Add permission dialog for file reading

Add a permission dialog for the apps READ_EXTERNAL_STORAGE permission.

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

@@ -9,8 +9,6 @@ import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.app.AppCompatDelegate
 import org.oxycblt.auxio.theme.accent
 
-const val PERM_READ_EXTERNAL_STORAGE = 2488
-
 class MainActivity : AppCompatActivity() {
 
     override fun onCreateView(name: String, context: Context, attrs: AttributeSet): View? {

app/src/main/java/org/oxycblt/auxio/loading/LoadingFragment.kt

@@ -1,10 +1,13 @@
 package org.oxycblt.auxio.loading
 
+import android.Manifest
 import android.os.Bundle
 import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import androidx.activity.result.ActivityResultLauncher
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.databinding.DataBindingUtil
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.ViewModelProvider
@@ -25,6 +28,7 @@ class LoadingFragment : Fragment() {
     }
 
     private lateinit var binding: FragmentLoadingBinding
+    private lateinit var permLauncher: ActivityResultLauncher<String>
 
     override fun onCreateView(
         inflater: LayoutInflater,
@@ -52,6 +56,37 @@ class LoadingFragment : Fragment() {
             }
         )
 
+        loadingModel.doGrant.observe(
+            viewLifecycleOwner,
+            { grant ->
+                onGrant(grant)
+            }
+        )
+
+        // Set up the permission launcher, as its disallowed outside of onCreate.
+        permLauncher = registerForActivityResult(ActivityResultContracts.RequestPermission())
+            { granted: Boolean ->
+
+                // If its actually granted, restart the loading process again.
+                if (granted) {
+                    binding.loadingBar.visibility = View.VISIBLE
+                    binding.errorText.visibility = View.GONE
+                    binding.statusIcon.visibility = View.GONE
+                    binding.retryButton.visibility = View.GONE
+                    binding.grantButton.visibility = View.GONE
+
+                    loadingModel.retry()
+                }
+            }
+
+        // This never seems to return true but Im apparently supposed to use it so
+        if (shouldShowRequestPermissionRationale(Manifest.permission.READ_EXTERNAL_STORAGE)) {
+            onMusicLoadResponse(MusicLoaderResponse.NO_PERMS)
+
+        } else {
+            loadingModel.go()
+        }
+
         Log.d(this::class.simpleName, "Fragment created.")
 
         return binding.root
@@ -65,20 +100,30 @@ class LoadingFragment : Fragment() {
                 this.findNavController().navigate(
                     LoadingFragmentDirections.actionToMain()
                 )
+
             } else {
                 // If the response wasn't a success, then show the specific error message
-                // depending on which error response was given, along with a retry button
+                // depending on which error response was given, along with a retry or grant button
-
                 binding.loadingBar.visibility = View.GONE
                 binding.errorText.visibility = View.VISIBLE
                 binding.statusIcon.visibility = View.VISIBLE
-                binding.retryButton.visibility = View.VISIBLE
 
-                binding.errorText.text =
+                when (response) {
-                    if (response == MusicLoaderResponse.NO_MUSIC)
+                    MusicLoaderResponse.NO_PERMS -> {
-                        getString(R.string.error_no_music)
+                        binding.grantButton.visibility = View.VISIBLE
-                    else
+                        binding.errorText.text = getString(R.string.error_no_perms)
-                        getString(R.string.error_music_load_failed)
+                    }
+
+                    MusicLoaderResponse.NO_MUSIC -> {
+                        binding.retryButton.visibility = View.VISIBLE
+                        binding.errorText.text = getString(R.string.error_no_music)
+                    }
+
+                    else -> {
+                        binding.retryButton.visibility = View.VISIBLE
+                        binding.errorText.text = getString(R.string.error_music_load_failed)
+                    }
+                }
             }
 
             loadingModel.doneWithResponse()
@@ -91,8 +136,17 @@ class LoadingFragment : Fragment() {
             binding.errorText.visibility = View.GONE
             binding.statusIcon.visibility = View.GONE
             binding.retryButton.visibility = View.GONE
+            binding.grantButton.visibility = View.GONE
 
             loadingModel.doneWithRetry()
         }
     }
+
+    private fun onGrant(grant: Boolean) {
+        if (grant) {
+            permLauncher.launch(Manifest.permission.READ_EXTERNAL_STORAGE)
+
+            loadingModel.doneWithGrant()
+        }
+    }
 }

app/src/main/java/org/oxycblt/auxio/loading/LoadingViewModel.kt

@@ -26,10 +26,19 @@ class LoadingViewModel(private val app: Application) : ViewModel() {
     private val mDoRetry = MutableLiveData<Boolean>()
     val doRetry: LiveData<Boolean> get() = mDoRetry
 
-    init {
+    private val mDoGrant = MutableLiveData<Boolean>()
-        startMusicRepo()
+    val doGrant: LiveData<Boolean> get() = mDoGrant
+
+    private var started = false
+
+    // Start the music loading. It has already been called, one needs to call retry() instead.
+    fun go() {
+        if (!started) {
+            startMusicRepo()
+        }
     }
 
