feat: add concrete-hard flag

- closes #4156

Bukkit/src/main/java/com/plotsquared/bukkit/listener/BlockEventListener.java

@@ -33,6 +33,7 @@ import com.plotsquared.core.plot.PlotArea;
 import com.plotsquared.core.plot.flag.implementations.BlockBurnFlag;
 import com.plotsquared.core.plot.flag.implementations.BlockIgnitionFlag;
 import com.plotsquared.core.plot.flag.implementations.BreakFlag;
+import com.plotsquared.core.plot.flag.implementations.ConcreteHardenFlag;
 import com.plotsquared.core.plot.flag.implementations.CoralDryFlag;
 import com.plotsquared.core.plot.flag.implementations.CropGrowFlag;
 import com.plotsquared.core.plot.flag.implementations.DisablePhysicsFlag;
@@ -586,6 +587,12 @@ public class BlockEventListener implements Listener {
                 event.setCancelled(true);
             }
         }
+        if (event.getNewState().getType().toString().endsWith("CONCRETE")) {
+            if (!plot.getFlag(ConcreteHardenFlag.class)) {
+                plot.debug("Concrete powder could not harden because concrete-harden = false");
+                event.setCancelled(true);
+            }
+        }
     }
 
     @EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)

Core/src/main/java/com/plotsquared/core/plot/flag/GlobalFlagContainer.java

@@ -29,6 +29,7 @@ import com.plotsquared.core.plot.flag.implementations.BlockIgnitionFlag;
 import com.plotsquared.core.plot.flag.implementations.BlockedCmdsFlag;
 import com.plotsquared.core.plot.flag.implementations.BreakFlag;
 import com.plotsquared.core.plot.flag.implementations.ChatFlag;
+import com.plotsquared.core.plot.flag.implementations.ConcreteHardenFlag;
 import com.plotsquared.core.plot.flag.implementations.CopperOxideFlag;
 import com.plotsquared.core.plot.flag.implementations.CoralDryFlag;
 import com.plotsquared.core.plot.flag.implementations.CropGrowFlag;
@@ -142,6 +143,7 @@ public final class GlobalFlagContainer extends FlagContainer {
         this.addFlag(BeaconEffectsFlag.BEACON_EFFECT_TRUE);
         this.addFlag(BlockIgnitionFlag.BLOCK_IGNITION_TRUE);
         this.addFlag(ChatFlag.CHAT_FLAG_TRUE);
+        this.addFlag(ConcreteHardenFlag.CONCRETE_HARDEN_TRUE);
         this.addFlag(CopperOxideFlag.COPPER_OXIDE_FALSE);
         this.addFlag(CoralDryFlag.CORAL_DRY_FALSE);
         this.addFlag(CropGrowFlag.CROP_GROW_TRUE);

Core/src/main/java/com/plotsquared/core/plot/flag/implementations/ConcreteHardenFlag.java

@@ -0,0 +1,39 @@
+/*
+ * PlotSquared, a land and world management plugin for Minecraft.
+ * Copyright (C) IntellectualSites <https://intellectualsites.com>
+ * Copyright (C) IntellectualSites team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.plotsquared.core.plot.flag.implementations;
+
+import com.plotsquared.core.configuration.caption.TranslatableCaption;
+import com.plotsquared.core.plot.flag.types.BooleanFlag;
+import org.checkerframework.checker.nullness.qual.NonNull;
+
+public class ConcreteHardenFlag extends BooleanFlag<ConcreteHardenFlag> {
+
+    public static final ConcreteHardenFlag CONCRETE_HARDEN_TRUE = new ConcreteHardenFlag(true);
+    public static final ConcreteHardenFlag CONCRETE_HARDEN_FALSE = new ConcreteHardenFlag(false);
+
+    private ConcreteHardenFlag(boolean value) {
+        super(value, TranslatableCaption.of("flags.flag_description_ice_form"));
+    }
+
+    @Override
+    protected ConcreteHardenFlag flagOf(@NonNull Boolean value) {
+        return value ? CONCRETE_HARDEN_TRUE : CONCRETE_HARDEN_FALSE;
+    }
+
+}