Android support

.github/workflows/android.yml

@@ -0,0 +1,49 @@
+name: Android Build
+
+on:
+  push:
+    paths-ignore:
+      - 'docs/**'
+      - '**.md'
+  pull_request:
+    paths-ignore:
+      - '**.md'
+      - 'docs/**'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - uses: actions/setup-java@v4
+      with:
+        java-version: '17'
+        distribution: 'temurin'
+
+    - uses: android-actions/setup-android@v3
+
+    - run: yes | sdkmanager --licenses || true
+
+    - run: |
+        sdkmanager --install "platforms;android-34"
+        sdkmanager --install "build-tools;34.0.0"
+        sdkmanager --install "ndk;25.2.9519653"
+        sdkmanager --install "cmake;3.22.1"
+
+    - uses: actions/cache@v4
+      with:
+        path: |
+          ~/.gradle/caches
+          ~/.gradle/wrapper
+        key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}
+        restore-keys: |
+          ${{ runner.os }}-gradle-
+
+    - run: chmod +x examples/android/gradlew
+
+    - run: |
+        cd examples/android
+        ./gradlew assembleDebug --no-daemon
+

.github/workflows/build_cmake.yml

@@ -9,6 +9,7 @@ on:
     paths-ignore:
       - '**.md'
       - 'docs/**'
+
 jobs:
   build:
     name: ${{ matrix.config.name }}

.github/workflows/mingw.yml

@@ -1,6 +1,14 @@
 name: MSYS2 build
 
-on: push
+on:
+  push:
+    paths-ignore:
+      - 'docs/**'
+      - '**.md'
+  pull_request:
+    paths-ignore:
+      - '**.md'
+      - 'docs/**'
 
 jobs:
   mingw:

.gitignore

@@ -93,3 +93,86 @@ build
 
 .vscode
 
+### Generated by gibo (https://github.com/simonwhitaker/gibo)
+### https://raw.github.com/github/gitignore/15d684578f37580886f29e4b8462f3a27f722cb5/Android.gitignore
+
+# Gradle files
+.gradle/
+build/
+
+# Local configuration file (sdk path, etc)
+local.properties
+
+# Log/OS Files
+*.log
+
+# Android Studio generated files and folders
+captures/
+.externalNativeBuild/
+.cxx/
+*.aab
+*.apk
+output-metadata.json
+
+# IntelliJ
+*.iml
+.idea/
+misc.xml
+deploymentTargetDropDown.xml
+render.experimental.xml
+
+# Keystore files
+*.jks
+*.keystore
+
+# Google Services (e.g. APIs or Firebase)
+google-services.json
+
+# Android Profiling
+*.hprof
+### Generated by gibo (https://github.com/simonwhitaker/gibo)
+### https://raw.github.com/github/gitignore/15d684578f37580886f29e4b8462f3a27f722cb5/Gradle.gitignore
+
+.gradle
+**/build/
+!**/src/**/build/
+
+# Ignore Gradle GUI config
+gradle-app.setting
+
+# Avoid ignoring Gradle wrapper jar file (.jar files are usually ignored)
+!gradle-wrapper.jar
+
+# Avoid ignore Gradle wrappper properties
+!gradle-wrapper.properties
+
+# Cache of project
+.gradletasknamecache
+
+# Eclipse Gradle plugin generated files
+# Eclipse Core
+.project
+# JDT-specific (Eclipse Java Development Tools)
+.classpath
+### Generated by gibo (https://github.com/simonwhitaker/gibo)
+### https://raw.github.com/github/gitignore/15d684578f37580886f29e4b8462f3a27f722cb5/CMake.gitignore
+
+CMakeLists.txt.user
+CMakeCache.txt
+CMakeFiles
+CMakeScripts
+Testing
+Makefile
+cmake_install.cmake
+install_manifest.txt
+compile_commands.json
+CTestTestfile.cmake
+_deps
+CMakeUserPresets.json
+
+# CLion
+#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
+#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
+#  and can be added to the global gitignore or merged into this file.  For a more nuclear
+#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
+#cmake-build-*

