feat(app): add a view model for a better architecture

app/src/main/java/io/github/thibaultbee/streampack/example/ApplicationConstants.kt

@@ -0,0 +1,14 @@
+package io.github.thibaultbee.streampack.example
+
+import android.content.pm.ActivityInfo
+
+/**
+ * Application configuration.
+ */
+object ApplicationConstants {
+    /**
+     * Default application orientation.
+     * Also set in `AndroidManifest.xml` `android:screenOrientation` attribute.
+     */
+    const val supportedOrientation = ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED
+}

app/src/main/java/io/github/thibaultbee/streampack/example/MainActivity.kt

@@ -3,40 +3,35 @@ package io.github.thibaultbee.streampack.example
 import android.Manifest
 import android.annotation.SuppressLint
 import android.content.pm.ActivityInfo
-import android.media.AudioFormat
-import android.media.MediaFormat
 import android.os.Bundle
 import android.util.Log
-import android.util.Size
+import androidx.activity.viewModels
 import androidx.annotation.RequiresPermission
 import androidx.appcompat.app.AppCompatActivity
-import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.lifecycleScope
-import io.github.thibaultbee.streampack.app.data.rotation.RotationRepository
-import io.github.thibaultbee.streampack.core.elements.sources.audio.audiorecord.MicrophoneSourceFactory
 import io.github.thibaultbee.streampack.core.elements.sources.video.camera.extensions.defaultCameraId
-import io.github.thibaultbee.streampack.core.interfaces.setCameraId
-import io.github.thibaultbee.streampack.core.interfaces.startStream
-import io.github.thibaultbee.streampack.core.streamers.dual.DualStreamer
 import io.github.thibaultbee.streampack.core.streamers.lifecycle.StreamerActivityLifeCycleObserver
-import io.github.thibaultbee.streampack.core.streamers.single.AudioConfig
-import io.github.thibaultbee.streampack.core.streamers.single.SingleStreamer
-import io.github.thibaultbee.streampack.core.streamers.single.VideoConfig
-import io.github.thibaultbee.streampack.core.utils.extensions.isClosedException
 import io.github.thibaultbee.streampack.example.databinding.ActivityMainBinding
 import io.github.thibaultbee.streampack.example.utils.PermissionsManager
 import io.github.thibaultbee.streampack.example.utils.showDialog
 import io.github.thibaultbee.streampack.example.utils.toast
-import kotlinx.coroutines.flow.filter
-import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.launch
 
 class MainActivity : AppCompatActivity() {
     private lateinit var binding: ActivityMainBinding
+    private val viewModel: MainViewModel by viewModels {
+        MainViewModelFactory(this.application)
+    }
 
     private val streamerRequiredPermissions =
-        listOf(Manifest.permission.CAMERA, Manifest.permission.RECORD_AUDIO)
+        listOf(
+            Manifest.permission.CAMERA,
+            Manifest.permission.RECORD_AUDIO
+        )
 
+    /**
+     * A minimalist permission manager
+     */
     @SuppressLint("MissingPermission")
     private val permissionsManager = PermissionsManager(
         this,
@@ -61,42 +56,10 @@ class MainActivity : AppCompatActivity() {
             )
         })
 
-    /**
-     * The streamer is the central object of StreamPack.
-     * It is responsible for the capture audio and video and the streaming process.
-     *
-     * If you need only 1 output (live only or record only), use [SingleStreamer].
-     * If you need 2 outputs (live and record), use [DualStreamer].
-     */
-    private val streamer by lazy {
-        // 1 output
-        SingleStreamer(
-            this, withAudio = true, withVideo = true
-        )
-        // 2 outputs: uncomment the line below
-        /*
-        DualStreamer(
-            this,
-            withAudio = true,
-            withVideo = true
-        )
-        */
-    }
-
     /**
      * Listen to lifecycle events. So we don't have to stop the streamer manually in `onPause` and release in `onDestroy
      */
-    private val streamerLifeCycleObserver by lazy { StreamerActivityLifeCycleObserver(streamer) }
-
-    /**
-     * Listen to device rotation.
-     */
-    private val rotationRepository by lazy { RotationRepository.getInstance(applicationContext) }
-
-    /**
-     * A LiveData to observe the connection state.
-     */
-    private val isTryingConnectionLiveData = MutableLiveData<Boolean>()
+    private val streamerLifeCycleObserver by lazy { StreamerActivityLifeCycleObserver(viewModel.streamer) }
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -116,47 +79,37 @@ class MainActivity : AppCompatActivity() {
                      */
                     lifecycleScope.launch {
                         try {
-                            isTryingConnectionLiveData.postValue(true)
-                            /**
-                             * For SRT, use srt://my.server.url:9998?streamid=myStreamId&passphrase=myPassphrase
-                             */
-                            streamer.startStream("rtmp://my.server.url:1935/app/streamKey")
+                            viewModel.startStream()
                         } catch (e: Exception) {
                             binding.liveButton.isChecked = false
                             Log.e(TAG, "Failed to connect", e)
                             toast("Connection failed: ${e.message}")
-                        } finally {
-                            isTryingConnectionLiveData.postValue(false)
                         }
                     }
                 } else {
                     lifecycleScope.launch {
-                        streamer.stopStream()
+                        viewModel.stopStream()
                     }
                 }
             }
         }
 
