Add Android platform support (stub implementation)

Author: lijy91

.gitignore

@@ -3,6 +3,7 @@
 .vscode/
 build/
 cmake-build-debug/
+build-android/
 
 # Generated test binaries and object files
 *.o

examples/menu_c_example/CMakeLists.txt

@@ -18,9 +18,11 @@ if(APPLE)
     target_link_libraries(menu_c_example ${COCOA_LIBRARY})
 elseif(WIN32)
     target_link_libraries(menu_c_example user32 kernel32)
-elseif(UNIX)
+elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
     find_package(PkgConfig REQUIRED)
     pkg_check_modules(GTK3 REQUIRED gtk+-3.0)
     target_include_directories(menu_c_example PRIVATE ${GTK3_INCLUDE_DIRS})
     target_link_libraries(menu_c_example ${GTK3_LIBRARIES})
+elseif(ANDROID)
+    target_link_libraries(menu_c_example log android)
 endif()

examples/menu_example/CMakeLists.txt

@@ -18,9 +18,11 @@ if(APPLE)
     target_link_libraries(menu_example ${COCOA_LIBRARY})
 elseif(WIN32)
     target_link_libraries(menu_example user32 kernel32)
-elseif(UNIX)
+elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
     find_package(PkgConfig REQUIRED)
     pkg_check_modules(GTK3 REQUIRED gtk+-3.0)
     target_include_directories(menu_example PRIVATE ${GTK3_INCLUDE_DIRS})
     target_link_libraries(menu_example ${GTK3_LIBRARIES})
+elseif(ANDROID)
+    target_link_libraries(menu_example log android)
 endif()

src/CMakeLists.txt

@@ -34,6 +34,8 @@ elseif(APPLE)
     file(GLOB PLATFORM_SOURCES "platform/macos/*.mm")
 elseif(WIN32)
     file(GLOB PLATFORM_SOURCES "platform/windows/*.cpp")
+elseif(ANDROID)
+    file(GLOB PLATFORM_SOURCES "platform/android/*.cpp")
 else()
     set(PLATFORM_SOURCES "")
 endif()
@@ -68,4 +70,6 @@ elseif (CMAKE_SYSTEM_NAME STREQUAL "Linux")
     target_link_libraries(nativeapi PUBLIC PkgConfig::GTK PkgConfig::X11 PkgConfig::XI PkgConfig::AYATANA_APPINDICATOR pthread)
 elseif(WIN32)
     target_link_libraries(nativeapi PUBLIC user32 shell32 dwmapi gdiplus crypt32)
+elseif(ANDROID)
+    target_link_libraries(nativeapi PUBLIC log android)
 endif ()

src/accessibility_manager.cpp

@@ -1,14 +1,31 @@
 #include "accessibility_manager.h"
 
+#ifdef ANDROID
+#include <android/log.h>
+#define LOG_TAG "NativeApi"
+#define ALOGW(...) __android_log_print(ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__)
+#endif
+
 namespace nativeapi {
 
 AccessibilityManager& AccessibilityManager::GetInstance() {
   static AccessibilityManager instance;
   return instance;
 }
 
-AccessibilityManager::AccessibilityManager() {}
+AccessibilityManager::AccessibilityManager() : enabled_(false) {}
 
 AccessibilityManager::~AccessibilityManager() {}
 
+void AccessibilityManager::Enable() {
+#ifdef ANDROID
+  ALOGW("AccessibilityManager::Enable requires AccessibilityService on Android");
+#endif
+  enabled_ = true;
+}
+
+bool AccessibilityManager::IsEnabled() {
+  return enabled_;
+}
+
 }  // namespace nativeapi

