Simplify and optimize Kotlin code snippets

app/src/main/java/com/github/gotify/MarkwonFactory.kt

@@ -28,8 +28,7 @@ internal object MarkwonFactory {
             .usePlugin(PicassoImagesPlugin.create(picasso))
             .usePlugin(StrikethroughPlugin.create())
             .usePlugin(TablePlugin.create(context))
-            .usePlugin(
+            .usePlugin(object : AbstractMarkwonPlugin() {
-                object : AbstractMarkwonPlugin() {
                 override fun configureTheme(builder: MarkwonTheme.Builder) {
                     builder.linkColor(ContextCompat.getColor(context, R.color.hyperLink))
                         .isLinkUnderlined(true)
@@ -39,17 +38,14 @@ internal object MarkwonFactory {
     }
 
     fun createForNotification(context: Context, picasso: Picasso): Markwon {
-        val headingSizes = floatArrayOf(
+        val headingSizes = floatArrayOf(2f, 1.5f, 1.17f, 1f, .83f, .67f)
-            2f, 1.5f, 1.17f, 1f, .83f, .67f
-        )
         val bulletGapWidth = (8 * context.resources.displayMetrics.density + 0.5f).toInt()
 
         return Markwon.builder(context)
             .usePlugin(CorePlugin.create())
             .usePlugin(PicassoImagesPlugin.create(picasso))
             .usePlugin(StrikethroughPlugin.create())
-            .usePlugin(
+            .usePlugin(object : AbstractMarkwonPlugin() {
-                object : AbstractMarkwonPlugin() {
                 override fun configureSpansFactory(builder: MarkwonSpansFactory.Builder) {
                     builder.setFactory(Heading::class.java) { _, props: RenderProps? ->
                         arrayOf<Any>(

app/src/main/java/com/github/gotify/MissedMessageUtil.kt

@@ -32,9 +32,9 @@ internal class MissedMessageUtil(private val api: MessageApi) {
                 val messages = pagedMessages!!.messages
                 val filtered = filter(messages, till)
                 result.addAll(filtered)
-                if (messages.size != filtered.size
+                if (messages.size != filtered.size ||
-                    || messages.size == 0
+                    messages.size == 0 ||
-                    || pagedMessages.paging.next == null) {
+                    pagedMessages.paging.next == null) {
                     break
                 }
                 since = pagedMessages.paging.since

app/src/main/java/com/github/gotify/SSLSettings.kt

@@ -1,3 +1,3 @@
 package com.github.gotify
 
-internal class SSLSettings(val validateSSL: Boolean, val cert: String)
+internal class SSLSettings(val validateSSL: Boolean, val cert: String?)

app/src/main/java/com/github/gotify/Settings.kt

@@ -9,8 +9,8 @@ internal class Settings(context: Context) {
     var url: String
         get() = sharedPreferences.getString("url", "")!!
         set(value) = sharedPreferences.edit().putString("url", value).apply()
-    var token: String
+    var token: String?
-        get() = sharedPreferences.getString("token", "")!!
+        get() = sharedPreferences.getString("token", null)
         set(value) = sharedPreferences.edit().putString("token", value).apply()
     var user: User? = null
         get() {
@@ -26,8 +26,8 @@ internal class Settings(context: Context) {
     var serverVersion: String
         get() = sharedPreferences.getString("version", "UNKNOWN")!!
         set(value) = sharedPreferences.edit().putString("version", value).apply()
-    var cert: String
+    var cert: String?
-        get() = sharedPreferences.getString("cert", "")!!
+        get() = sharedPreferences.getString("cert", null)
         set(value) = sharedPreferences.edit().putString("cert", value).apply()
     var validateSSL: Boolean
         get() = sharedPreferences.getBoolean("validateSSL", true)
@@ -37,13 +37,13 @@ internal class Settings(context: Context) {
         sharedPreferences = context.getSharedPreferences("gotify", Context.MODE_PRIVATE)
     }
 
-    fun tokenExists(): Boolean = token.isNotEmpty()
+    fun tokenExists(): Boolean = !token.isNullOrEmpty()
 
     fun clear() {
         url = ""
-        token = ""
+        token = null
         validateSSL = true
-        cert = ""
+        cert = null
     }
 
     fun setUser(name: String?, admin: Boolean) {

app/src/main/java/com/github/gotify/Utils.kt

@@ -49,7 +49,7 @@ internal object Utils {
             .toString()
     }
 
-    fun resolveAbsoluteUrl(baseURL: String?, target: String?): String? {
+    fun resolveAbsoluteUrl(baseURL: String, target: String?): String? {
         return if (target == null) {
             null
         } else try {

app/src/main/java/com/github/gotify/api/ApiException.kt

@@ -1,7 +1,6 @@
 package com.github.gotify.api
 
 import java.io.IOException
-import java.util.*
 import retrofit2.Response
 
 internal class ApiException : Exception {
@@ -23,12 +22,5 @@ internal class ApiException : Exception {
         code = 0
     }
 
