backup and restore settings

app/src/main/java/com/github/libretube/preferences/AdvancedSettings.kt

@@ -1,15 +1,40 @@
 package com.github.libretube.preferences
 
+import android.net.Uri
 import android.os.Bundle
+import androidx.activity.result.ActivityResultLauncher
+import androidx.activity.result.contract.ActivityResultContracts
 import androidx.preference.Preference
 import com.github.libretube.R
 import com.github.libretube.activities.SettingsActivity
+import com.github.libretube.util.BackupHelper
 import com.github.libretube.views.MaterialPreferenceFragment
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
 
 class AdvancedSettings : MaterialPreferenceFragment() {
     val TAG = "AdvancedSettings"
 
+    /**
+     * result listeners for importing and exporting subscriptions
+     */
+    private lateinit var getContent: ActivityResultLauncher<String>
+    private lateinit var createFile: ActivityResultLauncher<String>
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+         getContent =
+            registerForActivityResult(
+                ActivityResultContracts.GetContent()
+            ) { uri: Uri? ->
+                BackupHelper(requireContext()).restoreSharedPreferences(uri)
+            }
+        createFile = registerForActivityResult(
+            ActivityResultContracts.CreateDocument()
+        ) { uri: Uri? ->
+            BackupHelper(requireContext()).backupSharedPreferences(uri)
+        }
+        super.onCreate(savedInstanceState)
+    }
+
     override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) {
         setPreferencesFromResource(R.xml.advanced_settings, rootKey)
 
@@ -21,6 +46,20 @@ class AdvancedSettings : MaterialPreferenceFragment() {
             showResetDialog()
             true
         }
+
+        val backupSettings = findPreference<Preference>(PreferenceKeys.BACKUP_SETTINGS)
+        backupSettings?.setOnPreferenceClickListener {
+            createFile.launch("preferences.xml")
+            activity?.recreate()
+            true
+        }
+
+        val restoreSettings = findPreference<Preference>(PreferenceKeys.RESTORE_SETTINGS)
+        restoreSettings?.setOnPreferenceClickListener {
+            getContent.launch("*/*")
+            activity?.recreate()
+            true
+        }
     }
 
     private fun showResetDialog() {

app/src/main/java/com/github/libretube/preferences/InstanceSettings.kt

@@ -127,8 +127,7 @@ class InstanceSettings : MaterialPreferenceFragment() {
 
         val deleteAccount = findPreference<Preference>(PreferenceKeys.DELETE_ACCOUNT)
         deleteAccount?.setOnPreferenceClickListener {
-            val token = PreferenceHelper.getToken()
-            if (token != "") {
+            if (PreferenceHelper.getToken() != "") {
                 val newFragment = DeleteAccountDialog()
                 newFragment.show(childFragmentManager, DeleteAccountDialog::class.java.name)
             } else {

app/src/main/java/com/github/libretube/preferences/PreferenceKeys.kt

@@ -88,6 +88,8 @@ object PreferenceKeys {
     const val CLEAR_WATCH_HISTORY = "clear_watch_history"
     const val CLEAR_WATCH_POSITIONS = "clear_watch_positions"
     const val SHARE_WITH_TIME_CODE = "share_with_time_code"
+    const val BACKUP_SETTINGS = "backup_settings"
+    const val RESTORE_SETTINGS = "restore_settings"
 
     /**
      * History

app/src/main/java/com/github/libretube/util/BackupHelper.kt

@@ -0,0 +1,87 @@
+package com.github.libretube.util
+
+import android.content.Context
+import android.content.SharedPreferences
+import android.net.Uri
+import androidx.preference.PreferenceManager
+import java.io.FileInputStream
+import java.io.FileOutputStream
+import java.io.IOException
+import java.io.ObjectInputStream
+import java.io.ObjectOutputStream
+
+/**
+ * Backup and restore the preferences
+ */
+class BackupHelper(
+    private val context: Context
+) {
+    private val TAG = this::class.java.name
+
+    /**
+     * Backup the default shared preferences to a file
+     */
+    fun backupSharedPreferences(uri: Uri?) {
+        if (uri == null) return
+        var output: ObjectOutputStream? = null
+        try {
+            val fileDescriptor = context.contentResolver.openFileDescriptor(uri, "w")?.fileDescriptor
+            output = ObjectOutputStream(FileOutputStream(fileDescriptor))
+            val pref: SharedPreferences = PreferenceManager.getDefaultSharedPreferences(context)
+            // write all preference objects to the output file
+            output.writeObject(pref.all)
+        } catch (e: Exception) {
+            e.printStackTrace()
+        } finally {
+            try {
+                // close the outputStream
+                if (output != null) {
+                    output.flush()
+                    output.close()
+                }
+            } catch (ex: IOException) {
+                ex.printStackTrace()
+            }
+        }
+    }
+
+    /**
+     * restore the default shared preferences from a file
+     */
+    @Suppress("UNCHECKED_CAST")
+    fun restoreSharedPreferences(uri: Uri?) {
+        if (uri == null) return
+        var input: ObjectInputStream? = null
+        try {
+            val fileDescriptor = context.contentResolver.openFileDescriptor(uri, "r")?.fileDescriptor
+            input = ObjectInputStream(FileInputStream(fileDescriptor))
+            val editor = PreferenceManager.getDefaultSharedPreferences(context).edit()
+
+            // clear the previous settings
+            editor.clear()
+
+            // map all the preference keys and their values
+            val entries = input.readObject() as Map<String, *>
+
+            // decide for each preference which type it is and save it to the preferences
+            for ((key, value) in entries) {
+                if (value is Boolean) editor.putBoolean(key, value)
+                else if (value is Float) editor.putFloat(key, value)
+                else if (value is Int) editor.putInt(key, value)
+                else if (value is Long) editor.putLong(key, value)
+                else if (value is String) editor.putString(key, value)
+            }
+            editor.commit()
+        } catch (e: Exception) {
+            e.printStackTrace()
+        } finally {
+            try {
+                if (input != null) {
+                    input.close()
+                }
+            } catch (ex: IOException) {
+                ex.printStackTrace()
+            }
+        }
+    }
+}

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

@@ -310,4 +310,6 @@
     <string name="resize_mode_zoom">Zoom</string>
     <string name="repeat_mode_none">None</string>
     <string name="repeat_mode_current">Current</string>
+    <string name="backup_restore">Backup &amp; restore</string>
+    <string name="backup">Backup</string>
 </resources>

app/src/main/res/xml/advanced_settings.xml

@@ -47,4 +47,16 @@
 
     </PreferenceCategory>
 
+    <PreferenceCategory app:title="@string/backup_restore">
+
+        <Preference
+            app:title="@string/backup"
+            app:key="backup_settings" />
+
+        <Preference
+            app:title="@string/restore"
+            app:key="restore_settings" />
+
+    </PreferenceCategory>
+
 </PreferenceScreen>