home: rework loading screen

Move the loading screen into the home view.

Previously, we would use a Snackbar to track the music loading state.
This ended up being a pretty stupid and buggy idea, and would get even
worse with the new music loader changes. Instead, we re-implement the
loading screen into the home view to generally be more sane and
extendable compared to previously.

app/build.gradle

@@ -35,7 +35,6 @@ android {
 
     buildTypes {
         debug {
-            debuggable true
             applicationIdSuffix = ".debug"
             versionNameSuffix = "-DEBUG"
         }

app/src/main/java/org/oxycblt/auxio/MainFragment.kt

@@ -17,28 +17,23 @@
  
 package org.oxycblt.auxio
 
-import android.Manifest
 import android.os.Build
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
 import androidx.activity.OnBackPressedCallback
-import androidx.activity.result.ActivityResultLauncher
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.fragment.app.activityViewModels
 import androidx.navigation.findNavController
 import androidx.navigation.fragment.findNavController
-import com.google.android.material.snackbar.Snackbar
 import org.oxycblt.auxio.databinding.FragmentMainBinding
 import org.oxycblt.auxio.music.Music
-import org.oxycblt.auxio.music.MusicStore
 import org.oxycblt.auxio.music.MusicViewModel
 import org.oxycblt.auxio.music.Song
 import org.oxycblt.auxio.playback.PlaybackViewModel
 import org.oxycblt.auxio.ui.MainNavigationAction
 import org.oxycblt.auxio.ui.NavigationViewModel
 import org.oxycblt.auxio.ui.ViewBindingFragment
-import org.oxycblt.auxio.util.logD
 
 /**
  * A wrapper around the home fragment that shows the playback fragment and controls the more
@@ -86,11 +81,6 @@ class MainFragment : ViewBindingFragment<FragmentMainBinding>() {
         // TODO: Move this to a service [automatic rescanning]
         musicModel.loadMusic(requireContext())
 
-        // Handle the music loader response.
-        musicModel.loaderResponse.observe(viewLifecycleOwner) { response ->
-            handleLoaderResponse(response, permLauncher)
-        }
-
         navModel.mainNavigationAction.observe(viewLifecycleOwner, ::handleMainNavigation)
         navModel.exploreNavigationItem.observe(viewLifecycleOwner, ::handleExploreNavigation)
 
@@ -107,44 +97,6 @@ class MainFragment : ViewBindingFragment<FragmentMainBinding>() {
         callback?.isEnabled = false
     }
 
-    private fun handleLoaderResponse(
-        response: MusicStore.Response?,
-        permLauncher: ActivityResultLauncher<String>
-    ) {
-        val binding = requireBinding()
-
-        // Handle any error cases, showing a useful message.
-        when (response) {
-            is MusicStore.Response.Err -> {
-                logD("Received Response.Err")
-                Snackbar.make(binding.root, R.string.err_load_failed, Snackbar.LENGTH_INDEFINITE)
-                    .apply {
-                        setAction(R.string.lbl_retry) { musicModel.reloadMusic(context) }
-                        show()
-                    }
-            }
-            is MusicStore.Response.NoMusic -> {
-                logD("Received Response.NoMusic")
-                Snackbar.make(binding.root, R.string.err_no_music, Snackbar.LENGTH_INDEFINITE)
-                    .apply {
-                        setAction(R.string.lbl_retry) { musicModel.reloadMusic(context) }
-                        show()
-                    }
-            }
-            is MusicStore.Response.NoPerms -> {
-                logD("Received Response.NoPerms")
-                Snackbar.make(binding.root, R.string.err_no_perms, Snackbar.LENGTH_INDEFINITE)
-                    .apply {
-                        setAction(R.string.lbl_grant) {
-                            permLauncher.launch(Manifest.permission.READ_EXTERNAL_STORAGE)
-                        }
-                        show()
-                    }
-            }
-            else -> {}
-        }
-    }
-
     private fun handleMainNavigation(action: MainNavigationAction?) {
         if (action == null) return
 