-    override fun toString(): String {
+    override fun toString() = "Code($code) Response: ${body.take(200)}"
-        return String.format(
-            Locale.ENGLISH,
-            "Code(%d) Response: %s",
-            code,
-            body.substring(0, body.length.coerceAtMost(200))
-        )
-    }
 }

app/src/main/java/com/github/gotify/api/Callback.kt

@@ -17,13 +17,7 @@ internal class Callback<T> private constructor(
         fun onError(t: ApiException)
     }
 
-    private class RetrofitCallback<T>(callback: Callback<T>) : retrofit2.Callback<T> {
+    private class RetrofitCallback<T>(private val callback: Callback<T>) : retrofit2.Callback<T> {
-        private val callback: Callback<T>
-
-        init {
-            this.callback = callback
-        }
-
         override fun onResponse(call: Call<T>, response: Response<T>) {
             if (response.isSuccessful) {
                 callback.onSuccess.onSuccess(response.body())

app/src/main/java/com/github/gotify/api/CertUtils.kt

@@ -16,14 +16,14 @@ import okhttp3.OkHttpClient
 
 internal object CertUtils {
     @SuppressLint("CustomX509TrustManager")
-    private val trustAll: X509TrustManager = object : X509TrustManager {
+    private val trustAll = object : X509TrustManager {
         @SuppressLint("TrustAllX509TrustManager")
         override fun checkClientTrusted(chain: Array<X509Certificate>, authType: String) {}
 
         @SuppressLint("TrustAllX509TrustManager")
         override fun checkServerTrusted(chain: Array<X509Certificate>, authType: String) {}
 
-        override fun getAcceptedIssuers(): Array<X509Certificate> = arrayOf()
+        override fun getAcceptedIssuers() = arrayOf<X509Certificate>()
     }
 
     fun parseCertificate(cert: String): Certificate {
@@ -45,8 +45,9 @@ internal object CertUtils {
                 builder.hostnameVerifier { _, _ -> true }
                 return
             }
-            if (settings.cert != null) {
+            val cert = settings.cert
-                val trustManagers = certToTrustManager(settings.cert)
+            if (cert != null) {
+                val trustManagers = certToTrustManager(cert)
                 if (trustManagers.isNotEmpty()) {
                     val context = SSLContext.getInstance("TLS")
                     context.init(arrayOf(), trustManagers, SecureRandom())
@@ -66,7 +67,7 @@ internal object CertUtils {
     private fun certToTrustManager(cert: String): Array<TrustManager> {
         val certificateFactory = CertificateFactory.getInstance("X.509")
         val certificates = certificateFactory.generateCertificates(Utils.stringToInputStream(cert))
-        require(!certificates.isEmpty()) { "expected non-empty set of trusted certificates" }
+        require(certificates.isNotEmpty()) { "expected non-empty set of trusted certificates" }
 
         val caKeyStore = newEmptyKeyStore()
         certificates.forEachIndexed { index, certificate ->

app/src/main/java/com/github/gotify/api/ClientFactory.kt

@@ -9,23 +9,23 @@ import com.github.gotify.client.auth.ApiKeyAuth
 import com.github.gotify.client.auth.HttpBasicAuth
 
 internal object ClientFactory {
-    private fun unauthorized(baseUrl: String, sslSettings: SSLSettings
+    private fun unauthorized(baseUrl: String, sslSettings: SSLSettings): ApiClient {
-    ): ApiClient {
+        return defaultClient(arrayOf(), "$baseUrl/", sslSettings)
-        return defaultClient(arrayOfNulls(0), "$baseUrl/", sslSettings)
     }
 
     fun basicAuth(
         baseUrl: String,
         sslSettings: SSLSettings,
-        username: String?,
+        username: String,
-        password: String?
+        password: String
     ): ApiClient {
         val client = defaultClient(
             arrayOf("basicAuth"),
-            "$baseUrl/", sslSettings
+            "$baseUrl/",
+            sslSettings
         )
-        val auth = client.apiAuthorizations["basicAuth"] as HttpBasicAuth?
+        val auth = client.apiAuthorizations["basicAuth"] as HttpBasicAuth
-        auth!!.username = username
+        auth.username = username
         auth.password = password
         return client
     }

app/src/main/java/com/github/gotify/init/InitializationActivity.kt

@@ -80,7 +80,7 @@ internal class InitializationActivity : AppCompatActivity() {
         }
 
         var response = exception.body
-        response = response.substring(0, 200.coerceAtMost(response.length))
+        response = response.take(200)
         dialog(getString(R.string.other_error, settings.url, exception.code, response))
     }
 

app/src/main/java/com/github/gotify/log/Format.kt

@@ -2,7 +2,6 @@ package com.github.gotify.log
 
 import android.content.Context
 import com.hypertrack.hyperlog.LogFormat
-import java.util.*
 
 internal class Format(context: Context) : LogFormat(context) {
     override fun getFormattedLogMessage(
@@ -13,5 +12,5 @@ internal class Format(context: Context) : LogFormat(context) {
         senderName: String,
         osVersion: String,
         deviceUuid: String
-    ) = String.format(Locale.ENGLISH, "%s %s: %s", timeStamp, logLevelName, message)
+    ) = "$timeStamp $logLevelName: $message"
 }

