Show Backup Location screen before letting user choose backup folder

This screen can also be reached by tapping the previously inactive backup location setting.

app/src/main/java/com/stevesoltys/backup/settings/BackupLocationFragment.kt

@@ -0,0 +1,59 @@
+package com.stevesoltys.backup.settings
+
+import android.app.Activity.RESULT_OK
+import android.content.ActivityNotFoundException
+import android.content.Intent
+import android.content.Intent.*
+import android.os.Bundle
+import android.widget.Toast
+import android.widget.Toast.LENGTH_LONG
+import androidx.lifecycle.ViewModelProviders
+import androidx.preference.Preference
+import androidx.preference.PreferenceFragmentCompat
+import com.stevesoltys.backup.R
+
+private val TAG = BackupLocationFragment::class.java.name
+
+class BackupLocationFragment : PreferenceFragmentCompat() {
+
+    private lateinit var viewModel: SettingsViewModel
+
+    override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
+        setPreferencesFromResource(R.xml.backup_location, rootKey)
+
+        requireActivity().setTitle(R.string.settings_backup_location_title)
+
+        viewModel = ViewModelProviders.of(requireActivity()).get(SettingsViewModel::class.java)
+
+        val externalStorage = Preference(requireContext()).apply {
+            setIcon(R.drawable.ic_storage)
+            setTitle(R.string.settings_backup_external_storage)
+            setOnPreferenceClickListener {
+                showChooseFolderActivity()
+                true
+            }
+        }
+        preferenceScreen.addPreference(externalStorage)
+    }
+
+    private fun showChooseFolderActivity() {
+        val openTreeIntent = Intent(ACTION_OPEN_DOCUMENT_TREE)
+        openTreeIntent.addFlags(FLAG_GRANT_PERSISTABLE_URI_PERMISSION or
+                FLAG_GRANT_READ_URI_PERMISSION or FLAG_GRANT_WRITE_URI_PERMISSION)
+        try {
+            val documentChooser = createChooser(openTreeIntent, null)
+            startActivityForResult(documentChooser, REQUEST_CODE_OPEN_DOCUMENT_TREE)
+        } catch (ex: ActivityNotFoundException) {
+            Toast.makeText(requireContext(), "Please install a file manager.", LENGTH_LONG).show()
+        }
+    }
+
+    override fun onActivityResult(requestCode: Int, resultCode: Int, result: Intent?) {
+        if (resultCode == RESULT_OK && requestCode == REQUEST_CODE_OPEN_DOCUMENT_TREE) {
+            viewModel.handleChooseFolderResult(result)
+        } else {
+            super.onActivityResult(requestCode, resultCode, result)
+        }
+    }
+
+}

app/src/main/java/com/stevesoltys/backup/settings/RecoveryCodeViewModel.kt

@@ -1,6 +1,7 @@
 package com.stevesoltys.backup.settings
 
 import android.app.Application
+import android.util.ByteStringUtils.toHexString
 import androidx.lifecycle.AndroidViewModel
 import com.stevesoltys.backup.LiveEvent
 import com.stevesoltys.backup.MutableLiveEvent
@@ -33,7 +34,8 @@ class RecoveryCodeViewModel(application: Application) : AndroidViewModel(applica
     internal val confirmButtonClicked: LiveEvent<Boolean> = mConfirmButtonClicked
     internal fun onConfirmButtonClicked() = mConfirmButtonClicked.setEvent(true)
 
-    internal val recoveryCodeSaved = MutableLiveEvent<Boolean>()
+    private val mRecoveryCodeSaved = MutableLiveEvent<Boolean>()
+    internal val recoveryCodeSaved: LiveEvent<Boolean> = mRecoveryCodeSaved
 
     @Throws(WordNotFoundException::class, InvalidChecksumException::class)
     fun validateAndContinue(input: List<CharSequence>) {
@@ -47,7 +49,11 @@ class RecoveryCodeViewModel(application: Application) : AndroidViewModel(applica
         val mnemonic = input.joinToString(" ")
         val seed = SeedCalculator(JavaxPBKDF2WithHmacSHA512.INSTANCE).calculateSeed(mnemonic, "")
         KeyManager.storeBackupKey(seed)
-        recoveryCodeSaved.setEvent(true)
+
+        // TODO remove once encryption/decryption uses key from KeyStore
+        setBackupPassword(getApplication(), toHexString(seed))
+
+        mRecoveryCodeSaved.setEvent(true)
     }
 
