Refactor KeyboardMonitor to use generic event system (#16)

* Initial plan

* Refactor KeyboardMonitor to use generic event system

Co-authored-by: lijy91 <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: lijy91 <[email protected]>

Author: Copilot

src/capi/keyboard_monitor_c.cpp

@@ -1,25 +1,32 @@
 #include "keyboard_monitor_c.h"
 #include "../keyboard_monitor.h"
+#include "../keyboard_events.h"
 #include <memory>
 
 // Internal structure to hold C API state
 struct native_keyboard_monitor_t {
   std::unique_ptr<nativeapi::KeyboardMonitor> cpp_monitor;
-  std::unique_ptr<nativeapi::KeyboardEventHandler> event_handler;
 
   // Store C callback functions and user data
   native_key_pressed_callback_t on_key_pressed;
   native_key_released_callback_t on_key_released;
   native_modifier_keys_changed_callback_t on_modifier_keys_changed;
   void* user_data;
 
+  // Store listener IDs for cleanup
+  size_t key_pressed_listener_id;
+  size_t key_released_listener_id;
+  size_t modifier_keys_listener_id;
+  
   native_keyboard_monitor_t() 
     : cpp_monitor(nullptr), 
-      event_handler(nullptr),
       on_key_pressed(nullptr),
       on_key_released(nullptr),
       on_modifier_keys_changed(nullptr),
-      user_data(nullptr) {}
+      user_data(nullptr),
+      key_pressed_listener_id(0),
+      key_released_listener_id(0),
+      modifier_keys_listener_id(0) {}
 };
 
 // Helper function to convert C++ ModifierKey enum to C enum
@@ -88,41 +95,49 @@ bool native_keyboard_monitor_set_callbacks(
     return false;
   }
 
+  // Remove existing listeners if any
+  if (monitor->key_pressed_listener_id > 0) {
+    monitor->cpp_monitor->RemoveListener(monitor->key_pressed_listener_id);
+  }
+  if (monitor->key_released_listener_id > 0) {
+    monitor->cpp_monitor->RemoveListener(monitor->key_released_listener_id);
+  }
+  if (monitor->modifier_keys_listener_id > 0) {
+    monitor->cpp_monitor->RemoveListener(monitor->modifier_keys_listener_id);
+  }
+  
   // Store the C callbacks and user data
   monitor->on_key_pressed = on_key_pressed;
   monitor->on_key_released = on_key_released;
   monitor->on_modifier_keys_changed = on_modifier_keys_changed;
   monitor->user_data = user_data;
 
   try {
-    // Create C++ lambda callbacks that call the C callbacks
-    auto key_pressed_callback = [monitor](int keycode) {
-      if (monitor->on_key_pressed) {
-        monitor->on_key_pressed(keycode, monitor->user_data);
-      }
-    };
-    
-    auto key_released_callback = [monitor](int keycode) {
-      if (monitor->on_key_released) {
-        monitor->on_key_released(keycode, monitor->user_data);
-      }
-    };
-    
-    auto modifier_keys_changed_callback = [monitor](uint32_t modifier_keys) {
-      if (monitor->on_modifier_keys_changed) {
-        uint32_t c_modifier_keys = convert_modifier_keys_to_c(modifier_keys);
-        monitor->on_modifier_keys_changed(c_modifier_keys, monitor->user_data);
-      }
-    };
+    // Add event listeners with callback lambdas
+    if (on_key_pressed) {
+      monitor->key_pressed_listener_id = monitor->cpp_monitor->AddListener<nativeapi::KeyPressedEvent>(
+        [monitor](const nativeapi::KeyPressedEvent& event) {
+          monitor->on_key_pressed(event.GetKeycode(), monitor->user_data);
+        }
+      );
+    }
 
-    // Create the event handler with the lambda callbacks
-    monitor->event_handler = std::make_unique<nativeapi::KeyboardEventHandler>(
-        key_pressed_callback,
-        key_released_callback,
-        modifier_keys_changed_callback);
+    if (on_key_released) {
+      monitor->key_released_listener_id = monitor->cpp_monitor->AddListener<nativeapi::KeyReleasedEvent>(
+        [monitor](const nativeapi::KeyReleasedEvent& event) {
+          monitor->on_key_released(event.GetKeycode(), monitor->user_data);
+        }
+      );
+    }
 