CMakeLists.txt

@@ -35,6 +35,7 @@ option(LIBREMIDI_NO_JACK "Disable JACK back-end" OFF)
 option(LIBREMIDI_NO_PIPEWIRE "Disable PipeWire back-end" OFF)
 option(LIBREMIDI_NO_NETWORK "Disable Network back-end" OFF)
 option(LIBREMIDI_NO_KEYBOARD "Disable Computer keyboard back-end" OFF)
+cmake_dependent_option(LIBREMIDI_NO_ANDROID "Disable Android AMidi back-end" OFF "ANDROID" OFF)
 
 option(LIBREMIDI_NO_EXPORTS "Disable dynamic symbol exporting" OFF)
 option(LIBREMIDI_NO_BOOST "Do not use Boost if available" OFF)
@@ -70,6 +71,7 @@ include(libremidi.jack)
 include(libremidi.pipewire)
 include(libremidi.keyboard)
 include(libremidi.net)
+include(libremidi.android)
 
 ### Install ###
 include(libremidi.install)

cmake/libremidi.android.cmake

@@ -0,0 +1,18 @@
+### Android ###
+if(ANDROID AND NOT LIBREMIDI_NO_ANDROID)
+  # Check for AMidi API availability (API level 29+)
+  # Also we need API 31+ for JNI_GetCreatedJavaVMs
+  if(ANDROID_NATIVE_API_LEVEL AND ANDROID_NATIVE_API_LEVEL GREATER_EQUAL 31)
+    message(STATUS "libremidi: Using Android AMidi API")
+    message(STATUS "       !!! Remember to include MidiDeviceCallback.java in your Android app")
+    message(STATUS "       !!! See the example in examples/android/java/dev/celtera/libremidi")
+
+    target_compile_definitions(libremidi ${_public} LIBREMIDI_ANDROID=1)
+    target_link_libraries(libremidi ${_public} amidi log nativehelper)
+    target_sources(libremidi ${_public}
+      "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include/libremidi/backends/android/helpers.cpp>"
+    )
+  else()
+    message(FATAL_ERROR "libremidi: Android AMidi API requires API level 31+ (current: ${ANDROID_NATIVE_API_LEVEL})")
+  endif()
+endif()

examples/android/app/build.gradle

@@ -0,0 +1,51 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdk 34
+    ndkVersion "25.2.9519653"
+
+    defaultConfig {
+        applicationId "com.libremidi.example"
+        minSdk 31
+        targetSdk 34
+        versionCode 1
+        versionName "1.0"
+
+        externalNativeBuild {
+            cmake {
+                cppFlags "-std=c++20 -frtti -fexceptions"
+                arguments "-DANDROID_STL=c++_shared"
+            }
+        }
+        ndk {
+            abiFilters 'arm64-v8a', 'armeabi-v7a', 'x86', 'x86_64'
+        }
+    }
+
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
+        }
+    }
+
+    externalNativeBuild {
+        cmake {
+            path "src/main/cpp/CMakeLists.txt"
+            version "3.22.1"
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_11
+        targetCompatibility JavaVersion.VERSION_11
+    }
+
+    namespace 'com.libremidi.example'
+}
+
+dependencies {
+    implementation 'androidx.appcompat:appcompat:1.6.1'
+    implementation 'com.google.android.material:material:1.11.0'
+    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
+}

examples/android/app/src/main/AndroidManifest.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <uses-feature android:name="android.software.midi" android:required="true" />
+    <uses-permission android:name="android.permission.BIND_MIDI_DEVICE_SERVICE" />
+
+    <application
+        android:allowBackup="true"
+        android:icon="@android:drawable/ic_menu_manage"
+        android:label="LibreMIDI Example"
+        android:theme="@style/Theme.AppCompat.Light.DarkActionBar">
+
+        <activity
+            android:name=".MainActivity"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+
+    </application>
+
+</manifest>

