music: fix crash when adding music dirs

Fix a crash that would occur when trying to add music dirs without a
file manager to handle it.

Some users apparently disable the built-in file manager under the
assumption that the same intents will work with other file managers.
They do not, and so we need to handle that case and let the user know.

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## dev
+
+#### What's Fixed
+- Fixed crash that would occur in music folders dialog when user does not have a working
+file manager
+
 ## 3.0.1
 
 #### What's New

app/src/main/java/org/oxycblt/auxio/detail/DetailViewModel.kt

@@ -173,8 +173,8 @@ class DetailViewModel(application: Application) :
     }
 
     /**
-     * Set a new [currentSong] from it's [Music.UID]. If the [Music.UID] differs, [currentSong]
-     * and [songProperties] will be updated to align with the new [Song].
+     * Set a new [currentSong] from it's [Music.UID]. If the [Music.UID] differs, [currentSong] and
+     * [songProperties] will be updated to align with the new [Song].
      * @param uid The UID of the [Song] to load. Must be valid.
      */
     fun setSongUid(uid: Music.UID) {

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

@@ -140,8 +140,7 @@ class Date private constructor(private val tokens: List<Int>) : Comparable<Date>
                 min.resolveDate(context)
             }
 
-        override fun equals(other: Any?) =
-            other is Range && min == other.min && max == other.max
+        override fun equals(other: Any?) = other is Range && min == other.min && max == other.max
 
         override fun hashCode() = 31 * max.hashCode() + min.hashCode()
 

app/src/main/java/org/oxycblt/auxio/music/filesystem/MusicDirsDialog.kt

@@ -17,6 +17,7 @@
  
 package org.oxycblt.auxio.music.filesystem
 
+import android.content.ActivityNotFoundException
 import android.net.Uri
 import android.os.Bundle
 import android.os.storage.StorageManager
@@ -84,10 +85,16 @@ class MusicDirsDialog :
             val dialog = it as AlertDialog
             dialog.getButton(AlertDialog.BUTTON_NEUTRAL)?.setOnClickListener {
                 logD("Opening launcher")
-                requireNotNull(openDocumentTreeLauncher) {
+                val launcher = requireNotNull(openDocumentTreeLauncher) {
                     "Document tree launcher was not available"
                 }
-                    .launch(null)
+
+                try {
+                    launcher.launch(null)
+                } catch (e: ActivityNotFoundException) {
+                    // User doesn't have a capable file manager.
+                    requireContext().showToast(R.string.err_no_app)
+                }
             }
         }
 
@@ -97,7 +104,6 @@ class MusicDirsDialog :
         }
 
         var dirs = Settings(context).getMusicDirs(storageManager)
-
         if (savedInstanceState != null) {
             val pendingDirs = savedInstanceState.getStringArrayList(KEY_PENDING_DIRS)
             if (pendingDirs != null) {