app/src/main/java/com/github/gotify/login/LoginActivity.kt

@@ -83,7 +83,7 @@ internal class LoginActivity : AppCompatActivity() {
     }
 
     private fun doCheckUrl() {
-        val url = binding.gotifyUrl.text.toString()
+        var url = binding.gotifyUrl.text.toString()
         val parsedUrl = HttpUrl.parse(url)
         if (parsedUrl == null) {
             Utils.showSnackBar(this, "Invalid URL (include http:// or https://)")
@@ -97,19 +97,17 @@ internal class LoginActivity : AppCompatActivity() {
         binding.checkurlProgress.visibility = View.VISIBLE
         binding.checkurl.visibility = View.GONE
 
-        val trimmedUrl = url.trim()
+        url = url.trim()
-        val fixedUrl = if (trimmedUrl.endsWith("/")) {
+        if (url.endsWith("/")) url.dropLast(1)
-            trimmedUrl.substring(0, trimmedUrl.length - 1)
-        } else trimmedUrl
 
         try {
-            ClientFactory.versionApi(fixedUrl, tempSslSettings())
+            ClientFactory.versionApi(url, tempSslSettings())
                 ?.version
-                ?.enqueue(Callback.callInUI(this, onValidUrl(fixedUrl), onInvalidUrl(fixedUrl)))
+                ?.enqueue(Callback.callInUI(this, onValidUrl(url), onInvalidUrl(url)))
         } catch (e: Exception) {
             binding.checkurlProgress.visibility = View.GONE
             binding.checkurl.visibility = View.VISIBLE
-            val errorMsg = getString(R.string.version_failed, "$fixedUrl/version", e.message)
+            val errorMsg = getString(R.string.version_failed, "$url/version", e.message)
             Utils.showSnackBar(this, errorMsg)
         }
     }
@@ -169,7 +167,7 @@ internal class LoginActivity : AppCompatActivity() {
         super.onActivityResult(requestCode, resultCode, data)
         try {
             if (requestCode == FILE_SELECT_CODE) {
-                require(resultCode == RESULT_OK) { String.format("result was %d", resultCode) }
+                require(resultCode == RESULT_OK) { "result was $resultCode" }
                 requireNotNull(data) { "file path was null" }
 
                 val uri = data.data ?: throw IllegalArgumentException("file path was null")
@@ -268,7 +266,7 @@ internal class LoginActivity : AppCompatActivity() {
     private fun onCreatedClient(client: Client) {
         settings.token = client.token
         settings.validateSSL = !disableSslValidation
-        settings.cert = caCertContents.toString()
+        settings.cert = caCertContents
 
         Utils.showSnackBar(this, getString(R.string.created_client))
         startActivity(Intent(this, InitializationActivity::class.java))
@@ -291,6 +289,6 @@ internal class LoginActivity : AppCompatActivity() {
     }
 
     private fun tempSslSettings(): SSLSettings {
-        return SSLSettings(!disableSslValidation, caCertContents.toString())
+        return SSLSettings(!disableSslValidation, caCertContents)
     }
 }

app/src/main/java/com/github/gotify/messages/Extras.kt

@@ -3,9 +3,7 @@ package com.github.gotify.messages
 import com.github.gotify.client.model.Message
 
 internal object Extras {
-    fun useMarkdown(message: Message): Boolean {
+    fun useMarkdown(message: Message): Boolean = useMarkdown(message.extras)
-        return useMarkdown(message.extras)
-    }
 
     fun useMarkdown(extras: Map<String, Any>?): Boolean {
         if (extras == null) {

app/src/main/java/com/github/gotify/messages/ListMessageAdapter.kt

@@ -26,9 +26,9 @@ import com.github.gotify.databinding.MessageItemCompactBinding
 import com.github.gotify.messages.provider.MessageWithImage
 import com.squareup.picasso.Picasso
 import io.noties.markwon.Markwon
-import org.threeten.bp.OffsetDateTime
 import java.text.DateFormat
 import java.util.*
+import org.threeten.bp.OffsetDateTime
 
 internal class ListMessageAdapter(
     private val context: Context,
@@ -72,13 +72,13 @@ internal class ListMessageAdapter(
     override fun onBindViewHolder(holder: ViewHolder, position: Int) {
         val message = items[position]
         if (Extras.useMarkdown(message.message)) {
-            holder.message!!.autoLinkMask = 0
+            holder.message.autoLinkMask = 0
-            markwon.setMarkdown(holder.message!!, message.message.message)
+            markwon.setMarkdown(holder.message, message.message.message)
         } else {
-            holder.message!!.autoLinkMask = Linkify.WEB_URLS
+            holder.message.autoLinkMask = Linkify.WEB_URLS
-            holder.message!!.text = message.message.message
+            holder.message.text = message.message.message
         }
-        holder.title!!.text = message.message.title
+        holder.title.text = message.message.title
         picasso.load(Utils.resolveAbsoluteUrl("${settings.url}/", message.image))
             .error(R.drawable.ic_alarm)
             .placeholder(R.drawable.ic_placeholder)
@@ -87,10 +87,10 @@ internal class ListMessageAdapter(
         val prefs = PreferenceManager.getDefaultSharedPreferences(context)
         val timeFormat = prefs.getString(timeFormatPrefsKey, timeFormatRelative)
         holder.setDateTime(message.message.date, timeFormat == timeFormatRelative)
-        holder.date!!.setOnClickListener { holder.switchTimeFormat() }
+        holder.date.setOnClickListener { holder.switchTimeFormat() }
 
