android support (tested with yadaw)

.github/workflows/ci.yml

@@ -36,7 +36,7 @@ jobs:
           - { name: iOS (Mac Catalyst aarch64-apple-ios-macabi), os: macos-latest, target: aarch64-apple-ios-macabi, features: "", setup: ios-macabi }
           - { name: Linux (aarch64-unknown-linux-gnu), os: ubuntu-latest, target: aarch64-unknown-linux-gnu, features: "", setup: linux-aarch64 }
           - { name: Windows (ARM64 MSVC), os: windows-latest, target: aarch64-pc-windows-msvc, features: "", setup: windows-msvc }
-          #- { name: Android (aarch64/armv7/x86_64/i686; API 29), os: ubuntu-latest, target: "", features: "", setup: android }
+          - { name: Android (aarch64/armv7/x86_64/i686; API 29), os: ubuntu-latest, target: "", features: "", setup: android }
 
     steps:
       - name: Checkout

Cargo.toml

@@ -75,3 +75,13 @@ env_logger = "0.11" # only for examples
 
 [target.'cfg(target_arch = "wasm32")'.dev-dependencies]
 wasm-bindgen-test = "0.2"
+
+# Android parts.
+[target.'cfg(target_os = "android")'.dependencies]
+jni = { version = "0.21", default-features = false }
+ndk-context = "0.1"
+jni-min-helper = "0.3"
+
+# is already provided by the NDK. (will show a link error below API 29)
+[target.'cfg(target_os = "android")'.build-dependencies]
+cc = "1.0"

README.md

@@ -7,15 +7,25 @@ Cross-platform, realtime MIDI processing in Rust.
 
 <sup>* With the exception of message queues, but these can be implemented on top of callbacks using e.g. Rust's channels.</sup>
 
-**midir** currently supports the following platforms/backends: 
+**midir** currently supports the following platforms/backends:
 - [x] ALSA (Linux)
 - [x] WinMM (Windows)
 - [x] CoreMIDI (macOS, iOS)
 - [x] WinRT (Windows 8+), enable the `winrt` feature
 - [x] Jack (Linux, macOS), enable the `jack` feature
 - [x] Web MIDI (Chrome, Opera, perhaps others browsers)
+- [x] Android (API 29+, NDK AMidi + JNI)
 
 A higher-level API for parsing and assembling MIDI messages might be added in the future.
 
 ## Documentation & Example
 API docs can be found at [docs.rs](https://docs.rs/crate/midir/). You can find some examples in the [`examples`](examples/) directory. Or simply run `cargo run --example test_play` after cloning this repository.
+
+### Android
+- Requires Android API 29+ and the Android NDK (r20b+).
+- Build (example, to remove before merging):
+  - Install: `cargo install cargo-ndk`
+  - Targets: `rustup target add aarch64-linux-android`
+  - Build: `cargo ndk -t arm64-v8a -o ./app/src/main/jniLibs build --release`
+- Permissions/features:
+  - Manifest should declare `<uses-feature android:name="android.software.midi" android:required="false" />` (not needed for USB/BLE MIDI).

build.rs

@@ -0,0 +1,4 @@
+fn main() {
+    #[cfg(target_os = "android")]
+    println!("cargo:rustc-link-lib=amidi");
+}