Add RecipeCatalyst system (#195)

* Add RecipeCatalyst system

src/main/java/codechicken/nei/api/API.java

@@ -18,7 +18,9 @@ import codechicken.nei.config.OptionKeyBind;
 import codechicken.nei.recipe.GuiCraftingRecipe;
 import codechicken.nei.recipe.GuiUsageRecipe;
 import codechicken.nei.recipe.ICraftingHandler;
+import codechicken.nei.recipe.IRecipeHandler;
 import codechicken.nei.recipe.IUsageHandler;
+import codechicken.nei.recipe.RecipeCatalysts;
 import codechicken.nei.recipe.RecipeInfo;
 import codechicken.nei.recipe.StackInfo;
 import net.minecraft.block.Block;
@@ -30,6 +32,7 @@ import org.lwjgl.input.Keyboard;
 
 import java.util.Collections;
 import java.util.Comparator;
+import java.util.List;
 
 /**
  * This is the main class that handles item property configuration.
@@ -291,4 +294,24 @@ public class API
         StackInfo.stackStringifyHandlers.add(handler);
     }
 
+    /**
+     * Adds an association between an ingredient and what it can craft. (i.e. Furnace ItemStack -> Smelting and Fuel Recipes)
+     * Allows players to see what ingredient they need to craft in order to make recipes from a recipe category.
+     * @param stack the ingredient that can craft recipes (like a furnace or crafting table)
+     * @param handler the recipe category handled by the ingredient
+     */
+    public static void addRecipeCatalyst(ItemStack stack, Class<? extends IRecipeHandler> handler) {
+        addRecipeCatalyst(Collections.singletonList(stack), handler);
+    }
+
+    /**
+     * Adds an association between an ingredient and what it can craft. (i.e. Furnace ItemStack -> Smelting and Fuel Recipes)
+     * Allows players to see what ingredient they need to craft in order to make recipes from a recipe category.
+     * @param stacks the ingredients that can craft recipes (like a furnace or crafting table)
+     * @param handler the recipe category handled by the ingredient
+     */
+    public static void addRecipeCatalyst(List<ItemStack> stacks, Class<? extends IRecipeHandler> handler) {
+        RecipeCatalysts.addRecipeCatalyst(stacks, handler);
+    }
+
 }