-        holder.delete!!.setOnClickListener {
+        holder.delete.setOnClickListener {
-            delete.delete(holder.adapterPosition, message.message!!, false)
+            delete.delete(holder.adapterPosition, message.message, false)
         }
     }
 
@@ -102,14 +102,14 @@ internal class ListMessageAdapter(
     }
 
     class ViewHolder(binding: ViewBinding) : RecyclerView.ViewHolder(binding.root) {
-        var image: ImageView? = null
+        lateinit var image: ImageView
-        var message: TextView? = null
+        lateinit var message: TextView
-        var title: TextView? = null
+        lateinit var title: TextView
-        var date: TextView? = null
+        lateinit var date: TextView
-        var delete: ImageButton? = null
+        lateinit var delete: ImageButton
 
         private var relativeTimeFormat = true
-        private var dateTime: OffsetDateTime? = null
+        private lateinit var dateTime: OffsetDateTime
 
         init {
             enableCopyToClipboard()
@@ -133,38 +133,35 @@ internal class ListMessageAdapter(
             updateDate()
         }
 
-        fun setDateTime(dateTime: OffsetDateTime?, relativeTimeFormatPreference: Boolean) {
+        fun setDateTime(dateTime: OffsetDateTime, relativeTimeFormatPreference: Boolean) {
             this.dateTime = dateTime
             relativeTimeFormat = relativeTimeFormatPreference
             updateDate()
         }
 
         private fun updateDate() {
-            var text = "?"
+            val text = if (relativeTimeFormat) {
-            if (dateTime != null) {
-                text = if (relativeTimeFormat) {
                 // Relative time format
-                    Utils.dateToRelative(dateTime!!)
+                Utils.dateToRelative(dateTime)
             } else {
                 // Absolute time format
-                    val time = dateTime!!.toInstant().toEpochMilli()
+                val time = dateTime.toInstant().toEpochMilli()
                 val date = Date(time)
                 if (DateUtils.isToday(time)) {
                     DateFormat.getTimeInstance(DateFormat.SHORT).format(date)
                 } else {
-                        DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.SHORT)
+                    DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.SHORT).format(date)
-                            .format(date)
                 }
             }
-            }
+
-            date!!.text = text
+            date.text = text
         }
 
         private fun enableCopyToClipboard() {
             super.itemView.setOnLongClickListener { view: View ->
                 val clipboard = view.context
                     .getSystemService(Context.CLIPBOARD_SERVICE) as ClipboardManager?
-                val clip = ClipData.newPlainText("GotifyMessageContent", message!!.text.toString())
+                val clip = ClipData.newPlainText("GotifyMessageContent", message.text.toString())
                 if (clipboard != null) {
                     clipboard.setPrimaryClip(clip)
                     Toast.makeText(
@@ -178,7 +175,7 @@ internal class ListMessageAdapter(
         }
     }
 
-    interface Delete {
+    fun interface Delete {
         fun delete(position: Int, message: Message, listAnimation: Boolean)
     }
 }