 }

app/src/main/java/com/stevesoltys/backup/settings/SettingsActivity.kt

@@ -1,17 +1,13 @@
 package com.stevesoltys.backup.settings
 
-import android.content.ActivityNotFoundException
 import android.content.Intent
-import android.content.Intent.*
 import android.os.Bundle
 import android.util.Log
-import android.view.Menu
 import android.view.MenuItem
-import android.widget.Toast
-import android.widget.Toast.LENGTH_LONG
-import android.widget.Toast.LENGTH_SHORT
 import androidx.appcompat.app.AppCompatActivity
+import androidx.fragment.app.Fragment
 import androidx.lifecycle.ViewModelProviders
+import com.stevesoltys.backup.LiveEventHandler
 import com.stevesoltys.backup.R
 
 private val TAG = SettingsActivity::class.java.name
@@ -19,7 +15,6 @@ private val TAG = SettingsActivity::class.java.name
 const val REQUEST_CODE_OPEN_DOCUMENT_TREE = 1
 const val REQUEST_CODE_RECOVERY_CODE = 2
 
-
 class SettingsActivity : AppCompatActivity() {
 
     private lateinit var viewModel: SettingsViewModel
@@ -30,18 +25,25 @@ class SettingsActivity : AppCompatActivity() {
         setContentView(R.layout.activity_settings)
 
         viewModel = ViewModelProviders.of(this).get(SettingsViewModel::class.java)
+        viewModel.onLocationSet.observeEvent(this, LiveEventHandler { wasEmptyBefore ->
+            if (wasEmptyBefore) showFragment(SettingsFragment())
+            else supportFragmentManager.popBackStack()
+        })
+        viewModel.chooseBackupLocation.observeEvent(this, LiveEventHandler { show ->
+            if (show) showFragment(BackupLocationFragment(), true)
+        })
 
         supportActionBar!!.setDisplayHomeAsUpEnabled(true)
+
+        if (savedInstanceState == null) showFragment(SettingsFragment())
     }
 
     override fun onActivityResult(requestCode: Int, resultCode: Int, result: Intent?) {
         if (resultCode != RESULT_OK) {
             Log.w(TAG, "Error in activity result: $requestCode")
             finishAfterTransition()
-        }
+        } else {
-
+            super.onActivityResult(requestCode, resultCode, result)
-        if (requestCode == REQUEST_CODE_OPEN_DOCUMENT_TREE) {
-            viewModel.handleChooseFolderResult(result)
         }
     }
 
@@ -53,34 +55,16 @@ class SettingsActivity : AppCompatActivity() {
         if (!viewModel.recoveryCodeIsSet()) {
             showRecoveryCodeActivity()
         } else if (!viewModel.locationIsSet()) {
-            showChooseFolderActivity()
+            showFragment(BackupLocationFragment())
         }
     }
 
-    override fun onCreateOptionsMenu(menu: Menu): Boolean {
+    override fun onOptionsItemSelected(item: MenuItem): Boolean = when {
-        menuInflater.inflate(R.menu.settings_menu, menu)
+        item.itemId == android.R.id.home -> {
-        if (resources.getBoolean(R.bool.show_restore_in_settings)) {
+            onBackPressed()
-            menu.findItem(R.id.action_restore).isVisible = true
+            true
-        }
-        return true
-    }
-
-    override fun onOptionsItemSelected(item: MenuItem): Boolean {
-        return when {
-            item.itemId == android.R.id.home -> {
-                onBackPressed()
-                true
-            }
-            item.itemId == R.id.action_backup -> {
-                Toast.makeText(this, "Not yet implemented", LENGTH_SHORT).show()
-                true
-            }
-            item.itemId == R.id.action_restore -> {
-                Toast.makeText(this, "Not yet implemented", LENGTH_SHORT).show()
-                true
-            }
-            else -> super.onOptionsItemSelected(item)
         }
+        else -> super.onOptionsItemSelected(item)
     }
 
     private fun showRecoveryCodeActivity() {
@@ -88,17 +72,11 @@ class SettingsActivity : AppCompatActivity() {
         startActivityForResult(intent, REQUEST_CODE_RECOVERY_CODE)
     }
 
