Implmented Sengir's IPickupHandler.

http://www.mod-buildcraft.com/forums/topic/hook-intercept-item-pickups-by-player-entities/?view=all

forge/forge_common/net/minecraft/src/forge/ForgeHooks.java

@@ -7,6 +7,7 @@ package net.minecraft.src.forge;
 
 import net.minecraft.src.Block;
 import net.minecraft.src.Entity;
+import net.minecraft.src.EntityItem;
 import net.minecraft.src.EntityMinecart;
 import net.minecraft.src.EntityPlayer;
 import net.minecraft.src.IInventory;
@@ -137,6 +138,21 @@ public class ForgeHooks {
     }
 	static LinkedList<IConnectionHandler> connectionHandlers = new LinkedList<IConnectionHandler>();
 	
+	public static boolean onItemPickup(EntityPlayer player, EntityItem item)
+	{
+	    boolean cont = true;
+	    for (IPickupHandler handler : pickupHandlers)
+	    {
+	        cont = cont && handler.onItemPickup(player, item);
+	        if (!cont || item.item.stackSize <= 0)
+	        {
+	            return false;
+	        }
+	    }
+	    return cont;
+	}
+	static LinkedList<IPickupHandler> pickupHandlers = new LinkedList<IPickupHandler>();
+
 	// Plant Management
 	// ------------------------------------------------------------
 	static class ProbableItem {

forge/forge_common/net/minecraft/src/forge/IPickupHandler.java

@@ -0,0 +1,26 @@
+package net.minecraft.src.forge;
+
+import net.minecraft.src.EntityItem;
+import net.minecraft.src.EntityPlayer;
+import net.minecraft.src.ItemStack;
+
+public interface IPickupHandler 
+{
+
+    /**
+     * Raised when a player collides with a EntityItem.
+     * The handler may consume all, or part of the stack.
+     * The handler will only be called if the stack size is > 0
+     * The event may be cut part way through if the stack size 
+     * falls to 0 or a previous handler returns false;
+     * Will only be called if delay before pickup is 0.
+     * 
+     * The Entity will destroyed if the stack size falls to 0.
+     * 
+     * @param player Player that picked up the item
+     * @param item Item picked up as entity. May be manipulated
+     * @return True If processing should continue. 
+     */
+    public boolean onItemPickup(EntityPlayer player, EntityItem item);
+    
+}

forge/forge_common/net/minecraft/src/forge/MinecraftForge.java

@@ -92,6 +92,15 @@ public class MinecraftForge {
         ForgeHooks.connectionHandlers.add(handler);
     }
 
+    /**
+     * Registers a new Item Pickup event handler
+     * @param handler The Handler to be registered
+     */
+    public static void registerPickupHandler(IPickupHandler handler)
+    {
+        ForgeHooks.pickupHandlers.add(handler);
+    }
+
     /**
      * This is not supposed to be called outside of Minecraft internals.
      */

forge/patches/minecraft/net/minecraft/src/EntityItem.java.patch

@@ -0,0 +1,30 @@
+--- ../src_base/minecraft/net/minecraft/src/EntityItem.java	0000-00-00 00:00:00.000000000 -0000
++++ ../src_work/minecraft/net/minecraft/src/EntityItem.java	0000-00-00 00:00:00.000000000 -0000
+@@ -2,6 +2,8 @@
+ 
+ import java.util.Random;
+ 
++import net.minecraft.src.forge.ForgeHooks;
++
+ public class EntityItem extends Entity
+ {
+     public ItemStack item;
+@@ -139,6 +141,18 @@
+             return;
+         }
+         int i = item.stackSize;
++        if (delayBeforeCanPickup == 0 && !ForgeHooks.onItemPickup(entityplayer, this))
++        {
++            ModLoader.OnItemPickup(entityplayer, item);
++            worldObj.playSoundAtEntity(this, "random.pop", 0.2F, ((rand.nextFloat() - rand.nextFloat()) * 0.7F + 1.0F) * 2.0F);
++            entityplayer.onItemPickup(this, i);
++            if (item.stackSize <= 0)
++            {
++                setEntityDead();
++            }
++            return;
++        }
++        i = item.stackSize;
+         if (delayBeforeCanPickup == 0 && entityplayer.inventory.addItemStackToInventory(item))
+         {
+             if (item.itemID == Block.wood.blockID)

forge/patches/minecraft_server/net/minecraft/src/EntityItem.java.patch

@@ -0,0 +1,30 @@
+--- ../src_base/minecraft_server/net/minecraft/src/EntityItem.java	0000-00-00 00:00:00.000000000 -0000
++++ ../src_work/minecraft_server/net/minecraft/src/EntityItem.java	0000-00-00 00:00:00.000000000 -0000
+@@ -2,6 +2,8 @@
+ 
+ import java.util.Random;
+ 
++import net.minecraft.src.forge.ForgeHooks;
++
+ public class EntityItem extends Entity
+ {
+     public ItemStack item;
+@@ -139,6 +141,18 @@
+             return;
+         }
+         int i = item.stackSize;
++        if (delayBeforeCanPickup == 0 && !ForgeHooks.onItemPickup(entityplayer, this))
++        {
++            ModLoader.OnItemPickup(entityplayer, item);
++            worldObj.playSoundAtEntity(this, "random.pop", 0.2F, ((rand.nextFloat() - rand.nextFloat()) * 0.7F + 1.0F) * 2.0F);
++            entityplayer.onItemPickup(this, i);
++            if (item.stackSize <= 0)
++            {
++                setEntityDead();
++            }
++            return;
++        }
++        i = item.stackSize;
+         if (delayBeforeCanPickup == 0 && entityplayer.inventory.addItemStackToInventory(item))
+         {
+             if (item.itemID == Block.wood.blockID)