Allow changing backup location when flash drive isn't plugged in

grote · Dec 12, 2024 · b6d519b · b6d519b
1 parent c6fa60c
commit b6d519b
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Showing 2 changed files with 40 additions and 16 deletions.
diff --git a/app/src/main/java/com/stevesoltys/seedvault/settings/SettingsFragment.kt b/app/src/main/java/com/stevesoltys/seedvault/settings/SettingsFragment.kt
@@ -27,6 +27,7 @@ import com.stevesoltys.seedvault.R
 import com.stevesoltys.seedvault.backend.BackendManager
 import com.stevesoltys.seedvault.permitDiskReads
 import com.stevesoltys.seedvault.restore.RestoreActivity
+import com.stevesoltys.seedvault.settings.BackupPermission.BackupAllowed
 import com.stevesoltys.seedvault.ui.notification.BackupNotificationManager
 import com.stevesoltys.seedvault.ui.toRelativeTime
 import org.calyxos.seedvault.core.backends.BackendProperties
@@ -83,8 +84,8 @@ class SettingsFragment : PreferenceFragmentCompat() {
                             trySetBackupEnabled(false)
                             dialog.dismiss()
                         }
-                        .setNegativeButton(R.string.settings_backup_apk_dialog_cancel) { dialog,
-                            _ -> dialog.dismiss()
+                        .setNegativeButton(R.string.settings_backup_apk_dialog_cancel) { d, _ ->
+                            d.dismiss()
                         }
                         .show()
                     return@OnPreferenceChangeListener false
@@ -143,12 +144,16 @@ class SettingsFragment : PreferenceFragmentCompat() {
             }
         }
 
-        viewModel.backupPossible.observe(viewLifecycleOwner) { possible ->
-            toolbar.menu.findItem(R.id.action_backup)?.isEnabled = possible
-            toolbar.menu.findItem(R.id.action_restore)?.isEnabled = possible
-            backupLocation.isEnabled = possible
-            backupAppCheck.isEnabled = possible
-            backupFileCheck.isEnabled = possible
+        viewModel.backupPossible.observe(viewLifecycleOwner) { permission ->
+            val allowed = permission == BackupAllowed
+            toolbar.menu.findItem(R.id.action_backup)?.isEnabled = allowed
+            toolbar.menu.findItem(R.id.action_restore)?.isEnabled = allowed
+            // backup location can be changed when backup isn't allowed,
+            // because flash-drive isn't plugged in
+            backupLocation.isEnabled = allowed ||
+                (permission as? BackupPermission.BackupRestricted)?.unavailableUsb == true
+            backupAppCheck.isEnabled = allowed
+            backupFileCheck.isEnabled = allowed
         }
 
         viewModel.lastBackupTime.observe(viewLifecycleOwner) { time ->

diff --git a/app/src/main/java/com/stevesoltys/seedvault/settings/SettingsViewModel.kt b/app/src/main/java/com/stevesoltys/seedvault/settings/SettingsViewModel.kt
@@ -39,6 +39,8 @@ import com.stevesoltys.seedvault.backend.BackendManager
 import com.stevesoltys.seedvault.crypto.KeyManager
 import com.stevesoltys.seedvault.permitDiskReads
 import com.stevesoltys.seedvault.repo.Checker
+import com.stevesoltys.seedvault.settings.BackupPermission.BackupAllowed
+import com.stevesoltys.seedvault.settings.BackupPermission.BackupRestricted
 import com.stevesoltys.seedvault.storage.StorageBackupJobService
 import com.stevesoltys.seedvault.ui.LiveEvent
 import com.stevesoltys.seedvault.ui.MutableLiveEvent
@@ -64,6 +66,11 @@ import java.util.concurrent.TimeUnit.HOURS
 private const val TAG = "SettingsViewModel"
 private const val USER_FULL_DATA_BACKUP_AWARE = "user_full_data_backup_aware"
 
+sealed class BackupPermission {
+    object BackupAllowed : BackupPermission()
+    class BackupRestricted(val unavailableUsb: Boolean = false) : BackupPermission()
+}
+
 internal class SettingsViewModel(
     app: Application,
     settingsManager: SettingsManager,
@@ -86,8 +93,8 @@ internal class SettingsViewModel(
 
     private val isBackupRunning: StateFlow<Boolean>
     private val isCheckOrPruneRunning: StateFlow<Boolean>
-    private val mBackupPossible = MutableLiveData(false)
-    val backupPossible: LiveData<Boolean> = mBackupPossible
+    private val mBackupPossible = MutableLiveData<BackupPermission>(BackupRestricted())
+    val backupPossible: LiveData<BackupPermission> = mBackupPossible
 
     private val mBackupSize = MutableLiveData<Long>()
     val backupSize: LiveData<Long> = mBackupSize
@@ -183,12 +190,24 @@ internal class SettingsViewModel(
         onStoragePropertiesChanged()
     }
 
-    private fun onBackupRunningStateChanged() {
+    private suspend fun onBackupRunningStateChanged() = withContext(Dispatchers.IO) {
         val backupAllowed = !isBackupRunning.value && !isCheckOrPruneRunning.value
-        if (backupAllowed) viewModelScope.launch(Dispatchers.IO) {
-            val canDo = !backendManager.isOnUnavailableUsb()
-            mBackupPossible.postValue(canDo)
-        } else mBackupPossible.postValue(false)
+        if (backupAllowed) {
+            if (backendManager.isOnUnavailableUsb()) {
+                updateBackupPossible(BackupRestricted(unavailableUsb = true))
+            } else {
+                updateBackupPossible(BackupAllowed)
+            }
+        } else updateBackupPossible(BackupRestricted())
+    }
+
+    /**
+     * Updates [mBackupPossible] on the UiThread to avoid race conditions.
+     */
+    private suspend fun updateBackupPossible(newValue: BackupPermission) {
+        withContext(Dispatchers.Main) {
+            mBackupPossible.value = newValue
+        }
     }
 
     private fun onStoragePropertiesChanged() {
@@ -221,7 +240,7 @@ internal class SettingsViewModel(
             networkCallback.registered = true
         }
         // update whether we can do backups right now or not
-        onBackupRunningStateChanged()
+        viewModelScope.launch { onBackupRunningStateChanged() }
     }
 
     override fun onCleared() {