feat: add support for Forestry backpacks (#19)

dependencies.gradle

@@ -5,4 +5,5 @@ dependencies {
     compileOnly('com.github.GTNewHorizons:GT5-Unofficial:5.09.49.05:dev')
     compileOnly('com.github.GTNewHorizons:EnderIO:2.8.17:dev')
     compileOnly('com.github.GTNewHorizons:Draconic-Evolution:1.3.6-GTNH:dev')
+    api('com.github.GTNewHorizons:ForestryMC:4.9.16:dev')
 }

src/main/java/com/gtnh/findit/FindIt.java

@@ -28,22 +28,23 @@ public class FindIt {
     @Mod.Instance(MOD_ID)
     public static FindIt INSTANCE;
 
-    private boolean extraUtilitiesLoaded;
-    private boolean gregTechloaded;
-    private boolean enderIOloaded;
-
-    private boolean draconicEvolutionLoaded;
+    private boolean isDraconicEvolutionLoaded;
+    private boolean isEnderIOLoaded;
+    private boolean isExtraUtilitiesLoaded;
+    private boolean isForestryLoaded;
+    private boolean isGregTechLoaded;
 
     private SearchCooldownService cooldownService;
     private BlockFindService blockFindService;
     private ItemFindService itemFindService;
 
     @Mod.EventHandler
     public void preInit(FMLPreInitializationEvent event) {
-        this.extraUtilitiesLoaded = Loader.isModLoaded("ExtraUtilities");
-        this.gregTechloaded = Loader.isModLoaded("gregtech");
-        this.enderIOloaded = Loader.isModLoaded("EnderIO");
-        this.draconicEvolutionLoaded = Loader.isModLoaded("DraconicEvolution");
+        this.isExtraUtilitiesLoaded = Loader.isModLoaded("ExtraUtilities");
+        this.isGregTechLoaded = Loader.isModLoaded("gregtech");
+        this.isEnderIOLoaded = Loader.isModLoaded("EnderIO");
+        this.isDraconicEvolutionLoaded = Loader.isModLoaded("DraconicEvolution");
+        this.isForestryLoaded = Loader.isModLoaded("Forestry");
 
         FindItConfig.setup(event.getSuggestedConfigurationFile());
         boolean isClient = event.getSide() == Side.CLIENT;
@@ -66,18 +67,22 @@ public static ItemFindService getItemFindService() {
     }
 
     public static boolean isExtraUtilitiesLoaded() {
-        return INSTANCE.extraUtilitiesLoaded;
+        return INSTANCE.isExtraUtilitiesLoaded;
     }
 
     public static boolean isGregTechLoaded() {
-        return INSTANCE.gregTechloaded;
+        return INSTANCE.isGregTechLoaded;
     }
 
     public static boolean isEnderIOLoaded() {
-        return INSTANCE.enderIOloaded;
+        return INSTANCE.isEnderIOLoaded;
     }
 
     public static boolean isDraconicEvolutionLoaded() {
-        return INSTANCE.draconicEvolutionLoaded;
+        return INSTANCE.isDraconicEvolutionLoaded;
+    }
+
+    public static boolean isForestryLoaded() {
+        return INSTANCE.isForestryLoaded;
     }
 }

src/main/java/com/gtnh/findit/service/itemfinder/ClientItemFindService.java

@@ -95,10 +95,14 @@ public void onClientPostTick(TickEvent.ClientTickEvent event) {
                 return;
             }
 
+            // `WorldClient` is only available on the client-side, thus effectively checking if the game is running on
+            // the client. We are only interested in highlighting slots when the player is in a GUI; the operation is
+            // bound client-side.
             if (Minecraft.getMinecraft().theWorld == null) {
                 return;
             }
 
+            // We are only interested in GUIs that contain some kind of inventory.
             final GuiScreen screen = Minecraft.getMinecraft().currentScreen;
             if (!(screen instanceof GuiContainer)) {
                 return;
@@ -107,21 +111,26 @@ public void onClientPostTick(TickEvent.ClientTickEvent event) {
             final GuiContainer gui = (GuiContainer) screen;
             final HashSet<Slot> highlightedSlots = new HashSet<>();
 
+            // If the expiration time has passed, we reset the found item. This is done to prevent the item from being
+            // highlighted indefinitely.
             if (System.currentTimeMillis() > expirationTime) {
                 foundItem = null;
             }
+            if (foundItem == null) {
+                return;
+            }
 
