Fix warnings regarding PlotSquared flags

src/main/java/de/epiceric/shopchest/ShopChest.java

@@ -278,7 +278,7 @@ public class ShopChest extends JavaPlugin {
         }
 
         if (hasPlotSquared()) {
-            new PlotSquaredShopFlag().register(this);
+            PlotSquaredShopFlag.register(this);
         }
     }
 

src/main/java/de/epiceric/shopchest/external/PlotSquaredShopFlag.java

@@ -2,6 +2,10 @@ package de.epiceric.shopchest.external;
 
 import com.intellectualcrafters.plot.flag.Flag;
 import com.intellectualcrafters.plot.flag.Flags;
+import com.intellectualcrafters.plot.object.Plot;
+
+import org.bukkit.entity.Player;
+
 import de.epiceric.shopchest.ShopChest;
 
 import java.util.Locale;
@@ -14,30 +18,53 @@ public class PlotSquaredShopFlag {
         OWNERS, MEMBERS, TRUSTED, EVERYONE, NONE
     }
 
-    public static Flag CREATE_SHOP;
+    public static GroupFlag CREATE_SHOP = new GroupFlag("create-shop");
-    public static Flag USE_SHOP;
+    public static GroupFlag USE_SHOP = new GroupFlag("use-shop");
-    public static Flag USE_ADMIN_SHOP;
+    public static GroupFlag USE_ADMIN_SHOP = new GroupFlag("use-admin-shop");
 
-    private GroupFlag createShop = new GroupFlag("create-shop");
+    public static void register(ShopChest plugin) {
-    private GroupFlag useShop = new GroupFlag("use-shop");
-    private GroupFlag useAdminShop = new GroupFlag("use-admin-shop");
-
-    public void register(ShopChest plugin) {
         if (registered) return;
 
-        CREATE_SHOP = createShop;
+        Flags.registerFlag(CREATE_SHOP);
-        USE_SHOP = useShop;
+        Flags.registerFlag(USE_SHOP);
-        USE_ADMIN_SHOP = useAdminShop;
+        Flags.registerFlag(USE_ADMIN_SHOP);
-
-        Flags.registerFlag(createShop);
-        Flags.registerFlag(useShop);
-        Flags.registerFlag(useAdminShop);
         registered = true;
 
         plugin.debug("Registered custom PlotSquared flags");
     }
 
-    public class GroupFlag extends Flag<Group> {
+    /**
+     * Check if a flag is allowed for a player on a plot from PlotSquared
+     * @param plot Plot from PlotSquared
+     * @param flag Flag to check
+     * @param p Player to check
+     * @return Whether the flag is allowed for the player
+     */
+    public static boolean isFlagAllowedOnPlot(Plot plot, GroupFlag flag, Player p) {
+        if (plot != null && flag != null) {
+            Group group = plot.getFlag(flag, PlotSquaredShopFlag.Group.NONE);
+            ShopChest.getInstance().debug("Flag " + flag.getName() + " is set to " + group);
+
+            switch (group) {
+                case OWNERS:
+                    return plot.getOwners().contains(p.getUniqueId());
+                case TRUSTED:
+                    return plot.getOwners().contains(p.getUniqueId()) || plot.getTrusted().contains(p.getUniqueId());
+                case MEMBERS:
+                    return plot.getOwners().contains(p.getUniqueId()) || plot.getTrusted().contains(p.getUniqueId()) || plot.getMembers().contains(p.getUniqueId());
+                case EVERYONE:
+                    return true;
+                case NONE:
+                    return false;
+            }
+        }
+
+        ShopChest.getInstance().debug("Flag or plot is null, or value of flag is not a group");
+
+        return true;
+    }
+
+    public static class GroupFlag extends Flag<Group> {
 
         public GroupFlag(String name) {
             super(name);

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

@@ -216,7 +216,7 @@ public class ChestProtectListener implements Listener {
                 com.intellectualcrafters.plot.object.Location loc =
                         new com.intellectualcrafters.plot.object.Location(b.getWorld().getName(), b.getX(), b.getY(), b.getZ());
 
-                externalPluginsAllowed = Utils.isFlagAllowedOnPlot(loc.getOwnedPlot(), PlotSquaredShopFlag.CREATE_SHOP, p);
+                externalPluginsAllowed = PlotSquaredShopFlag.isFlagAllowedOnPlot(loc.getOwnedPlot(), PlotSquaredShopFlag.CREATE_SHOP, p);
             }
 
             if (externalPluginsAllowed && plugin.hasUSkyBlock() && Config.enableUSkyblockIntegration) {

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

@@ -1,7 +1,6 @@
 package de.epiceric.shopchest.listeners;
 
 import com.google.gson.JsonPrimitive;
-import com.intellectualcrafters.plot.flag.Flag;
 import com.intellectualcrafters.plot.object.Plot;
 import com.palmergames.bukkit.towny.object.Resident;
 import com.palmergames.bukkit.towny.object.Town;
@@ -18,6 +17,7 @@ import de.epiceric.shopchest.event.ShopInfoEvent;
 import de.epiceric.shopchest.event.ShopOpenEvent;
 import de.epiceric.shopchest.event.ShopRemoveEvent;
 import de.epiceric.shopchest.external.PlotSquaredShopFlag;
+import de.epiceric.shopchest.external.PlotSquaredShopFlag.GroupFlag;
 import de.epiceric.shopchest.language.LanguageUtils;
 import de.epiceric.shopchest.language.Message;
 import de.epiceric.shopchest.language.Replacement;
@@ -216,7 +216,7 @@ public class ShopInteractListener implements Listener {
                                                     loc.getWorld().getName(), loc.getBlockX(), loc.getBlockY(), loc.getBlockZ());
 
