diff --git a/app/src/main/java/it/danieleverducci/lunatracker/MainActivity.kt b/app/src/main/java/it/danieleverducci/lunatracker/MainActivity.kt
index 0d51fd0..1678bf6 100644
--- a/app/src/main/java/it/danieleverducci/lunatracker/MainActivity.kt
+++ b/app/src/main/java/it/danieleverducci/lunatracker/MainActivity.kt
@@ -47,9 +47,9 @@ import java.util.Date
 
 class MainActivity : AppCompatActivity() {
     companion object {
-        val TAG = "MainActivity"
-        val UPDATE_EVERY_SECS: Long = 30
-        val DEBUG_CHECK_LOGBOOK_CONSISTENCY = false
+        const val TAG = "MainActivity"
+        const val UPDATE_EVERY_SECS: Long = 30
+        const val DEBUG_CHECK_LOGBOOK_CONSISTENCY = false
     }
 
     var logbook: Logbook? = null
@@ -113,24 +113,24 @@ class MainActivity : AppCompatActivity() {
         moreButton.setOnClickListener {
             showOverflowPopupWindow(moreButton)
         }
-        findViewById<View>(R.id.button_no_connection_settings).setOnClickListener({
+        findViewById<View>(R.id.button_no_connection_settings).setOnClickListener {
             showSettings()
-        })
-        findViewById<View>(R.id.button_settings).setOnClickListener({
+        }
+        findViewById<View>(R.id.button_settings).setOnClickListener {
             showSettings()
-        })
-        findViewById<View>(R.id.button_no_connection_retry).setOnClickListener({
+        }
+        findViewById<View>(R.id.button_no_connection_retry).setOnClickListener {
             // This may happen at start, when logbook is still null: better ask the logbook list
             loadLogbookList()
-        })
-        findViewById<View>(R.id.button_sync).setOnClickListener({
+        }
+        findViewById<View>(R.id.button_sync).setOnClickListener {
             loadLogbookList()
-        })
+        }
     }
 
     private fun setListAdapter(items: ArrayList<LunaEvent>) {
         val adapter = LunaEventRecyclerAdapter(this, items)
-        adapter.onItemClickListener = object: LunaEventRecyclerAdapter.OnItemClickListener{
+        adapter.onItemClickListener = object: LunaEventRecyclerAdapter.OnItemClickListener {
             override fun onItemClick(event: LunaEvent) {
                 showEventDetailDialog(event, items)
             }
diff --git a/app/src/main/java/it/danieleverducci/lunatracker/SettingsActivity.kt b/app/src/main/java/it/danieleverducci/lunatracker/SettingsActivity.kt
index 0cbd0cf..7d03b4e 100644
--- a/app/src/main/java/it/danieleverducci/lunatracker/SettingsActivity.kt
+++ b/app/src/main/java/it/danieleverducci/lunatracker/SettingsActivity.kt
@@ -61,9 +61,9 @@ open class SettingsActivity : AppCompatActivity() {
         switchNoBreastfeeding.isChecked = noBreastfeeding
 
         if (webDavCredentials != null) {
-            textViewWebDAVUrl.setText(webDavCredentials[0])
-            textViewWebDAVUser.setText(webDavCredentials[1])
-            textViewWebDAVPass.setText(webDavCredentials[2])
+            textViewWebDAVUrl.text = webDavCredentials[0]
+            textViewWebDAVUser.text = webDavCredentials[1]
+            textViewWebDAVPass.text = webDavCredentials[2]
         }
     }
 