app/src/main/java/com/github/gotify/messages/MessagesActivity.kt

@@ -46,10 +46,8 @@ import com.github.gotify.init.InitializationActivity
 import com.github.gotify.log.Log
 import com.github.gotify.log.LogsActivity
 import com.github.gotify.login.LoginActivity
-import com.github.gotify.messages.ListMessageAdapter.Delete
 import com.github.gotify.messages.provider.*
 import com.github.gotify.service.WebSocketService
-import com.github.gotify.service.WebSocketService.Companion.NEW_MESSAGE_BROADCAST
 import com.github.gotify.settings.SettingsActivity
 import com.github.gotify.sharing.ShareActivity
 import com.google.android.material.navigation.NavigationView
@@ -86,8 +84,7 @@ internal class MessagesActivity :
         super.onCreate(savedInstanceState)
         binding = ActivityMessagesBinding.inflate(layoutInflater)
         setContentView(binding.root)
-        viewModel = ViewModelProvider(this, MessagesModelFactory(this))
+        viewModel = ViewModelProvider(this, MessagesModelFactory(this))[MessagesModel::class.java]
-            .get(MessagesModel::class.java)
         Log.i("Entering " + javaClass.simpleName)
         initDrawer()
         val layoutManager = LinearLayoutManager(this)
@@ -99,16 +96,14 @@ internal class MessagesActivity :
             this,
             viewModel.settings,
             viewModel.picassoHandler.get(),
-            emptyList(),
+            emptyList()
-            object : Delete {
+        ) { position, message, listAnimation ->
-                override fun delete(position: Int, message: Message, listAnimation: Boolean) {
             scheduleDeletion(
                 position,
                 message,
                 listAnimation
             )
         }
-            })
         messagesView.addItemDecoration(dividerItemDecoration)
         messagesView.setHasFixedSize(true)
         messagesView.layoutManager = layoutManager
@@ -191,23 +186,18 @@ internal class MessagesActivity :
         viewModel.targetReferences.clear()
         updateMessagesAndStopLoading(viewModel.messages[viewModel.appId])
         var selectedItem = menu.findItem(R.id.nav_all_messages)
-        for (i in applications.indices) {
+        applications.indices.forEach {
-            val app = applications[i]
+            val app = applications[it]
-            val item = menu.add(R.id.apps, i, APPLICATION_ORDER, app.name)
+            val item = menu.add(R.id.apps, it, APPLICATION_ORDER, app.name)
             item.isCheckable = true
             if (app.id == viewModel.appId) selectedItem = item
-            val t = Utils.toDrawable(
+            val t = Utils.toDrawable(resources) { icon: Drawable? ->
-                resources
+                item.icon = icon
-            ) { icon: Drawable? -> item.icon = icon }
+            }
             viewModel.targetReferences.add(t)
-            viewModel
+            viewModel.picassoHandler
-                .picassoHandler
                 .get()
-                .load(
+                .load(Utils.resolveAbsoluteUrl(viewModel.settings.url + "/", app.image))
-                    Utils.resolveAbsoluteUrl(
-                        viewModel.settings.url + "/", app.image
-                    )
-                )
                 .error(R.drawable.ic_alarm)
                 .placeholder(R.drawable.ic_placeholder)
                 .resize(100, 100)
@@ -239,10 +229,8 @@ internal class MessagesActivity :
         version.text =
             getString(R.string.versions, BuildConfig.VERSION_NAME, settings.serverVersion)
         val refreshAll = headerView.findViewById<ImageButton>(R.id.refresh_all)
-        refreshAll.setOnClickListener { view: View? ->
+        refreshAll.setOnClickListener {
-            onRefreshAll(
+            onRefreshAll(it)
-                view
-            )
         }
     }
 
@@ -259,7 +247,7 @@ internal class MessagesActivity :
         val id = item.itemId
         if (item.groupId == R.id.apps) {
             val app = viewModel.appsHolder.get()[id]
-            updateAppOnDrawerClose = if (app != null) app.id else MessageState.ALL_MESSAGES
+            updateAppOnDrawerClose = app.id
             startLoading()
             binding.appBarDrawer.toolbar.subtitle = item.title
         } else if (id == R.id.nav_all_messages) {
@@ -273,7 +261,7 @@ internal class MessagesActivity :
                 .setPositiveButton(R.string.yes) { _, _ ->
                     doLogout()
                 }
-                .setNegativeButton(R.string.cancel) { a, b -> }
+                .setNegativeButton(R.string.cancel, null)
                 .show()
         } else if (id == R.id.nav_logs) {
             startActivity(Intent(this, LogsActivity::class.java))
@@ -309,22 +297,22 @@ internal class MessagesActivity :
         val nManager = context.getSystemService(NOTIFICATION_SERVICE) as NotificationManager
         nManager.cancelAll()
         val filter = IntentFilter()
-        filter.addAction(NEW_MESSAGE_BROADCAST)
+        filter.addAction(WebSocketService.NEW_MESSAGE_BROADCAST)
         registerReceiver(receiver, filter)
         launchCoroutine {
             updateMissedMessages(viewModel.messages.getLastReceivedMessage())
         }
-        var selectedIndex: Int = R.id.nav_all_messages
+        var selectedIndex = R.id.nav_all_messages
         val appId = viewModel.appId
         if (appId != MessageState.ALL_MESSAGES) {
             val apps = viewModel.appsHolder.get()
-            for (i in apps.indices) {
+            apps.indices.forEach {
-                if (apps[i].id == appId) {
+                if (apps[it].id == appId) {
-                    selectedIndex = i
+                    selectedIndex = it
                 }
             }
         }
-        listMessageAdapter!!.notifyDataSetChanged()
+        listMessageAdapter.notifyDataSetChanged()
         selectAppInMenu(binding.navView.menu.findItem(selectedIndex))
         super.onResume()
     }
@@ -337,17 +325,26 @@ internal class MessagesActivity :
     private fun selectAppInMenu(appItem: MenuItem?) {
         if (appItem != null) {
             appItem.isChecked = true
-            if (appItem.itemId != R.id.nav_all_messages) binding.appBarDrawer.toolbar.subtitle =
+            if (appItem.itemId != R.id.nav_all_messages) {
-                appItem.title
+                binding.appBarDrawer.toolbar.subtitle = appItem.title
+            }
         }
     }
 