-        bindAndPrepareStreamer()
-    }
-
-    private fun bindAndPrepareStreamer() {
         // Register the lifecycle observer
         lifecycle.addObserver(streamerLifeCycleObserver)
 
         // Configure the streamer
         configureStreamer()
 
-        // Listen to rotation
-        lifecycleScope.launch {
-            rotationRepository.rotationFlow.collect {
-                streamer.setTargetRotation(it)
-            }
+        // Bind events
+        viewModel.closedThrowableLiveData.observe(this) {
+            toast("Connection error: ${it.message}")
         }
 
-        // Lock and unlock orientation on isStreaming state.
-        lifecycleScope.launch {
-            streamer.isStreamingFlow.collect { isStreaming ->
+        viewModel.throwableLiveData.observe(this) {
+            toast("Error: ${it.message}")
+        }
+
+        viewModel.isStreamingLiveData.observe(this) { isStreaming ->
             if (isStreaming) {
                 lockOrientation()
             } else {
@@ -164,29 +117,20 @@ class MainActivity : AppCompatActivity() {
             }
             if (isStreaming) {
                 binding.liveButton.isChecked = true
-                } else if (isTryingConnectionLiveData.value == true) {
+            } else if (viewModel.isTryingConnectionLiveData.value == true) {
                 binding.liveButton.isChecked = true
             } else {
                 binding.liveButton.isChecked = false
             }
         }
-        }
 
-        // General error handling
-        lifecycleScope.launch {
-            streamer.throwableFlow.filterNotNull().filter { !it.isClosedException }
-                .collect { throwable ->
-                    Log.e(TAG, "Error: ${throwable.message}", throwable)
-                    toast("Error: ${throwable.message}")
-                }
-        }
-
-        // Connection error handling
-        lifecycleScope.launch {
-            streamer.throwableFlow.filterNotNull().filter { it.isClosedException }
-                .collect { throwable ->
-                    Log.e(TAG, "Connection lost: ${throwable.message}", throwable)
-                    toast("Connection lost: ${throwable.message}")
+        viewModel.isTryingConnectionLiveData.observe(this) { isWaitingForConnection ->
+            if (isWaitingForConnection) {
+                binding.liveButton.isChecked = true
+            } else if (viewModel.isStreamingLiveData.value == true) {
+                binding.liveButton.isChecked = true
+            } else {
+                binding.liveButton.isChecked = false
             }
         }
     }
@@ -202,7 +146,7 @@ class MainActivity : AppCompatActivity() {
     }
 
     private fun unlockOrientation() {
-        requestedOrientation = ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED
+        requestedOrientation = ApplicationConstants.supportedOrientation
     }
 
     override fun onStart() {
@@ -220,54 +164,32 @@ class MainActivity : AppCompatActivity() {
     private fun setAVSource() {
         // Set audio and video sources.
         lifecycleScope.launch {
-            streamer.setAudioSource(MicrophoneSourceFactory())
-            streamer.setCameraId(this@MainActivity.defaultCameraId)
+            viewModel.setAudioSource()
+            viewModel.setCameraId(this@MainActivity.defaultCameraId)
         }
     }
 
     private fun setStreamerView() {
         lifecycleScope.launch {
-            binding.preview.setVideoSourceProvider(streamer) // Bind the streamer to the preview
+            binding.preview.setVideoSourceProvider(viewModel.streamer) // Bind the streamer to the preview
         }
     }
 