src/platform/android/README.md

@@ -0,0 +1,96 @@
+# Android Platform Implementation
+
+This directory contains Android-specific implementations of the nativeapi library.
+
+## Overview
+
+The Android implementation uses the Android NDK to provide access to native system APIs. Due to Android's unique application model, some desktop concepts are mapped differently:
+
+- **Windows** → Activities/Views (`ANativeWindow`)
+- **Menus** → Context menus or ActionBar menus
+- **Tray Icons** → System notifications
+- **Display Management** → Display Manager API
+- **Keyboard Monitoring** → Accessibility Services
+
+## Files
+
+- `window_android.cpp` - Window management using `ANativeWindow`
+- `window_manager_android.cpp` - Window manager for Activity lifecycle
+- `display_android.cpp` - Display information (stub)
+- `display_manager_android.cpp` - Display manager (stub)
+- `menu_android.cpp` - Menu implementation (stub)
+- `tray_icon_android.cpp` - Tray icon using notifications (stub)
+- `tray_manager_android.cpp` - Tray manager (stub)
+- `keyboard_monitor_android.cpp` - Keyboard monitoring via AccessibilityService (stub)
+- `accessibility_manager_android.cpp` - Accessibility manager (stub)
+- `application_android.cpp` - Application lifecycle (stub)
+- `image_android.cpp` - Image loading (stub)
+
+## Building
+
+These files are automatically included when building with the Android NDK:
+
+```bash
+cmake -DCMAKE_SYSTEM_NAME=Android \
+      -DCMAKE_ANDROID_NDK=/path/to/android-ndk \
+      ..
+```
+
+## Android NDK Requirements
+
+- Android NDK r21 or later
+- Minimum Android SDK: API level 24 (Android 7.0)
+- Recommended: API level 29+ (Android 10.0+)
+
+## Key Differences from Desktop
+
+### Window Management
+
+Android uses `ANativeWindow` instead of platform-specific window handles:
+
+```cpp
+// Desktop: HWND (Windows), NSWindow* (macOS), GdkWindow* (Linux)
+// Android: ANativeWindow*
+
+void* Window::GetNativeObjectInternal() const {
+    return static_cast<void*>(pimpl_->native_window_);
+}
+```
+
+### Activity Lifecycle
+
+Windows in Android are created and managed through the Activity lifecycle. Window creation happens automatically when the Activity creates a native window surface.
+
+### Logging
+
+Android uses the logging API instead of standard output:
+
+```cpp
+#include <android/log.h>
+
+#define LOG_TAG "NativeApi"
+#define ALOGI(...) __android_log_print(ANDROID_LOG_INFO, LOG_TAG, __VA_ARGS__)
+```
+
+## Implementation Status
+
+| Component | Status | Notes |
+|-----------|--------|-------|
+| Window | ✅ Implemented | Uses ANativeWindow API |
+| Window Manager | ✅ Implemented | Activity lifecycle integration |
+| Display | ⚠️ Stub | Basic implementation |
+| Display Manager | ⚠️ Stub | Basic implementation |
+| Menu | ⚠️ Stub | Needs Context menu integration |
+| Tray Icon | ⚠️ Stub | Needs Notification API |
+| Tray Manager | ⚠️ Stub | Needs Notification API |
+| Keyboard Monitor | ⚠️ Stub | Needs AccessibilityService |
+| Accessibility Manager | ⚠️ Stub | Needs Android permissions |
+| Application | ⚠️ Stub | Basic lifecycle |
+| Image | ⚠️ Stub | Needs Bitmap loading |
+
+## See Also
+
+- [Android NDK Documentation](https://developer.android.com/ndk)
+- [ANativeWindow API](https://developer.android.com/ndk/reference/group/native-activity#anativewindow)
+- [docs/ANDROID.md](../../../docs/ANDROID.md) - User-facing Android documentation
+

src/platform/android/application_android.cpp

@@ -0,0 +1,62 @@
+#include <android/log.h>
+#include "../../application.h"
+
+#define LOG_TAG "NativeApi"
+#define ALOGW(...) __android_log_print(ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__)
+
+namespace nativeapi {
+
+class Application::Impl {
+ public:
+  Impl() {}
+};
+
+Application::Application() : pimpl_(std::make_unique<Impl>()) {}
+Application::~Application() {}
+
+int Application::Run() {
+  ALOGW("Application::Run not applicable on Android (handled by Activity lifecycle)");
+  return 0;
+}
+
+int Application::Run(std::shared_ptr<Window> window) {
+  ALOGW("Application::Run with window not applicable on Android");
+  return 0;
+}
+
+void Application::Quit(int exit_code) {
+  ALOGW("Application::Quit requests Activity finish");
+}
+
+bool Application::IsRunning() const {
+  return true;
+}
+
+bool Application::IsSingleInstance() const {
+  return false;
+}
+
+bool Application::SetIcon(const std::string& icon_path) {
+  ALOGW("Application::SetIcon not implemented on Android");
+  return false;
+}
+
+bool Application::SetDockIconVisible(bool visible) {
+  ALOGW("Application::SetDockIconVisible not applicable on Android");
+  return false;
+}
+
+bool Application::SetMenuBar(std::shared_ptr<Menu> menu) {
+  ALOGW("Application::SetMenuBar not implemented on Android");
+  return false;
+}
+
+std::shared_ptr<Window> Application::GetPrimaryWindow() const {
+  return nullptr;
+}
+
+void Application::SetPrimaryWindow(std::shared_ptr<Window> window) {
+  ALOGW("Application::SetPrimaryWindow not implemented on Android");
+}
+
+}  // namespace nativeapi

