Added initial GUI system

eco-core/core-plugin/src/main/java/com/willfp/eco/spigot/EcoSpigotPlugin.java

@@ -25,6 +25,7 @@ import com.willfp.eco.spigot.eventlisteners.ArmorListener;
 import com.willfp.eco.spigot.eventlisteners.DispenserArmorListener;
 import com.willfp.eco.spigot.eventlisteners.EntityDeathByEntityListeners;
 import com.willfp.eco.spigot.eventlisteners.NaturalExpGainListeners;
+import com.willfp.eco.spigot.gui.GUIListener;
 import com.willfp.eco.spigot.integrations.anticheat.*;
 import com.willfp.eco.spigot.integrations.antigrief.AntigriefCombatLogX;
 import com.willfp.eco.spigot.integrations.antigrief.AntigriefFactionsUUID;
@@ -83,11 +84,6 @@ public class EcoSpigotPlugin extends EcoPlugin {
     @Override
     public void enable() {
         new CollatedRunnable(this);
-        this.getEventManager().registerListener(new NaturalExpGainListeners());
-        this.getEventManager().registerListener(new ArmorListener());
-        this.getEventManager().registerListener(new DispenserArmorListener());
-        this.getEventManager().registerListener(new EntityDeathByEntityListeners(this));
-        this.getEventManager().registerListener(new ShapedRecipeListener());
     }
 
     @Override
@@ -157,7 +153,14 @@ public class EcoSpigotPlugin extends EcoPlugin {
 
     @Override
     public List<Listener> getListeners() {
-        return new ArrayList<>();
+        return Arrays.asList(
+                new NaturalExpGainListeners(),
+                new ArmorListener(),
+                new DispenserArmorListener(),
+                new EntityDeathByEntityListeners(this),
+                new ShapedRecipeListener(),
+                new GUIListener(this)
+        );
     }
 
     @Override

eco-core/core-plugin/src/main/java/com/willfp/eco/spigot/gui/GUIListener.java

@@ -0,0 +1,63 @@
+package com.willfp.eco.spigot.gui;
+
+import com.willfp.eco.core.EcoPlugin;
+import com.willfp.eco.core.PluginDependent;
+import com.willfp.eco.core.gui.menu.Menu;
+import com.willfp.eco.internal.gui.EcoMenu;
+import com.willfp.eco.internal.gui.EcoSlot;
+import com.willfp.eco.internal.gui.MenuHandler;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.inventory.InventoryClickEvent;
+import org.bukkit.event.inventory.InventoryCloseEvent;
+import org.jetbrains.annotations.NotNull;
+
+public class GUIListener extends PluginDependent implements Listener {
+    /**
+     * Pass an {@link EcoPlugin} in order to interface with it.
+     *
+     * @param plugin The plugin to manage.
+     */
+    public GUIListener(@NotNull final EcoPlugin plugin) {
+        super(plugin);
+    }
+
+    @EventHandler
+    public void handleSlotClick(@NotNull final InventoryClickEvent event) {
+        if (!(event.getWhoClicked() instanceof Player)) {
+            return;
+        }
+
+        if (event.getClickedInventory() == null) {
+            return;
+        }
+        Menu menu = MenuHandler.getMenu(event.getClickedInventory());
+        if (menu == null) {
+            return;
+        }
+
+        int row = Math.floorDiv(event.getSlot(), 9);
+        int column = event.getSlot() - (row * 9);
+
+        EcoSlot slot = (EcoSlot) menu.getSlot(row, column);
+        event.setCancelled(true);
+        slot.handleInventoryClick(event);
+    }
+
+    @EventHandler
+    public void handleClose(@NotNull final InventoryCloseEvent event) {
+        if (!(event.getPlayer() instanceof Player)) {
+            return;
+        }
+
+        EcoMenu menu = (EcoMenu) MenuHandler.getMenu(event.getInventory());
+        if (menu == null) {
+            return;
+        }
+
+        menu.handleClose(event);
+
+        this.getPlugin().getScheduler().run(() -> MenuHandler.unregisterMenu(event.getInventory()));
+    }
+}