.RedstoneCardTier1,
-      Constants.BlockName.ScreenTier1,
       Constants.ItemName.AngelUpgrade,
       Constants.ItemName.CraftingUpgrade,
       Constants.ItemName.HoverUpgradeTier1,
       Constants.ItemName.HoverUpgradeTier2)
     blacklistHost(classOf[internal.Microcontroller],
+      Constants.BlockName.Keyboard,
+      Constants.BlockName.ScreenTier1,
       Constants.ItemName.APUTier1,
       Constants.ItemName.APUTier2,
       Constants.ItemName.GraphicsCardTier1,
       Constants.ItemName.GraphicsCardTier2,
       Constants.ItemName.GraphicsCardTier3,
-      Constants.BlockName.Keyboard,
-      Constants.BlockName.ScreenTier1,
       Constants.ItemName.AngelUpgrade,
       Constants.ItemName.ChunkloaderUpgrade,
       Constants.ItemName.CraftingUpgrade,
@@ -202,11 +206,13 @@ object ModOpenComputers extends ModProxy {
       Constants.ItemName.TractorBeamUpgrade,
       Constants.ItemName.LeashUpgrade)
     blacklistHost(classOf[internal.Robot],
+      Constants.BlockName.Transposer,
       Constants.ItemName.LeashUpgrade)
     blacklistHost(classOf[internal.Tablet],
+      Constants.BlockName.ScreenTier1,
+      Constants.BlockName.Transposer,
       Constants.ItemName.NetworkCard,
       Constants.ItemName.RedstoneCardTier1,
-      Constants.BlockName.ScreenTier1,
       Constants.ItemName.AngelUpgrade,
       Constants.ItemName.ChunkloaderUpgrade,
       Constants.ItemName.CraftingUpgrade,

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

@@ -6,6 +6,7 @@ import li.cil.oc.api.internal
 import li.cil.oc.api.machine.Arguments
 import li.cil.oc.api.machine.Callback
 import li.cil.oc.api.machine.Context
+import li.cil.oc.common.entity
 import li.cil.oc.server.agent.ActivationType
 import li.cil.oc.server.agent.Player
 import li.cil.oc.util.BlockPosition
@@ -303,7 +304,7 @@ trait Agent extends traits.WorldControl with traits.InventoryControl with traits
       player.side.getFrontOffsetZ * range)
     val hit = world.rayTraceBlocks(origin, target)
     player.closestEntity[Entity]() match {
-      case Some(entity@(_: EntityLivingBase | _: EntityMinecart)) if hit == null || new Vec3(player.posX, player.posY, player.posZ).distanceTo(hit.hitVec) > player.getDistanceToEntity(entity) => new MovingObjectPosition(entity)
+      case Some(entity@(_: EntityLivingBase | _: EntityMinecart | _: entity.Drone)) if hit == null || new Vec3(player.posX, player.posY, player.posZ).distanceTo(hit.hitVec) > player.getDistanceToEntity(entity) => new MovingObjectPosition(entity)
       case _ => hit
     }
   }

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

@@ -440,9 +440,9 @@ object DebugCard {
               tileEntity.markDirty()
               world.markBlockForUpdate(blockPos)
               result(true)
-            case nbt => result(null, s"nbt tag compound expected, got '${NBTBase.NBT_TYPES(nbt.getId)}'")
+            case nbt => result(Unit, s"nbt tag compound expected, got '${NBTBase.NBT_TYPES(nbt.getId)}'")
           }
-        case _ => result(null, "no tile entity")
+        case _ => result(Unit, "no tile entity")
       }
     }
 
@@ -524,7 +524,7 @@ object DebugCard {
           val removed = inventory.decrStackSize(slot, count)
           if (removed == null) result(0)
           else result(removed.stackSize)
-        case _ => result(null, "no inventory")
+        case _ => result(Unit, "no inventory")
       }
     }
 
@@ -540,7 +540,7 @@ object DebugCard {
       val side = args.checkSide(5, EnumFacing.values: _*)
       world.getTileEntity(position) match {
         case handler: IFluidHandler => result(handler.fill(side, new FluidStack(fluid, amount), true))
-        case _ => result(null, "no tank")
+        case _ => result(Unit, "no tank")
       }
     }
 
@@ -552,7 +552,7 @@ object DebugCard {
       val side = args.checkSide(4, EnumFacing.values: _*)
       world.getTileEntity(position) match {
         case handler: IFluidHandler => result(handler.drain(side, amount, true))
-        case _ => result(null, "no tank")
+        case _ => result(Unit, "no tank")
       }
     }
 