src/platform/android/display_android.cpp

@@ -0,0 +1,70 @@
+#include <android/log.h>
+#include "../../display.h"
+
+#define LOG_TAG "NativeApi"
+#define ALOGW(...) __android_log_print(ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__)
+
+namespace nativeapi {
+
+class Display::Impl {
+ public:
+  Impl() {}
+};
+
+Display::Display() : pimpl_(std::make_unique<Impl>()) {}
+Display::Display(void* display) : pimpl_(std::make_unique<Impl>()) {}
+Display::~Display() {}
+
+Display::Display(const Display& other) : pimpl_(std::make_unique<Impl>()) {}
+Display& Display::operator=(const Display& other) { return *this; }
+Display::Display(Display&& other) noexcept : pimpl_(std::move(other.pimpl_)) {}
+Display& Display::operator=(Display&& other) noexcept {
+  pimpl_ = std::move(other.pimpl_);
+  return *this;
+}
+
+void* Display::GetNativeObjectInternal() const {
+  return nullptr;
+}
+
+std::string Display::GetId() const {
+  return "android_display_0";
+}
+
+std::string Display::GetName() const {
+  return "Android Display";
+}
+
+Point Display::GetPosition() const {
+  return Point{0, 0};
+}
+
+Size Display::GetSize() const {
+  return Size{1080, 1920};
+}
+
+Rectangle Display::GetWorkArea() const {
+  return Rectangle{0, 0, 1080, 1920};
+}
+
+double Display::GetScaleFactor() const {
+  return 2.0;
+}
+
+bool Display::IsPrimary() const {
+  return true;
+}
+
+DisplayOrientation Display::GetOrientation() const {
+  return DisplayOrientation::kPortrait;
+}
+
+int Display::GetRefreshRate() const {
+  return 60;
+}
+
+int Display::GetBitDepth() const {
+  return 24;
+}
+
+}  // namespace nativeapi

src/platform/android/display_manager_android.cpp

@@ -0,0 +1,24 @@
+#include <android/log.h>
+#include "../../display_manager.h"
+
+#define LOG_TAG "NativeApi"
+#define ALOGW(...) __android_log_print(ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__)
+
+namespace nativeapi {
+
+DisplayManager::DisplayManager() {}
+DisplayManager::~DisplayManager() {}
+
+std::vector<Display> DisplayManager::GetAll() {
+  return {Display()};
+}
+
+Display DisplayManager::GetPrimary() {
+  return Display();
+}
+
+Point DisplayManager::GetCursorPosition() {
+  return Point{0, 0};
+}
+
+}  // namespace nativeapi

src/platform/android/image_android.cpp

@@ -0,0 +1,41 @@
+#include <android/log.h>
+#include "../../image.h"
+
+#define LOG_TAG "NativeApi"
+#define ALOGW(...) __android_log_print(ANDROID_LOG_WARN, LOG_TAG, __VA_ARGS__)
+
+namespace nativeapi {
+
+class Image::Impl {
+ public:
+  Impl() {}
+};
+
+Image::Image() : pimpl_(std::make_unique<Impl>()) {}
+Image::~Image() {}
+Image::Image(const Image& other) : pimpl_(std::make_unique<Impl>()) {}
+Image::Image(Image&& other) noexcept : pimpl_(std::move(other.pimpl_)) {}
+
+std::shared_ptr<Image> Image::FromFile(const std::string& file_path) {
+  ALOGW("Image::FromFile not implemented on Android");
+  return nullptr;
+}
+
+std::shared_ptr<Image> Image::FromBase64(const std::string& base64_data) {
+  ALOGW("Image::FromBase64 not implemented on Android");
+  return nullptr;
+}
+
+Size Image::GetSize() const {
+  return Size{0, 0};
+}
+
+std::string Image::GetFormat() const {
+  return "";
+}
+
+void* Image::GetNativeObjectInternal() const {
+  return nullptr;
+}
+
+}  // namespace nativeapi