-    private fun scheduleDeletion(position: Int, message: Message, listAnimation: Boolean) {
+    private fun scheduleDeletion(
+        position: Int,
+        message: Message,
+        listAnimation: Boolean
+    ) {
         val adapter = binding.messagesView.adapter as ListMessageAdapter
         val messages = viewModel.messages
         messages.deleteLocal(message)
         adapter.items = messages[viewModel.appId]
-        if (listAnimation) adapter.notifyItemRemoved(position) else adapter.notifyDataSetChanged()
+        if (listAnimation) {
+            adapter.notifyItemRemoved(position)
+        } else {
+            adapter.notifyDataSetChanged()
+        }
         showDeletionSnackbar()
     }
 
@@ -358,17 +355,19 @@ internal class MessagesActivity :
             val adapter = binding.messagesView.adapter as ListMessageAdapter
             val appId = viewModel.appId
             adapter.items = messages[appId]
-            val insertPosition =
+            val insertPosition = if (appId == MessageState.ALL_MESSAGES) {
-                if (appId == MessageState.ALL_MESSAGES) deletion.allPosition else deletion.appPosition
+                deletion.allPosition
+            } else {
+                deletion.appPosition
+            }
             adapter.notifyItemInserted(insertPosition)
         }
     }
 
     private fun showDeletionSnackbar() {
         val view: View = binding.swipeRefresh
-        val snackbar: Snackbar =
+        val snackbar = Snackbar.make(view, R.string.snackbar_deleted, Snackbar.LENGTH_LONG)
-            Snackbar.make(view, R.string.snackbar_deleted, Snackbar.LENGTH_LONG)
+        snackbar.setAction(R.string.snackbar_undo) { undoDelete() }
-        snackbar.setAction(R.string.snackbar_undo) { v -> undoDelete() }
         snackbar.addCallback(SnackbarCallback())
         snackbar.show()
     }
@@ -389,8 +388,9 @@ internal class MessagesActivity :
         }
     }
 
-    private inner class SwipeToDeleteCallback(private val adapter: ListMessageAdapter) :
+    private inner class SwipeToDeleteCallback(
-        ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT or ItemTouchHelper.RIGHT) {
+        private val adapter: ListMessageAdapter
+    ) : ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT or ItemTouchHelper.RIGHT) {
         private var icon: Drawable?
         private val background: ColorDrawable
 
@@ -411,9 +411,7 @@ internal class MessagesActivity :
             recyclerView: RecyclerView,
             viewHolder: RecyclerView.ViewHolder,
             target: RecyclerView.ViewHolder
-        ): Boolean {
+        ) = false
-            return false
-        }
 
         override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
             val position = viewHolder.adapterPosition
@@ -475,14 +473,15 @@ internal class MessagesActivity :
 
     private inner class MessageListOnScrollListener : RecyclerView.OnScrollListener() {
         override fun onScrollStateChanged(view: RecyclerView, scrollState: Int) {}
+
         override fun onScrolled(view: RecyclerView, dx: Int, dy: Int) {
             val linearLayoutManager = view.layoutManager as LinearLayoutManager?
             if (linearLayoutManager != null) {
                 val lastVisibleItem = linearLayoutManager.findLastVisibleItemPosition()
                 val totalItemCount = view.adapter!!.itemCount
-                if (lastVisibleItem > totalItemCount - 15 && totalItemCount != 0 && viewModel.messages.canLoadMore(
+                if (lastVisibleItem > totalItemCount - 15 &&
-                        viewModel.appId
+                    totalItemCount != 0 &&
-                    )
+                    viewModel.messages.canLoadMore(viewModel.appId)
                 ) {
                     if (!isLoadMore) {
                         isLoadMore = true
@@ -540,13 +539,8 @@ internal class MessagesActivity :
         client.createService(ApplicationApi::class.java)
             .deleteApp(appId)
             .enqueue(
-                Callback.callInUI(
+                Callback.callInUI(this, { refreshAll() }) {
-                    this,
+                    Utils.showSnackBar(this, getString(R.string.error_delete_app))
-                    { refreshAll() }
-                ) {
-                    Utils.showSnackBar(
-                        this, getString(R.string.error_delete_app)
-                    )
                 })
     }
 

app/src/main/java/com/github/gotify/messages/MessagesModel.kt

@@ -4,7 +4,6 @@ import android.app.Activity
 import androidx.lifecycle.ViewModel
 import com.github.gotify.Settings
 import com.github.gotify.api.ClientFactory
-import com.github.gotify.client.ApiClient
 import com.github.gotify.client.api.MessageApi
 import com.github.gotify.messages.provider.ApplicationHolder
 import com.github.gotify.messages.provider.MessageFacade
@@ -13,22 +12,14 @@ import com.github.gotify.picasso.PicassoHandler
 import com.squareup.picasso.Target
 
 internal class MessagesModel(parentView: Activity) : ViewModel() {
-    val settings: Settings
+    val settings = Settings(parentView)
-    val picassoHandler: PicassoHandler
+    val picassoHandler = PicassoHandler(parentView, settings)
-    val client: ApiClient
+    val client = ClientFactory.clientToken(settings.url, settings.sslSettings(), settings.token)
-    val appsHolder: ApplicationHolder
+    val appsHolder = ApplicationHolder(parentView, client)
-    val messages: MessageFacade
+    val messages = MessageFacade(client.createService(MessageApi::class.java), appsHolder)
 