app/src/main/java/org/oxycblt/auxio/home/HomeFragment.kt

@@ -17,12 +17,17 @@
  
 package org.oxycblt.auxio.home
 
+import android.Manifest
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.MenuItem
+import android.view.View
+import androidx.activity.result.ActivityResultLauncher
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.appcompat.widget.Toolbar
 import androidx.core.view.isVisible
 import androidx.core.view.iterator
+import androidx.core.view.updatePadding
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.activityViewModels
 import androidx.navigation.fragment.findNavController
@@ -51,6 +56,8 @@ import org.oxycblt.auxio.ui.ViewBindingFragment
 import org.oxycblt.auxio.util.logD
 import org.oxycblt.auxio.util.logE
 import org.oxycblt.auxio.util.logTraceOrThrow
+import org.oxycblt.auxio.util.systemBarInsetsCompat
+import org.oxycblt.auxio.util.textSafe
 import org.oxycblt.auxio.util.unlikelyToBeNull
 
 /**
@@ -69,6 +76,12 @@ class HomeFragment : ViewBindingFragment<FragmentHomeBinding>(), Toolbar.OnMenuI
     override fun onBindingCreated(binding: FragmentHomeBinding, savedInstanceState: Bundle?) {
         val sortItem: MenuItem
 
+        // Build the permission launcher here as you can only do it in onCreateView/onCreate
+        val permLauncher =
+            registerForActivityResult(ActivityResultContracts.RequestPermission()) {
+                musicModel.reloadMusic(requireContext())
+            }
+
         binding.homeToolbar.apply {
             sortItem = menu.findItem(R.id.submenu_sorting)
             setOnMenuItemClickListener(this@HomeFragment)
@@ -76,6 +89,11 @@ class HomeFragment : ViewBindingFragment<FragmentHomeBinding>(), Toolbar.OnMenuI
 
         updateTabConfiguration()
 
+        binding.homeLoadingContainer.setOnApplyWindowInsetsListener { v, insets ->
+            v.updatePadding(bottom = insets.systemBarInsetsCompat.bottom)
+            insets
+        }
+
         binding.homePager.apply {
             adapter = HomePagerAdapter()
 
@@ -104,7 +122,10 @@ class HomeFragment : ViewBindingFragment<FragmentHomeBinding>(), Toolbar.OnMenuI
         homeModel.currentTab.observe(viewLifecycleOwner) { tab -> updateCurrentTab(sortItem, tab) }
         homeModel.recreateTabs.observe(viewLifecycleOwner, ::handleRecreateTabs)
 
-        musicModel.loaderResponse.observe(viewLifecycleOwner, ::handleLoaderResponse)
+        musicModel.loaderResponse.observe(viewLifecycleOwner) { response ->
+            handleLoaderResponse(response, permLauncher)
+        }
+
         navModel.exploreNavigationItem.observe(viewLifecycleOwner, ::handleNavigation)
     }
 
@@ -236,15 +257,61 @@ class HomeFragment : ViewBindingFragment<FragmentHomeBinding>(), Toolbar.OnMenuI
         }
     }
 
-    private fun handleLoaderResponse(response: MusicStore.Response?) {
+    private fun handleLoaderResponse(
+        response: MusicStore.Response?,
+        permLauncher: ActivityResultLauncher<String>
+    ) {
         val binding = requireBinding()
-        when (response) {
-            is MusicStore.Response.Ok -> binding.homeFab.show()
 