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

@@ -1,15 +1,27 @@
 package li.cil.oc.server.component
 
-import java.io.{BufferedWriter, FileNotFoundException, IOException, InputStream, OutputStreamWriter}
+import java.io.BufferedWriter
+import java.io.FileNotFoundException
+import java.io.IOException
+import java.io.InputStream
+import java.io.OutputStreamWriter
 import java.net._
 import java.nio.ByteBuffer
 import java.nio.channels.SocketChannel
-import java.util.concurrent.{Callable, ConcurrentLinkedQueue, ExecutionException, Future}
+import java.util.concurrent.Callable
+import java.util.concurrent.ConcurrentLinkedQueue
+import java.util.concurrent.ExecutionException
+import java.util.concurrent.Future
 
-import li.cil.oc.{OpenComputers, Settings, api}
+import li.cil.oc.OpenComputers
-import li.cil.oc.api.machine.{Arguments, Callback, Context}
+import li.cil.oc.Settings
+import li.cil.oc.api
+import li.cil.oc.api.Network
+import li.cil.oc.api.machine.Arguments
+import li.cil.oc.api.machine.Callback
+import li.cil.oc.api.machine.Context
 import li.cil.oc.api.network._
-import li.cil.oc.api.{Network, prefab}
+import li.cil.oc.api.prefab
 import li.cil.oc.api.prefab.AbstractValue
 import li.cil.oc.util.ExtendedNBT._
 import li.cil.oc.util.ThreadPoolFactory
@@ -190,7 +202,7 @@ object InternetCard {
       if (checkConnected()) {
         val buffer = ByteBuffer.allocate(n)
         val read = channel.read(buffer)
-        if (read == -1) result(null)
+        if (read == -1) result(Unit)
         else result(buffer.array.view(0, read).toArray)
       }
       else result(Array.empty[Byte])
@@ -297,7 +309,7 @@ object InternetCard {
     def response(context: Context, args: Arguments): Array[AnyRef] = this.synchronized {
       response match {
         case Some((code, message, headers)) => result(code, message, headers)
-        case _ => result(null)
+        case _ => result(Unit)
       }
     }
 
@@ -305,7 +317,7 @@ object InternetCard {
     def read(context: Context, args: Arguments): Array[AnyRef] = this.synchronized {
       val n = math.min(Settings.get.maxReadBuffer, math.max(0, args.optInteger(1, Int.MaxValue)))
       if (checkResponse()) {
-        if (eof && queue.isEmpty) result(null)
+        if (eof && queue.isEmpty) result(Unit)
         else {
           val buffer = ByteBuffer.allocate(n)
           var read = 0

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

@@ -2,68 +2,49 @@ package li.cil.oc.server.component
 
 import li.cil.oc.Settings
 import li.cil.oc.api
+import li.cil.oc.api.driver.EnvironmentHost
 import li.cil.oc.api.machine.Arguments
-import li.cil.oc.api.machine.Callback
-import li.cil.oc.api.machine.Context
 import li.cil.oc.api.network.Visibility
 import li.cil.oc.api.prefab
 import li.cil.oc.common.tileentity
 import li.cil.oc.server.{PacketSender => ServerPacketSender}
 import li.cil.oc.util.BlockPosition
 import li.cil.oc.util.ExtendedArguments._
-import li.cil.oc.util.FluidUtils
-import li.cil.oc.util.InventoryUtils
 import net.minecraft.util.EnumFacing
 
 import scala.language.existentials
 
-class Transposer(val host: tileentity.Transposer) extends prefab.ManagedEnvironment with traits.WorldInventoryAnalytics with traits.WorldTankAnalytics {
+object Transposer {
+
+  abstract class Common extends prefab.ManagedEnvironment with traits.WorldInventoryAnalytics with traits.WorldTankAnalytics with traits.InventoryTransfer {
     override val node = api.Network.newNode(this, Visibility.Network).
       withComponent("transposer").
       withConnector().
       create()
 
+    override protected def checkSideForAction(args: Arguments, n: Int) =
+      args.checkSide(n, EnumFacing.values: _*)
+
+    override def onTransferContents(): Option[String] = {
+      if (node.tryChangeBuffer(-Settings.get.transposerCost)) None
+      else Option("not enough energy")
+    }
+  }
+
+  class Block(val host: tileentity.Transposer) extends Common {
     override def position = BlockPosition(host)
 
