Add Music Loading

Add a Music Repository/Loader, along with a boilerplate ViewModel for LibraryFragment.

app/build.gradle

@@ -8,7 +8,7 @@ android {
 
     defaultConfig {
         applicationId "org.oxycblt.auxio"
-        minSdkVersion 23
+        minSdkVersion 24
         targetSdkVersion 30
         versionCode 1
         versionName "1.0"

app/src/main/AndroidManifest.xml

@@ -1,6 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="org.oxycblt.auxio">
+    
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
 
     <application
         android:allowBackup="true"

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

@@ -7,17 +7,23 @@ import android.view.View
 import android.view.ViewGroup
 import androidx.databinding.DataBindingUtil
 import androidx.fragment.app.Fragment
+import androidx.lifecycle.ViewModelProvider
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.databinding.FragmentLibraryBinding
 
 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)
+    }
+
     override fun onCreateView(
         inflater: LayoutInflater,
         container: ViewGroup?,
         savedInstanceState: Bundle?
     ): View? {
-
         val binding = DataBindingUtil.inflate<FragmentLibraryBinding>(
             inflater, R.layout.fragment_library, container, false
         )

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

@@ -0,0 +1,14 @@
+package org.oxycblt.auxio.library
+
+import android.util.Log
+import androidx.lifecycle.ViewModel
+
+class LibraryViewModel() : ViewModel() {
+
+    // TODO: Implement music data in ViewModel
+
+    init {
+
+        Log.d(this::class.simpleName, "ViewModel created.")
+    }
+}

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

@@ -0,0 +1,118 @@
+package org.oxycblt.auxio.music
+
+import android.app.Application
+import android.content.ContentResolver
+import android.database.Cursor
+import android.provider.MediaStore
+import android.provider.MediaStore.Audio.AudioColumns
+import android.util.Log
+
+// Storage for music data. Design largely adapted from Music Player GO:
+// https://github.com/enricocid/Music-Player-GO
+class MusicRepository() {
+
+    var rawMusicList = mutableListOf<RawMusic>()
+
+    fun getMusic(app: Application): MutableList<RawMusic> {
+        findMusic(app)?.let { rm ->
+
+            // TODO: Sort the raw music
+            rawMusicList = rm
+        }
+
+        return rawMusicList
+    }
+
+    private fun findMusic(app: Application): MutableList<RawMusic>? {
+
+        try {
+            val musicCursor = getCursor(
+                app.contentResolver
+            )
+
+            // Index music files from shared storage
+            musicCursor?.use { cursor ->
+
+                val nameIndex = cursor.getColumnIndexOrThrow(AudioColumns.TITLE)
+                val artistIndex = cursor.getColumnIndexOrThrow(AudioColumns.ARTIST)
+                val albumIndex = cursor.getColumnIndexOrThrow(AudioColumns.ALBUM)
+                val yearIndex = cursor.getColumnIndexOrThrow(AudioColumns.YEAR)
+                val trackIndex = cursor.getColumnIndexOrThrow(AudioColumns.TRACK)
+                val durationIndex = cursor.getColumnIndexOrThrow(AudioColumns.DURATION)
+                val idIndex = cursor.getColumnIndexOrThrow(AudioColumns._ID)
+
+                while (cursor.moveToNext()) {
+                    rawMusicList.add(
+                        RawMusic(
+                            cursor.getString(nameIndex),
+                            cursor.getString(artistIndex),
+                            cursor.getString(albumIndex),
+                            cursor.getInt(yearIndex),
+                            cursor.getInt(trackIndex),
+                            cursor.getLong(durationIndex),
+                            cursor.getLong(idIndex)
+                        )
+                    )
+                }
+            }
+
+            Log.d(
+                this::class.simpleName,
+                "Music search ended with " + rawMusicList.size.toString() + " Songs found."
+            )
+
+            return rawMusicList
+        } catch (error: Exception) {
+            // TODO: Add better error handling
+
+            Log.e(this::class.simpleName, "Something went horribly wrong.")
+            error.printStackTrace()
+
+            return null
+        }
+    }
+
+    private fun getCursor(resolver: ContentResolver): Cursor? {
+        Log.i(this::class.simpleName, "Getting music cursor.")
+
+        return resolver.query(
+            MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
+            arrayOf(
+                AudioColumns.TITLE,
+                AudioColumns.ARTIST,
+                AudioColumns.ALBUM,
+                AudioColumns.YEAR,
+                AudioColumns.TRACK,
+                AudioColumns.DURATION,
+                AudioColumns._ID
+            ),
+            AudioColumns.IS_MUSIC + "=1", null,
+            MediaStore.Audio.Media.DEFAULT_SORT_ORDER
+        )
+    }
+
+    companion object {
+        @Volatile
+        private var INSTANCE: MusicRepository? = null
+
+        fun getInstance(): MusicRepository {
+            val tempInstance = INSTANCE
+
+            if (tempInstance != null) {
+                return tempInstance
+            }
+
+            synchronized(this) {
+                val newInstance = MusicRepository()
+                INSTANCE = newInstance
+
+                Log.d(
+                    MusicRepository::class.simpleName,
+                    "Created an instance of MusicRepository."
+                )
+
+                return newInstance
+            }
+        }
+    }
+}

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

@@ -0,0 +1,13 @@
+package org.oxycblt.auxio.music
+
+// Class containing all relevant values for a song
+// TODO: Is broken into Artist, Album, and Song classes
+data class RawMusic(
+    val name: String?,
+    val artist: String?,
+    val album: String?,
+    val year: Int,
+    val track: Int,
+    val duration: Long,
+    val id: Long?
+)

app/src/main/res/layout/activity_main.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<layout
+<layout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:tools="http://schemas.android.com/tools"
     tools:context=".MainActivity">

app/src/main/res/layout/fragment_library.xml

@@ -1,13 +1,11 @@
 <?xml version="1.0" encoding="utf-8"?>
-<layout
+<layout xmlns:app="http://schemas.android.com/apk/res-auto"
-    xmlns:app="http://schemas.android.com/apk/res-auto"
     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools">
 
     <androidx.constraintlayout.widget.ConstraintLayout
         android:layout_width="match_parent"
-        android:layout_height="match_parent"
+        android:layout_height="match_parent">
-        android:background="?attr/background">
 
         <androidx.appcompat.widget.Toolbar
             android:id="@+id/toolbar"
@@ -18,7 +16,7 @@
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toTopOf="parent"
             app:title="@string/fragment_library_title"
-            tools:titleTextColor="@color/primaryTextColor"/>
+            tools:titleTextColor="@color/primaryTextColor" />
 
     </androidx.constraintlayout.widget.ConstraintLayout>
 </layout>

app/src/main/res/navigation/nav_main.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<navigation
+<navigation xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:app="http://schemas.android.com/apk/res-auto"
     android:id="@+id/nav_main"
     app:startDestination="@id/playerFragment">

app/src/main/res/values/styles.xml

@@ -5,6 +5,5 @@
         <item name="colorPrimary">@color/primaryColor</item>
         <item name="colorPrimaryDark">@color/primaryColor</item>
         <item name="colorAccent">@color/primaryColor</item>
-        <item name="background">@color/secondaryColor</item>
     </style>
 </resources>