+    // Start the music loading sequence.
     private fun startMusicRepo() {
         val repo = MusicRepository.getInstance()
 
@@ -40,10 +49,14 @@ class LoadingViewModel(private val app: Application) : ViewModel() {
             // Then actually notify listeners of the response in the Main thread
             withContext(Dispatchers.Main) {
                 mMusicRepoResponse.value = response
+
+                started = true
             }
         }
     }
 
+    // Functions for communicating between LoadingFragment & LoadingViewModel
+
     fun doneWithResponse() {
         mMusicRepoResponse.value = null
     }
@@ -58,6 +71,14 @@ class LoadingViewModel(private val app: Application) : ViewModel() {
         mDoRetry.value = false
     }
 
+    fun grant() {
+        mDoGrant.value = true
+    }
+
+    fun doneWithGrant() {
+        mDoGrant.value = false
+    }
+
     override fun onCleared() {
         super.onCleared()
 

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

@@ -1,7 +1,10 @@
 package org.oxycblt.auxio.music
 
+import android.Manifest
 import android.app.Application
+import android.content.pm.PackageManager
 import android.util.Log
+import androidx.core.content.ContextCompat
 import org.oxycblt.auxio.R
 import org.oxycblt.auxio.music.models.Album
 import org.oxycblt.auxio.music.models.Artist
@@ -20,6 +23,12 @@ class MusicRepository {
     lateinit var songs: List<Song>
 
     fun init(app: Application): MusicLoaderResponse {
+        if (!checkPerms(app)) {
+            Log.i(this::class.simpleName, "No permissions, aborting...")
+
+            return MusicLoaderResponse.NO_PERMS
+        }
+
         Log.i(this::class.simpleName, "Starting initial music load...")
 
         val start = System.currentTimeMillis()
@@ -52,7 +61,13 @@ class MusicRepository {
             )
         }
 
-        return MusicLoaderResponse.NO_MUSIC
+        return loader.response
+    }
+
+    private fun checkPerms(app: Application): Boolean {
+        return ContextCompat.checkSelfPermission(
+            app.applicationContext, Manifest.permission.READ_EXTERNAL_STORAGE
+        ) == PackageManager.PERMISSION_GRANTED
     }
 
     companion object {

app/src/main/java/org/oxycblt/auxio/music/processing/MusicLoader.kt

@@ -15,7 +15,7 @@ import org.oxycblt.auxio.music.toAlbumArtURI
 import org.oxycblt.auxio.music.toNamedGenre
 
 enum class MusicLoaderResponse {
-    DONE, FAILURE, NO_MUSIC
+    DONE, FAILURE, NO_MUSIC, NO_PERMS
 }
 
 // Class that loads music from the FileSystem.

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

@@ -39,6 +39,7 @@
             android:indeterminateTintMode="src_in"
             android:src="@drawable/ic_error"
             android:contentDescription="@string/description_error_icon"
+            android:visibility="gone"
             app:layout_constraintBottom_toTopOf="@+id/error_text"
             app:layout_constraintEnd_toEndOf="parent"
             app:layout_constraintStart_toStartOf="parent"
@@ -76,9 +77,27 @@
             app:layout_constraintHorizontal_bias="0.5"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toBottomOf="@+id/error_text"
+            app:layout_constraintBottom_toTopOf="@+id/grant_button"
             app:layout_constraintVertical_bias="0.673"
             tools:textColor="@color/blue"
             tools:visibility="visible" />
 
+        <Button
+            android:id="@+id/grant_button"
+            style="@style/Widget.AppCompat.Button.Borderless.Colored"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:fontFamily="@font/inter_semibold"
+            android:onClick="@{() -> loadingModel.grant()}"
+            android:text="@string/label_grant"
+            android:textColor="?attr/colorPrimary"
+            android:visibility="gone"
+            app:layout_constraintBottom_toBottomOf="parent"
+            app:layout_constraintEnd_toEndOf="parent"
+            app:layout_constraintStart_toStartOf="parent"
+            app:layout_constraintTop_toBottomOf="@+id/retry_button"
+            tools:textColor="@color/blue"
+            tools:visibility="visible" />
+
     </androidx.constraintlayout.widget.ConstraintLayout>
 </layout>

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

@@ -7,9 +7,10 @@
 
     <string name="error_no_music">No music found.</string>
     <string name="error_music_load_failed">Music loading failed.</string>
-    <string name="error_no_perms">Auxio needs to be allowed to read your music library.</string>
+    <string name="error_no_perms">Auxio needs access to your music library.</string>
 
     <string name="label_retry">Retry</string>
+    <string name="label_grant">Grant</string>
     <string name="label_single_song">1 Song</string>
     <string name="label_unknown_genre">Unknown Genre</string>
     <string name="label_unknown_artist">Unknown Artist</string>