Refactor AccessibilityManager to use singleton pattern

Add GetInstance() method and update usage to enforce singleton. Improve
documentation in headers and update C API to use singleton.

Author: lijy91

examples/window_example/main.cpp

@@ -13,6 +13,11 @@ using nativeapi::WindowManager;
 using nativeapi::WindowOptions;
 
 int main() {
+
+  native_accessibility_manager_enable();
+  bool is_enabled= native_accessibility_manager_is_enabled();
+  std::cout << "is_enabled: " << is_enabled << std::endl;
+
   DisplayManager& display_manager = DisplayManager::GetInstance();
   TrayManager& tray_manager = TrayManager::GetInstance();
   WindowManager& window_manager = WindowManager::GetInstance();

src/accessibility_manager.cpp

@@ -1,9 +1,12 @@
-#include <iostream>
-
 #include "accessibility_manager.h"
 
 namespace nativeapi {
 
+AccessibilityManager& AccessibilityManager::GetInstance() {
+  static AccessibilityManager instance;
+  return instance;
+}
+
 AccessibilityManager::AccessibilityManager() {}
 
 AccessibilityManager::~AccessibilityManager() {}

src/accessibility_manager.h

@@ -2,18 +2,90 @@
 
 namespace nativeapi {
 
-// AccessibilityManager is a singleton that manages all accessibility on the
-// system.
+/**
+ * @class AccessibilityManager
+ * @brief A singleton class that manages system accessibility features
+ * 
+ * The AccessibilityManager provides a centralized interface for managing
+ * accessibility functionality across the system. It follows the singleton
+ * pattern to ensure only one instance exists throughout the application
+ * lifecycle, providing consistent state management for accessibility features.
+ * 
+ * Key responsibilities:
+ * - Enable/disable system accessibility features
+ * - Query accessibility state
+ * - Provide thread-safe access to accessibility functionality
+ * 
+ * Usage example:
+ * @code
+ * AccessibilityManager& manager = AccessibilityManager::GetInstance();
+ * manager.Enable();
+ * bool enabled = manager.IsEnabled();
+ * @endcode
+ */
 class AccessibilityManager {
  public:
-  AccessibilityManager();
+  /**
+   * @brief Gets the singleton instance of AccessibilityManager
+   * @return Reference to the singleton instance
+   * 
+   * This method provides thread-safe access to the singleton instance.
+   * The instance is created on first access and remains alive for the
+   * duration of the application.
+   */
+  static AccessibilityManager& GetInstance();
+
+  /**
+   * @brief Virtual destructor
+   * 
+   * Ensures proper cleanup of resources when the manager is destroyed.
+   * Note: In singleton pattern, this is typically called only at application
+   * shutdown.
+   */
   virtual ~AccessibilityManager();
 
-  // Enable the accessibility
+  /**
+   * @brief Enables system accessibility features
+   * 
+   * Activates accessibility functionality across the system. This method
+   * should be called to make accessibility features available to users.
+   * The operation is idempotent - calling it multiple times has the same
+   * effect as calling it once.
+   * 
+   * @note This operation may require system permissions depending on the
+   *       platform implementation.
+   */
   void Enable();
 
-  // Whether the accessibility is enabled
+  /**
+   * @brief Checks if accessibility features are currently enabled
+   * @return true if accessibility is enabled, false otherwise
+   * 
+   * This method provides a quick way to query the current state of
+   * accessibility features without modifying the system state.
+   */
   bool IsEnabled();
+
+  // Delete copy constructor and assignment operator to prevent copies
+  AccessibilityManager(const AccessibilityManager&) = delete;
+  AccessibilityManager& operator=(const AccessibilityManager&) = delete;
+
+ private:
+  /**
+   * @brief Private constructor for singleton pattern
+   * 
+   * Initializes the AccessibilityManager instance. This constructor is
+   * private to prevent direct instantiation - use GetInstance() instead.
+   */
+  AccessibilityManager();
+
+  /**
+   * @brief Internal flag tracking accessibility state
+   * 
+   * Maintains the current enabled/disabled state of accessibility features.
+   * This member is used internally by Enable() and IsEnabled() methods.
+   */
+  bool enabled_;
 };
 
-}  // namespace nativeapi
+}  // namespace nativeapi

src/capi/accessibility_manager_c.cpp

@@ -1,19 +1,16 @@
-#include <string.h>
-#include <iostream>
-
-#include "../accessibility_manager.h"
 #include "accessibility_manager_c.h"
+#include "../accessibility_manager.h"
 
-using namespace nativeapi;
-
-static AccessibilityManager g_accessibility_manager = AccessibilityManager();
+static nativeapi::AccessibilityManager& AccessibilityManagerInstance() {
+  return nativeapi::AccessibilityManager::GetInstance();
+}
 
 FFI_PLUGIN_EXPORT
 void native_accessibility_manager_enable() {
-  g_accessibility_manager.Enable();
+  AccessibilityManagerInstance().Enable();
 }
 
 FFI_PLUGIN_EXPORT
 bool native_accessibility_manager_is_enabled() {
-  return g_accessibility_manager.IsEnabled();
+  return AccessibilityManagerInstance().IsEnabled();
 }

src/capi/accessibility_manager_c.h

@@ -1,3 +1,5 @@
+#pragma once
+
 #include <stdbool.h>
 
 #if _WIN32
@@ -10,9 +12,27 @@
 extern "C" {
 #endif
 
+/**
+ * @brief Enables system accessibility features
+ *
+ * This function activates accessibility functionality across the system.
+ * The operation is idempotent - calling it multiple times has the same
+ * effect as calling it once.
+ *
+ * @note This operation may require system permissions depending on the
+ *       platform implementation.
+ */
 FFI_PLUGIN_EXPORT
 void native_accessibility_manager_enable();
 
+/**
+ * @brief Checks if accessibility features are currently enabled
+ *
+ * @return true if accessibility is enabled, false otherwise
+ *
+ * This function provides a quick way to query the current state of
+ * accessibility features without modifying the system state.
+ */
 FFI_PLUGIN_EXPORT
 bool native_accessibility_manager_is_enabled();
 

src/platform/macos/accessibility_manager_macos.mm

@@ -1,8 +1,7 @@
-#include "../../accessibility_manager.h"
-
-// Import Cocoa headers
 #import <Cocoa/Cocoa.h>
 
+#include "../../accessibility_manager.h"
+
 namespace nativeapi {
 
 void AccessibilityManager::Enable() {