-            // While loading or during an error, make sure we keep the shuffle fab hidden so
+        if (response is MusicStore.Response.Ok) {
-            // that any kind of playback is impossible. PlaybackStateManager also relies on this
+            binding.homeFab.show()
-            // invariant, so please don't change it.
+            binding.homeLoadingContainer.visibility = View.INVISIBLE
-            else -> binding.homeFab.hide()
+            binding.homePager.visibility = View.VISIBLE
+        } else {
+            binding.homeFab.hide()
+            binding.homePager.visibility = View.INVISIBLE
+            binding.homeLoadingContainer.visibility = View.VISIBLE
+
+            logD("Received non-ok response $response")
+
+            when (response) {
+                is MusicStore.Response.Ok -> error("Unreachable")
+                is MusicStore.Response.Err -> {
+                    logD("Received Response.Err")
+                    binding.homeLoadingProgress.visibility = View.INVISIBLE
+                    binding.homeLoadingStatus.textSafe = getString(R.string.err_load_failed)
+                    binding.homeLoadingAction.apply {
+                        visibility = View.VISIBLE
+                        text = getString(R.string.lbl_retry)
+                        setOnClickListener { musicModel.reloadMusic(requireContext()) }
+                    }
+                }
+                is MusicStore.Response.NoMusic -> {
+                    binding.homeLoadingProgress.visibility = View.INVISIBLE
+                    binding.homeLoadingStatus.textSafe = getString(R.string.err_no_music)
+                    binding.homeLoadingAction.apply {
+                        visibility = View.VISIBLE
+                        text = getString(R.string.lbl_retry)
+                        setOnClickListener { musicModel.reloadMusic(requireContext()) }
+                    }
+                }
+                is MusicStore.Response.NoPerms -> {
+                    binding.homeLoadingProgress.visibility = View.INVISIBLE
+                    binding.homeLoadingStatus.textSafe = getString(R.string.err_no_perms)
+                    binding.homeLoadingAction.apply {
+                        visibility = View.VISIBLE
+                        text = getString(R.string.lbl_grant)
+                        setOnClickListener {
+                            permLauncher.launch(Manifest.permission.READ_EXTERNAL_STORAGE)
+                        }
+                    }
+                }
+                null -> {
+                    binding.homeLoadingStatus.textSafe = getString(R.string.lbl_loading)
+                    binding.homeLoadingAction.visibility = View.INVISIBLE
+                    binding.homeLoadingProgress.visibility = View.VISIBLE
+                }
+            }
         }
     }
 

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

@@ -53,17 +53,13 @@ class MusicStore private constructor() {
 
     private val callbacks = mutableListOf<Callback>()
 
-    /**
+    /** Add a callback to this instance. Make sure to remove it when done. */
-     * Add a callback to this instance. Make sure to remove it when done.
-     */
     fun addCallback(callback: Callback) {
         response?.let(callback::onMusicUpdate)
         callbacks.add(callback)
     }
 
-    /**
+    /** Remove a callback from this instance. */
-     * Remove a callback from this instance.
-     */
     fun removeCallback(callback: Callback) {
         callbacks.remove(callback)
     }
@@ -78,7 +74,7 @@ class MusicStore private constructor() {
         return newResponse
     }
 
-    private fun loadImpl(context: Context): Response {
+    private suspend fun loadImpl(context: Context): Response {
         val notGranted =
             ContextCompat.checkSelfPermission(context, Manifest.permission.READ_EXTERNAL_STORAGE) ==
                 PackageManager.PERMISSION_DENIED

app/src/main/java/org/oxycblt/auxio/music/indexer/ExoPlayerBackend.kt

@@ -62,8 +62,10 @@ class ExoPlayerBackend(private val inner: MediaStoreBackend) : Indexer.Backend {
         val songs = ConcurrentLinkedQueue<Song>()
 
         while (cursor.moveToNext()) {
+            // Note: This call to buildAudio does not populate the genre field. This is
+            // because indexing genres is quite slow with MediaStore, and so keeping the
+            // field blank on unsupported ExoPlayer formats ends up being preferable.
             val audio = inner.buildAudio(context, cursor)
-
             val audioUri = requireNotNull(audio.id) { "Malformed audio: No id" }.audioUri
 
             while (true) {
@@ -182,11 +184,7 @@ class ExoPlayerBackend(private val inner: MediaStoreBackend) : Indexer.Backend {
     }
 
