Get Rust SDK Android Example working

examples/mobile/android/.gitignore

@@ -7,9 +7,20 @@
 /.idea/workspace.xml
 /.idea/navEditor.xml
 /.idea/assetWizardSettings.xml
+/.idea/AndroidProjectSystem.xml
+/.idea/migrations.xml
+/.idea/misc.xml
+/.idea/vcs.xml
+/.idea/codeStyles
+/.idea/runConfigurations.xml
+/.idea/gradle.xml
+/.idea/deploymentTargetSelector.xml
 .DS_Store
 /build
 /captures
 .externalNativeBuild
 .cxx
 local.properties
+
+# Generated native libraries (built via cargo-ndk)
+/app/src/main/jniLibs/

examples/mobile/android/app/build.gradle

@@ -5,12 +5,12 @@ plugins {
 
 android {
     namespace 'io.livekit.rustexample'
-    compileSdk 33
+    compileSdk 34
 
     defaultConfig {
         applicationId "io.livekit.rustexample"
         minSdk 24
-        targetSdk 33
+        targetSdk 34
         versionCode 1
         versionName "1.0"
 
@@ -27,17 +27,17 @@ android {
         }
     }
     compileOptions {
-        sourceCompatibility JavaVersion.VERSION_1_8
-        targetCompatibility JavaVersion.VERSION_1_8
+        sourceCompatibility JavaVersion.VERSION_17
+        targetCompatibility JavaVersion.VERSION_17
     }
     kotlinOptions {
-        jvmTarget = '1.8'
+        jvmTarget = '17'
     }
     buildFeatures {
         compose true
     }
     composeOptions {
-        kotlinCompilerExtensionVersion '1.3.2'
+        kotlinCompilerExtensionVersion '1.5.8'
     }
     packagingOptions {
         resources {
@@ -48,19 +48,19 @@ android {
 
 dependencies {
     implementation files('libs/libwebrtc.jar')
-    implementation 'androidx.core:core-ktx:1.8.0'
-    implementation platform('org.jetbrains.kotlin:kotlin-bom:1.8.0')
-    implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.3.1'
-    implementation 'androidx.activity:activity-compose:1.5.1'
-    implementation platform('androidx.compose:compose-bom:2022.10.00')
+    implementation 'androidx.core:core-ktx:1.12.0'
+    implementation platform('org.jetbrains.kotlin:kotlin-bom:1.9.22')
+    implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.7.0'
+    implementation 'androidx.activity:activity-compose:1.8.2'
+    implementation platform('androidx.compose:compose-bom:2024.02.01')
     implementation 'androidx.compose.ui:ui'
     implementation 'androidx.compose.ui:ui-graphics'
     implementation 'androidx.compose.ui:ui-tooling-preview'
     implementation 'androidx.compose.material3:material3'
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'androidx.test.ext:junit:1.1.5'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
-    androidTestImplementation platform('androidx.compose:compose-bom:2022.10.00')
+    androidTestImplementation platform('androidx.compose:compose-bom:2024.02.01')
     androidTestImplementation 'androidx.compose.ui:ui-test-junit4'
     debugImplementation 'androidx.compose.ui:ui-tooling'
     debugImplementation 'androidx.compose.ui:ui-test-manifest'

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

@@ -3,6 +3,8 @@
     xmlns:tools="http://schemas.android.com/tools">
 
     <uses-permission android:name="android.permission.INTERNET"/>
+    <uses-permission android:name="android.permission.RECORD_AUDIO"/>
+    <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS"/>
 
     <application
         android:allowBackup="true"

examples/mobile/android/app/src/main/java/io/livekit/rustexample/App.kt

@@ -1,9 +1,91 @@
 package io.livekit.rustexample
 
+import android.util.Log
+
 class App {
+    private val nativeAvailable: Boolean
+
     init {
-        System.loadLibrary("mobile")
+        nativeAvailable = try {
+            System.loadLibrary("mobile")
+            true
+        } catch (error: UnsatisfiedLinkError) {
+            Log.w(TAG, "Native library not found; skipping LiveKit init.", error)
+            false
+        }
+    }
+
+    // Connection methods
+    private external fun connectNative(url: String, token: String)
+    private external fun disconnectNative()
+    private external fun isConnectedNative(): Boolean
+
+    // Audio methods
+    private external fun pushAudioNative(samples: ShortArray): Int
+    private external fun pullAudioNative(buffer: ShortArray): Int
+    private external fun getPlaybackBufferSizeNative(): Int
+
+    fun connect(url: String, token: String) {
+        if (!nativeAvailable) {
+            Log.w(TAG, "LiveKit native library unavailable; connect() ignored.")
+            return
+        }
+        connectNative(url, token)
+    }
+
+    fun disconnect() {
+        if (!nativeAvailable) {
+            Log.w(TAG, "LiveKit native library unavailable; disconnect() ignored.")
+            return
+        }
+        disconnectNative()
+    }
+
+    fun isConnected(): Boolean {
+        if (!nativeAvailable) {
+            return false
+        }
+        return isConnectedNative()
+    }
+
+    /**
+     * Push captured microphone audio to LiveKit.
+     * @param samples 16-bit PCM samples (mono, 48kHz expected)
+     * @return Number of samples consumed
+     */
+    fun pushAudio(samples: ShortArray): Int {
+        if (!nativeAvailable) {
+            return 0
+        }
+        return pushAudioNative(samples)
+    }
+
+    /**
+     * Pull playback audio from LiveKit (remote participants).
+     * @param buffer Buffer to fill with 16-bit PCM samples
+     * @return Number of actual samples written (rest is silence)
+     */
+    fun pullAudio(buffer: ShortArray): Int {
+        if (!nativeAvailable) {
+            return 0
+        }
+        return pullAudioNative(buffer)
     }
 
-    external fun connect(url: String, token: String)
-}
+    /**
+     * Get the number of samples available in the playback buffer.
+     * Useful for monitoring buffer health.
+     */
+    fun getPlaybackBufferSize(): Int {
+        if (!nativeAvailable) {
+            return 0
+        }
+        return getPlaybackBufferSizeNative()
+    }
+
+    fun isNativeAvailable(): Boolean = nativeAvailable
+
+    private companion object {
+        private const val TAG = "LiveKitApp"
+    }
+}