Basic development

src/main/java/net/xevianlight/aphelion/util/SidedSlotHandler.java

@@ -0,0 +1,64 @@
+package net.xevianlight.aphelion.util;
+
+import net.minecraft.world.item.ItemStack;
+import net.neoforged.neoforge.items.IItemHandler;
+import net.neoforged.neoforge.items.IItemHandlerModifiable;
+
+public class SidedSlotHandler implements IItemHandler {
+
+    private final IItemHandlerModifiable backing;
+    private final int[] slots;
+    private final boolean allowInsert;
+    private final boolean allowExtract;
+
+    public SidedSlotHandler(IItemHandlerModifiable backing, int[] slots, boolean allowInsert, boolean allowExtract) {
+        this.backing = backing;
+        this.slots = slots;
+        this.allowInsert = allowInsert;
+        this.allowExtract = allowExtract;
+    }
+
+    private int toBackingSlot(int localSlot) {
+        if (localSlot < 0 || localSlot >= slots.length) return -1;
+        return slots[localSlot];
+    }
+
+
+    @Override
+    public int getSlots() {
+        return slots.length;
+    }
+
+    @Override
+    public ItemStack getStackInSlot(int slot) {
+        int s = toBackingSlot(slot);
+        return s < 0 ? ItemStack.EMPTY : backing.getStackInSlot(s);
+    }
+
+    @Override
+    public ItemStack insertItem(int slot, ItemStack stack, boolean simulate) {
+        if (!allowInsert || stack.isEmpty()) return stack;
+        int s = toBackingSlot(slot);
+        return s < 0 ? stack : backing.insertItem(s, stack, simulate);
+    }
+
+    @Override
+    public ItemStack extractItem(int slot, int amount, boolean simulate) {
+        if (!allowExtract || amount <= 0) return ItemStack.EMPTY;
+        int s = toBackingSlot(slot);
+        return s < 0 ? ItemStack.EMPTY : backing.extractItem(s, amount, simulate);
+    }
+
+    @Override
+    public int getSlotLimit(int slot) {
+        int s = toBackingSlot(slot);
+        return s < 0 ? 0 : backing.getSlotLimit(s);
+    }
+
+    @Override
+    public boolean isItemValid(int slot, ItemStack stack) {
+        if (!allowInsert) return false;
+        int s = toBackingSlot(slot);
+        return s >= 0 && backing.isItemValid(s, stack);
+    }
+}