     companion object {
-        /**
+        /** The amount of tasks this backend can run efficiently at once. */
-         * The amount of tasks this backend can run efficiently at one time. Eight was chosen here
-         * as higher values made little difference in speed, and lower values generally caused
-         * bottlenecks.
-         */
         private const val TASK_CAPACITY = 8
     }
 }

app/src/main/java/org/oxycblt/auxio/music/indexer/Indexer.kt

@@ -74,11 +74,11 @@ object Indexer {
         // Sanity check: Ensure that all songs are linked up to albums/artists/genres.
         for (song in songs) {
             if (song._isMissingAlbum || song._isMissingArtist || song._isMissingGenre) {
-                throw IllegalStateException(
+                error(
-                    "Found malformed song: ${song.rawName} [" +
+                    "Found unlinked song: ${song.rawName} [" +
-                        "album: ${!song._isMissingAlbum} " +
+                        "missing album: ${song._isMissingAlbum} " +
-                        "artist: ${!song._isMissingArtist} " +
+                        "missing artist: ${song._isMissingArtist} " +
-                        "genre: ${!song._isMissingGenre}]")
+                        "missing genre: ${song._isMissingGenre}]")
             }
         }
 
@@ -99,8 +99,10 @@ object Indexer {
             backend.query(context).use { cursor ->
                 val loadStart = System.currentTimeMillis()
                 logD("Successfully queried media database in ${loadStart - queryStart}ms")
+
                 val songs = backend.loadSongs(context, cursor)
                 logD("Successfully loaded songs in ${System.currentTimeMillis() - loadStart}ms")
+
                 songs
             }
 
@@ -181,7 +183,6 @@ object Indexer {
         for (entry in albumsByArtist) {
             // The first album will suffice for template metadata.
             val templateAlbum = entry.value[0]
-
             artists.add(Artist(rawName = templateAlbum._artistGroupingName, albums = entry.value))
         }
 
@@ -213,4 +214,10 @@ object Indexer {
         /** Create a list of songs from the [Cursor] queried in [query]. */
         fun loadSongs(context: Context, cursor: Cursor): Collection<Song>
     }
+
+    sealed class Event {
+        object Query : Event()
+        object LoadSongs : Event()
+        object BuildLibrary : Event()
+    }
 }

app/src/main/java/org/oxycblt/auxio/music/indexer/MediaStoreBackend.kt

@@ -135,7 +135,7 @@ abstract class MediaStoreBackend : Indexer.Backend {
 
         // The audio is not actually complete at this point, as we cannot obtain a genre
         // through a song query. Instead, we have to do the hack where we iterate through
-        // every genre and assign it's name to each component song.
+        // every genre and assign it's name to audios that match it's child ID.
 
         context.contentResolverSafe.useQuery(
             MediaStore.Audio.Genres.EXTERNAL_CONTENT_URI,
@@ -149,35 +149,24 @@ abstract class MediaStoreBackend : Indexer.Backend {
                 // anyway, so we skip genres that have them.
                 val id = genreCursor.getLong(idIndex)
                 val name = genreCursor.getStringOrNull(nameIndex) ?: continue
-                linkGenreAudios(context, id, name, audios)
+
+                context.contentResolverSafe.useQuery(
+                    MediaStore.Audio.Genres.Members.getContentUri(VOLUME_EXTERNAL, id),
+                    arrayOf(MediaStore.Audio.Genres.Members._ID)) { cursor ->
+                    val songIdIndex =
+                        cursor.getColumnIndexOrThrow(MediaStore.Audio.Genres.Members._ID)
+
+                    while (cursor.moveToNext()) {
+                        val songId = cursor.getLong(songIdIndex)
+                        audios.find { it.id == songId }?.let { song -> song.genre = name }
+                    }
+                }
             }
         }
 
