Added Flags#LEAF_DECAY

src/main/java/world/bentobox/bentobox/listeners/flags/settings/DecayListener.java

@@ -0,0 +1,33 @@
+package world.bentobox.bentobox.listeners.flags.settings;
+
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.block.LeavesDecayEvent;
+import world.bentobox.bentobox.api.flags.FlagListener;
+import world.bentobox.bentobox.database.objects.Island;
+import world.bentobox.bentobox.lists.Flags;
+
+import java.util.Optional;
+
+/**
+ * Handles {@link world.bentobox.bentobox.lists.Flags#LEAF_DECAY}.
+ * @author Poslovitch
+ * @since 1.4.0
+ */
+public class DecayListener extends FlagListener {
+
+    /**
+     * Prevents leaves from decaying.
+     * @param e event
+     */
+    @EventHandler(priority = EventPriority.LOW, ignoreCancelled = true)
+    public void onLeavesDecay(LeavesDecayEvent e) {
+        if (!getIWM().inWorld(e.getBlock().getLocation())) {
+            return;
+        }
+
+        Optional<Island> island = getIslands().getIslandAt(e.getBlock().getLocation());
+        // Cancel the event if needed - this means if this is not allowed on the island or in the world.
+        e.setCancelled(island.map(i -> !i.isAllowed(Flags.LEAF_DECAY)).orElse(!Flags.LEAF_DECAY.isSetForWorld(e.getBlock().getWorld())));
+    }
+}

src/main/java/world/bentobox/bentobox/lists/Flags.java

@@ -32,6 +32,7 @@ import world.bentobox.bentobox.listeners.flags.protection.ShearingListener;
 import world.bentobox.bentobox.listeners.flags.protection.TNTListener;
 import world.bentobox.bentobox.listeners.flags.protection.TeleportationListener;
 import world.bentobox.bentobox.listeners.flags.protection.ThrowingListener;
+import world.bentobox.bentobox.listeners.flags.settings.DecayListener;
 import world.bentobox.bentobox.listeners.flags.settings.MobSpawnListener;
 import world.bentobox.bentobox.listeners.flags.settings.PVPListener;
 import world.bentobox.bentobox.listeners.flags.worldsettings.ChestDamageListener;
@@ -263,6 +264,13 @@ public final class Flags {
             .listener(new MobSpawnListener()).build();
     public static final Flag MONSTER_SPAWN = new Flag.Builder("MONSTER_SPAWN", Material.SPAWNER).defaultSetting(true).type(Type.SETTING).build();
 
+    /**
+     * If {@code false}, prevents leaves from disappearing.
+     * @since 1.4.0
+     * @see DecayListener
+     */
+    public static final Flag LEAF_DECAY = new Flag.Builder("LEAF_DECAY", Material.OAK_LEAVES).type(Type.SETTING).listener(new DecayListener()).defaultSetting(true).build();
+
     /*
      * World Settings - they apply to every island in the game worlds.
      */

src/main/resources/locales/en-US.yml

@@ -693,6 +693,9 @@ protection:
       description: "Toggle usage"
       name: "Jukebox use"
       hint: "No jukebox use allowed"
+    LEAF_DECAY:
+      name: "Leaf decay"
+      description: "Allow leaves to naturally decay"
     LEASH: 
       description: "Toggle use"
       name: "Leash use"