-    private fun showChooseFolderActivity() {
+    private fun showFragment(f: Fragment, addToBackStack: Boolean = false) {
-        val openTreeIntent = Intent(ACTION_OPEN_DOCUMENT_TREE)
+        val fragmentTransaction = supportFragmentManager.beginTransaction()
-        openTreeIntent.addFlags(FLAG_GRANT_PERSISTABLE_URI_PERMISSION or
+                .replace(R.id.fragment, f)
-                FLAG_GRANT_READ_URI_PERMISSION or FLAG_GRANT_WRITE_URI_PERMISSION)
+        if (addToBackStack) fragmentTransaction.addToBackStack(null)
-        // TODO StringRes
+        fragmentTransaction.commit()
-        try {
-            val documentChooser = createChooser(openTreeIntent, "Select the backup location")
-            startActivityForResult(documentChooser, REQUEST_CODE_OPEN_DOCUMENT_TREE)
-        } catch (ex: ActivityNotFoundException) {
-            Toast.makeText(this, "Please install a file manager.", LENGTH_LONG).show()
-        }
     }
 
 }

app/src/main/java/com/stevesoltys/backup/settings/SettingsFragment.kt

@@ -15,6 +15,11 @@ import com.stevesoltys.backup.R
 import android.content.Context.BACKUP_SERVICE
 import android.os.ServiceManager.getService
 import android.provider.Settings.Secure.BACKUP_AUTO_RESTORE
+import android.view.Menu
+import android.view.MenuInflater
+import android.view.MenuItem
+import android.widget.Toast
+import androidx.lifecycle.ViewModelProviders
 import androidx.preference.Preference
 import androidx.preference.Preference.OnPreferenceChangeListener
 
@@ -24,14 +29,19 @@ class SettingsFragment : PreferenceFragmentCompat() {
 
     private lateinit var backupManager: IBackupManager
 
+    private lateinit var viewModel: SettingsViewModel
+
     private lateinit var backup: TwoStatePreference
     private lateinit var autoRestore: TwoStatePreference
 
     override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
         setPreferencesFromResource(R.xml.settings, rootKey)
+        setHasOptionsMenu(true)
 
         backupManager = IBackupManager.Stub.asInterface(getService(BACKUP_SERVICE))
 
+        viewModel = ViewModelProviders.of(requireActivity()).get(SettingsViewModel::class.java)
+
         backup = findPreference("backup") as TwoStatePreference
         backup.onPreferenceChangeListener = OnPreferenceChangeListener { _, newValue ->
             val enabled = newValue as Boolean
@@ -45,6 +55,12 @@ class SettingsFragment : PreferenceFragmentCompat() {
             }
         }
 
+        val backupLocation = findPreference("backup_location")
+        backupLocation.setOnPreferenceClickListener {
+            viewModel.chooseBackupLocation()
+            true
+        }
+
         autoRestore = findPreference("auto_restore") as TwoStatePreference
         autoRestore.onPreferenceChangeListener = OnPreferenceChangeListener { _, newValue ->
             val enabled = newValue as Boolean
@@ -62,6 +78,9 @@ class SettingsFragment : PreferenceFragmentCompat() {
     override fun onStart() {
         super.onStart()
 
+        // we need to re-set the title when returning to this fragment
+        requireActivity().setTitle(R.string.app_name)
+
         try {
             backup.isChecked = backupManager.isBackupEnabled
             backup.isEnabled = true
@@ -74,4 +93,24 @@ class SettingsFragment : PreferenceFragmentCompat() {
         autoRestore.isChecked = Settings.Secure.getInt(resolver, BACKUP_AUTO_RESTORE, 1) == 1
     }
 
