Move MusicRepository initialization to coroutine

Move the init call to MusicRepostiory to a coroutine so that it doesnt stop the UI thread.

app/src/main/java/org/oxycblt/auxio/library/LibraryFragment.kt

@@ -10,14 +10,18 @@ import androidx.fragment.app.Fragment
 import androidx.lifecycle.ViewModelProvider
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.databinding.FragmentLibraryBinding
-import org.oxycblt.auxio.music.MusicRepository
 
 class LibraryFragment : Fragment() {
 
     // Lazily initiate the ViewModel when its first referenced.
     // Not because this does anything, it just looks nicer.
     private val libraryModel: LibraryViewModel by lazy {
-        ViewModelProvider(this).get(LibraryViewModel::class.java)
+        ViewModelProvider(
+            this,
+            LibraryViewModel.Factory(
+                requireActivity().application
+            )
+        ).get(LibraryViewModel::class.java)
     }
 
     override fun onCreateView(
@@ -29,7 +33,7 @@ class LibraryFragment : Fragment() {
             inflater, R.layout.fragment_library, container, false
         )
 
-        MusicRepository.getInstance().init(requireActivity().application)
+        libraryModel
 
         Log.d(this::class.simpleName, "Fragment created.")
 

app/src/main/java/org/oxycblt/auxio/library/LibraryViewModel.kt

@@ -1,13 +1,42 @@
 package org.oxycblt.auxio.library
 
+import android.app.Application
 import android.util.Log
 import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.launch
+import org.oxycblt.auxio.music.MusicRepository
 
-class LibraryViewModel() : ViewModel() {
+class LibraryViewModel(private val app: Application) : ViewModel() {
 
-    // TODO: Implement music data in ViewModel
+    private val viewModelJob = Job()
+    private val ioScope = CoroutineScope(
+        Dispatchers.IO
+    )
 
     init {
+        startMusicRepo()
+
         Log.d(this::class.simpleName, "ViewModel created.")
     }
+
+    // TODO: Temp function, remove when LoadingFragment is added
+    private fun startMusicRepo() {
+        ioScope.launch {
+            MusicRepository.getInstance().init(app)
+        }
+    }
+
+    class Factory(private val application: Application) : ViewModelProvider.Factory {
+        @Suppress("unchecked_cast")
+        override fun <T : ViewModel?> create(modelClass: Class<T>): T {
+            if (modelClass.isAssignableFrom(LibraryViewModel::class.java)) {
+                return LibraryViewModel(application) as T
+            }
+            throw IllegalArgumentException("Unknown ViewModel class")
+        }
+    }
 }

app/src/main/java/org/oxycblt/auxio/music/MusicRepository.kt

@@ -4,7 +4,6 @@ import android.app.Application
 import android.content.ContentResolver
 import android.content.ContentUris
 import android.database.Cursor
-import android.graphics.Bitmap
 import android.media.MediaMetadataRetriever
 import android.provider.MediaStore
 import android.provider.MediaStore.Audio.AudioColumns
@@ -47,13 +46,15 @@ class MusicRepository {
                 app.contentResolver
             )
 
+            Log.i(this::class.simpleName, "Starting music search...")
+
             // Index music files from shared storage
             musicCursor?.use { cursor ->
 
                 val idIndex = cursor.getColumnIndexOrThrow(AudioColumns._ID)
                 val displayIndex = cursor.getColumnIndexOrThrow(AudioColumns.DISPLAY_NAME)
 
-                var retriever = MediaMetadataRetriever()
+                val retriever = MediaMetadataRetriever()
 
                 while (cursor.moveToNext()) {
                     val id = cursor.getLong(idIndex)
@@ -84,17 +85,22 @@ class MusicRepository {
                         MediaMetadataRetriever.METADATA_KEY_GENRE
                     )
 
-                    val year = (retriever.extractMetadata(
-                        MediaMetadataRetriever.METADATA_KEY_YEAR
-                    ) ?: "0").toInt()
+                    val year = (
+                        retriever.extractMetadata(
+                            MediaMetadataRetriever.METADATA_KEY_YEAR
+                        ) ?: "0"
+                        ).toInt()
 
                     // Track is formatted as X/0, so trim off the /0 part to parse
                     // the track number correctly.
-                    val track = (retriever.extractMetadata(
-                        MediaMetadataRetriever.METADATA_KEY_CD_TRACK_NUMBER
-                    ) ?: "0/0").split("/")[0].toInt()
+                    val track = (
+                        retriever.extractMetadata(
+                            MediaMetadataRetriever.METADATA_KEY_CD_TRACK_NUMBER
+                        ) ?: "0/0"
+                        ).split("/")[0].toInt()
 
-                    // Something has gone horribly wrong if a file has no duration.
+                    // Something has gone horribly wrong if a file has no duration,
+                    // so assert it as such.
                     val duration = retriever.extractMetadata(
                         MediaMetadataRetriever.METADATA_KEY_DURATION
                     )!!.toLong()
@@ -117,7 +123,7 @@ class MusicRepository {
                     )
                 }
 
-                // Close the retriever when done so that it gets garbage collected
+                // Close the retriever when done so that it gets garbage collected [I hope]
                 retriever.close()
             }
 
@@ -127,7 +133,6 @@ class MusicRepository {
             )
 
             return songList
-
         } catch (error: Exception) {
             // TODO: Add better error handling