Prevent blocks from being placed or pushed above the chest

Fixes #6

lang/de_DE.lang

@@ -1,5 +1,7 @@
 message.shop-created=&6Shop erstellt.
 message.chest-already-shop=&cTruhe ist bereits ein Shop.
+message.chest-blocked=&cÜber der Truhe ist kein Platz.
+message.double-chest-blocked=&cÜber der Truhe ist kein Platz.
 message.shop-removed=&6Shop entfernt.
 message.chest-no-shop=&cTruhe ist kein Shop.
 message.shop-create-not-enough-money=&cNicht genug Geld. Du brauchst &6%CREATION-PRICE% &cum einen Shop zu erstellen.

lang/en_US.lang

@@ -4,6 +4,13 @@ message.shop-created=&6Shop created.
 # Set the message when the clicked chest already is a shop.
 message.chest-already-shop=&cChest already is shop.
 
+# Set the message when there is a block above the clicked chest.
+message.chest-blocked=&cThere must not be a block above the chest.
+
+# Set the message when a player tries to place a chest next to a shop's chest
+# to create a double chest shop, but there is a block above the placed chest.
+message.double-chest-blocked=&cThere must not be a block above the chest.
+
 # Set the message when the clicked shop is removed.
 message.shop-removed=&6Shop removed.
 

src/de/epiceric/shopchest/language/LocalizedMessage.java

@@ -44,6 +44,8 @@ public class LocalizedMessage {
     public enum Message {
         SHOP_CREATED,
         CHEST_ALREADY_SHOP,
+        CHEST_BLOCKED,
+        DOUBLE_CHEST_BLOCKED,
         SHOP_REMOVED,
         CHEST_NO_SHOP,
         SHOP_CREATE_NOT_ENOUGH_MONEY,

src/de/epiceric/shopchest/listeners/ChestProtectListener.java

@@ -8,6 +8,7 @@ import de.epiceric.shopchest.shop.Shop;
 import de.epiceric.shopchest.utils.ShopUtils;
 import org.bukkit.Material;
 import org.bukkit.block.Block;
+import org.bukkit.block.BlockFace;
 import org.bukkit.block.Chest;
 import org.bukkit.block.DoubleChest;
 import org.bukkit.event.EventHandler;
@@ -71,6 +72,7 @@ public class ChestProtectListener implements Listener {
                 Chest l = (Chest) dc.getLeftSide();
 
                 if (ShopUtils.isShop(r.getLocation()) || ShopUtils.isShop(l.getLocation())) {
+                    if (b.getRelative(BlockFace.UP).getType() == Material.AIR) {
                         Shop shop;
 
                         if (b.getLocation().equals(r.getLocation())) {
@@ -85,6 +87,10 @@ public class ChestProtectListener implements Listener {
 
                         Shop newShop = new Shop(shop.getID(), ShopChest.getInstance(), shop.getVendor(), shop.getProduct(), shop.getLocation(), shop.getBuyPrice(), shop.getSellPrice(), shop.getShopType());
                         ShopUtils.addShop(newShop, true);
+                    } else {
+                        e.setCancelled(true);
+                        e.getPlayer().sendMessage(LanguageUtils.getMessage(LocalizedMessage.Message.CHEST_BLOCKED));
+                    }
                 }
 
             }

src/de/epiceric/shopchest/listeners/ItemProtectListener.java

@@ -1,10 +1,18 @@
 package de.epiceric.shopchest.listeners;
 