examples/android/app/src/main/cpp/CMakeLists.txt

@@ -0,0 +1,28 @@
+cmake_minimum_required(VERSION 3.22.1)
+project(libremidi-example)
+
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+# Find libremidi in the parent directory
+set(LIBREMIDI_NO_ANDROID 0)
+set(BUILD_SHARED_LIBS 1)
+set(LIBREMIDI_ROOT "${CMAKE_CURRENT_SOURCE_DIR}/../../../../../..")
+add_subdirectory(${LIBREMIDI_ROOT} libremidi-build)
+
+# Create shared library
+add_library(libremidi-example SHARED
+    native-lib.cpp
+)
+
+# Link libremidi
+target_link_libraries(libremidi-example
+    libremidi
+    android
+    log
+)
+
+# Include directories
+target_include_directories(libremidi-example PRIVATE
+    ${LIBREMIDI_ROOT}/include
+)

examples/android/app/src/main/cpp/native-lib.cpp

@@ -0,0 +1,73 @@
+#include <jni.h>
+#include <string>
+#include <vector>
+#include <sstream>
+#include <libremidi/libremidi.hpp>
+
+#include <android/log.h>
+extern "C" JNIEXPORT jstring JNICALL
+Java_com_libremidi_example_MainActivity_getMidiDevices(JNIEnv* env, jobject /* this */) {
+    std::stringstream result;
+    __android_log_print(ANDROID_LOG_WARN, "libremidi", "Java_com_libremidi_example_MainActivity_getMidiDevices!!");
+
+    try {
+        auto api = libremidi::API::ANDROID_AMIDI;
+        libremidi::observer obs{{.track_any = true}, libremidi::observer_configuration_for(api)};
+
+        result << "=== MIDI Input Devices ===\n";
+        auto inputs = obs.get_input_ports();
+        if (inputs.empty()) {
+            result << "No input devices found\n";
+        } else {
+            for (const auto& port : inputs) {
+                result << "Port " << port.port << ": " << port.port_name;
+                if (!port.device_name.empty() && port.device_name != port.port_name) {
+                    result << " (Device: " << port.device_name << ")";
+                }
+                if (!port.display_name.empty() && port.display_name != port.port_name) {
+                    result << " [" << port.display_name << "]";
+                }
+                result << "\n";
+
+                __android_log_print(ANDROID_LOG_WARN, "libremidi", "opening: %s", port.port_name.c_str());
+                auto midi_in = new libremidi::midi_in{{.on_message{[](const libremidi::message& m) {
+                    __android_log_print(ANDROID_LOG_WARN, "libremidi", "ayy!!");
+                }}}, libremidi::midi_in_configuration_for(api)};
+
+                auto p = midi_in->get_current_api();
+
+                __android_log_print(ANDROID_LOG_WARN, "libremidi", ">> ??! %s", libremidi::get_api_name(p).data());
+                __android_log_print(ANDROID_LOG_WARN, "libremidi", ">> open port?!");
+                midi_in->open_port(port);
+            }
+        }
+
+        result << "\n=== MIDI Output Devices ===\n";
+        auto outputs = obs.get_output_ports();
+        if (outputs.empty()) {
+            result << "No output devices found\n";
+        } else {
+            for (const auto& port : outputs) {
+                result << "Port " << port.port << ": " << port.port_name;
+                if (!port.device_name.empty() && port.device_name != port.port_name) {
+                    result << " (Device: " << port.device_name << ")";
+                }
+                if (!port.display_name.empty() && port.display_name != port.port_name) {
+                    result << " [" << port.display_name << "]";
+                }
+                result << "\n";
+            }
+        }
+
+    } catch (const std::exception& e) {
+        result << "Error: " << e.what() << "\n";
+    }
+
+    __android_log_print(ANDROID_LOG_WARN, "libremidi", "FINITO!!");
+    return env->NewStringUTF(result.str().c_str());
+}
+
+extern "C" JNIEXPORT jstring JNICALL
+Java_com_libremidi_example_MainActivity_getLibremidiVersion(JNIEnv* env, jobject /* this */) {
+    return env->NewStringUTF("libremidi Android example");
+}