Saveable/Reactive Preferences

Author: Stefterv

app/src/processing/app/Preferences.kt

@@ -2,9 +2,13 @@ package processing.app
 
 import androidx.compose.runtime.*
 import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.FlowPreview
+import kotlinx.coroutines.flow.debounce
+import kotlinx.coroutines.flow.dropWhile
 import kotlinx.coroutines.launch
 import java.io.File
 import java.io.InputStream
+import java.io.OutputStream
 import java.nio.file.*
 import java.util.Properties
 
@@ -15,35 +19,58 @@ const val DEFAULTS_FILE_NAME = "defaults.txt"
 fun PlatformStart(){
     Platform.inst ?: Platform.init()
 }
+class ReactiveProperties: Properties() {
+    val _stateMap = mutableStateMapOf<String, String>()
 
+    override fun setProperty(key: String, value: String) {
+        super.setProperty(key, value)
+        _stateMap[key] = value
+    }
+
+    override fun getProperty(key: String): String? {
+        return _stateMap[key] ?: super.getProperty(key)
+    }
+
+    operator fun get(key: String): String? = getProperty(key)
+}
+val LocalPreferences = compositionLocalOf<ReactiveProperties> { error("No preferences provided") }
+@OptIn(FlowPreview::class)
 @Composable
-fun loadPreferences(): Properties{
+fun PreferencesProvider(content: @Composable () -> Unit){
     PlatformStart()
 
     val settingsFolder = Platform.getSettingsFolder()
     val preferencesFile = settingsFolder.resolve(PREFERENCES_FILE_NAME)
 
-    if(!preferencesFile.exists()){
-        preferencesFile.createNewFile()
-    }
-    watchFile(preferencesFile)
-    var update by remember { mutableStateOf(System.currentTimeMillis()) }
+    val update = watchFile(preferencesFile)
+    val properties = remember(preferencesFile, update) { ReactiveProperties().apply {
+        load((ClassLoader.getSystemResourceAsStream(DEFAULTS_FILE_NAME)?: InputStream.nullInputStream()).reader(Charsets.UTF_8))
+        load(preferencesFile.inputStream().reader(Charsets.UTF_8))
+    }}
 
-    // TODO: Make observable when preferences change
-    // TODO: Save to file when preferences change
-    class ObservableProperties : Properties() {
-        override fun setProperty(key: String, value: String): Any? {
-            update = System.currentTimeMillis()
-            return super.setProperty(key, value)
-        }
+    val initialState = remember(properties) { properties._stateMap.toMap() }
+
+    LaunchedEffect(properties) {
+        snapshotFlow { properties._stateMap.toMap() }
+            .dropWhile { it == initialState }
+            .debounce(1000)
+            .collect {
+                preferencesFile.outputStream().use { output ->
+                    output.write(
+                        properties.entries
+                            .sortedWith(compareBy(String.CASE_INSENSITIVE_ORDER) { it.key.toString() })
+                            .joinToString("\n") { (key, value) -> "$key=$value" }
+                            .toByteArray()
+                    )
+                }
+            }
     }
 
-    return ObservableProperties().apply {
-        load(ClassLoader.getSystemResourceAsStream(DEFAULTS_FILE_NAME) ?: InputStream.nullInputStream())
-        load(preferencesFile.inputStream())
+    CompositionLocalProvider(LocalPreferences provides properties){
+        content()
     }
-}
 
+}
 @Composable
 fun watchFile(file: File): Any? {
     val scope = rememberCoroutineScope()
@@ -72,12 +99,4 @@ fun watchFile(file: File): Any? {
         }
     }
     return event
-}
-val LocalPreferences = compositionLocalOf<Properties> { error("No preferences provided") }
-@Composable
-fun PreferencesProvider(content: @Composable () -> Unit){
-    val preferences = loadPreferences()
-    CompositionLocalProvider(LocalPreferences provides preferences){
-        content()
-    }
 }

app/src/processing/app/contrib/ui/ContributionManager.kt

@@ -22,8 +22,9 @@ import androidx.compose.ui.window.application
 import com.charleskorn.kaml.Yaml
 import com.charleskorn.kaml.YamlConfiguration
 import kotlinx.serialization.Serializable
+import processing.app.LocalPreferences
 import processing.app.Platform
-import processing.app.loadPreferences
+import processing.app.ReactiveProperties
 import java.net.URL
 import java.util.*
 import javax.swing.JFrame
@@ -106,7 +107,7 @@ fun contributionsManager(){
     var localContributions by remember { mutableStateOf(listOf<Contribution>()) }
     var error by remember { mutableStateOf<Exception?>(null) }
 
-    val preferences = loadPreferences()
+    val preferences = LocalPreferences.current
 
     LaunchedEffect(preferences){
         try {
@@ -284,9 +285,9 @@ fun contributionsManager(){
 }
 
 
-fun loadContributionProperties(preferences: Properties): List<Pair<Type, Properties>>{
+fun loadContributionProperties(preferences: ReactiveProperties): List<Pair<Type, Properties>>{
     val result = mutableListOf<Pair<Type, Properties>>()
-    val sketchBook = Path(preferences.getProperty("sketchbook.path.four", Platform.getDefaultSketchbookFolder().path))
+    val sketchBook = Path(preferences.getProperty("sketchbook.path.four") ?: Platform.getDefaultSketchbookFolder().path)
     sketchBook.forEachDirectoryEntry{ contributionsFolder ->
         if(!contributionsFolder.isDirectory()) return@forEachDirectoryEntry
         val typeName = contributionsFolder.fileName.toString()

app/src/processing/app/ui/theme/Theme.kt

@@ -16,7 +16,7 @@ import java.util.Properties
 class Theme(themeFile: String? = "") : Properties() {
     init {
         load(ClassLoader.getSystemResourceAsStream("theme.txt"))
-        load(ClassLoader.getSystemResourceAsStream(themeFile) ?: InputStream.nullInputStream())
+        load(ClassLoader.getSystemResourceAsStream(themeFile ?: "") ?: InputStream.nullInputStream())
     }
     fun getColor(key: String): Color {
         return Color(getProperty(key).toColorInt())