     @SuppressLint("MissingPermission")
     private fun configureStreamer() {
-        /**
-         * To get the parameters supported by the device, the [SingleStreamer] have a
-         * [SingleStreamer.getInfo] method.
-         */
-
-        /**
-         * There are other parameters in the [VideoConfig] such as:
-         * - bitrate
-         * - profile
-         * - level
-         * - gopSize
-         * They will be initialized with an appropriate default value.
-         */
-        val videoConfig = VideoConfig(
-            mimeType = MediaFormat.MIMETYPE_VIDEO_AVC, resolution = Size(1280, 720), fps = 25
-        )
-
-        /**
-         * There are other parameters in the [AudioConfig] such as:
-         * - byteFormat
-         * - enableEchoCanceler
-         * - enableNoiseSuppressor
-         * They will be initialized with an appropriate default value.
-         */
-        val audioConfig = AudioConfig(
-            mimeType = MediaFormat.MIMETYPE_AUDIO_AAC,
-            sampleRate = 44100,
-            channelConfig = AudioFormat.CHANNEL_IN_STEREO
-        )
-
         lifecycleScope.launch {
-            streamer.setConfig(audioConfig, videoConfig)
+            viewModel.setAudioConfig()
+            viewModel.setVideoConfig()
         }
     }
 
+    override fun onDestroy() {
+        super.onDestroy()
+
+        // Unregister the lifecycle observer
+        lifecycle.removeObserver(streamerLifeCycleObserver)
+    }
+
     private fun toast(message: String) {
         runOnUiThread { applicationContext.toast(message) }
     }

app/src/main/java/io/github/thibaultbee/streampack/example/MainViewModel.kt

@@ -0,0 +1,156 @@
+package io.github.thibaultbee.streampack.example
+
+import android.Manifest
+import android.media.AudioFormat
+import android.media.MediaFormat
+import android.util.Size
+import androidx.annotation.RequiresPermission
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.asLiveData
+import androidx.lifecycle.viewModelScope
+import io.github.thibaultbee.streampack.app.data.rotation.RotationRepository
+import io.github.thibaultbee.streampack.core.elements.sources.audio.audiorecord.MicrophoneSourceFactory
+import io.github.thibaultbee.streampack.core.interfaces.setCameraId
+import io.github.thibaultbee.streampack.core.interfaces.startStream
+import io.github.thibaultbee.streampack.core.streamers.single.AudioConfig
+import io.github.thibaultbee.streampack.core.streamers.single.SingleStreamer
+import io.github.thibaultbee.streampack.core.streamers.single.VideoConfig
+import io.github.thibaultbee.streampack.core.utils.extensions.isClosedException
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.filter
+import kotlinx.coroutines.flow.filterNotNull
+import kotlinx.coroutines.launch
+
+class MainViewModel(
+    private val rotationRepository: RotationRepository,
+    val streamer: SingleStreamer
+) : ViewModel() {
+    private val defaultDispatcher = Dispatchers.Default
+
+    /**
+     * A LiveData to observe the stream state.
+     */
+    val isStreamingLiveData: LiveData<Boolean>
+        get() = streamer.isStreamingFlow.asLiveData()
+
+    /**
+     * A LiveData to observe the pending connection state.
+     */
+    private val _isTryingConnectionLiveData = MutableLiveData<Boolean>()
+    val isTryingConnectionLiveData: LiveData<Boolean> = _isTryingConnectionLiveData
+
+    /**
+     * A LiveData to observe async disconnection errors.
+     */
+    val closedThrowableLiveData: LiveData<Throwable> =
+        streamer.throwableFlow.filterNotNull().filter { it.isClosedException }.asLiveData()
+
+    /**
+     * A LiveData to observe streamer errors.
+     */
+    val throwableLiveData: LiveData<Throwable> =
+        streamer.throwableFlow.filterNotNull().filter { !it.isClosedException }.asLiveData()
+
+
+    init {
+        /**
+         * Listens to device rotation.
+         */
+        viewModelScope.launch(defaultDispatcher) {
+            rotationRepository.rotationFlow.collect {
+                streamer.setTargetRotation(it)
+            }
+        }
+    }
+
+    /**
+     * Starts the stream.
+     *
+     * Replace with a valid URL.
+     */
+    suspend fun startStream() {
+        _isTryingConnectionLiveData.postValue(true)
+        try {
+            /**
+             * For SRT, use srt://my.server.url:9998?streamid=myStreamId&passphrase=myPassphrase
+             */
+            streamer.startStream("rtmp://my.server.url:1935/app/streamKey")
+        } finally {
+            _isTryingConnectionLiveData.postValue(false)
+        }
+    }
+
+    /**
+     * Stops the stream.
+     */
+    suspend fun stopStream() {
+        streamer.stopStream()
+    }
+
+    /**
+     * Sets the audio configuration.
+     *
+     * You can verify the device supported configuration with [SingleStreamer.getInfo].
+     */
+    @RequiresPermission(Manifest.permission.RECORD_AUDIO)
+    suspend fun setAudioConfig() {
+        /**
+         * There are other parameters in the [AudioConfig] such as:
+         * - byteFormat
+         * - enableEchoCanceler
+         * - enableNoiseSuppressor
+         * They will be initialized with an appropriate default value.
+         */
+        val audioConfig = AudioConfig(
+            mimeType = MediaFormat.MIMETYPE_AUDIO_AAC,
+            sampleRate = 44100,
+            channelConfig = AudioFormat.CHANNEL_IN_STEREO
+        )
+
+        streamer.setAudioConfig(audioConfig)
+    }
+
+    /**
+     * Sets the video configuration.
+     *
+     * You can verify the device supported configuration with [SingleStreamer.getInfo].
+     */
+    suspend fun setVideoConfig() {
+        /**
+         * There are other parameters in the [VideoConfig] such as:
+         * - bitrate
+         * - profile
+         * - level
+         * - gopSize
+         * They will be initialized with an appropriate default value.
+         */
+        val videoConfig = VideoConfig(
+            mimeType = MediaFormat.MIMETYPE_VIDEO_AVC, resolution = Size(1280, 720), fps = 25
+        )
+
+        streamer.setVideoConfig(videoConfig)
+    }
+
+    /**
+     * Sets the microphone as the audio source.
+     */
+    suspend fun setAudioSource() {
+        streamer.setAudioSource(MicrophoneSourceFactory())
+    }
+
+    /**
+     * Sets the camera with the given id as the video source.
+     *
+     * @param cameraId The camera id.
+     */
+    @RequiresPermission(Manifest.permission.CAMERA)
+    suspend fun setCameraId(cameraId: String) {
+        streamer.setCameraId(cameraId)
+    }
+
+    companion object {
+        private const val TAG = "MainViewModel"
+    }
+}

