Added IMC callback to add custom ink providers (i.e. callbacks that let us know how much ink an item is worth). Closes #1135.

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

@@ -7,6 +7,7 @@ import com.typesafe.config.Config
 import cpw.mods.fml.common.event.FMLInterModComms.IMCEvent
 import li.cil.oc.OpenComputers
 import li.cil.oc.Settings
+import li.cil.oc.common.item.data.PrintData
 import li.cil.oc.common.template.AssemblerTemplates
 import li.cil.oc.common.template.DisassemblerTemplates
 import li.cil.oc.integration.util.ItemCharge
@@ -84,6 +85,12 @@ object IMC {
           case t: Throwable => OpenComputers.log.warn("Failed registering assembler template filter.", t)
         }
       }
+      else if (message.key == "registerInkProvider" && message.isStringMessage) {
+        OpenComputers.log.info(s"Registering new ink provider '${message.getStringValue}' from mod ${message.getSender}.")
+        try PrintData.addInkProvider(getStaticMethod(message.getStringValue, classOf[ItemStack])) catch {
+          case t: Throwable => OpenComputers.log.warn("Failed registering ink provider.", t)
+        }
+      }
       else {
         OpenComputers.log.warn(s"Got an unrecognized or invalid IMC message '${message.key}' from mod ${message.getSender}.")
       }

src/main/scala/li/cil/oc/common/item/data/PrintData.scala

@@ -1,9 +1,11 @@
 package li.cil.oc.common.item.data
 
+import java.lang.reflect.Method
+
 import li.cil.oc.Constants
 import li.cil.oc.Settings
 import li.cil.oc.api
-import li.cil.oc.util.Color
+import li.cil.oc.common.IMC
 import li.cil.oc.util.ExtendedAABB._
 import li.cil.oc.util.ExtendedNBT._
 import net.minecraft.item.ItemStack
@@ -103,6 +105,10 @@ object PrintData {
   private val step = stepping / 16f
   private val invMaxVolume = 1f / (stepping * stepping * stepping)
 
+  private val inkProviders = mutable.LinkedHashSet.empty[Method]
+
+  def addInkProvider(provider: Method): Unit = inkProviders += provider
+
   def computeApproximateOpacity(shapes: Iterable[PrintData.Shape]) = {
     var volume = 1f
     if (shapes.size > 0) for (x <- 0 until 16 / stepping; y <- 0 until 16 / stepping; z <- 0 until 16 / stepping) {
@@ -133,7 +139,6 @@ object PrintData {
   }
 
   private val materialPerItem = Settings.get.printMaterialValue
-  private val inkPerCartridge = Settings.get.printInkValue
 
   def materialValue(stack: ItemStack) = {
     if (api.Items.get(stack) == api.Items.get(Constants.ItemName.Chamelium))
@@ -148,12 +153,14 @@ object PrintData {
     else 0
   }
 
-  def inkValue(stack: ItemStack) = {
-    if (api.Items.get(stack) == api.Items.get(Constants.ItemName.InkCartridge))
-      inkPerCartridge
-    else if (Color.isDye(stack))
-      inkPerCartridge / 10
-    else 0
+  def inkValue(stack: ItemStack): Int = {
+    for (provider <- inkProviders) {
+      val value = IMC.tryInvokeStatic(provider, stack)(0)
+      if (value > 0) {
+        return value
+      }
+    }
+    0
   }
 
   def nbtToShape(nbt: NBTTagCompound): Shape = {

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

@@ -36,6 +36,7 @@ import li.cil.oc.integration.util.BundledRedstone
 import li.cil.oc.integration.util.WirelessRedstone
 import li.cil.oc.server.network.Waypoints
 import li.cil.oc.server.network.WirelessNetwork
+import li.cil.oc.util.Color
 import li.cil.oc.util.ExtendedNBT._
 import net.minecraft.entity.player.EntityPlayer
 import net.minecraft.item.ItemStack
@@ -57,12 +58,16 @@ object ModOpenComputers extends ModProxy {
     TemplateBlacklist.register()
 
     FMLInterModComms.sendMessage(Mods.IDs.OpenComputers, "registerWrenchTool", "li.cil.oc.integration.opencomputers.ModOpenComputers.useWrench")
+
     val chargerNbt = new NBTTagCompound()
     chargerNbt.setString("name", "OpenComputers")
     chargerNbt.setString("canCharge", "li.cil.oc.integration.opencomputers.ModOpenComputers.canCharge")
     chargerNbt.setString("charge", "li.cil.oc.integration.opencomputers.ModOpenComputers.charge")
     FMLInterModComms.sendMessage(Mods.IDs.OpenComputers, "registerItemCharge", chargerNbt)
 
+    FMLInterModComms.sendMessage(Mods.IDs.OpenComputers, "registerInkProvider", "li.cil.oc.integration.opencomputers.ModOpenComputers.inkCartridgeInkProvider")
+    FMLInterModComms.sendMessage(Mods.IDs.OpenComputers, "registerInkProvider", "li.cil.oc.integration.opencomputers.ModOpenComputers.dyeInkProvider")
+
     ForgeChunkManager.setForcedChunkLoadingCallback(OpenComputers, ChunkloaderUpgradeHandler)
 
     FMLCommonHandler.instance.bus.register(EventHandler)
@@ -254,6 +259,20 @@ object ModOpenComputers extends ModProxy {
     }
   }
 
+  def inkCartridgeInkProvider(stack: ItemStack): Int = {
+    if (api.Items.get(stack) == api.Items.get(Constants.ItemName.InkCartridge))
+      Settings.get.printInkValue
+    else
+      0
+  }
+
+  def dyeInkProvider(stack: ItemStack): Int = {
+    if (Color.isDye(stack))
+      Settings.get.printInkValue / 10
+    else
+      0
+  }
+
   private def blacklistHost(host: Class[_], itemNames: String*) {
     for (itemName <- itemNames) {
       val nbt = new NBTTagCompound()