attachment_engine_windows 0.0.1-dev.0

The Windows implementation of attachment_engine. Paths and open-externally via path_provider/url_launcher (both flutter.dev-published, official Flutter team plugins); download via dart:io. Share (nati [...]

attachment_engine_windows

The Windows implementation of attachment_engine.

Status

Development preview — not feature-complete, and the native (C++) code described below has NOT been build-verified. This machine has no Windows compiler (cl.exe/msbuild) available, and flutter create --platforms=windows refuses to scaffold a native template here, so the C++ files under windows/ could not be compiled or even syntax-checked in this environment. They were written to closely mirror official Microsoft documentation and the same channel-name/method/event contract already proven out by the working Android (Kotlin) and iOS (Swift) implementations — but they are "written, not yet build-verified" and need a real Windows build (local machine or CI) to confirm.

Pure Dart (verified — flutter analyze/dart format/flutter test all pass)

• Paths (getApplicationSupportDirectory, getApplicationCacheDirectory) — via path_provider (flutter.dev-published, official)
• Open externally (openExternally, and openOfficePreview falling back to it) — via url_launcher (flutter.dev-published, official)
• Download (startDownload, resumeDownload, cancelDownload, downloadEvents) — via dart:io's built-in HttpClient, with Range-header resume support

Native (unverified by build — see windows/*.cpp/*.h header comments)

• Share (shareFile, shareText) — windows/share_channel.cpp, using the documented IDataTransferManagerInterop/DataTransferManager COM API to show the real Windows share flyout from this app's top-level HWND: https://learn.microsoft.com/en-us/windows/win32/api/shobjidl_core/nn-shobjidl_core-idatatransfermanagerinterop
• Audio playback (audioLoad/audioPlay/audioPause/audioSeek/ audioSetSpeed/audioSetVolume/audioDispose/audioEvents) — windows/audio_channel.cpp, using Media Foundation's IMFMediaEngine: https://learn.microsoft.com/en-us/windows/win32/api/mfmediaengine/nn-mfmediaengine-imfmediaengine
• Video playback + embedding (same method shape as audio, plus videoBuildView) — windows/video_channel.cpp, same IMFMediaEngine API, rendering to a child HWND (MF_MEDIA_ENGINE_PLAYBACK_HWND) that the Dart-side widget keeps positioned via an explicit setLayout call. This is a documented, functional tradeoff versus true Flutter compositing — see the "Embedding tradeoff" comment in windows/video_channel.h for why, and what a fuller frame-server + TextureRegistrar implementation would look like instead.

Still not yet implemented (throws UnimplementedError):

• PDF native rendering and embedded native webview surfaces — no native-view integration has been wired up for either yet.

You should not need to depend on this package directly — add attachment_engine to your app instead, and the right platform implementation is selected automatically.