Add a hook to allow continuously using items through stack changes (#4834)

* Add a hook to allow continuously using items through stack changes

* Update licences

patches/minecraft/net/minecraft/entity/EntityLivingBase.java.patch

@@ -401,7 +401,11 @@
      public abstract EnumHandSide func_184591_cq();
  
      public boolean func_184587_cr()
-@@ -2595,12 +2670,19 @@
+@@ -2592,15 +2667,23 @@
+         if (this.func_184587_cr())
+         {
+             ItemStack itemstack = this.func_184586_b(this.func_184600_cs());
++            if (net.minecraftforge.common.ForgeHooks.canContinueUsing(this.field_184627_bm, itemstack)) this.field_184627_bm = itemstack;
  
              if (itemstack == this.field_184627_bm)
              {
@@ -422,7 +426,7 @@
                  {
                      this.func_71036_o();
                  }
-@@ -2618,8 +2700,10 @@
+@@ -2618,8 +2701,10 @@
  
          if (!itemstack.func_190926_b() && !this.func_184587_cr())
          {
@@ -434,7 +438,7 @@
  
              if (!this.field_70170_p.field_72995_K)
              {
-@@ -2700,7 +2784,10 @@
+@@ -2700,7 +2785,10 @@
          if (!this.field_184627_bm.func_190926_b() && this.func_184587_cr())
          {
              this.func_184584_a(this.field_184627_bm, 16);
@@ -446,7 +450,7 @@
              this.func_184602_cy();
          }
      }
-@@ -2724,7 +2811,8 @@
+@@ -2724,7 +2812,8 @@
      {
          if (!this.field_184627_bm.func_190926_b())
          {
@@ -456,7 +460,7 @@
          }
  
          this.func_184602_cy();
-@@ -2852,6 +2940,31 @@
+@@ -2852,6 +2941,31 @@
          return true;
      }
  
@@ -488,7 +492,7 @@
      public boolean func_190631_cK()
      {
          return true;
-@@ -2861,4 +2974,30 @@
+@@ -2861,4 +2975,30 @@
      public void func_191987_a(BlockPos p_191987_1_, boolean p_191987_2_)
      {
      }

patches/minecraft/net/minecraft/item/Item.java.patch

@@ -68,7 +68,7 @@
          CreativeTabs creativetabs = this.func_77640_w();
          return creativetabs != null && (p_194125_1_ == CreativeTabs.field_78027_g || p_194125_1_ == creativetabs);
      }
-@@ -435,11 +441,766 @@
+@@ -435,11 +441,779 @@
          return false;
      }
  
@@ -698,6 +698,19 @@
 +    }
 +
 +    /**
++     * Called while an item is in 'active' use to determine if usage should continue.
++     * Allows items to continue being used while sustaining damage, for example.
++     *
++     * @param oldStack the previous 'active' stack
++     * @param newStack the stack currently in the active hand
++     * @return true to set the new stack to active and continue using it
++     */
++    public boolean canContinueUsing(ItemStack oldStack, ItemStack newStack)
++    {
++        return oldStack.equals(newStack);
++    }
++
++    /**
 +     * Called to get the Mod ID of the mod that *created* the ItemStack,
 +     * instead of the real Mod ID that *registered* it.
 +     *
@@ -835,7 +848,7 @@
      public static void func_150900_l()
      {
          func_179214_a(Blocks.field_150350_a, new ItemAir(Blocks.field_150350_a));
-@@ -999,6 +1760,8 @@
+@@ -999,6 +1773,8 @@
          private final float field_78010_h;
          private final float field_78011_i;
          private final int field_78008_j;
@@ -844,7 +857,7 @@
  
          private ToolMaterial(int p_i1874_3_, int p_i1874_4_, float p_i1874_5_, float p_i1874_6_, int p_i1874_7_)
          {
-@@ -1034,6 +1797,7 @@
+@@ -1034,6 +1810,7 @@
              return this.field_78008_j;
          }
  
@@ -852,7 +865,7 @@
          public Item func_150995_f()
          {
              if (this == WOOD)
-@@ -1057,5 +1821,21 @@
+@@ -1057,5 +1834,21 @@
                  return this == DIAMOND ? Items.field_151045_i : null;
              }
          }

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

@@ -195,6 +195,15 @@ public class ForgeHooks
         return entry.getStack(rand, fortune);
     }
 
