macOS

The macOS backend uses AppKit, Core Graphics and ImageIO. It does not require X11 or Cairo. Existing C++ controls and the by-value rect API are preserved.

Build

Install Xcode Command Line Tools and CMake 3.16 or later. The default macOS deployment target is 10.15. Runtime validation is performed on Apple Silicon; Intel and universal builds can be produced with CMAKE_OSX_ARCHITECTURES.

cmake -S . -B build-macos -DCMAKE_BUILD_TYPE=Release
cmake --build build-macos --parallel
open build-macos/examples/demo/demo.app

The hello_world and simple examples also build as application bundles. Resources are copied into Contents/Resources/res. Relative resource paths are resolved against the working directory first, then the application bundle. The library does not change the working directory. Use an explicit writable path for INI configuration when launching from Finder, for example in Application Support.

cmake -S . -B build-macos-universal -DCMAKE_OSX_ARCHITECTURES="arm64;x86_64" \
  -DWUI_BUILD_EXAMPLES=OFF -DCMAKE_BUILD_TYPE=Release
cmake --build build-macos-universal --parallel

Consumers can use add_subdirectory(path/to/wui) and target_link_libraries(my_app PRIVATE wui). Public headers remain plain C++; Objective-C++ and Apple frameworks are handled by the wui target.

Behavior

Run initialization, the event loop, and UI operations on the main thread. Control and timer callbacks run on that thread. window::emit_event() can be called from a worker thread and delivers asynchronously on the main thread.

Coordinates are logical points; bitmap buffers follow the display's Retina scale. Font size follows WUI's line-height convention. Text measurement does not require an open window. The backend supports UTF-8 and IME composition through NSTextInputClient, Cmd+A/C/X/V, Tab/Shift+Tab, mouse input, vertical scrolling, embedded and physical modal windows, moving, resizing and minimizing. Window decorations use the existing WUI controls.

Colors retain WUI's POSIX transparency convention: the fourth make_color argument is 0 for opaque and 255 for transparent. tray_icon uses an NSStatusItem; show_message() displays a popover, not a Notification Center alert.

Tests and limitations

cmake -S . -B build-macos -DWUI_BUILD_TESTS=ON -DCMAKE_BUILD_TYPE=Debug
cmake --build build-macos --parallel
ctest --test-dir build-macos --output-on-failure

Tests require an active macOS graphical session. They open temporary windows, exercise events, UTF-8, clipboard, dialogs, timers and bitmap pixels, and launch all three examples. Screenshots are saved as /tmp/wui-macos-*.png.

Device hotplug notifications are not implemented; enable_device_change_handling(true) reports this through window::get_error(). Per-window taskbar visibility has no equivalent in the application-wide Dock. Full control accessibility and horizontal trackpad scrolling are not yet implemented.