Add Villager Trading Events (#6016)

src/main/java/net/minecraftforge/common/BasicTrade.java

@@ -0,0 +1,78 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2019.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation version 2.1
+ * of the License.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+package net.minecraftforge.common;
+
+import java.util.Random;
+
+import javax.annotation.Nullable;
+
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.merchant.villager.VillagerTrades.ITrade;
+import net.minecraft.item.ItemStack;
+import net.minecraft.item.Items;
+import net.minecraft.item.MerchantOffer;
+
+/**
+ * A default, exposed implementation of ITrade.  All of the other implementations of ITrade (in VillagerTrades) are not public.
+ * This class contains everything needed to make a MerchantOffer, the actual "trade" object shown in trading guis.
+ */
+public class BasicTrade implements ITrade
+{
+
+    protected final ItemStack price;
+    protected final ItemStack price2;
+    protected final ItemStack forSale;
+    protected final int maxTrades;
+    protected final int xp;
+    protected final float priceMult;
+
+    public BasicTrade(ItemStack price, ItemStack price2, ItemStack forSale, int maxTrades, int xp, float priceMult)
+    {
+        this.price = price;
+        this.price2 = price2;
+        this.forSale = forSale;
+        this.maxTrades = maxTrades;
+        this.xp = xp;
+        this.priceMult = priceMult;
+    }
+
+    public BasicTrade(ItemStack price, ItemStack forSale, int maxTrades, int xp, float priceMult)
+    {
+        this(price, ItemStack.EMPTY, forSale, maxTrades, xp, priceMult);
+    }
+
+    public BasicTrade(int emeralds, ItemStack forSale, int maxTrades, int xp, float mult)
+    {
+        this(new ItemStack(Items.EMERALD, emeralds), forSale, maxTrades, xp, mult);
+    }
+
+    public BasicTrade(int emeralds, ItemStack forSale, int maxTrades, int xp)
+    {
+        this(new ItemStack(Items.EMERALD, emeralds), forSale, maxTrades, xp, 1);
+    }
+
+    @Override
+    @Nullable
+    public MerchantOffer getOffer(Entity merchant, Random rand)
+    {
+        return new MerchantOffer(price, price2, forSale, maxTrades, xp, priceMult);
+    }
+
+}