Add basic BlockChangeNotifier & BlockChangeListener

src/main/java/com/gtnewhorizon/structurelib/event/BlockChangeListener.java

@@ -0,0 +1,11 @@
+package com.gtnewhorizon.structurelib.event;
+
+import net.minecraft.block.Block;
+import net.minecraft.world.World;
+import net.minecraft.world.chunk.Chunk;
+
+public interface BlockChangeListener {
+
+    void onBlockChange(World world, Chunk chunk, int x, int y, int z, Block oldBlock, Block newBlock, int oldMeta,
+            int newMeta);
+}

src/main/java/com/gtnewhorizon/structurelib/event/BlockChangeNotifier.java

@@ -0,0 +1,33 @@
+package com.gtnewhorizon.structurelib.event;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import net.minecraft.block.Block;
+import net.minecraft.world.World;
+import net.minecraft.world.chunk.Chunk;
+
+@SuppressWarnings("ForLoopReplaceableByForEach")
+public class BlockChangeNotifier {
+
+    private static final List<BlockChangeListener> listeners = new ArrayList<>();
+
+    public static synchronized void addListener(BlockChangeListener listener) {
+        listeners.add(listener);
+    }
+
+    public static void onBlockChange(World world, Chunk chunk, int x, int y, int z, Block oldBlock, Block newBlock,
+            int oldMeta, int newMeta) {
+        if (oldBlock == newBlock && oldMeta == newMeta) return;
+
+        if (chunk == null) {
+            chunk = world.getChunkFromBlockCoords(x, z);
+        }
+
+        final int numListeners = listeners.size();
+        for (int i = 0; i < numListeners; i++) {
+            final BlockChangeListener listener = listeners.get(i);
+            listener.onBlockChange(world, chunk, x, y, z, oldBlock, newBlock, oldMeta, newMeta);
+        }
+    }
+}

src/main/java/com/gtnewhorizon/structurelib/mixins/Mixins.java

@@ -13,12 +13,9 @@ import cpw.mods.fml.relauncher.FMLLaunchHandler;
 
 public enum Mixins {
 
-    EMPTY(new Builder("Empty").setPhase(Phase.EARLY).addMixinClasses("com.gtnewhorizon.structurelib.mixins.EmptyMixin")
-            .addTargetedMod(TargetedMod.VANILLA).setSide(Side.BOTH).setApplyIf(() -> false));
-    // DISABLE_MODDED_CHUNK_POPULATION(new Builder("Disable all other mod chunk population (e.g. Natura clouds")
-    // .setPhase(Phase.EARLY).addMixinClasses("minecraft.MixinChunkProviderServer_DisableModGeneration")
-    // .addTargetedMod(TargetedMod.VANILLA).setSide(Side.BOTH)
-    // .setApplyIf(() -> TweaksConfig.disableModdedChunkPopulation));
+    BLOCK_CHANGE_NOTIFIER(new Builder("Block Change Notifier").setPhase(Phase.EARLY)
+            .addMixinClasses("blockChangeNotifier.MixinForgeHooks", "blockChangeNotifier.MixinWorld")
+            .addTargetedMod(TargetedMod.VANILLA).setSide(Side.BOTH).setApplyIf(() -> true));
 
     private final List<String> mixinClasses;
     private final List<TargetedMod> targetedMods;

src/main/java/com/gtnewhorizon/structurelib/mixins/early/blockChangeNotifier/MixinForgeHooks.java

