Added Rule updateSuppressionBlock (#877)

Pull Request for https://github.com/fxmorin/UpdateSuppressionBlock

src/main/java/carpet/CarpetSettings.java

@@ -52,6 +52,7 @@ public class CarpetSettings
     public static boolean chainStoneStickToAll = false;
     public static Block structureBlockIgnoredBlock = Blocks.STRUCTURE_VOID;
     public static final int vanillaStructureBlockLimit = 48;
+    public static int updateSuppressionBlockSetting = -1;
 
     private static class LanguageValidator extends Validator<String> {
         @Override public String validate(ServerCommandSource source, ParsedRule<String> currentRule, String newValue, String string) {
@@ -905,4 +906,48 @@ public class CarpetSettings
             category = {BUGFIX}
     )
     public static boolean lightningKillsDropsFix = false;
+
+    @Rule(
+            desc = "Placing an activator rail on top of a barrier block will update suppress when the rail turns off.",
+            extra = {"Entering an integer will make the update suppression block auto-reset","Integer entered is the delay in ticks for it to reset"},
+            category = {CREATIVE, "extras"},
+            options = {"false","true","1","6"},
+            strict = false,
+            validate = updateSuppressionBlockModes.class
+    )
+    public static String updateSuppressionBlock = "false";
+
+    public static int getInteger(String s) {
+        try {
+            return Integer.parseInt(s);
+        } catch(NumberFormatException e) {
+            return -1;
+        }
+    }
+
+    private static class updateSuppressionBlockModes extends Validator<String> {
+        @Override
+        public String validate(ServerCommandSource source, ParsedRule<String> currentRule, String newValue, String string) {
+            if (!currentRule.get().equals(newValue)) {
+                if (newValue.equalsIgnoreCase("false")) {
+                    updateSuppressionBlockSetting = -1;
+                } else if (newValue.equalsIgnoreCase("true")) {
+                    updateSuppressionBlockSetting = 0;
+                } else {
+                    int parsedInt = getInteger(newValue);
+                    if (parsedInt <= 0) {
+                        updateSuppressionBlockSetting = -1;
+                        return "false";
+                    } else {
+                        updateSuppressionBlockSetting = parsedInt;
+                    }
+                }
+            }
+            return newValue;
+        }
+        @Override
+        public String description() {
+            return "Cannot be negative, can be true, false, or # > 0";
+        }
+    }
 }

src/main/java/carpet/mixins/BarrierBlock_updateSuppressionBlockMixin.java

@@ -0,0 +1,55 @@
+package carpet.mixins;
+
+import carpet.CarpetSettings;
+import net.minecraft.block.BarrierBlock;
+import net.minecraft.block.Block;
+import net.minecraft.block.BlockState;
+import net.minecraft.block.Blocks;
+import net.minecraft.block.PoweredRailBlock;
+import net.minecraft.server.world.ServerWorld;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.Direction;
+import net.minecraft.world.BlockView;
+import net.minecraft.world.World;
+import org.spongepowered.asm.mixin.Mixin;
+
+import java.util.Random;
+
+@Mixin(BarrierBlock.class)
+public class BarrierBlock_updateSuppressionBlockMixin extends Block {
+    private boolean shouldPower = false;
+
+    public BarrierBlock_updateSuppressionBlockMixin(Settings settings) { super(settings); }
+
+    @Override
+    public int getWeakRedstonePower(BlockState state, BlockView world, BlockPos pos, Direction direction) {
+        return (shouldPower && direction == Direction.DOWN) ? 15 : 0;
+    }
+
+    @Override
+    public void neighborUpdate(BlockState state, World world, BlockPos pos, Block block, BlockPos fromPos, boolean notify) {
+        if (CarpetSettings.updateSuppressionBlockSetting != -1) {
+            if (fromPos.equals(pos.up())) {
+                BlockState stateAbove = world.getBlockState(fromPos);
+                if (stateAbove.isOf(Blocks.ACTIVATOR_RAIL) && !stateAbove.get(PoweredRailBlock.POWERED)) {
+                    if (CarpetSettings.updateSuppressionBlockSetting > 0) {
+                        world.getBlockTickScheduler().schedule(pos, this, CarpetSettings.updateSuppressionBlockSetting);
+                    }
+                    throw new StackOverflowError("updateSuppressionBlock");
+                }
+            }
+        }
+        super.neighborUpdate(state, world, pos, block, fromPos, notify);
+    }
+
+    @Override
+    public void scheduledTick(BlockState state, ServerWorld world, BlockPos pos, Random random) {
+        BlockPos posAbove = pos.up();
+        BlockState stateAbove = world.getBlockState(posAbove);
+        if (stateAbove.isOf(Blocks.ACTIVATOR_RAIL) && !stateAbove.get(PoweredRailBlock.POWERED)) {
+            shouldPower = true;
+            world.setBlockState(posAbove, stateAbove.with(PoweredRailBlock.POWERED, true), 3);
+            shouldPower = false;
+        }
+    }
+}

src/main/resources/carpet.mixins.json

@@ -4,6 +4,8 @@
   "package": "carpet.mixins",
   "compatibilityLevel": "JAVA_8",
   "mixins": [
+    "BarrierBlock_updateSuppressionBlockMixin",
+
     "SpawnHelperInnerMixin",
     "CommandManagerMixin",
 
@@ -227,4 +229,4 @@
   "injectors": {
     "defaultRequire": 1
   }
-}
+}