@@ -170,7 +170,7 @@ open class SettingsActivity : AppCompatActivity() {
      */
     private fun copyLocalLogbooksToWebdav(webDAVLogbookRepository: WebDAVLogbookRepository, listener: OnCopyLocalLogbooksToWebdavFinishedListener) {
         Thread(Runnable {
-            var errors = StringBuilder()
+            val errors = StringBuilder()
             val fileLogbookRepo = FileLogbookRepository()
             val logbooks = fileLogbookRepo.getAllLogbooks(this)
             for (logbook in logbooks) {
diff --git a/app/src/main/java/it/danieleverducci/lunatracker/adapters/LunaEventRecyclerAdapter.kt b/app/src/main/java/it/danieleverducci/lunatracker/adapters/LunaEventRecyclerAdapter.kt
index ea07924..409471f 100644
--- a/app/src/main/java/it/danieleverducci/lunatracker/adapters/LunaEventRecyclerAdapter.kt
+++ b/app/src/main/java/it/danieleverducci/lunatracker/adapters/LunaEventRecyclerAdapter.kt
@@ -53,7 +53,7 @@ class LunaEventRecyclerAdapter: RecyclerView.Adapter<LunaEventRecyclerAdapter.Lu
         holder.quantity.setTextColor(ContextCompat.getColor(context, R.color.textColor))
         // Contents
         holder.type.text = item.getTypeEmoji(context)
-        holder.description.text = when(item.type) {
+        holder.description.text = when (item.type) {
             LunaEvent.TYPE_MEDICINE -> item.notes
             LunaEvent.TYPE_NOTE -> item.notes
             LunaEvent.TYPE_CUSTOM -> item.notes
diff --git a/app/src/main/java/it/danieleverducci/lunatracker/entities/LunaEvent.kt b/app/src/main/java/it/danieleverducci/lunatracker/entities/LunaEvent.kt
index 30444c9..a56c8a2 100644
--- a/app/src/main/java/it/danieleverducci/lunatracker/entities/LunaEvent.kt
+++ b/app/src/main/java/it/danieleverducci/lunatracker/entities/LunaEvent.kt
@@ -128,7 +128,7 @@ class LunaEvent: Comparable<LunaEvent> {
     }
 
     override fun toString(): String {
-        return "${type} qty: $quantity time: ${Date(time * 1000)}"
+        return "$type qty: $quantity time: ${Date(time * 1000)}"
     }
 
     override fun compareTo(other: LunaEvent): Int {
diff --git a/app/src/main/java/it/danieleverducci/lunatracker/repository/FileLogbookRepository.kt b/app/src/main/java/it/danieleverducci/lunatracker/repository/FileLogbookRepository.kt
index 3e976f7..4b0904b 100644
--- a/app/src/main/java/it/danieleverducci/lunatracker/repository/FileLogbookRepository.kt
+++ b/app/src/main/java/it/danieleverducci/lunatracker/repository/FileLogbookRepository.kt
@@ -13,9 +13,9 @@ import java.io.FilenameFilter
 
 class FileLogbookRepository: LogbookRepository {
     companion object {
-        val TAG = "FileLogbookRepository"
-        val FILE_NAME_START = "data"
-        val FILE_NAME_END = ".json"
+        const val TAG = "FileLogbookRepository"
+        const val FILE_NAME_START = "data"
+        const val FILE_NAME_END = ".json"
     }
 
     override fun loadLogbook(context: Context, name: String, listener: LogbookLoadedListener) {
@@ -32,7 +32,7 @@ class FileLogbookRepository: LogbookRepository {
     fun loadLogbook(context: Context, name: String): Logbook {
         val logbook = Logbook(name)
         val fileName = getFileName(name)
-        val file = File(context.getFilesDir(), fileName)
+        val file = File(context.filesDir, fileName)
         val json = FileInputStream(file).bufferedReader().use { it.readText() }
         val ja = JSONArray(json)
         for (i in 0 until ja.length()) {
@@ -58,7 +58,7 @@ class FileLogbookRepository: LogbookRepository {
 
     fun saveLogbook(context: Context, logbook: Logbook) {
         val fileName = getFileName(logbook.name)
-        val file = File(context.getFilesDir(), fileName)
+        val file = File(context.filesDir, fileName)
         val ja = JSONArray()
         for (l in logbook.logs) {
             ja.put(l.toJson())
@@ -82,7 +82,7 @@ class FileLogbookRepository: LogbookRepository {
     }
 
     private fun listLogbooks(context: Context): ArrayList<String> {
-        val logbooksFileNames = context.getFilesDir().list(object: FilenameFilter {
+        val logbooksFileNames = context.filesDir.list(object: FilenameFilter {
             override fun accept(dir: File?, name: String?): Boolean {
                 if (name == null)
                     return false
diff --git a/app/src/main/java/it/danieleverducci/lunatracker/repository/LocalSettingsRepository.kt b/app/src/main/java/it/danieleverducci/lunatracker/repository/LocalSettingsRepository.kt
index ede0b93..577d8f5 100644
--- a/app/src/main/java/it/danieleverducci/lunatracker/repository/LocalSettingsRepository.kt
+++ b/app/src/main/java/it/danieleverducci/lunatracker/repository/LocalSettingsRepository.kt
@@ -7,13 +7,13 @@ import androidx.core.content.edit
 
