Added PotionBrewEvent.Pre/Post. To allow for modification and cancelation of Brewing. Closes #1248

src/main/java/net/minecraftforge/event/ForgeEventFactory.java

@@ -18,6 +18,7 @@ import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.entity.player.EntityPlayerMP;
 import net.minecraft.init.Blocks;
 import net.minecraft.item.ItemStack;
+import net.minecraft.tileentity.TileEntityBrewingStand;
 import net.minecraft.world.Explosion;
 import net.minecraft.world.World;
 import net.minecraft.world.WorldServer;
@@ -28,6 +29,8 @@ import net.minecraft.world.storage.SaveHandler;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.common.util.BlockSnapshot;
 import net.minecraftforge.common.util.ForgeDirection;
+import net.minecraftforge.event.brewing.PotionBrewEvent;
+import net.minecraftforge.event.brewing.PotionBrewedEvent;
 import net.minecraftforge.event.entity.EntityStruckByLightningEvent;
 import net.minecraftforge.event.entity.living.LivingHealEvent;
 import net.minecraftforge.event.entity.living.LivingPackSizeEvent;
@@ -253,4 +256,31 @@ public class ForgeEventFactory
         LivingHealEvent event = new LivingHealEvent(entity, amount);
         return (MinecraftForge.EVENT_BUS.post(event) ? 0 : event.amount);
     }
+
+    public static boolean onPotionAttemptBreaw(ItemStack[] stacks)
+    {
+        ItemStack[] tmp = new ItemStack[stacks.length];
+        for (int x = 0; x < tmp.length; x++)
+            tmp[x] = stacks[x].copy();
+
+        PotionBrewEvent.Pre event = new PotionBrewEvent.Pre(tmp);
+        if (MinecraftForge.EVENT_BUS.post(event))
+        {
+            boolean changed = false;
+            for (int x = 0; x < stacks.length; x++)
+            {
+                changed |= ItemStack.areItemStacksEqual(tmp[x], stacks[x]);
+                stacks[x] = event.getItem(x);
+            }
+            if (changed)
+                onPotionBrewed(stacks);
+            return true;
+        }
+        return false;
+    }
+
+    public static void onPotionBrewed(ItemStack[] brewingItemStacks)
+    {
+        MinecraftForge.EVENT_BUS.post(new PotionBrewEvent.Post(brewingItemStacks));
+    }
 }

src/main/java/net/minecraftforge/event/brewing/PotionBrewEvent.java

@@ -0,0 +1,83 @@
+package net.minecraftforge.event.brewing;
+
+import net.minecraft.item.ItemStack;
+import cpw.mods.fml.common.eventhandler.Cancelable;
+import cpw.mods.fml.common.eventhandler.Event;
+import cpw.mods.fml.common.eventhandler.Event.HasResult;
+
+
+public class PotionBrewEvent extends Event
+{
+    private ItemStack[] stacks;
+
+    protected PotionBrewEvent(ItemStack[] stacks)
+    {
+        this.stacks = stacks;
+    }
+
+    public ItemStack getItem(int index)
+    {
+        if (index >= stacks.length) return null;
+        return stacks[index];
+    }
+
+    public void setItem(int index, ItemStack stack)
+    {
+        if (index < stacks.length)
+        {
+            stacks[index] = stack;
+        }
+    }
+
+    public int getLength()
+    {
+        return stacks.length;
+    }
+
+    /**
+     * PotionBrewEvent.Pre is fired before vanilla brewing takes place.
+     * All changes made to the event's array will be made to the TileEntity if the event is canceled.
+     * <br>
+     * The event is fired during the TileEntityBrewingStand#brewPotions() method invocation.<br>
+     * <br>
+     * {@link #brewingStacks} contains the itemstack array from the TileEntityBrewer holding all items in Brewer.<br>
+     * <br>
+     * This event is {@link Cancelable}.<br>
+     * If the event is not canceled, the vanilla brewing will take place instead of modded brewing.
+     * <br>
+     * This event does not have a result. {@link HasResult}<br>
+     * <br>
+     * This event is fired on the {@link MinecraftForge#EVENT_BUS}.<br>
+     * <br>
+     * If this event is canceled, and items have been modified, PotionBrewEvent.Post will automatically be fired.
+     **/
+    @Cancelable
+    public static class Pre extends PotionBrewEvent
+    {
+        public Pre(ItemStack[] stacks)
+        {
+            super(stacks);
+        }
+    }
+
+    /**
+     * PotionBrewEvent.Post is fired when a potion is brewed in the brewing stand.
+     * <br>
+     * The event is fired during the TileEntityBrewingStand#brewPotions() method invocation.<br>
+     * <br>
+     * {@link #brewingStacks} contains the itemstack array from the TileEntityBrewer holding all items in Brewer.<br>
+     * <br>
+     * This event is not {@link Cancelable}.<br>
+     * <br>
+     * This event does not have a result. {@link HasResult}<br>
+     * <br>
+     * This event is fired on the {@link MinecraftForge#EVENT_BUS}.<br>
+     **/
+    public static class Post extends PotionBrewedEvent
+    {
+        public Post(ItemStack[] stacks)
+        {
+            super(stacks);
+        }
+    }
+}

src/main/java/net/minecraftforge/event/brewing/PotionBrewedEvent.java

@@ -1,5 +1,6 @@
 package net.minecraftforge.event.brewing;
 
+import cpw.mods.fml.common.eventhandler.Cancelable;
 import cpw.mods.fml.common.eventhandler.Event;
 import net.minecraft.item.ItemStack;
 
@@ -16,14 +17,18 @@ import net.minecraft.item.ItemStack;
  * <br>
  * This event is fired on the {@link MinecraftForge#EVENT_BUS}.<br>
  **/
-public class PotionBrewedEvent extends Event
+@Deprecated //Remove in 1.8.1
+public class PotionBrewedEvent extends PotionBrewEvent
 {
     /**
      * The brewing stacks in the brewing stand.  Each index has the possibility to be null, so make sure you check.
+     * Changing this array to another one has no effect.
      */
+    @Deprecated
     public ItemStack[] brewingStacks;
     public PotionBrewedEvent(ItemStack[] brewingStacks)
     {
+        super(brewingStacks);
         this.brewingStacks = brewingStacks;
     }
 }