app/src/main/java/io/github/thibaultbee/streampack/example/MainViewModelFactory.kt

@@ -0,0 +1,52 @@
+package io.github.thibaultbee.streampack.example
+
+import android.app.Application
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import io.github.thibaultbee.streampack.app.data.rotation.RotationRepository
+import io.github.thibaultbee.streampack.core.streamers.dual.DualStreamer
+import io.github.thibaultbee.streampack.core.streamers.single.SingleStreamer
+
+/**
+ * Factory for constructing [MainViewModelFactory] from the [Application].
+ */
+class MainViewModelFactory(private val application: Application) :
+    ViewModelProvider.Factory {
+    private val rotationRepository = RotationRepository.getInstance(application)
+
+    @Suppress("UNCHECKED_CAST")
+
+    override fun <T : ViewModel> create(modelClass: Class<T>): T {
+        if (modelClass.isAssignableFrom(MainViewModel::class.java)) {
+            val streamer = createStreamer(application)
+            return MainViewModel(rotationRepository, streamer) as T
+        }
+        throw IllegalArgumentException("Unknown ViewModel class")
+    }
+
+    companion object {
+        /**
+         * Creates a streamer instance.
+         *
+         * The streamer is the central object of StreamPack.
+         * It is responsible for the capture audio and video and the streaming process.
+         *
+         * If you need only 1 output (live only or record only), use [SingleStreamer].
+         * If you need 2 outputs (live and record), use [DualStreamer].
+         */
+        private fun createStreamer(application: Application): SingleStreamer {
+            // 1 output
+            return SingleStreamer(
+                application, withAudio = true, withVideo = true
+            )
+            // 2 outputs: uncomment the line below
+            /*
+            DualStreamer(
+                this,
+                withAudio = true,
+                withVideo = true
+            )
+            */
+        }
+    }
+}