@@ -0,0 +1,44 @@
+package com.gtnewhorizon.structurelib.mixins.early.blockChangeNotifier;
+
+import net.minecraft.block.Block;
+import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.item.ItemStack;
+import net.minecraft.world.World;
+import net.minecraftforge.common.ForgeHooks;
+import net.minecraftforge.common.util.BlockSnapshot;
+
+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 com.gtnewhorizon.structurelib.event.BlockChangeNotifier;
+import com.llamalad7.mixinextras.sugar.Local;
+
+@Mixin(ForgeHooks.class)
+public class MixinForgeHooks {
+
+    @Inject(
+            method = "onPlaceItemIntoWorld",
+            at = @At(
+                    value = "INVOKE",
+                    target = "Lnet/minecraft/world/World;markAndNotifyBlock(IIILnet/minecraft/world/chunk/Chunk;Lnet/minecraft/block/Block;Lnet/minecraft/block/Block;I)V",
+                    shift = At.Shift.AFTER),
+            remap = false)
+    private static void onBlockChange(ItemStack itemstack, EntityPlayer player, World world, int x, int y, int z,
+            int side, float hitX, float hitY, float hitZ, CallbackInfoReturnable<Boolean> cir,
+            @Local(name = "blocksnapshot") BlockSnapshot blocksnapshot, @Local(name = "newBlock") Block newBlock,
+            @Local(name = "metadata") int newMetadata) {
+        BlockChangeNotifier.onBlockChange(
+                world,
+                null,
+                blocksnapshot.x,
+                blocksnapshot.y,
+                blocksnapshot.z,
+                blocksnapshot.replacedBlock,
+                newBlock,
+                blocksnapshot.meta,
+                newMetadata);
+    }
+
+}

src/main/java/com/gtnewhorizon/structurelib/mixins/early/blockChangeNotifier/MixinWorld.java

@@ -0,0 +1,55 @@
+package com.gtnewhorizon.structurelib.mixins.early.blockChangeNotifier;
+
+import net.minecraft.block.Block;
+import net.minecraft.world.World;
+import net.minecraft.world.chunk.Chunk;
+
+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 com.gtnewhorizon.structurelib.event.BlockChangeNotifier;
+import com.llamalad7.mixinextras.sugar.Local;
+import com.llamalad7.mixinextras.sugar.Share;
+import com.llamalad7.mixinextras.sugar.ref.LocalIntRef;
+import com.llamalad7.mixinextras.sugar.ref.LocalRef;
+
+@Mixin(World.class)
+public class MixinWorld {
+
+    @Inject(
+            method = "Lnet/minecraft/world/World;setBlock(IIILnet/minecraft/block/Block;II)Z",
+            at = @At(
+                    value = "INVOKE",
+                    target = "Lnet/minecraft/world/World;markAndNotifyBlock(IIILnet/minecraft/world/chunk/Chunk;Lnet/minecraft/block/Block;Lnet/minecraft/block/Block;I)V",
+                    shift = At.Shift.AFTER,
+                    remap = false))
+    public void setBlockObserve(int x, int y, int z, Block newBlock, int newMeta, int flags,
+            CallbackInfoReturnable<Boolean> cir, @Local(name = "block1") Block originalBlock,
+            @Share("originalMeta") LocalIntRef originalMeta, @Share("chunk") LocalRef<Chunk> chunkLocalRef) {
+        BlockChangeNotifier.onBlockChange(
+                (World) ((Object) (this)),
+                chunkLocalRef.get(),
+                x,
+                y,
+                z,
+                originalBlock,
+                newBlock,
+                originalMeta.get(),
+                newMeta);
+    }
+
+    @Inject(
+            method = "Lnet/minecraft/world/World;setBlock(IIILnet/minecraft/block/Block;II)Z",
+            at = @At(
+                    value = "INVOKE",
+                    target = "Lnet/minecraft/world/chunk/Chunk;func_150807_a(IIILnet/minecraft/block/Block;I)Z",
+                    shift = At.Shift.BEFORE))
+    public void captureChunkAndOriginalMetadata(int x, int y, int z, Block blockIn, int metadataIn, int flags,
+            CallbackInfoReturnable<Boolean> cir, @Local(name = "chunk") Chunk chunk,
+            @Share("originalMeta") LocalIntRef originalMeta, @Share("chunk") LocalRef<Chunk> chunkLocalRef) {
+        chunkLocalRef.set(chunk);
+        originalMeta.set(chunk.getBlockMetadata(x & 15, y, z & 15));
+    }
+}