implemented redo (to be tested)

composeApp/src/commonMain/kotlin/ui/EditClusterScreen.kt

@@ -104,6 +104,9 @@ fun EditClusterTopBar(
             IconButton(onClick = viewModel::undo) {
                 Icon(painterResource("icons/undo.xml"), contentDescription = "Undo")
             }
+            IconButton(onClick = viewModel::redo) {
+                Icon(painterResource("icons/redo.xml"), contentDescription = "Redo")
+            }
 //            IconButton(onClick = viewModel::cancelAndGoBack) {
 //                Icon(Icons.Default.Close, contentDescription = "Cancel")
 //            }

composeApp/src/commonMain/kotlin/ui/EditClusterViewModel.kt

@@ -49,11 +49,13 @@ class EditClusterViewModel(
     val handleIsDown = mutableStateOf(false)
     val grabbedCircleIx = mutableStateOf<Int?>(null)
 
+    // tagged & grouped gap buffer
     private val commands = ArrayDeque<Command>(HISTORY_SIZE)
+    private val redoCommands = ArrayDeque<Command>(HISTORY_SIZE)
     // we group history by commands and record it only when the new command differs from the previous one
     // NOTE: history doesn't survive background app kill
-    // TODO: redo stack
     private val history = ArrayDeque<UiState>(HISTORY_SIZE)
+    private val redoHistory = ArrayDeque<UiState>(HISTORY_SIZE)
 
     private val _decayingCircles = MutableSharedFlow<DecayingCircles>()
     val decayingCircles = _decayingCircles.asSharedFlow()
@@ -94,14 +96,32 @@ class EditClusterViewModel(
     fun undo() {
         if (history.size > 1) {
             val previousState = history.removeLast()
+            val previousCommand = commands.removeLast()
             selection.clear()
             parts.clear()
             circles.clear()
             circles.addAll(previousState.circles)
             parts.addAll(previousState.parts)
             switchSelectionMode(previousState.selectionMode)
             selection.addAll(previousState.selection)
-            commands.removeLast()
+            redoCommands.addFirst(previousCommand)
+            redoHistory.addFirst(previousState)
+        }
+    }
+
+    fun redo() {
+        if (redoHistory.isNotEmpty()) {
+            val nextState = redoHistory.removeFirst()
+            val nextCommand = redoCommands.removeFirst()
+            selection.clear()
+            parts.clear()
+            circles.clear()
+            circles.addAll(nextState.circles)
+            parts.addAll(nextState.parts)
+            switchSelectionMode(nextState.selectionMode)
+            selection.addAll(nextState.selection)
+            commands.addLast(nextCommand)
+            history.addLast(nextState)
         }
     }
 
@@ -111,9 +131,11 @@ class EditClusterViewModel(
                 history.removeFirst()
                 commands.removeFirst()
             }
-            history.add(UiState.save(this))
-            commands.add(command)
+            history.addLast(UiState.save(this))
+            commands.addLast(command)
         }
+        redoCommands.clear()
+        redoHistory.clear()
     }
 
     suspend fun createNewCircle() {
@@ -198,11 +220,11 @@ class EditClusterViewModel(
                 selection.clear()
         } else if (selectionMode.value == SelectionMode.SelectRegion && newMode == SelectionMode.SelectRegion) {
             if (parts.isEmpty()) {
-                recordCommand(Command.SELECT_PART)
+//                recordCommand(Command.SELECT_PART)
                 // select interlacing, todo: proper 2^n -> even # of 1's -> {0101001} -> parts
                 parts.add(Cluster.Part(emptySet(), circles.indices.toSet()))
             } else {
-                recordCommand(Command.SELECT_PART)
+//                recordCommand(Command.SELECT_PART)
                 parts.clear()
             }
         }

composeApp/src/wasmJsMain/kotlin/data/io/OpenFile.wasmJs.kt

@@ -36,7 +36,8 @@ actual fun OpenFileButton(
 fun queryFile(callback: (file: File?) -> Unit) {
     val input = document.createElement("input") as HTMLInputElement
     input.type = "file"
-    input.accept = "text/plain"
+//    input.accept = "text/plain" // doesnt detect custom formats
+//    input.accept = "*/*"
     input.onchange = { event ->
         val file = input.files?.get(0)
 //        val file = extractFileFromEvent(event)

composeApp/src/wasmJsMain/kotlin/data/io/SaveFile.wasmJs.kt

@@ -37,6 +37,8 @@ actual fun SaveFileButton(
     }
 }
 
+// showSaveFilePicker() is still experimental, cmon js bros...
+
 // global js function
 external fun encodeURIComponent(str: String): String
 

gradle/libs.versions.toml

@@ -14,6 +14,7 @@ kotlinx-serialization = "1.6.2"
 compose = "1.5.4"
 compose-compiler = "1.5.6"
 compose-plugin = "1.6.0-alpha01"
+material3 = "1.1.2"
 junit = "4.13.2"
 #noinspection GradleDependency
 kotlin = "1.9.21"
@@ -34,6 +35,8 @@ compose-ui-tooling = { module = "androidx.compose.ui:ui-tooling", version.ref =
 compose-ui-tooling-preview = { module = "androidx.compose.ui:ui-tooling-preview", version.ref = "compose" }
 compose-foundation = { module = "androidx.compose.foundation:foundation", version.ref = "compose" }
 compose-material = { module = "androidx.compose.material:material", version.ref = "compose" }
+compose-material3 = { module = "androidx.compose.material3:material3", version.ref = "material3" }
+compose-material3-window-size-klass = { module = "androidx.compose.material3:material3-window-size-class", version.ref = "material3" }
 kotlinx-serialization-json = { module = "org.jetbrains.kotlinx:kotlinx-serialization-json", version.ref = "kotlinx-serialization"}
 
 [plugins]