-            if (foundItem != null) {
-                @SuppressWarnings("unchecked")
-                List<Slot> slots = gui.inventorySlots.inventorySlots;
+            // We continue to iterate over each slot of the given GUI's inventory and checking if the slot contains the
+            // item that we are looking for.
+            @SuppressWarnings("unchecked")
+            List<Slot> slots = gui.inventorySlots.inventorySlots;
 
-                for (Slot slot : slots) {
-                    if (!(slot.inventory instanceof InventoryPlayer) && foundItem.isStackSatisfies(slot.getStack())) {
-                        highlightedSlots.add(slot);
+            for (Slot slot : slots) {
+                if (!(slot.inventory instanceof InventoryPlayer) && foundItem.isStackSatisfies(slot.getStack())) {
+                    highlightedSlots.add(slot);
 
-                        if (highlightedSlots.size() > 256) {
-                            break;
-                        }
+                    if (highlightedSlots.size() > 256) {
+                        break;
                     }
                 }
             }
@@ -152,6 +161,10 @@ protected boolean findStack(ItemStack stack) {
         }
     }
 
+    /**
+     * This class is responsible for removing the NEI ping handler from the list of input handlers. This is done to
+     * prevent the NEI ping handler from interfering with the FindIt keybind.
+     */
     public static class NEIEventListener {
 
         @SubscribeEvent
@@ -164,6 +177,9 @@ public void onNEIConfigsLoaded(NEIConfigsLoadedEvent event) {
         }
     }
 
+    /**
+     * Returns the instance of the client item find service.
+     */
     public static ClientItemFindService getInstance() {
         return (ClientItemFindService) FindIt.getItemFindService();
     }

src/main/java/com/gtnh/findit/service/itemfinder/FindItemRequest.java

@@ -1,11 +1,14 @@
 package com.gtnh.findit.service.itemfinder;
 
+import java.util.Optional;
+
 import net.minecraft.item.ItemStack;
 import net.minecraftforge.fluids.FluidStack;
 
 import com.gtnh.findit.FindIt;
 import com.gtnh.findit.service.blockfinder.BlockFoundResponse;
 import com.gtnh.findit.util.ProtoUtils;
+import com.gtnh.findit.util.mods.ForestryUtils;
 
 import codechicken.nei.recipe.StackInfo;
 import cpw.mods.fml.common.network.simpleimpl.IMessage;
@@ -60,6 +63,25 @@ public boolean isStackSatisfies(ItemStack stack) {
             return targetFluidStack.isFluidEqual(StackInfo.getFluid(stack));
         }
 
+        // Additionally check for backpacks that might contain the item itself.
+        if (FindIt.isForestryLoaded()) {
+            Optional<Boolean> result = ForestryUtils.getInventoryOfPotentialStorageItem(stack).map(inventory -> {
+                for (int i = 0; i < inventory.getSizeInventory(); i++) {
+                    // This does a recursive call, but backpacks cannot store other backpacks, so we won't run into
+                    // StackOverflowExceptions.
+                    if (inventory.getStackInSlot(i) != null && isStackSatisfies(inventory.getStackInSlot(i))) {
+                        return true;
+                    }
+                }
+
+                // None of the inventory slots contained the item we were looking for.
+                return false;
+            });
+            if (result.isPresent()) {
+                return result.get();
+            }
+        }
+
         return StackInfo.equalItemAndNBT(targetStack, stack, true);
     }
 

src/main/java/com/gtnh/findit/util/mods/ForestryUtils.java

@@ -0,0 +1,37 @@
+package com.gtnh.findit.util.mods;
+
+import java.util.Optional;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.inventory.IInventory;
+import net.minecraft.item.Item;
+import net.minecraft.item.ItemStack;
+
+import forestry.storage.inventory.ItemInventoryBackpack;
+import forestry.storage.items.ItemBackpack;
+
+public class ForestryUtils {
+
+    private ForestryUtils() {}
+
+    public static Optional<IInventory> getInventoryOfPotentialStorageItem(ItemStack potentialBackpackItemStack) {
+        // Checks for Forestry backpacks.
+        Item item = potentialBackpackItemStack.getItem();
+        if (item instanceof ItemBackpack) {
+            ItemBackpack backpack = (ItemBackpack) item;
+
+            // We're running the GUI code client-side only, thus the only player interacting with the GUI is the
+            // player that the backpack's inventory is checked against.
+            EntityPlayer player = Minecraft.getMinecraft().thePlayer;
+
+            ItemInventoryBackpack inventory = new ItemInventoryBackpack(
+                    player,
+                    backpack.getBackpackSize(),
+                    potentialBackpackItemStack);
+            return Optional.of(inventory);
+        }
+
+        return Optional.empty();
+    }
+}