         return audios.map { it.toSong() }
     }
 
-    /**
-     * Links up the given genre data ([genreId] and [genreName]) to the child audios connected to
-     * [genreId].
-     */
-    private fun linkGenreAudios(
-        context: Context,
-        genreId: Long,
-        genreName: String,
-        audios: List<Audio>
-    ) {
-        context.contentResolverSafe.useQuery(
-            MediaStore.Audio.Genres.Members.getContentUri(VOLUME_EXTERNAL, genreId),
-            arrayOf(MediaStore.Audio.Genres.Members._ID)) { cursor ->
-            val idIndex = cursor.getColumnIndexOrThrow(MediaStore.Audio.Genres.Members._ID)
-
-            while (cursor.moveToNext()) {
-                val id = cursor.getLong(idIndex)
-                audios.find { it.id == id }?.let { song -> song.genre = genreName }
-            }
-        }
-    }
-
     /**
      * The projection to use when querying media. Add version-specific columns here in an
      * implementation.

app/src/main/java/org/oxycblt/auxio/playback/state/PlaybackStateManager.kt

@@ -90,9 +90,7 @@ class PlaybackStateManager private constructor() {
 
     private val callbacks = mutableListOf<Callback>()
 
-    /**
+    /** Add a callback to this instance. Make sure to remove it when done. */
-     * Add a callback to this instance. Make sure to remove it when done.
-     */
     fun addCallback(callback: Callback) {
         if (isInitialized) {
             callback.onNewPlayback(index, queue, parent)

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

@@ -28,13 +28,62 @@
 
     </org.oxycblt.auxio.ui.EdgeAppBarLayout>
 
-    <androidx.viewpager2.widget.ViewPager2
+    <FrameLayout
-        android:id="@+id/home_pager"
         android:layout_width="match_parent"
         android:layout_height="match_parent"
-        app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
+        android:animateLayoutChanges="true"
-        app:layout_behavior="com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior"
+        app:layout_behavior="com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior">
-        tools:layout="@layout/fragment_home_list" />
+
+        <androidx.constraintlayout.widget.ConstraintLayout
+            android:id="@+id/home_loading_container"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:animateLayoutChanges="true"
+            android:paddingStart="@dimen/spacing_medium"
+            android:paddingEnd="@dimen/spacing_medium"
+            tools:visibility="invisible">
+
+            <TextView
+                android:id="@+id/home_loading_status"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:gravity="center"
+                android:layout_marginBottom="@dimen/spacing_medium"
+                android:textAppearance="@style/TextAppearance.Auxio.BodyLarge"
+                app:layout_constraintBottom_toTopOf="@+id/home_loading_action"
+                app:layout_constraintTop_toTopOf="parent"
+                app:layout_constraintVertical_chainStyle="packed"
+                tools:text="Status" />
+
+            <com.google.android.material.progressindicator.LinearProgressIndicator
+                android:id="@+id/home_loading_progress"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:indeterminate="true"
+                app:indeterminateAnimationType="disjoint"
+                app:layout_constraintBottom_toBottomOf="@+id/home_loading_action"
+                app:layout_constraintTop_toTopOf="@+id/home_loading_action"
+                app:trackColor="@color/sel_track" />
+
+            <Button
+                android:id="@+id/home_loading_action"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:text="@string/lbl_retry"
+                app:layout_constraintBottom_toBottomOf="parent"
+                app:layout_constraintTop_toBottomOf="@+id/home_loading_status" />
+
+        </androidx.constraintlayout.widget.ConstraintLayout>
+
+        <androidx.viewpager2.widget.ViewPager2
+            android:id="@+id/home_pager"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            app:layoutManager="androidx.recyclerview.widget.LinearLayoutManager"
+            app:layout_behavior="com.google.android.material.appbar.AppBarLayout$ScrollingViewBehavior"
+            tools:layout="@layout/fragment_home_list" />
+
+    </FrameLayout>
 
     <org.oxycblt.auxio.home.EdgeFabContainer
         android:layout_width="wrap_content"

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

@@ -6,6 +6,7 @@
     <string name="info_widget_desc">View and control music playback</string>
 
     <!-- Label Namespace | Static Labels -->
+    <string name="lbl_loading">Loading your music library…</string>
     <string name="lbl_retry">Retry</string>
     <string name="lbl_grant">Grant</string>