Add support for food items

src/client/java/xyz/twokilohertz/HotbarReplace.java

@@ -50,8 +50,7 @@ public class HotbarReplace implements ClientModInitializer {
                 // I honestly do not know Minecraft internals enough to be sure that there won't
                 // be de-sync issues.
 
-                int current_fps = client.getCurrentFps();
+               final int click_delay_ms = 50;
-                int click_delay = Math.round(1.0f / (float) current_fps) * 1000;
 
                 client.interactionManager.clickSlot(player.currentScreenHandler.syncId, i, GLFW.GLFW_MOUSE_BUTTON_1,
                         SlotActionType.PICKUP, player);
@@ -62,7 +61,7 @@ public class HotbarReplace implements ClientModInitializer {
                     client.interactionManager.clickSlot(player.currentScreenHandler.syncId,
                             slot + PlayerInventory.MAIN_SIZE, GLFW.GLFW_MOUSE_BUTTON_1,
                             SlotActionType.PICKUP, player);
-                }, click_delay, TimeUnit.MILLISECONDS);
+                }, click_delay_ms, TimeUnit.MILLISECONDS);
 
                 return;
             }

src/client/java/xyz/twokilohertz/mixin/ItemStackMixin.java

@@ -22,28 +22,54 @@ public class ItemStackMixin {
     @Inject(at = @At("HEAD"), method = "use")
     private void ItemStack_use_HEAD(World world, PlayerEntity player, Hand hand,
             CallbackInfoReturnable<ActionResult> info) {
-        lastUsedItem = player.getStackInHand(hand).getItem();
+        if (!world.isClient())
+            return;
+
+        Item item = player.getStackInHand(hand).getItem();
+        if (item == null)
+            return;
+
+        lastUsedItem = item;
     }
 
     @Inject(at = @At("HEAD"), method = "useOnBlock")
     private void ItemStack_useOnBlock_HEAD(ItemUsageContext context,
             CallbackInfoReturnable<ActionResult> info) {
-        lastUsedItem = context.getPlayer().getStackInHand(context.getHand()).getItem();
+        if (!context.getWorld().isClient())
+            return;
+
+        Item item = context.getPlayer().getStackInHand(context.getHand()).getItem();
+        if (item == null)
+            return;
+
+        lastUsedItem = item;
     }
 
     @Inject(at = @At("HEAD"), method = "useOnEntity")
     private void ItemStack_useOnEntity_HEAD(PlayerEntity player, LivingEntity entity, Hand hand,
             CallbackInfoReturnable<ActionResult> info) {
-        lastUsedItem = player.getStackInHand(hand).getItem();
+        if (!player.getWorld().isClient())
+            return;
+
+        Item item = player.getStackInHand(hand).getItem();
+        if (item == null)
+            return;
+
+        lastUsedItem = item;
     }
 
     @Inject(at = @At("TAIL"), method = "use")
     private void ItemStack_use_TAIL(World world, PlayerEntity player, Hand hand,
             CallbackInfoReturnable<ActionResult> info) {
+        if (!world.isClient())
+            return;
+
         if (info.getReturnValue() != ActionResult.SUCCESS)
             return;
 
-        if (player.getStackInHand(hand).getCount() != 0)
+        ItemStack stack = player.getStackInHand(hand);
+
+        if (stack.getCount() > 1)
             return;
 
         HotbarReplace.tryReplaceSlot(player, hand, lastUsedItem);
@@ -51,13 +77,17 @@ public class ItemStackMixin {
 
     @Inject(at = @At("TAIL"), method = "useOnBlock")
     private void ItemStack_useOnBlock_TAIL(ItemUsageContext context, CallbackInfoReturnable<ActionResult> info) {
+        if (!context.getWorld().isClient())
+            return;
+
         if (info.getReturnValue() != ActionResult.SUCCESS)
             return;
 
         PlayerEntity player = context.getPlayer();
         Hand hand = context.getHand();
+        ItemStack stack = player.getStackInHand(hand);
 
-        if (player.getStackInHand(hand).getCount() != 0)
+        if (stack.getCount() != 0)
             return;
 
         HotbarReplace.tryReplaceSlot(player, hand, lastUsedItem);
@@ -69,9 +99,38 @@ public class ItemStackMixin {
         if (info.getReturnValue() != ActionResult.SUCCESS)
             return;
 
-        if (player.getStackInHand(hand).getCount() != 0)
+        ItemStack stack = player.getStackInHand(hand);
+
+        if (stack.getCount() > 1)
             return;
 
         HotbarReplace.tryReplaceSlot(player, hand, lastUsedItem);
     }
+
+    @Inject(at = @At("HEAD"), method = "Lnet/minecraft/item/ItemStack;finishUsing(Lnet/minecraft/world/World;Lnet/minecraft/entity/LivingEntity;)Lnet/minecraft/item/ItemStack;")
+    private void ItemStack_finishUsing_HEAD(World world, LivingEntity user,
+            CallbackInfoReturnable<ItemStack> info) {
+        if (!world.isClient())
+            return;
+
+        ItemStack stack = (ItemStack) (Object) this;
+        // ItemStack stack = info.getReturnValue(); -- only applicable when injecting at TAIL
+
+        if (lastUsedItem != stack.getItem())
+            return;
+
+        // Food items disappear into thin (minecraft:)air before their stack size reaches 0
+        if (stack.getCount() > 1)
+            return;
+
+        if (!user.isPlayer())
+            return;
+
+        PlayerEntity player = (PlayerEntity) user;
+
+        if (!player.isMainPlayer())
+            return;
+
+        HotbarReplace.tryReplaceSlot(player, player.getActiveHand(), lastUsedItem);
+    }
 }

src/client/resources/hotbarreplace.mixins.json

@@ -6,6 +6,7 @@
   "client": [
     "ItemStackMixin"
   ],
+  "server": [],
   "injectors": {
     "defaultRequire": 1
   }