+    override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
+        super.onCreateOptionsMenu(menu, inflater)
+        inflater.inflate(R.menu.settings_menu, menu)
+        if (resources.getBoolean(R.bool.show_restore_in_settings)) {
+            menu.findItem(R.id.action_restore).isVisible = true
+        }
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean = when {
+        item.itemId == R.id.action_backup -> {
+            Toast.makeText(requireContext(), "Not yet implemented", Toast.LENGTH_SHORT).show()
+            true
+        }
+        item.itemId == R.id.action_restore -> {
+            Toast.makeText(requireContext(), "Not yet implemented", Toast.LENGTH_SHORT).show()
+            true
+        }
+        else -> super.onOptionsItemSelected(item)
+    }
+
 }

app/src/main/java/com/stevesoltys/backup/settings/SettingsViewModel.kt

@@ -5,12 +5,25 @@ import android.content.Intent
 import android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION
 import android.content.Intent.FLAG_GRANT_WRITE_URI_PERMISSION
 import androidx.lifecycle.AndroidViewModel
+import com.stevesoltys.backup.LiveEvent
+import com.stevesoltys.backup.MutableLiveEvent
 import com.stevesoltys.backup.security.KeyManager
 
 class SettingsViewModel(application: Application) : AndroidViewModel(application) {
 
     private val app = application
 
+    private val mLocationWasSet = MutableLiveEvent<Boolean>()
+    /**
+     * Will be set to true if this is the initial location.
+     * It will be false if an existing location was changed.
+     */
+    internal val onLocationSet: LiveEvent<Boolean> = locationWasSet
+
+    private val mChooseBackupLocation = MutableLiveEvent<Boolean>()
+    internal val chooseBackupLocation: LiveEvent<Boolean> = mChooseBackupLocation
+    internal fun chooseBackupLocation() = mChooseBackupLocation.setEvent(true)
+
     fun recoveryCodeIsSet() = KeyManager.hasBackupKey()
     fun locationIsSet() = getBackupFolderUri(getApplication()) != null
 
@@ -21,8 +34,14 @@ class SettingsViewModel(application: Application) : AndroidViewModel(application
         val takeFlags = result.flags and (FLAG_GRANT_READ_URI_PERMISSION or FLAG_GRANT_WRITE_URI_PERMISSION)
         app.contentResolver.takePersistableUriPermission(folderUri, takeFlags)
 
+        // check if this is initial set-up or a later change
+        val wasEmptyBefore = getBackupFolderUri(app) == null
+
         // store backup folder location in settings
         setBackupFolderUri(app, folderUri)
+
+        // notify the UI that the location has been set
+        mLocationWasSet.setEvent(wasEmptyBefore)
     }
 
 }

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

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<fragment xmlns:android="http://schemas.android.com/apk/res/android"
+<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:id="@+id/fragment"
-    android:name="com.stevesoltys.backup.settings.SettingsFragment"
     android:layout_width="match_parent"
     android:layout_height="match_parent" />

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

@@ -26,6 +26,8 @@
     <!-- Settings -->
     <string name="settings_backup">Backup my data</string>
     <string name="settings_backup_location">Backup location</string>
+    <string name="settings_backup_location_title">Backup Location</string>
+    <string name="settings_backup_location_info">Choose where to store your backups. More options might get added in the future.</string>
     <string name="settings_backup_external_storage">External Storage</string>
     <string name="settings_info">All backups are encrypted on your phone. To restore from backup you will need your 12-word recovery code.</string>
     <string name="settings_auto_restore_title">Automatic restore</string>

app/src/main/res/xml/backup_location.xml

@@ -0,0 +1,11 @@
+<androidx.preference.PreferenceScreen xmlns:app="http://schemas.android.com/apk/res-auto">
+
+    <androidx.preference.Preference
+        app:allowDividerAbove="true"
+        app:allowDividerBelow="false"
+        app:icon="@drawable/ic_info_outline"
+        app:selectable="false"
+        app:order="1337"
+        app:summary="@string/settings_backup_location_info" />
+
+</androidx.preference.PreferenceScreen>

app/src/main/res/xml/settings.xml

@@ -10,7 +10,6 @@
         app:dependency="backup"
         app:icon="@drawable/ic_storage"
         app:key="backup_location"
-        app:selectable="false"
         app:summary="@string/settings_backup_external_storage"
         app:title="@string/settings_backup_location" />