     // we need to keep the target references otherwise they get gc'ed before they can be called.
     val targetReferences = mutableListOf<Target>()
 
     var appId = MessageState.ALL_MESSAGES
-
-    init {
-        settings = Settings(parentView)
-        picassoHandler = PicassoHandler(parentView, settings)
-        client = ClientFactory.clientToken(settings.url, settings.sslSettings(), settings.token)
-        appsHolder = ApplicationHolder(parentView, client)
-        messages = MessageFacade(client.createService(MessageApi::class.java), appsHolder)
-    }
 }

app/src/main/java/com/github/gotify/messages/provider/ApplicationHolder.kt

@@ -9,13 +9,11 @@ import com.github.gotify.client.api.ApplicationApi
 import com.github.gotify.client.model.Application
 
 internal class ApplicationHolder(private val activity: Activity, private val client: ApiClient) {
-    private var state: List<Application> = listOf()
+    private var state = listOf<Application>()
     private var onUpdate: Runnable? = null
     private var onUpdateFailed: Runnable? = null
 
-    fun wasRequested(): Boolean {
+    fun wasRequested() = state.isNotEmpty()
-        return state.isNotEmpty()
-    }
 
     fun request() {
         client.createService(ApplicationApi::class.java)

app/src/main/java/com/github/gotify/messages/provider/MessageFacade.kt

@@ -4,13 +4,8 @@ import com.github.gotify.client.api.MessageApi
 import com.github.gotify.client.model.Message
 
 internal class MessageFacade(api: MessageApi, private val applicationHolder: ApplicationHolder) {
-    private val requester: MessageRequester
+    private val requester = MessageRequester(api)
-    private val state: MessageStateHolder
+    private val state = MessageStateHolder()
-
-    init {
-        requester = MessageRequester(api)
-        state = MessageStateHolder()
-    }
 
     @Synchronized
     operator fun get(appId: Long): List<MessageWithImage> {

app/src/main/java/com/github/gotify/messages/provider/MessageRequester.kt

@@ -11,7 +11,7 @@ import com.github.gotify.log.Log
 internal class MessageRequester(private val messageApi: MessageApi) {
     fun loadMore(state: MessageState): PagedMessages? {
         return try {
-            Log.i("Loading more messages for " + state.appId)
+            Log.i("Loading more messages for ${state.appId}")
             if (MessageState.ALL_MESSAGES == state.appId) {
                 Api.execute(messageApi.getMessages(LIMIT, state.nextSince))
             } else {
@@ -24,7 +24,7 @@ internal class MessageRequester(private val messageApi: MessageApi) {
     }
 
     fun asyncRemoveMessage(message: Message) {
-        Log.i("Removing message with id " + message.id)
+        Log.i("Removing message with id ${message.id}")
         messageApi.deleteMessage(message.id).enqueue(Callback.call())
     }
 

app/src/main/java/com/github/gotify/picasso/PicassoDataRequestHandler.kt

@@ -28,7 +28,7 @@ internal class PicassoDataRequestHandler : RequestHandler() {
         val bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.size)
 
         if (bitmap == null) {
-            val show = if (uri.length > 50) uri.substring(0, 49) + "..." else uri
+            val show = if (uri.length > 50) uri.take(50) + "..." else uri
             val malformed = RuntimeException("Malformed data uri: $show")
             Log.e("Could not load image", malformed)
             throw malformed

app/src/main/java/com/github/gotify/picasso/PicassoHandler.kt

@@ -14,10 +14,10 @@ import com.github.gotify.log.Log
 import com.github.gotify.messages.provider.MessageImageCombiner
 import com.squareup.picasso.OkHttp3Downloader
 import com.squareup.picasso.Picasso
-import okhttp3.Cache
-import okhttp3.OkHttpClient
 import java.io.File
 import java.io.IOException
+import okhttp3.Cache
+import okhttp3.OkHttpClient
 
 internal class PicassoHandler(private val context: Context, private val settings: Settings) {
     companion object {
@@ -31,7 +31,7 @@ internal class PicassoHandler(private val context: Context, private val settings
     )
 
     private val picasso: Picasso = makePicasso()
-    private val appIdToAppImage: MutableMap<Long, String> = mutableMapOf()
+    private val appIdToAppImage = mutableMapOf<Long, String>()
 
     private fun makePicasso(): Picasso {
         val builder = OkHttpClient.Builder()
@@ -45,9 +45,7 @@ internal class PicassoHandler(private val context: Context, private val settings
     }
 