 
+import de.epiceric.shopchest.utils.ShopUtils;
+import org.bukkit.block.Block;
+import org.bukkit.block.BlockFace;
+import org.bukkit.block.BlockState;
 import org.bukkit.entity.Item;
 import org.bukkit.event.EventHandler;
 import org.bukkit.event.EventPriority;
 import org.bukkit.event.Listener;
+import org.bukkit.event.block.BlockMultiPlaceEvent;
+import org.bukkit.event.block.BlockPistonExtendEvent;
+import org.bukkit.event.block.BlockPistonRetractEvent;
+import org.bukkit.event.block.BlockPlaceEvent;
 import org.bukkit.event.entity.ItemDespawnEvent;
 import org.bukkit.event.inventory.InventoryPickupItemEvent;
 import org.bukkit.event.inventory.InventoryType;
@@ -30,4 +38,46 @@ public class ItemProtectListener implements Listener {
         }
     }
 
+    @EventHandler(priority = EventPriority.HIGH)
+    public void onBlockPlace(BlockPlaceEvent e) {
+        Block b = e.getBlockPlaced();
+        Block below = b.getRelative(BlockFace.DOWN);
+
+        if (ShopUtils.isShop(below.getLocation())) e.setCancelled(true);
+    }
+
+    @EventHandler(priority = EventPriority.HIGH)
+    public void onMultiBlockPlace(BlockMultiPlaceEvent e) {
+        for (BlockState blockState : e.getReplacedBlockStates()) {
+            Block below = blockState.getBlock().getRelative(BlockFace.DOWN);
+            if (ShopUtils.isShop(below.getLocation())) e.setCancelled(true);
+        }
+    }
+
+    @EventHandler(priority = EventPriority.HIGH)
+    public void onPistonExtend(BlockPistonExtendEvent e) {
+        // If the piston would only move itself
+        Block airAfterPiston = e.getBlock().getRelative(e.getDirection());
+        Block belowAir = airAfterPiston.getRelative(BlockFace.DOWN);
+        if (ShopUtils.isShop(belowAir.getLocation())) {
+            e.setCancelled(true);
+            return;
+        }
+
+        for (Block b : e.getBlocks()) {
+            Block newBlock = b.getRelative(e.getDirection());
+            Block belowNewBlock = newBlock.getRelative(BlockFace.DOWN);
+            if (ShopUtils.isShop(belowNewBlock.getLocation())) e.setCancelled(true);
+        }
+    }
+
+    @EventHandler(priority = EventPriority.HIGH)
+    public void onPistonRetract(BlockPistonRetractEvent e) {
+        for (Block b : e.getBlocks()) {
+            Block newBlock = b.getRelative(e.getDirection());
+            Block belowNewBlock = newBlock.getRelative(BlockFace.DOWN);
+            if (ShopUtils.isShop(belowNewBlock.getLocation())) e.setCancelled(true);
+        }
+    }
+
 }

src/de/epiceric/shopchest/listeners/ShopInteractListener.java

@@ -20,6 +20,7 @@ import org.bukkit.Bukkit;
 import org.bukkit.Location;
 import org.bukkit.Material;
 import org.bukkit.block.Block;
+import org.bukkit.block.BlockFace;
 import org.bukkit.block.Chest;
 import org.bukkit.enchantments.Enchantment;
 import org.bukkit.entity.Player;
@@ -92,6 +93,7 @@ public class ShopInteractListener implements Listener {
 
 
                                 if (!ShopUtils.isShop(b.getLocation())) {
+                                    if (b.getRelative(BlockFace.UP).getType() == Material.AIR) {
                                         ClickType clickType = ClickType.getPlayerClickType(p);
                                         ItemStack product = clickType.getProduct();
                                         double buyPrice = clickType.getBuyPrice();
@@ -99,6 +101,9 @@ public class ShopInteractListener implements Listener {
                                         ShopType shopType = clickType.getShopType();
 
                                         create(p, b.getLocation(), product, buyPrice, sellPrice, shopType);
+                                    } else {
+                                        p.sendMessage(LanguageUtils.getMessage(LocalizedMessage.Message.CHEST_BLOCKED));
+                                    }
                                 } else {
                                     p.sendMessage(LanguageUtils.getMessage(LocalizedMessage.Message.CHEST_ALREADY_SHOP));
                                 }