Add initial listener classes

build.gradle.kts

@@ -47,9 +47,9 @@ bukkit {
 
 fun gitCommit(): String {
     val os = ByteArrayOutputStream()
-//    project.exec {
+    project.exec {
-//        commandLine = "git rev-parse --short HEAD".split(" ")
+        commandLine = "git rev-parse --short HEAD".split(" ")
-//        standardOutput = os
+        standardOutput = os
-//    }
+    }
     return String(os.toByteArray()).trim()
 }

src/main/java/com/alttd/playershops/listener/EventListener.java

@@ -0,0 +1,20 @@
+package com.alttd.playershops.listener;
+
+import org.bukkit.Bukkit;
+import org.bukkit.event.HandlerList;
+import org.bukkit.plugin.java.JavaPlugin;
+
+public class EventListener implements org.bukkit.event.Listener {
+    protected boolean isRegistered = false;
+
+    protected void register(JavaPlugin instance) {
+        Bukkit.getServer().getPluginManager().registerEvents(this, instance);
+        isRegistered = true;
+    }
+
+    protected void unregister() {
+        HandlerList.unregisterAll(this);
+        isRegistered = false;
+    }
+
+}

src/main/java/com/alttd/playershops/listener/InventoryListener.java

@@ -0,0 +1,39 @@
+package com.alttd.playershops.listener;
+
+import org.bukkit.OfflinePlayer;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.EventPriority;
+import org.bukkit.event.inventory.InventoryCloseEvent;
+import org.bukkit.event.inventory.InventoryDragEvent;
+import org.bukkit.event.player.PlayerQuitEvent;
+import org.bukkit.inventory.Inventory;
+
+public class InventoryListener extends EventListener {
+
+    protected final Inventory inventory;
+    protected boolean cancelCloseUnregister = false;
+
+    public InventoryListener(Inventory inv) {
+        this.inventory = inv;
+    }
+
+    @EventHandler(ignoreCancelled = true)
+    public void unregisterOnClose(InventoryCloseEvent event) {
+        if (event.getView().getTopInventory().equals(inventory) && !cancelCloseUnregister) unregister();
+    }
+
+    @EventHandler(ignoreCancelled = true)
+    public void unregisterOnLeaveEvent(PlayerQuitEvent event) {
+        if ((inventory.getHolder() instanceof OfflinePlayer) && event.getPlayer().getUniqueId().equals(((OfflinePlayer) inventory.getHolder()).getUniqueId()))
+            unregister();
+    }
+
+    @EventHandler(ignoreCancelled = true, priority = EventPriority.LOWEST)
+    public void onInventoryDrag(InventoryDragEvent event) {
+        if (event.getView().getTopInventory().equals(inventory)) for (int slot : event.getRawSlots()) if (slot < inventory.getSize()) {
+            event.setCancelled(true);
+            return;
+        }
+    }
+
+}