-  override protected def checkSideForAction(args: Arguments, n: Int) = args.checkSide(n, EnumFacing.values: _*)
+    override def onTransferContents(): Option[String] = {
-
+      val result = super.onTransferContents()
-  @Callback(doc = """function(sourceSide:number, sinkSide:number[, count:number[, sourceSlot:number, sinkSlot:number]]):number -- Transfer some items between two inventories.""")
+      if (result.isEmpty) ServerPacketSender.sendTransposerActivity(host)
-  def transferItem(context: Context, args: Arguments): Array[AnyRef] = {
+      result
-    val sourceSide = checkSideForAction(args, 0)
-    val sourcePos = position.offset(sourceSide)
-    val sinkSide = checkSideForAction(args, 1)
-    val sinkPos = position.offset(sinkSide)
-    val count = args.optItemCount(2)
-
-    if (node.tryChangeBuffer(-Settings.get.transposerCost)) {
-      ServerPacketSender.sendTransposerActivity(host)
-
-      if (args.count > 3) {
-        val sourceSlot = args.checkSlot(InventoryUtils.inventoryAt(sourcePos).getOrElse(throw new IllegalArgumentException("no inventory")), 3)
-        val sinkSlot = args.checkSlot(InventoryUtils.inventoryAt(sinkPos).getOrElse(throw new IllegalArgumentException("no inventory")), 4)
-
-        result(InventoryUtils.transferBetweenInventoriesSlotsAt(sourcePos, sourceSide.getOpposite, sourceSlot, sinkPos, Option(sinkSide.getOpposite), sinkSlot, count))
     }
-      else result(InventoryUtils.transferBetweenInventoriesAt(sourcePos, sourceSide.getOpposite, sinkPos, Option(sinkSide.getOpposite), count))
-    }
-    else result(Unit, "not enough energy")
   }
 
-  @Callback(doc = """function(sourceSide:number, sinkSide:number[, count:number]):number -- Transfer some items between two inventories.""")
+  class Upgrade(val host: EnvironmentHost) extends Common {
-  def transferFluid(context: Context, args: Arguments): Array[AnyRef] = {
+    node.setVisibility(Visibility.Neighbors)
-    val sourceSide = checkSideForAction(args, 0)
-    val sourcePos = position.offset(sourceSide)
-    val sinkSide = checkSideForAction(args, 1)
-    val sinkPos = position.offset(sinkSide)
-    val count = args.optFluidCount(2)
 
-    if (node.tryChangeBuffer(-Settings.get.transposerCost)) {
+    override def position = BlockPosition(host)
-      ServerPacketSender.sendTransposerActivity(host)
+  }
 
-      val moved = FluidUtils.transferBetweenFluidHandlersAt(sourcePos, sourceSide.getOpposite, sinkPos, sinkSide.getOpposite, count)
-      if (moved > 0) context.pause(moved / 1000 * 0.25) // Allow up to 4 buckets per second.
-      result(moved > 0, moved)
-    }
-    else result(Unit, "not enough energy")
-  }
 }

src/main/scala/li/cil/oc/server/component/traits/InventoryTransfer.scala

@@ -0,0 +1,54 @@
+package li.cil.oc.server.component.traits
+
+import li.cil.oc.api.machine.Arguments
+import li.cil.oc.api.machine.Callback
+import li.cil.oc.api.machine.Context
+import li.cil.oc.server.component._
+import li.cil.oc.util.ExtendedArguments._
+import li.cil.oc.util.FluidUtils
+import li.cil.oc.util.InventoryUtils
+
+trait InventoryTransfer extends traits.WorldAware with traits.SideRestricted {
+  // Return None on success, else Some("failure reason")
+  def onTransferContents(): Option[String]
+
+  @Callback(doc = """function(sourceSide:number, sinkSide:number[, count:number[, sourceSlot:number[, sinkSlot:number]]]):number -- Transfer some items between two inventories.""")
+  def transferItem(context: Context, args: Arguments): Array[AnyRef] = {
+    val sourceSide = checkSideForAction(args, 0)
+    val sourcePos = position.offset(sourceSide)
+    val sinkSide = checkSideForAction(args, 1)
+    val sinkPos = position.offset(sinkSide)
+    val count = args.optItemCount(2)
+
+    onTransferContents() match {
+      case Some(reason) =>
+        result(Unit, reason)
+      case _ =>
+        if (args.count > 3) {
+          val sourceSlot = args.checkSlot(InventoryUtils.inventoryAt(sourcePos).getOrElse(throw new IllegalArgumentException("no inventory")), 3)
+          val sinkSlot = args.optSlot(InventoryUtils.inventoryAt(sinkPos).getOrElse(throw new IllegalArgumentException("no inventory")), 4, -1)
+
+          result(InventoryUtils.transferBetweenInventoriesSlotsAt(sourcePos, sourceSide.getOpposite, sourceSlot, sinkPos, Option(sinkSide.getOpposite), if (sinkSlot < 0) None else Option(sinkSlot), count))
+        }
+        else result(InventoryUtils.transferBetweenInventoriesAt(sourcePos, sourceSide.getOpposite, sinkPos, Option(sinkSide.getOpposite), count))
+    }
+  }
+
+  @Callback(doc = """function(sourceSide:number, sinkSide:number[, count:number]):number -- Transfer some items between two inventories.""")
+  def transferFluid(context: Context, args: Arguments): Array[AnyRef] = {
+    val sourceSide = checkSideForAction(args, 0)
+    val sourcePos = position.offset(sourceSide)
+    val sinkSide = checkSideForAction(args, 1)
+    val sinkPos = position.offset(sinkSide)
+    val count = args.optFluidCount(2)
+
+    onTransferContents() match {
+      case Some(reason) =>
+        result(Unit, reason)
+      case _ =>
+        val moved = FluidUtils.transferBetweenFluidHandlersAt(sourcePos, sourceSide.getOpposite, sinkPos, sinkSide.getOpposite, count)
+        if (moved > 0) context.pause(moved / 1000 * 0.25) // Allow up to 4 buckets per second.
+        result(moved > 0, moved)
+    }
+  }
+}