-    // Set the event handler on the keyboard monitor
-    monitor->cpp_monitor->SetEventHandler(monitor->event_handler.get());
+    if (on_modifier_keys_changed) {
+      monitor->modifier_keys_listener_id = monitor->cpp_monitor->AddListener<nativeapi::ModifierKeysChangedEvent>(
+        [monitor](const nativeapi::ModifierKeysChangedEvent& event) {
+          uint32_t c_modifier_keys = convert_modifier_keys_to_c(event.GetModifierKeys());
+          monitor->on_modifier_keys_changed(c_modifier_keys, monitor->user_data);
+        }
+      );
+    }
 
     return true;
   } catch (...) {

src/keyboard_events.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include "event.h"
+#include "keyboard_monitor.h"
+
+namespace nativeapi {
+
+/**
+ * Event fired when a key is pressed.
+ */
+class KeyPressedEvent : public TypedEvent<KeyPressedEvent> {
+ public:
+  explicit KeyPressedEvent(int keycode) : keycode_(keycode) {}
+
+  int GetKeycode() const { return keycode_; }
+
+  std::string GetTypeName() const override { return "KeyPressedEvent"; }
+
+ private:
+  int keycode_;
+};
+
+/**
+ * Event fired when a key is released.
+ */
+class KeyReleasedEvent : public TypedEvent<KeyReleasedEvent> {
+ public:
+  explicit KeyReleasedEvent(int keycode) : keycode_(keycode) {}
+
+  int GetKeycode() const { return keycode_; }
+
+  std::string GetTypeName() const override { return "KeyReleasedEvent"; }
+
+ private:
+  int keycode_;
+};
+
+/**
+ * Event fired when modifier keys change.
+ */
+class ModifierKeysChangedEvent : public TypedEvent<ModifierKeysChangedEvent> {
+ public:
+  explicit ModifierKeysChangedEvent(uint32_t modifier_keys) : modifier_keys_(modifier_keys) {}
+
+  uint32_t GetModifierKeys() const { return modifier_keys_; }
+
+  std::string GetTypeName() const override { return "ModifierKeysChangedEvent"; }
+
+ private:
+  uint32_t modifier_keys_;
+};
+
+}  // namespace nativeapi

src/keyboard_monitor.cpp

@@ -4,6 +4,9 @@
 #include <memory>
 #include <string>
 
+#include "event_dispatcher.h"
+#include "keyboard_events.h"
+
 namespace nativeapi {
 
 enum class ModifierKey : uint32_t {
@@ -18,37 +21,42 @@ enum class ModifierKey : uint32_t {
   ScrollLock = 1 << 7
 };
 
-// KeyboardEventHandler uses callbacks to handle keyboard events.
-class KeyboardEventHandler {
- public:
-  // Constructor that takes callbacks for keyboard events
-  KeyboardEventHandler(
-      std::function<void(int)> onKeyPressedCallback,
-      std::function<void(int)> onKeyReleasedCallback,
-      std::function<void(uint32_t)> onModifierKeysChangedCallback);
-
-  // Handle key pressed event
-  void OnKeyPressed(int keycode);
-
-  // Handle key released event
-  void OnKeyReleased(int keycode);
+// Bitwise operators for ModifierKey enum
+inline ModifierKey operator|(ModifierKey a, ModifierKey b) {
+  return static_cast<ModifierKey>(static_cast<uint32_t>(a) | static_cast<uint32_t>(b));
+}
 
-  // Handle modifier keys changed event
-  void OnModifierKeysChanged(uint32_t modifier_keys);
-
- private:
-  std::function<void(int)> onKeyPressedCallback_;
-  std::function<void(int)> onKeyReleasedCallback_;
-  std::function<void(uint32_t)> onModifierKeysChangedCallback_;
-};
+inline ModifierKey operator&(ModifierKey a, ModifierKey b) {
+  return static_cast<ModifierKey>(static_cast<uint32_t>(a) & static_cast<uint32_t>(b));
+}
 
 class KeyboardMonitor {
  public:
   KeyboardMonitor();
   virtual ~KeyboardMonitor();
 
-  // Set the event handler for the keyboard monitor
-  void SetEventHandler(KeyboardEventHandler* event_handler);
+  // Add a listener for keyboard events
+  template<typename EventType>
+  size_t AddListener(TypedEventListener<EventType>* listener) {
+    return event_dispatcher_.AddListener(listener);
+  }
+
+  // Add a callback-based listener for keyboard events
+  template<typename EventType>
+  size_t AddListener(std::function<void(const EventType&)> callback) {
+    return event_dispatcher_.AddListener(std::move(callback));
+  }
+
+  // Remove a listener by ID
+  bool RemoveListener(size_t listener_id) {
+    return event_dispatcher_.RemoveListener(listener_id);
+  }
+
+  // Remove all listeners for a specific event type
+  template<typename EventType>
+  void RemoveAllListeners() {
+    event_dispatcher_.RemoveAllListeners<EventType>();
+  }
 
   // Start the keyboard monitor
   void Start();
@@ -59,13 +67,17 @@ class KeyboardMonitor {
   // Check if the keyboard monitor is monitoring
   bool IsMonitoring() const;
 
-  // Get the event handler
-  KeyboardEventHandler* GetEventHandler() const { return event_handler_; }
+  // Get access to the event dispatcher for advanced usage
+  EventDispatcher& GetEventDispatcher() { return event_dispatcher_; }
 
  private:
   class Impl;
   std::unique_ptr<Impl> impl_;
-  KeyboardEventHandler* event_handler_;
+  EventDispatcher event_dispatcher_;
+
+  // Internal method for dispatching events from platform code
+  void DispatchEvent(const Event& event);
+  friend class Impl;
 };
 
