feat: add ExampleListener to handle events

include/example_listener.h

@@ -0,0 +1,19 @@
+// Copyright (c) 2024, The Endstone Project. (https://endstone.dev) All Rights Reserved.
+
+#pragma once
+
+#include "endstone/event/server/server_load_event.h"
+#include "endstone/plugin/plugin.h"
+
+class ExampleListener {
+public:
+    explicit ExampleListener(endstone::Plugin &plugin) : plugin_(plugin) {}
+
+    void onServerLoad(endstone::ServerLoadEvent &event)
+    {
+        plugin_.getLogger().info("ServerLoadEvent is passed to ExampleListener::onServerLoad");
+    }
+
+private:
+    endstone::Plugin &plugin_;
+};

include/example_plugin.h

@@ -1,10 +1,16 @@
 // Copyright (c) 2024, The Endstone Project. (https://endstone.dev) All Rights Reserved.
 
 #include "endstone/command/plugin_command.h"
+#include "endstone/event/server/server_command_event.h"
+#include "endstone/event/server/server_load_event.h"
 #include "endstone/plugin/plugin.h"
 #include "endstone/util/color_format.h"
+#include "example_listener.h"
 #include "fibonacci_command.h"
 
+#include <memory>
+#include <vector>
+
 class ExamplePlugin : public endstone::Plugin {
 public:
     void onLoad() override
@@ -15,9 +21,16 @@ class ExamplePlugin : public endstone::Plugin {
     void onEnable() override
     {
         getLogger().info("onEnable is called");
+
         if (auto *command = getCommand("fibonacci")) {
             command->setExecutor(std::make_unique<FibonacciCommandExecutor>());
         }
+
+        registerEventHandler<endstone::ServerLoadEvent>(&ExamplePlugin::onServerLoad, *this);
+
+        listener_ = std::make_unique<ExampleListener>(*this);
+        registerEventHandler<endstone::ServerLoadEvent>(&ExampleListener::onServerLoad, *listener_,
+                                                        endstone::EventPriority::HIGH);
     }
 
     void onDisable() override
@@ -42,4 +55,12 @@ class ExamplePlugin : public endstone::Plugin {
         sender.sendErrorMessage("Unknown command: /{}", command.getName());
         return false;
     }
+
+    void onServerLoad(endstone::ServerLoadEvent &event)
+    {
+        getLogger().info("ServerLoadEvent is passed to ExamplePlugin::onServerLoad");
+    }
+
+private:
+    std::unique_ptr<ExampleListener> listener_;
 };