                                             Plot plot = plotLocation.getOwnedPlot();
-                                            externalPluginsAllowed &= Utils.isFlagAllowedOnPlot(plot, PlotSquaredShopFlag.CREATE_SHOP, p);
+                                            externalPluginsAllowed &= PlotSquaredShopFlag.isFlagAllowedOnPlot(plot, PlotSquaredShopFlag.CREATE_SHOP, p);
                                         }
                                     }
 
@@ -450,9 +450,9 @@ public class ShopInteractListener implements Listener {
                                                     new com.intellectualcrafters.plot.object.Location(b.getWorld().getName(), b.getX(), b.getY(), b.getZ());
 
                                             Plot plot = plotLocation.getOwnedPlot();
-                                            Flag flag = (shop.getShopType() == Shop.ShopType.ADMIN ? PlotSquaredShopFlag.USE_ADMIN_SHOP : PlotSquaredShopFlag.USE_SHOP);
+                                            GroupFlag flag = shop.getShopType() == Shop.ShopType.ADMIN ? PlotSquaredShopFlag.USE_ADMIN_SHOP : PlotSquaredShopFlag.USE_SHOP;
 
-                                            externalPluginsAllowed = Utils.isFlagAllowedOnPlot(plot, flag, p);
+                                            externalPluginsAllowed = PlotSquaredShopFlag.isFlagAllowedOnPlot(plot, flag, p);
                                         }
 
                                         if (externalPluginsAllowed && plugin.hasWorldGuard() && Config.enableWorldGuardIntegration) {
@@ -559,9 +559,9 @@ public class ShopInteractListener implements Listener {
                                                     new com.intellectualcrafters.plot.object.Location(b.getWorld().getName(), b.getX(), b.getY(), b.getZ());
 
                                             Plot plot = plotLocation.getOwnedPlot();
-                                            Flag flag = (shop.getShopType() == Shop.ShopType.ADMIN ? PlotSquaredShopFlag.USE_ADMIN_SHOP : PlotSquaredShopFlag.USE_SHOP);
+                                            GroupFlag flag = shop.getShopType() == Shop.ShopType.ADMIN ? PlotSquaredShopFlag.USE_ADMIN_SHOP : PlotSquaredShopFlag.USE_SHOP;
                                             
-                                            externalPluginsAllowed = Utils.isFlagAllowedOnPlot(plot, flag, p);
+                                            externalPluginsAllowed = PlotSquaredShopFlag.isFlagAllowedOnPlot(plot, flag, p);
                                         }
 
                                         if (externalPluginsAllowed && plugin.hasWorldGuard() && Config.enableWorldGuardIntegration) {

src/main/java/de/epiceric/shopchest/utils/Utils.java

@@ -1,10 +1,7 @@
 package de.epiceric.shopchest.utils;
 
-import com.intellectualcrafters.plot.flag.Flag;
-import com.intellectualcrafters.plot.object.Plot;
 import de.epiceric.shopchest.ShopChest;
 import de.epiceric.shopchest.config.Placeholder;
-import de.epiceric.shopchest.external.PlotSquaredShopFlag;
 import de.epiceric.shopchest.language.LanguageUtils;
 import de.epiceric.shopchest.language.Message;
 import de.epiceric.shopchest.language.Replacement;
@@ -225,42 +222,6 @@ public class Utils {
         return item != null && axes.contains(item.getType().toString());
     }
 
-    /**
-     * Check if a flag is allowed for a player on a plot from PlotSquared
-     * @param plot Plot from PlotSquared
-     * @param flag Flag to check
-     * @param p Player to check
-     * @return Whether the flag is allowed for the player
-     */
-    public static boolean isFlagAllowedOnPlot(Plot plot, Flag flag, Player p) {
-        if (plot != null && flag != null) {
-            Object o = plot.getFlag(flag, PlotSquaredShopFlag.Group.NONE);
-
-            if (o instanceof PlotSquaredShopFlag.Group) {
-                PlotSquaredShopFlag.Group group = (PlotSquaredShopFlag.Group) o;
-
-                ShopChest.getInstance().debug("Flag " + flag.getName() + " is set to " + group);
-
-                switch (group) {
-                    case OWNERS:
-                        return plot.getOwners().contains(p.getUniqueId());
-                    case TRUSTED:
-                        return plot.getOwners().contains(p.getUniqueId()) || plot.getTrusted().contains(p.getUniqueId());
-                    case MEMBERS:
-                        return plot.getOwners().contains(p.getUniqueId()) || plot.getTrusted().contains(p.getUniqueId()) || plot.getMembers().contains(p.getUniqueId());
-                    case EVERYONE:
-                        return true;
-                    case NONE:
-                        return false;
-                }
-            }
-        }
-
-        ShopChest.getInstance().debug("Flag or plot is null, or value of flag is not a group");
-
-        return true;
-    }
-
     /**
      * <p>Check if a player is allowed to create a shop that sells or buys the given item.</p>
      * @param player Player to check