WIP: Add playing demo at Android app

juicy-noise-android/app/src/main/java/com/danand/juicynoise/AudioOutput.kt

@@ -0,0 +1,58 @@
+package com.danand.juicynoise
+
+import android.media.AudioAttributes
+import android.media.AudioFormat
+import android.media.AudioTrack
+
+import kotlin.random.Random
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.cancel
+import kotlinx.coroutines.isActive
+import kotlinx.coroutines.launch
+
+class AudioOutput {
+    private lateinit var scope: CoroutineScope
+
+    fun play(
+        samplingRate: Int,
+        bufferSize: Int,
+        ) {
+        scope = CoroutineScope(Dispatchers.IO + SupervisorJob())
+
+        scope.launch(Dispatchers.IO) {
+            val audioTrack = AudioTrack.Builder()
+                .setAudioAttributes(
+                    AudioAttributes.Builder()
+                        .setUsage(AudioAttributes.USAGE_MEDIA)
+                        .setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
+                        .build()
+                )
+                .setAudioFormat(
+                    AudioFormat.Builder()
+                        .setEncoding(AudioFormat.ENCODING_PCM_FLOAT)
+                        .setSampleRate(samplingRate)
+                        .setChannelMask(AudioFormat.CHANNEL_OUT_STEREO)
+                        .build()
+                )
+                .setTransferMode(AudioTrack.MODE_STREAM)
+                .setBufferSizeInBytes(bufferSize)
+                .build()
+
+            audioTrack.play()
+
+            while (isActive) {
+                val floatArray = FloatArray(bufferSize) { Random.Default.nextFloat() }
+                audioTrack.write(floatArray, 0, bufferSize, AudioTrack.WRITE_NON_BLOCKING)
+            }
+
+            audioTrack.stop()
+        }
+    }
+
+    fun stop() {
+        scope.cancel()
+    }
+}

juicy-noise-android/app/src/main/java/com/danand/juicynoise/MainActivity.kt

@@ -87,6 +87,8 @@ class MainActivity : ComponentActivity(), SensorEventListener {
 
     private lateinit var sensorManager: SensorManager
 
+    private var audioOutput: AudioOutput = AudioOutput()
+
     private var gyroscope: Sensor? = null
     private var accelerometer: Sensor? = null
     private var rotationVector: Sensor? = null
@@ -157,6 +159,7 @@ class MainActivity : ComponentActivity(), SensorEventListener {
                     sampleRateState,
                     locationClient,
                     connectivityManager,
+                    audioOutput,
                 )
             }
         }
@@ -290,6 +293,7 @@ fun ColumnMain(
     sampleRateState: MutableState<Int>,
     locationClient: FusedLocationProviderClient,
     connectivityManager: ConnectivityManager,
+    audioOutput: AudioOutput,
 ) {
     LaunchedEffect(portState) {
         val subnet = findSubnet(connectivityManager)
@@ -377,6 +381,11 @@ fun ColumnMain(
             ButtonDisconnect(
                 isRunningState,
             )
+
+            ButtonStopDemo(
+                isRunningState,
+                audioOutput,
+            )
         } else {
             ButtonConnect(
                 ipState.value,
@@ -390,6 +399,15 @@ fun ColumnMain(
             ) {
                 checkIsValidIp(ipState.value)
             }
+
+            ButtonPlayDemo(
+                isRunningState,
+                sensorsState,
+                audioBufferSizeState,
+                sampleRateState,
+                locationClient,
+                audioOutput,
+            )
         }
 
         Spacer(modifier = Modifier.height(24.dp))
@@ -537,6 +555,44 @@ fun ButtonConnect(
     }
 }
 
+@Composable
+fun ButtonPlayDemo(
+    isRunningState: MutableState<Boolean>,
+    sensorsState: MutableState<Sensors>,
+    audioBufferSizeState: MutableState<AudioBufferSize>,
+    sampleRateState: MutableState<Int>,
+    locationClient: FusedLocationProviderClient,
+    audioOutput: AudioOutput,
+) {
+    Button(
+        onClick = {
+            isRunningState.value = true
+
+            runReadingLocation(
+                locationClient,
+                isRunningState,
+                sensorsState,
+            )
+
+            audioOutput.play(
+                sampleRateState.value,
+                audioBufferSizeState.value.value,
+            )
+        },
+        colors = textButtonColors(
+            containerColor = MaterialTheme.colorScheme.primaryContainer
+        ),
+        elevation = ButtonDefaults.buttonElevation(
+            defaultElevation = 0.dp,
+            pressedElevation = 16.dp,
+            disabledElevation = 0.dp,
+        ),
+        enabled = true
+    ) {
+        Text("Play demo")
+    }
+}
+
 @Composable
 fun ButtonDisconnect(
     isRunning: MutableState<Boolean>,
@@ -558,6 +614,29 @@ fun ButtonDisconnect(
     }
 }
 
+@Composable
+fun ButtonStopDemo(
+    isRunning: MutableState<Boolean>,
+    audioOutput: AudioOutput,
+) {
+    Button(
+        onClick = {
+            isRunning.value = false
+            audioOutput.stop()
+        },
+        colors = textButtonColors(
+            containerColor = MaterialTheme.colorScheme.primaryContainer
+        ),
+        elevation = ButtonDefaults.buttonElevation(
+            defaultElevation = 0.dp,
+            pressedElevation = 16.dp,
+            disabledElevation = 0.dp,
+        ),
+    ) {
+        Text("Stop demo")
+    }
+}
+
 fun createAddressState(): AddressState = AddressState(
     ip = mutableStateOf("192.168.0.128"),
     port = mutableStateOf(6660u),