add export/import of my list

fixes #39

app/build.gradle

@@ -10,8 +10,8 @@ android {
         applicationId "org.mosad.teapod"
         minSdkVersion 23
         targetSdkVersion 30
-        versionCode 4100 //00.04.100
+        versionCode 4180 //00.04.100
-        versionName "0.4.1"
+        versionName "0.4.2-alpha1"
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         resValue "string", "build_time", buildTime()

app/src/main/java/org/mosad/teapod/ui/activity/main/fragments/AccountFragment.kt

@@ -1,5 +1,6 @@
 package org.mosad.teapod.ui.activity.main.fragments
 
+import android.app.Activity
 import android.content.Intent
 import android.net.Uri
 import android.os.Bundle
@@ -7,6 +8,7 @@ import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import android.widget.Toast
 import androidx.core.view.isVisible
 import androidx.fragment.app.Fragment
 import com.afollestad.materialdialogs.MaterialDialog
@@ -14,20 +16,24 @@ import com.afollestad.materialdialogs.list.listItemsSingleChoice
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 import org.mosad.teapod.BuildConfig
-import org.mosad.teapod.ui.activity.main.MainActivity
 import org.mosad.teapod.R
 import org.mosad.teapod.databinding.FragmentAccountBinding
 import org.mosad.teapod.parser.AoDParser
 import org.mosad.teapod.preferences.EncryptedPreferences
 import org.mosad.teapod.preferences.Preferences
+import org.mosad.teapod.ui.activity.main.MainActivity
 import org.mosad.teapod.ui.components.LoginDialog
 import org.mosad.teapod.util.DataTypes.Theme
+import org.mosad.teapod.util.StorageController
 import org.mosad.teapod.util.showFragment
 
 class AccountFragment : Fragment() {
 
     private lateinit var binding: FragmentAccountBinding
 
+    private val exportFileCode = 1111
+    private val importFileCode = 1122
+
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
         binding = FragmentAccountBinding.inflate(inflater, container, false)
         return binding.root
@@ -60,6 +66,30 @@ class AccountFragment : Fragment() {
         initActions()
     }
 
+    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
+        // return if the result was not ok
+        if (resultCode != Activity.RESULT_OK) {
+            Log.e(javaClass.name, "Error while computing result. Result code is: $resultCode")
+            return
+        }
+
+        when(requestCode) {
+            exportFileCode -> data?.data?.also { uri ->
+                StorageController.exportMyList(requireContext(), uri)
+            }
+
+            importFileCode -> data?.data?.also { uri ->
+                val success = StorageController.importMyList(requireContext(), uri)
+                if (success == 0) {
+                    Toast.makeText(
+                        context, getString(R.string.import_data_success),
+                        Toast.LENGTH_SHORT
+                    ).show()
+                }
+            }
+        }
+    }
+
     private fun initActions() {
         binding.linearAccountLogin.setOnClickListener {
             showLoginDialog(true)
@@ -86,11 +116,20 @@ class AccountFragment : Fragment() {
         }
 
         binding.linearExportData.setOnClickListener {
-            println("TODO")
+            val i = Intent(Intent.ACTION_CREATE_DOCUMENT).apply {
+                addCategory(Intent.CATEGORY_OPENABLE)
+                type = "text/json"
+                putExtra(Intent.EXTRA_TITLE, "my-list.json")
+            }
+            startActivityForResult(i, exportFileCode)
         }
 
         binding.linearImportData.setOnClickListener {
-            println("TODO")
+            val i = Intent(Intent.ACTION_OPEN_DOCUMENT).apply {
+                addCategory(Intent.CATEGORY_OPENABLE)
+                type = "*/*"
+            }
+            startActivityForResult(i, importFileCode)
         }
     }
 
@@ -120,7 +159,7 @@ class AccountFragment : Fragment() {
                 when(index) {
                     0 -> Preferences.saveTheme(context, Theme.LIGHT)
                     1 -> Preferences.saveTheme(context, Theme.DARK)
-                    else -> Preferences.saveTheme(context, Theme.LIGHT)
+                    else -> Preferences.saveTheme(context, Theme.DARK)
                 }
 
                 (activity as MainActivity).restart()

app/src/main/java/org/mosad/teapod/util/StorageController.kt

@@ -1,12 +1,18 @@
 package org.mosad.teapod.util
 
 import android.content.Context
+import android.net.Uri
 import android.util.Log
+import android.widget.Toast
 import com.google.gson.Gson
 import com.google.gson.JsonParser
 import kotlinx.coroutines.*
+import org.mosad.teapod.R
 import java.io.File
+import java.io.FileReader
+import java.io.FileWriter
 import java.lang.Exception
+import java.net.URI
 
 /**
  * This controller contains the logic for permanently saved data.
@@ -19,6 +25,10 @@ object StorageController {
     val myList = ArrayList<Int>() // a list of saved mediaIds
 
     fun load(context: Context) {
+        loadMyList(context)
+    }
+
+    fun loadMyList(context: Context) {
         val file = File(context.filesDir, fileNameMyList)
 
         if (!file.exists()) runBlocking { saveMyList(context).join() }
@@ -30,7 +40,6 @@ object StorageController {
             myList.clear()
             Log.e(javaClass.name, "Parsing of My-List failed.")
         }
-
     }
 
     fun saveMyList(context: Context): Job {
@@ -41,4 +50,44 @@ object StorageController {
         }
     }
 
+    fun exportMyList(context: Context, uri: Uri) {
+        try {
+            context.contentResolver.openFileDescriptor(uri, "w")?.use {
+                FileWriter(it.fileDescriptor).use { writer ->
+                    writer.write(Gson().toJson(myList.distinct()))
+                }
+            }
+        } catch (ex: Exception) {
+            Log.e(javaClass.name, "Exporting my list failed.", ex)
+        }
+    }
+
+    /**
+     * import my list from a (previously exported) json file
+     * @param context the current context
+     * @param uri the uri of the selected file
+     * @return 0 if import was successfull, else 1
+     */
+    fun importMyList(context: Context, uri: Uri): Int {
+        try {
+            val text = context.contentResolver.openFileDescriptor(uri, "r")?.use {
+                FileReader(it.fileDescriptor).use { reader ->
+                    reader.readText()
+                }
+            }
+
+            myList.clear()
+            myList.addAll(JsonParser.parseString(text).asJsonArray.map { it.asInt }.distinct())
+
+            // after the list has been imported also save it
+            saveMyList(context)
+        } catch (ex: Exception) {
+            myList.clear()
+            Log.e(javaClass.name, "Importing my list failed.", ex)
+            return 1
+        }
+
+        return 0
+    }
+
 }

app/src/main/res/values-de-rDE/strings.xml

@@ -51,6 +51,7 @@
     <string name="export_data_desc">Speichere "meine Liste" in eine Datei</string>
     <string name="import_data">Daten importieren</string>
     <string name="import_data_desc">Lade "meine Liste" aus einer Datei</string>
+    <string name="import_data_success">"meine Liste" erfolgreich importiert</string>
 
     <!-- about fragment -->
     <string name="version">Version</string>

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

@@ -59,9 +59,10 @@
     <string name="theme_dark">Dark</string>
     <string name="dev_settings">Developer Settings</string>
     <string name="export_data">export data</string>
-    <string name="export_data_desc">export my list to a file</string>
+    <string name="export_data_desc">export "my list" to a file</string>
     <string name="import_data">import data</string>
-    <string name="import_data_desc">import my list from a file</string>
+    <string name="import_data_desc">import "my list" from a file</string>
+    <string name="import_data_success">imported "my list" successfully</string>
 
 
     <!-- about fragment -->