Java tutorial
/* * Minecraft Forge * Copyright (c) 2016. * * 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 com.DragonFerocity.expanded.handlers; import net.minecraft.block.Block; import net.minecraft.item.ItemStack; import net.minecraft.tileentity.TileEntity; import net.minecraft.util.math.BlockPos; import net.minecraft.util.EnumFacing; import net.minecraft.world.World; import net.minecraftforge.items.IItemHandler; import net.minecraftforge.items.IItemHandlerModifiable; import java.lang.ref.WeakReference; import com.DragonFerocity.expanded.entities.ModTileEntityChest; import com.google.common.base.Objects; import javax.annotation.Nonnull; import javax.annotation.Nullable; public class ModVanillaDoubleChestItemHandler extends WeakReference<ModTileEntityChest> implements IItemHandlerModifiable { // Dummy cache value to signify that we have checked and definitely found no adjacent chests public static final ModVanillaDoubleChestItemHandler NO_ADJACENT_CHESTS_INSTANCE = new ModVanillaDoubleChestItemHandler( null, null, false); private final boolean mainChestIsUpper; private final ModTileEntityChest mainChest; private final int hashCode; public ModVanillaDoubleChestItemHandler(@Nullable ModTileEntityChest mainChest, @Nullable ModTileEntityChest other, boolean mainChestIsUpper) { super(other); this.mainChest = mainChest; this.mainChestIsUpper = mainChestIsUpper; hashCode = Objects.hashCode(mainChestIsUpper ? mainChest : other) * 31 + Objects.hashCode(!mainChestIsUpper ? mainChest : other); } @Nullable public static ModVanillaDoubleChestItemHandler get(ModTileEntityChest chest) { World world = chest.getWorld(); BlockPos pos = chest.getPos(); if (world == null || pos == null || !world.isBlockLoaded(pos)) return null; // Still loading Block blockType = chest.getBlockType(); EnumFacing[] horizontals = EnumFacing.HORIZONTALS; for (int i = horizontals.length - 1; i >= 0; i--) // Use reverse order so we can return early { EnumFacing enumfacing = horizontals[i]; BlockPos blockpos = pos.offset(enumfacing); Block block = world.getBlockState(blockpos).getBlock(); if (block == blockType) { TileEntity otherTE = world.getTileEntity(blockpos); if (otherTE instanceof ModTileEntityChest) { ModTileEntityChest otherChest = (ModTileEntityChest) otherTE; return new ModVanillaDoubleChestItemHandler(chest, otherChest, enumfacing != net.minecraft.util.EnumFacing.WEST && enumfacing != net.minecraft.util.EnumFacing.NORTH); } } } return NO_ADJACENT_CHESTS_INSTANCE; //All alone } @Nullable public ModTileEntityChest getChest(boolean accessingUpper) { if (accessingUpper == mainChestIsUpper) return mainChest; else { return getOtherChest(); } } @Nullable private ModTileEntityChest getOtherChest() { ModTileEntityChest tileEntityChest = get(); return tileEntityChest != null && !tileEntityChest.isInvalid() ? tileEntityChest : null; } @Override public int getSlots() { return 27 * 2; } @Override @Nonnull public ItemStack getStackInSlot(int slot) { boolean accessingUpperChest = slot < 27; int targetSlot = accessingUpperChest ? slot : slot - 27; ModTileEntityChest chest = getChest(accessingUpperChest); return chest != null ? chest.getStackInSlot(targetSlot) : ItemStack.EMPTY; } @Override public void setStackInSlot(int slot, @Nonnull ItemStack stack) { boolean accessingUpperChest = slot < 27; int targetSlot = accessingUpperChest ? slot : slot - 27; ModTileEntityChest chest = getChest(accessingUpperChest); if (chest != null) { IItemHandler singleHandler = chest.getSingleChestHandler(); if (singleHandler instanceof IItemHandlerModifiable) { ((IItemHandlerModifiable) singleHandler).setStackInSlot(targetSlot, stack); } } chest = getChest(!accessingUpperChest); if (chest != null) chest.markDirty(); } @Override @Nonnull public ItemStack insertItem(int slot, @Nonnull ItemStack stack, boolean simulate) { boolean accessingUpperChest = slot < 27; int targetSlot = accessingUpperChest ? slot : slot - 27; ModTileEntityChest chest = getChest(accessingUpperChest); if (chest == null) return stack; int starting = stack.getCount(); ItemStack ret = chest.getSingleChestHandler().insertItem(targetSlot, stack, simulate); if (ret.getCount() != starting && !simulate) { chest = getChest(!accessingUpperChest); if (chest != null) chest.markDirty(); } return ret; } @Override @Nonnull public ItemStack extractItem(int slot, int amount, boolean simulate) { boolean accessingUpperChest = slot < 27; int targetSlot = accessingUpperChest ? slot : slot - 27; ModTileEntityChest chest = getChest(accessingUpperChest); if (chest == null) return ItemStack.EMPTY; ItemStack ret = chest.getSingleChestHandler().extractItem(targetSlot, amount, simulate); if (!ret.isEmpty() && !simulate) { chest = getChest(!accessingUpperChest); if (chest != null) chest.markDirty(); } return ret; } @Override public int getSlotLimit(int slot) { boolean accessingUpperChest = slot < 27; return getChest(accessingUpperChest).getInventoryStackLimit(); } @Override public boolean equals(Object o) { if (this == o) return true; if (o == null || getClass() != o.getClass()) return false; ModVanillaDoubleChestItemHandler that = (ModVanillaDoubleChestItemHandler) o; if (hashCode != that.hashCode) return false; final ModTileEntityChest otherChest = getOtherChest(); if (mainChestIsUpper == that.mainChestIsUpper) return Objects.equal(mainChest, that.mainChest) && Objects.equal(otherChest, that.getOtherChest()); else return Objects.equal(mainChest, that.getOtherChest()) && Objects.equal(otherChest, that.mainChest); } @Override public int hashCode() { return hashCode; } public boolean needsRefresh() { if (this == NO_ADJACENT_CHESTS_INSTANCE) return false; ModTileEntityChest tileEntityChest = get(); return tileEntityChest == null || tileEntityChest.isInvalid(); } }