+    public static boolean canContinueUsing(@Nonnull ItemStack from, @Nonnull ItemStack to)
+    {
+        if (!from.isEmpty() && !to.isEmpty())
+        {
+            return from.getItem().canContinueUsing(from, to);
+        }
+        return false;
+    }
+
     private static boolean toolInit = false;
     //static HashSet<List> toolEffectiveness = new HashSet<List>();
 

src/test/java/net/minecraftforge/debug/item/ContinuousUseItemTest.java

@@ -0,0 +1,133 @@
+/*
+ * Minecraft Forge
+ * Copyright (c) 2016-2018.
+ *
+ * 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.debug.item;
+
+import net.minecraft.client.renderer.block.model.ModelResourceLocation;
+import net.minecraft.creativetab.CreativeTabs;
+import net.minecraft.entity.EntityLivingBase;
+import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.item.EnumAction;
+import net.minecraft.item.Item;
+import net.minecraft.item.ItemStack;
+import net.minecraft.util.ActionResult;
+import net.minecraft.util.EnumActionResult;
+import net.minecraft.util.EnumHand;
+import net.minecraft.world.World;
+import net.minecraftforge.client.event.ModelRegistryEvent;
+import net.minecraftforge.client.model.ModelLoader;
+import net.minecraftforge.event.RegistryEvent;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
+import net.minecraftforge.fml.common.registry.GameRegistry;
+import net.minecraftforge.fml.relauncher.Side;
+
+@Mod(modid = ContinuousUseItemTest.MOD_ID, name = "Test for canContinueUsing", version = "1.0", acceptableRemoteVersions = "*")
+@Mod.EventBusSubscriber
+public class ContinuousUseItemTest
+{
+    static final String MOD_ID = "continuous_use_item_test";
+    static final boolean ENABLED = false;
+
+    @GameRegistry.ObjectHolder(TestItem.NAME)
+    public static final Item TEST_ITEM = null;
+
+    @SubscribeEvent
+    public static void registerItem(RegistryEvent.Register<Item> event)
+    {
+        if (ENABLED)
+        {
+            event.getRegistry().register(
+                    new TestItem().setRegistryName(MOD_ID, TestItem.NAME)
+                                  .setUnlocalizedName(MOD_ID + "." + TestItem.NAME)
+                                  .setCreativeTab(CreativeTabs.MISC)
+            );
+        }
+    }
+
+    @Mod.EventBusSubscriber(value = Side.CLIENT, modid = MOD_ID)
+    public static class ClientEventHandler
+    {
+        @SubscribeEvent
+        public static void registerModels(ModelRegistryEvent event)
+        {
+            if (ENABLED)
+            {
+                ModelLoader.setCustomModelResourceLocation(TEST_ITEM, 0, new ModelResourceLocation("minecraft:stick", "inventory"));
+            }
+        }
+    }
+
+    static class TestItem extends Item
+    {
+        static final String NAME = "test_item";
+
+        TestItem()
+        {
+            maxStackSize = 1;
+            setMaxDamage(60);
+        }
+
+        @Override
+        public boolean hasEffect(ItemStack stack)
+        {
+            return true;
+        }
+
+        @Override
+        public EnumAction getItemUseAction(ItemStack stack)
+        {
+            return EnumAction.BOW;
+        }
+
+        @Override
+        public int getMaxItemUseDuration(ItemStack stack)
+        {
+            return 72000;
+        }
+
+        @Override
+        public ActionResult<ItemStack> onItemRightClick(World worldIn, EntityPlayer playerIn, EnumHand handIn)
+        {
+            playerIn.setActiveHand(handIn);
+            return new ActionResult<>(EnumActionResult.SUCCESS, playerIn.getHeldItem(handIn));
+        }
+
+        @Override
+        public void onUsingTick(ItemStack stack, EntityLivingBase living, int count)
+        {
+            if (count % 10 == 0)
+            {
+                stack.damageItem(1, living);
+            }
+        }
+
+        @Override
+        public boolean shouldCauseReequipAnimation(ItemStack oldStack, ItemStack newStack, boolean slotChanged)
+        {
+            return slotChanged || oldStack.getItem() != newStack.getItem();
+        }
+
+        @Override
+        public boolean canContinueUsing(ItemStack oldStack, ItemStack newStack)
+        {
+            return oldStack.getItem() == newStack.getItem();
+        }
+    }
+}