implement the database exporting functionality

app/src/main/kotlin/com/simplemobiletools/calendar/activities/MainActivity.kt

@@ -36,6 +36,7 @@ import com.simplemobiletools.commons.helpers.LICENSE_STETHO
 import com.simplemobiletools.commons.models.Release
 import kotlinx.android.synthetic.main.activity_main.*
 import org.joda.time.DateTime
+import java.io.*
 import java.util.*
 
 class MainActivity : SimpleActivity(), NavigationListener {
@@ -238,7 +239,49 @@ class MainActivity : SimpleActivity(), NavigationListener {
     }
 
     private fun exportDatabase() {
+        FilePickerDialog(this, pickFile = false) {
+            val source = getDatabasePath(DBHelper.DB_NAME)
+            val destination = File(it, DBHelper.DB_NAME)
+            if (isShowingPermDialog(destination)) {
+                return@FilePickerDialog
+            }
 
+            Thread({
+                if (source.exists()) {
+                    val inputStream = FileInputStream(source)
+                    val outputStream: OutputStream?
+
+                    if (needsStupidWritePermissions(destination.absolutePath)) {
+                        var document = getFileDocument(destination.absolutePath, config.treeUri)
+                        if (!destination.exists()) {
+                            document = document.createFile("", destination.name)
+                        }
+                        outputStream = contentResolver.openOutputStream(document.uri)
+                    } else {
+                        outputStream = FileOutputStream(destination)
+                    }
+
+                    copyStream(inputStream, outputStream)
+                    inputStream.close()
+                    outputStream?.close()
+
+                    runOnUiThread {
+                        toast(R.string.database_exported_successfully)
+                    }
+                }
+            }).start()
+        }
+    }
+
+    private fun copyStream(inputStream: InputStream, out: OutputStream?) {
+        val buf = ByteArray(1024)
+        var len: Int
+        while (true) {
+            len = inputStream.read(buf)
+            if (len <= 0)
+                break
+            out?.write(buf, 0, len)
+        }
     }
 
     private fun launchSettings() {

app/src/main/kotlin/com/simplemobiletools/calendar/helpers/DBHelper.kt

@@ -49,8 +49,8 @@ class DBHelper private constructor(val context: Context) : SQLiteOpenHelper(cont
     private val mDb: SQLiteDatabase = writableDatabase
 
     companion object {
-        private val DB_NAME = "events.db"
         private val DB_VERSION = 7
+        val DB_NAME = "events.db"
         val REGULAR_EVENT_ID = 1
 
         private var mEventsListener: EventUpdateListener? = null

app/src/main/res/values-ca-rES/strings.xml

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Importing some events failed</string>
     <string name="invalid_file_format">Invalid file format</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">Título</string>

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

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">einige Termine wurden nicht erfolgreich importiert</string>
     <string name="invalid_file_format">ungültiges Dateiformat</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">Titel</string>

app/src/main/res/values-es-rES/strings.xml

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Importing some events failed</string>
     <string name="invalid_file_format">Invalid file format</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">Título</string>

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

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Importing some events failed</string>
     <string name="invalid_file_format">Invalid file format</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">Titre</string>

app/src/main/res/values-gl-rES/strings.xml

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Importing some events failed</string>
     <string name="invalid_file_format">Invalid file format</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">Título</string>

app/src/main/res/values-hi-rIN/strings.xml

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Importing some events failed</string>
     <string name="invalid_file_format">Invalid file format</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">शीर्षक</string>

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

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Importing some events failed</string>
     <string name="invalid_file_format">Invalid file format</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">Név</string>

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

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Importing some events failed</string>
     <string name="invalid_file_format">Invalid file format</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">Titolo</string>

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

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Importing some events failed</string>
     <string name="invalid_file_format">Invalid file format</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">כותרת</string>

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

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Importing some events failed</string>
     <string name="invalid_file_format">Invalid file format</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">タイトル</string>

app/src/main/res/values-pt-rPT/strings.xml

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Alguns eventos não foram importados</string>
     <string name="invalid_file_format">Formato de ficheiro inválido</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">Título</string>

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

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Ошибка импорта</string>
     <string name="invalid_file_format">Неправильный формат файла</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">Заголовок</string>

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

@@ -104,6 +104,7 @@
     <string name="importing_some_events_failed">Importovanie niektorých udalostí zlyhalo</string>
     <string name="invalid_file_format">Nesprávny formát súboru</string>
     <string name="export_raw_database">Exportovať surovú databázu</string>
+    <string name="database_exported_successfully">Databáza bola úspešne exportovaná</string>
 
     <!-- Event details -->
     <string name="title">Názov</string>

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

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Importing some events failed</string>
     <string name="invalid_file_format">Invalid file format</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">Titel</string>

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

@@ -97,6 +97,7 @@
     <string name="importing_some_events_failed">Importing some events failed</string>
     <string name="invalid_file_format">Invalid file format</string>
     <string name="export_raw_database">Export raw database</string>
+    <string name="database_exported_successfully">Database exported successfully</string>
 
     <!-- Event details -->
     <string name="title">Title</string>