     @Throws(IOException::class)
-    fun getImageFromUrl(url: String?): Bitmap {
+    fun getImageFromUrl(url: String?): Bitmap = picasso.load(url).get()
-        return picasso.load(url).get()
-    }
 
     fun getIcon(appId: Long): Bitmap {
         if (appId == -1L) {

app/src/main/java/com/github/gotify/service/WebSocketConnection.kt

@@ -19,7 +19,7 @@ import okhttp3.*
 internal class WebSocketConnection(
     private val baseUrl: String,
     settings: SSLSettings,
-    private val token: String,
+    private val token: String?,
     private val connectivityManager: ConnectivityManager,
     private val alarmManager: AlarmManager
 ) {
@@ -33,12 +33,12 @@ internal class WebSocketConnection(
     private var errorCount = 0
 
     private var webSocket: WebSocket? = null
-    private var onMessage: SuccessCallback<Message>? = null
+    private lateinit var onMessage: SuccessCallback<Message>
-    private var onClose: Runnable? = null
+    private lateinit var onClose: Runnable
-    private var onOpen: Runnable? = null
+    private lateinit var onOpen: Runnable
-    private var onBadRequest: BadRequestRunnable? = null
+    private lateinit var onBadRequest: BadRequestRunnable
-    private var onNetworkFailure: OnNetworkFailureRunnable? = null
+    private lateinit var onNetworkFailure: OnNetworkFailureRunnable
-    private var onReconnected: Runnable? = null
+    private lateinit var onReconnected: Runnable
     private var state: State? = null
 
     init {
@@ -149,10 +149,10 @@ internal class WebSocketConnection(
             syncExec {
                 state = State.Connected
                 Log.i("WebSocket($id): opened")
-                onOpen!!.run()
+                onOpen.run()
 
                 if (errorCount > 0) {
-                    onReconnected!!.run()
+                    onReconnected.run()
                     errorCount = 0
                 }
             }
@@ -163,7 +163,7 @@ internal class WebSocketConnection(
             syncExec {
                 Log.i("WebSocket($id): received message $text")
                 val message = Utils.JSON.fromJson(text, Message::class.java)
-                onMessage!!.onSuccess(message)
+                onMessage.onSuccess(message)
             }
             super.onMessage(webSocket, text)
         }
@@ -172,7 +172,7 @@ internal class WebSocketConnection(
             syncExec {
                 if (state == State.Connected) {
                     Log.w("WebSocket($id): closed")
-                    onClose!!.run()
+                    onClose.run()
                 }
                 state = State.Disconnected
             }
@@ -186,7 +186,7 @@ internal class WebSocketConnection(
             syncExec {
                 state = State.Disconnected
                 if (response != null && response.code() >= 400 && response.code() <= 499) {
-                    onBadRequest!!.execute(message)
+                    onBadRequest.execute(message)
                     close()
                     return@syncExec
                 }
@@ -200,7 +200,7 @@ internal class WebSocketConnection(
 
                 val minutes = (errorCount * 2 - 1).coerceAtMost(20)
 
-                onNetworkFailure!!.execute(minutes)
+                onNetworkFailure.execute(minutes)
                 scheduleReconnect(TimeUnit.MINUTES.toSeconds(minutes.toLong()))
             }
             super.onFailure(webSocket, t, response)
@@ -215,11 +215,11 @@ internal class WebSocketConnection(
         }
     }
 
-    internal interface BadRequestRunnable {
+    internal fun interface BadRequestRunnable {
         fun execute(message: String)
     }
 
-    internal interface OnNetworkFailureRunnable {
+    internal fun interface OnNetworkFailureRunnable {
         fun execute(minutes: Int)
     }
 

app/src/main/java/com/github/gotify/service/WebSocketService.kt

@@ -95,16 +95,8 @@ internal class WebSocketService : Service() {
         )
             .onOpen { onOpen() }
             .onClose { onClose() }
-            .onBadRequest(object : BadRequestRunnable {
+            .onBadRequest { message -> onBadRequest(message) }
-                override fun execute(message: String) {
+            .onNetworkFailure { minutes -> onNetworkFailure(minutes) }
-                    onBadRequest(message)
-                }
-            })
-            .onNetworkFailure(object : OnNetworkFailureRunnable {
-                override fun execute(minutes: Int) {
-                    onNetworkFailure(minutes)
-                }
-            })
             .onMessage { if (it != null) onMessage(it) }
             .onReconnected { notifyMissedNotifications() }
             .start()

app/src/main/java/com/github/gotify/settings/SettingsActivity.kt

@@ -47,7 +47,9 @@ internal class SettingsActivity : AppCompatActivity(), OnSharedPreferenceChangeL
     override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
         if (getString(R.string.setting_key_theme) == key) {
             ThemeHelper.setTheme(
-                this, sharedPreferences.getString(key, getString(R.string.theme_default))!!)
+                this,
+                sharedPreferences.getString(key, getString(R.string.theme_default))!!
+            )
         }
     }
 

app/src/main/java/com/github/gotify/sharing/ShareActivity.kt

@@ -52,8 +52,11 @@ internal class ShareActivity : AppCompatActivity() {
         }
 
         if (!settings.tokenExists()) {
-            Toast.makeText(applicationContext, R.string.not_loggedin_share, Toast.LENGTH_SHORT)
+            Toast.makeText(
-                .show()
+                applicationContext,
+                R.string.not_loggedin_share,
+                Toast.LENGTH_SHORT
+            ).show()
             finish()
             return
         }