 }  // namespace nativeapi

src/keyboard_monitor.h

@@ -37,7 +37,7 @@ class KeyboardMonitor::Impl {
   uint32_t GetModifierState();
 };
 
-KeyboardMonitor::KeyboardMonitor() : impl_(std::make_unique<Impl>(this)), event_handler_(nullptr) {}
+KeyboardMonitor::KeyboardMonitor() : impl_(std::make_unique<Impl>(this)), event_dispatcher_() {}
 
 KeyboardMonitor::~KeyboardMonitor() {
   Stop();
@@ -154,15 +154,18 @@ void KeyboardMonitor::Impl::MonitoringLoop() {
         if (XGetEventData(display_, &event.xcookie)) {
           XIDeviceEvent* xi_event = (XIDeviceEvent*)event.xcookie.data;
 
-          auto* eventHandler = monitor_->GetEventHandler();
-          if (eventHandler) {
-            if (xi_event->evtype == XI_KeyPress) {
-              eventHandler->OnKeyPressed(xi_event->detail);
-              eventHandler->OnModifierKeysChanged(GetModifierState());
-            } else if (xi_event->evtype == XI_KeyRelease) {
-              eventHandler->OnKeyReleased(xi_event->detail);
-              eventHandler->OnModifierKeysChanged(GetModifierState());
-            }
+          if (xi_event->evtype == XI_KeyPress) {
+            KeyPressedEvent key_event(xi_event->detail);
+            monitor_->DispatchEvent(key_event);
+            
+            ModifierKeysChangedEvent modifier_event(GetModifierState());
+            monitor_->DispatchEvent(modifier_event);
+          } else if (xi_event->evtype == XI_KeyRelease) {
+            KeyReleasedEvent key_event(xi_event->detail);
+            monitor_->DispatchEvent(key_event);
+            
+            ModifierKeysChangedEvent modifier_event(GetModifierState());
+            monitor_->DispatchEvent(modifier_event);
           }
 
           XFreeEventData(display_, &event.xcookie);
@@ -213,4 +216,8 @@ bool KeyboardMonitor::IsMonitoring() const {
   return impl_->monitoring_;
 }
 
+void KeyboardMonitor::DispatchEvent(const Event& event) {
+  event_dispatcher_.DispatchSync(event);
+}
+
 }  // namespace nativeapi

src/platform/linux/keyboard_monitor_linux.cpp

@@ -19,7 +19,7 @@
   KeyboardMonitor* monitor_;
 };
 
-KeyboardMonitor::KeyboardMonitor() : impl_(std::make_unique<Impl>(this)), event_handler_(nullptr) {}
+KeyboardMonitor::KeyboardMonitor() : impl_(std::make_unique<Impl>(this)), event_dispatcher_() {}
 
 KeyboardMonitor::~KeyboardMonitor() {
   Stop();
@@ -34,17 +34,15 @@ static CGEventRef keyboardEventCallback(CGEventTapProxy proxy,
   if (!monitor)
     return event;
 
-  auto* eventHandler = monitor->GetEventHandler();
-  if (!eventHandler)
-    return event;
-
   // Get the key code
   CGKeyCode keyCode = (CGKeyCode)CGEventGetIntegerValueField(event, kCGKeyboardEventKeycode);
 
   if (type == kCGEventKeyDown) {
-    eventHandler->OnKeyPressed(keyCode);
+    KeyPressedEvent key_event(keyCode);
+    monitor->DispatchEvent(key_event);
   } else if (type == kCGEventKeyUp) {
-    eventHandler->OnKeyReleased(keyCode);
+    KeyReleasedEvent key_event(keyCode);
+    monitor->DispatchEvent(key_event);
   } else if (type == kCGEventFlagsChanged) {
     CGEventFlags flags = CGEventGetFlags(event);
     uint32_t modifier_keys = static_cast<uint32_t>(ModifierKey::None);
@@ -69,7 +67,8 @@ static CGEventRef keyboardEventCallback(CGEventTapProxy proxy,
     if (flags & kCGEventFlagMaskNumericPad) {
       modifier_keys |= static_cast<uint32_t>(ModifierKey::NumLock);
     }
-    eventHandler->OnModifierKeysChanged(modifier_keys);
+    ModifierKeysChangedEvent modifier_event(modifier_keys);
+    monitor->DispatchEvent(modifier_event);
   }
   return event;
 }
@@ -131,4 +130,8 @@ static CGEventRef keyboardEventCallback(CGEventTapProxy proxy,
   return impl_->eventTap != nullptr;
 }
 
+void KeyboardMonitor::DispatchEvent(const Event& event) {
+  event_dispatcher_.DispatchSync(event);
+}
+
 }  // namespace nativeapi