Add the flower pot modify event (#47)

src/main/java/xyz/nucleoid/stimuli/event/block/FlowerPotModifyEvent.java

@@ -0,0 +1,38 @@
+package xyz.nucleoid.stimuli.event.block;
+
+import net.minecraft.block.FlowerPotBlock;
+import net.minecraft.server.network.ServerPlayerEntity;
+import net.minecraft.util.ActionResult;
+import net.minecraft.util.Hand;
+import net.minecraft.util.hit.BlockHitResult;
+import xyz.nucleoid.stimuli.event.StimulusEvent;
+
+/**
+ * Called when a {@link FlowerPotBlock} is interacted with in a way that would cause the contents of the flower pot to change.
+ * An empty stack in the given hand represents a flower pot being emptied, while a non-empty stack represents a flower being potted.
+ *
+ * <p>Upon return:
+ * <ul>
+ * <li>{@link ActionResult#SUCCESS} cancels further processing and allows the flower pot to be modified.
+ * <li>{@link ActionResult#FAIL} cancels further processing and cancels the modification.
+ * <li>{@link ActionResult#PASS} moves on to the next listener.</ul>
+ * <p>
+ * If all listeners return {@link ActionResult#PASS}, the modification succeeds and proceeds with normal logic.
+ */
+public interface FlowerPotModifyEvent {
+    StimulusEvent<FlowerPotModifyEvent> EVENT = StimulusEvent.create(FlowerPotModifyEvent.class, ctx -> (player, hand, hitResult) -> {
+        try {
+            for (var listener : ctx.getListeners()) {
+                var result = listener.onModifyFlowerPot(player, hand, hitResult);
+                if (result != ActionResult.PASS) {
+                    return result;
+                }
+            }
+        } catch (Throwable t) {
+            ctx.handleException(t);
+        }
+        return ActionResult.PASS;
+    });
+
+    ActionResult onModifyFlowerPot(ServerPlayerEntity player, Hand hand, BlockHitResult hitResult);
+}

src/main/java/xyz/nucleoid/stimuli/mixin/block/FlowerPotBlockMixin.java

@@ -0,0 +1,43 @@
+package xyz.nucleoid.stimuli.mixin.block;
+
+import net.minecraft.block.BlockState;
+import net.minecraft.block.FlowerPotBlock;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.network.packet.s2c.play.ScreenHandlerSlotUpdateS2CPacket;
+import net.minecraft.server.network.ServerPlayerEntity;
+import net.minecraft.util.ActionResult;
+import net.minecraft.util.Hand;
+import net.minecraft.util.hit.BlockHitResult;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.World;
+import org.objectweb.asm.Opcodes;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+import xyz.nucleoid.stimuli.Stimuli;
+import xyz.nucleoid.stimuli.event.block.FlowerPotModifyEvent;
+
+@Mixin(FlowerPotBlock.class)
+public class FlowerPotBlockMixin {
+    // After 'if (noPottedBlock != this.isEmpty()) {'
+    @Inject(method = "onUse", at = @At(value = "JUMP", opcode = Opcodes.IF_ICMPEQ, ordinal = 0, shift = At.Shift.AFTER), cancellable = true)
+    private void onModifyFlowerPot(BlockState state, World world, BlockPos pos, PlayerEntity player, Hand hand, BlockHitResult hitResult, CallbackInfoReturnable<ActionResult> ci) {
+        if (!(player instanceof ServerPlayerEntity serverPlayer)) {
+            return;
+        }
+
+        try (var invokers = Stimuli.select().forEntityAt(serverPlayer, pos)) {
+            var result = invokers.get(FlowerPotModifyEvent.EVENT).onModifyFlowerPot(serverPlayer, hand, hitResult);
+
+            if (result == ActionResult.FAIL) {
+                // notify the client that this action did not go through
+                int slot = hand == Hand.MAIN_HAND ? serverPlayer.getInventory().selectedSlot : 40;
+                var stack = serverPlayer.getStackInHand(hand);
+                serverPlayer.networkHandler.sendPacket(new ScreenHandlerSlotUpdateS2CPacket(ScreenHandlerSlotUpdateS2CPacket.UPDATE_PLAYER_INVENTORY_SYNC_ID, 0, slot, stack));
+
+                ci.setReturnValue(ActionResult.CONSUME);
+            }
+        }
+    }
+}

src/main/resources/stimuli.mixins.json

@@ -13,6 +13,7 @@
     "block.DispenserBlockMixin",
     "block.DropperBlockMixin",
     "block.FarmlandBlockMixin",
+    "block.FlowerPotBlockMixin",
     "block.TurtleEggBlockMixin",
     "entity.LivingEntityMixin",
     "entity.ShearableEntityMixin",