 class LocalSettingsRepository(val context: Context) {
     companion object {
-        val SHARED_PREFS_FILE_NAME = "lunasettings"
-        val SHARED_PREFS_BB_CONTENT = "bbcontent"
-        val SHARED_PREFS_DATA_REPO = "data_repo"
-        val SHARED_PREFS_DAV_URL = "webdav_url"
-        val SHARED_PREFS_DAV_USER = "webdav_user"
-        val SHARED_PREFS_DAV_PASS = "webdav_password"
-        val SHARED_PREFS_NO_BREASTFEEDING = "no_breastfeeding"
+        const val SHARED_PREFS_FILE_NAME = "lunasettings"
+        const val SHARED_PREFS_BB_CONTENT = "bbcontent"
+        const val SHARED_PREFS_DATA_REPO = "data_repo"
+        const val SHARED_PREFS_DAV_URL = "webdav_url"
+        const val SHARED_PREFS_DAV_USER = "webdav_user"
+        const val SHARED_PREFS_DAV_PASS = "webdav_password"
+        const val SHARED_PREFS_NO_BREASTFEEDING = "no_breastfeeding"
     }
     enum class DATA_REPO {LOCAL_FILE, WEBDAV}
     val sharedPreferences: SharedPreferences
@@ -23,7 +23,7 @@ class LocalSettingsRepository(val context: Context) {
     }
 
     fun saveBabyBottleContent(content: Int) {
-        sharedPreferences.edit().putInt(SHARED_PREFS_BB_CONTENT, content).apply()
+        sharedPreferences.edit { putInt(SHARED_PREFS_BB_CONTENT, content) }
     }
 
     fun loadBabyBottleContent(): Int {
@@ -31,7 +31,7 @@ class LocalSettingsRepository(val context: Context) {
     }
 
     fun saveNoBreastfeeding(content: Boolean) {
-        sharedPreferences.edit().putBoolean(SHARED_PREFS_NO_BREASTFEEDING, content).apply()
+        sharedPreferences.edit { putBoolean(SHARED_PREFS_NO_BREASTFEEDING, content) }
     }
 
     fun loadNoBreastfeeding(): Boolean {
@@ -39,15 +39,15 @@ class LocalSettingsRepository(val context: Context) {
     }
 
     fun saveDataRepository(repo: DATA_REPO) {
-        val spe = sharedPreferences.edit()
-        spe.putString(
-            SHARED_PREFS_DATA_REPO,
-            when (repo) {
-                DATA_REPO.WEBDAV -> "webdav"
-                DATA_REPO.LOCAL_FILE -> "localfile"
-            }
-        )
-        spe.commit()
+        sharedPreferences.edit(commit = true) {
+            putString(
+                SHARED_PREFS_DATA_REPO,
+                when (repo) {
+                    DATA_REPO.WEBDAV -> "webdav"
+                    DATA_REPO.LOCAL_FILE -> "localfile"
+                }
+            )
+        }
     }
 
     fun loadDataRepository(): DATA_REPO {
@@ -60,11 +60,11 @@ class LocalSettingsRepository(val context: Context) {
     }
 
     fun saveWebdavCredentials(url: String, username: String, password: String) {
-        val spe = sharedPreferences.edit()
-        spe.putString(SHARED_PREFS_DAV_URL, url)
-        spe.putString(SHARED_PREFS_DAV_USER, username)
-        spe.putString(SHARED_PREFS_DAV_PASS, password)
-        spe.commit()
+        sharedPreferences.edit(commit = true) {
+            putString(SHARED_PREFS_DAV_URL, url)
+            putString(SHARED_PREFS_DAV_USER, username)
+            putString(SHARED_PREFS_DAV_PASS, password)
+        }
     }
 
     fun loadWebdavCredentials(): Array<String>? {