src/main/scala/li/cil/oc/server/component/traits/WorldInventoryAnalytics.scala

@@ -62,7 +62,7 @@ trait WorldInventoryAnalytics extends WorldAware with SideRestricted with Networ
     val facing = checkSideForAction(args, 0)
     withInventory(facing, inventory => result(inventory.getStackInSlot(args.checkSlot(inventory, 1))))
   }
-  else result(null, "not enabled in config")
+  else result(Unit, "not enabled in config")
 
   @Callback(doc = """function(side:number, slot:number, dbAddress:string, dbSlot:number):boolean -- Store an item stack description in the specified slot of the database with the specified address.""")
   def store(context: Context, args: Arguments): Array[AnyRef] = {
@@ -80,6 +80,6 @@ trait WorldInventoryAnalytics extends WorldAware with SideRestricted with Networ
   private def withInventory(side: EnumFacing, f: IInventory => Array[AnyRef]) =
     InventoryUtils.inventoryAt(position.offset(side)) match {
       case Some(inventory) if inventory.isUseableByPlayer(fakePlayer) && mayInteract(position.offset(side), side.getOpposite) => f(inventory)
-      case _ => result(null, "no inventory")
+      case _ => result(Unit, "no inventory")
     }
 }

src/main/scala/li/cil/oc/util/InventoryUtils.scala

@@ -249,9 +249,15 @@ object InventoryUtils {
   /**
    * Like <tt>transferBetweenInventories</tt> but moving between specific slots.
    */
-  def transferBetweenInventoriesSlots(source: IInventory, sourceSide: EnumFacing, sourceSlot: Int, sink: IInventory, sinkSide: Option[EnumFacing], sinkSlot: Int, limit: Int = 64) =
+  def transferBetweenInventoriesSlots(source: IInventory, sourceSide: EnumFacing, sourceSlot: Int, sink: IInventory, sinkSide: Option[EnumFacing], sinkSlot: Option[Int], limit: Int = 64) =
+    sinkSlot match {
+      case Some(explicitSinkSlot) =>
         extractFromInventorySlot(
-      insertIntoInventorySlot(_, sink, sinkSide, sinkSlot, limit), source, sourceSide, sourceSlot, limit)
+          insertIntoInventorySlot(_, sink, sinkSide, explicitSinkSlot, limit), source, sourceSide, sourceSlot, limit)
+      case _ =>
+        extractFromInventorySlot(
+          insertIntoInventory(_, sink, sinkSide, limit), source, sourceSide, sourceSlot, limit)
+    }
 
   /**
    * Utility method for calling <tt>transferBetweenInventories</tt> on inventories
@@ -266,7 +272,7 @@ object InventoryUtils {
    * Utility method for calling <tt>transferBetweenInventoriesSlots</tt> on inventories
    * in the world.
    */
-  def transferBetweenInventoriesSlotsAt(sourcePos: BlockPosition, sourceSide: EnumFacing, sourceSlot: Int, sinkPos: BlockPosition, sinkSide: Option[EnumFacing], sinkSlot: Int, limit: Int = 64) =
+  def transferBetweenInventoriesSlotsAt(sourcePos: BlockPosition, sourceSide: EnumFacing, sourceSlot: Int, sinkPos: BlockPosition, sinkSide: Option[EnumFacing], sinkSlot: Option[Int], limit: Int = 64) =
     inventoryAt(sourcePos).exists(sourceInventory =>
       inventoryAt(sinkPos).exists(sinkInventory =>
         transferBetweenInventoriesSlots(sourceInventory, sourceSide, sourceSlot, sinkInventory, sinkSide, sinkSlot, limit)))