desktop: saving settings in a safer way to handle process death

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/ui/theme/ThemeManager.kt

@@ -101,7 +101,9 @@ object ThemeManager {
   }
 
   fun applyTheme(theme: String) {
-    appPrefs.currentTheme.set(theme)
+    if (appPrefs.currentTheme.get() != theme) {
+      appPrefs.currentTheme.set(theme)
+    }
     CurrentColors.value = currentColors(null, null, chatModel.currentUser.value?.uiThemes, appPrefs.themeOverrides.get())
     platform.androidSetNightModeIfSupported()
     val c = CurrentColors.value.colors

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/helpers/Utils.kt

@@ -316,8 +316,8 @@ fun removeWallpaperFile(fileName: String? = null) {
   WallpaperType.cachedImages.remove(fileName)
 }
 
-fun <T> createTmpFileAndDelete(onCreated: (File) -> T): T {
-  val tmpFile = File(tmpDir, UUID.randomUUID().toString())
+fun <T> createTmpFileAndDelete(dir: File = tmpDir, onCreated: (File) -> T): T {
+  val tmpFile = File(dir, UUID.randomUUID().toString())
   tmpFile.deleteOnExit()
   ChatModel.filesToDelete.add(tmpFile)
   try {

apps/multiplatform/common/src/commonMain/kotlin/chat/simplex/common/views/onboarding/WhatsNewView.kt

@@ -17,6 +17,7 @@ import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.desktop.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
+import chat.simplex.common.model.ChatController.appPrefs
 import chat.simplex.common.model.ChatModel
 import chat.simplex.common.platform.*
 import chat.simplex.common.ui.theme.*
@@ -654,7 +655,9 @@ private val versionDescriptions: List<VersionDescription> = listOf(
 private val lastVersion = versionDescriptions.last().version
 
 fun setLastVersionDefault(m: ChatModel) {
-  m.controller.appPrefs.whatsNewVersion.set(lastVersion)
+  if (appPrefs.whatsNewVersion.get() != lastVersion) {
+    appPrefs.whatsNewVersion.set(lastVersion)
+  }
 }
 
 fun shouldShowWhatsNew(m: ChatModel): Boolean {

apps/multiplatform/common/src/desktopMain/kotlin/chat/simplex/common/platform/Resources.desktop.kt

@@ -16,6 +16,8 @@ import dev.icerock.moko.resources.StringResource
 import dev.icerock.moko.resources.desc.desc
 import kotlinx.coroutines.*
 import java.io.File
+import java.nio.file.Files
+import java.nio.file.StandardCopyOption
 import java.util.*
 import java.util.concurrent.Executors
 
@@ -35,6 +37,12 @@ catch (e: Exception) {
   false
 }
 
+private val settingsTmpDir = File(desktopPlatform.configPath, "tmp")
+  .also {
+    it.deleteRecursively()
+    it.mkdirs()
+  }
+
 private val settingsFile =
   File(desktopPlatform.configPath + File.separator + "settings.properties")
     .also { it.parentFile.mkdirs() }
@@ -64,8 +72,16 @@ private val settingsThemesProps =
 
 private val settingsWriterThread = Executors.newSingleThreadExecutor().asCoroutineDispatcher()
 
-actual val settings: Settings = PropertiesSettings(settingsProps) { CoroutineScope(settingsWriterThread).launch { settingsFile.writer().use { settingsProps.store(it, "") } } }
-actual val settingsThemes: Settings = PropertiesSettings(settingsThemesProps) { CoroutineScope(settingsWriterThread).launch { settingsThemesFile.writer().use { settingsThemesProps.store(it, "") } } }
+actual val settings: Settings = PropertiesSettings(settingsProps) { CoroutineScope(settingsWriterThread).launch {
+  createTmpFileAndDelete(settingsTmpDir) { tmpFile ->
+    tmpFile.writer().use { settingsProps.store(it, "") }
+    Files.move(tmpFile.toPath(), settingsFile.toPath(), StandardCopyOption.REPLACE_EXISTING)
+  } } }
+actual val settingsThemes: Settings = PropertiesSettings(settingsThemesProps) { CoroutineScope(settingsWriterThread).launch {
+  createTmpFileAndDelete(settingsTmpDir) { tmpFile ->
+    tmpFile.writer().use { settingsThemesProps.store(it, "") }
+    Files.move(tmpFile.toPath(), settingsThemesFile.toPath(), StandardCopyOption.REPLACE_EXISTING)
+  } } }
 
 actual fun windowOrientation(): WindowOrientation =
   if (simplexWindowState.windowState.size.width > simplexWindowState.windowState.size.height) {