feat: Add audio file export to file system

gradle/libs.versions.toml

@@ -22,6 +22,7 @@ horologist = "0.7.15"
 coreSplashscreen = "1.0.1"
 wear-input = "1.2.0"
 androidxDataStore = "1.1.7"
+documentfile = "1.0.1"
 #material-icons-extended = "1.7.8"
 
 [libraries]
@@ -63,6 +64,7 @@ wear-input = { group = "androidx.wear", name = "wear-input", version.ref = "wear
 androidx-compose-material3 = { group = "androidx.compose.material3", name = "material3" }
 androidx-lifecycle-viewmodel-compose = { module = "androidx.lifecycle:lifecycle-viewmodel-compose", version.ref = "androidx-lifecycle" }
 androidx-dataStore-preferences = { group = "androidx.datastore", name = "datastore-preferences", version.ref = "androidxDataStore" }
+androidx-documentfile = { group = "androidx.documentfile", name = "documentfile", version.ref = "documentfile" }
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }

mobile/build.gradle.kts

@@ -79,6 +79,7 @@ dependencies {
   implementation(libs.kotlinx.coroutines.play.services)
   implementation(libs.androidx.dataStore.preferences)
   implementation(libs.androidx.work.ktx)
+  implementation(libs.androidx.documentfile)
 
   implementation(libs.androidx.compose.material.iconsExtended)
 }

mobile/src/main/java/dev/tberghuis/voicememos/MobileScreen.kt

@@ -1,5 +1,9 @@
 package dev.tberghuis.voicememos
 
+import android.content.Intent
+import android.net.Uri
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Row
@@ -24,12 +28,14 @@ import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
 import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
+import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.viewmodel.compose.viewModel
 import dev.tberghuis.voicememos.common.calcDuration
 import dev.tberghuis.voicememos.common.formatTimestampFromFilename
@@ -40,6 +46,28 @@ import java.io.File
 fun MobileScreen(
   vm: MobileViewModel = viewModel()
 ) {
+  val context = LocalContext.current
+
+  val exportLauncher = rememberLauncherForActivityResult(
+    contract = ActivityResultContracts.OpenDocumentTree()
+  ) { uri: Uri? ->
+    uri?.let {
+      vm.exportToFolder(it)
+    }
+  }
+
+  LaunchedEffect(Unit) {
+    vm.exportRecordingsTrigger.collect {
+      exportLauncher.launch(null)
+    }
+  }
+
+  LaunchedEffect(Unit) {
+    vm.snackbarMessage.collect {
+      vm.snackbarHostState.showSnackbar(it)
+    }
+  }
+
   Scaffold(topBar = {
     TopAppBar(title = { Text(stringResource(R.string.app_name)) })
   }, bottomBar = {
@@ -55,6 +83,9 @@ fun MobileScreen(
         }) {
           Text("Delete All Watch")
         }
+        Button(modifier = Modifier.padding(start = 10.dp), onClick = { vm.exportRecordings() }) {
+          Text("Export")
+        }
       }
     }
   }, snackbarHost = {

mobile/src/main/java/dev/tberghuis/voicememos/MobileViewModel.kt

@@ -1,10 +1,12 @@
 package dev.tberghuis.voicememos
 
 import android.app.Application
+import android.net.Uri
 import androidx.compose.material3.SnackbarHostState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
+import androidx.documentfile.provider.DocumentFile
 import androidx.lifecycle.AndroidViewModel
 import androidx.lifecycle.viewModelScope
 import com.google.android.gms.wearable.CapabilityClient
@@ -14,9 +16,12 @@ import dev.tberghuis.voicememos.common.AudioController
 import dev.tberghuis.voicememos.common.deleteFileCommon
 import dev.tberghuis.voicememos.common.logd
 import java.io.File
+import java.io.FileInputStream
 import kotlinx.coroutines.async
 import kotlinx.coroutines.awaitAll
+import kotlinx.coroutines.flow.MutableSharedFlow
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asSharedFlow
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.tasks.await
 
@@ -47,6 +52,12 @@ class MobileViewModel(private val application: Application) : AndroidViewModel(a
     }
   }
 
+  private val _exportRecordingsTrigger = MutableSharedFlow<Unit>()
+  val exportRecordingsTrigger = _exportRecordingsTrigger.asSharedFlow()
+
+  private val _snackbarMessage = MutableSharedFlow<String>()
+  val snackbarMessage = _snackbarMessage.asSharedFlow()
+
   init {
     logd("MobileViewModel init")
     refreshRecordingFiles()
@@ -129,4 +140,47 @@ class MobileViewModel(private val application: Application) : AndroidViewModel(a
 
     }
   }
-}
+
+  fun exportRecordings() {
+    viewModelScope.launch {
+      _exportRecordingsTrigger.emit(Unit)
+    }
+  }
+
+  fun exportToFolder(treeUri: Uri) {
+    viewModelScope.launch {
+      var copiedCount = 0
+      try {
+        application.contentResolver.takePersistableUriPermission(
+          treeUri,
+          android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION or
+              android.content.Intent.FLAG_GRANT_WRITE_URI_PERMISSION
+        )
+
+        val folder = DocumentFile.fromTreeUri(application, treeUri)
+          ?: throw Exception("Could not get DocumentFile from URI")
+
+        recordingFilesStateFlow.value.forEach { file ->
+          val newFile = folder.createFile("audio/pcm", file.name)
+            ?: throw Exception("Could not create file ${file.name} in selected folder")
+
+          application.contentResolver.openOutputStream(newFile.uri)?.use { outputStream ->
+            FileInputStream(file).use { inputStream ->
+              inputStream.copyTo(outputStream)
+            }
+          }
+          copiedCount++
+        }
+        _snackbarMessage.emit("Exported $copiedCount recordings to selected folder")
+      } catch (e: Exception) {
+        logd("Error exporting recordings: $e")
+        _snackbarMessage.emit("Error exporting recordings: ${e.localizedMessage}")
+      } finally {
+        // It's generally good practice to release permissions when no longer needed,
+        // but for a chosen folder, the user might expect it to persist.
+        // For simplicity and to match common patterns, we will not release it here.
+        // If a more complex permission management is needed, this would be the place.
+      }
+    }
+  }
+}