Using specialized VisionChange

README.md

@@ -3,6 +3,8 @@
 
 ![Gradle build](https://github.com/mipt-npm/visionforge/workflows/Gradle%20build/badge.svg)
 
+[![Slack](https://img.shields.io/badge/slack-channel-green?logo=slack)](https://kotlinlang.slack.com/archives/CEXV2QWNM)
+
 # DataForge Visualization Platform
 
 ## Table of Contents

demo/muon-monitor/src/jvmMain/kotlin/ru/mipt/npm/muon/monitor/server/MMServer.kt

@@ -27,9 +27,11 @@ import org.apache.commons.math3.random.JDKRandomGenerator
 import ru.mipt.npm.muon.monitor.Model
 import ru.mipt.npm.muon.monitor.sim.Cos2TrackGenerator
 import ru.mipt.npm.muon.monitor.sim.simulateOne
+import io.ktor.response.respondText
 import java.awt.Desktop
 import java.io.File
 import java.net.URI
+import io.ktor.http.HttpStatusCode
 
 private val generator = Cos2TrackGenerator(JDKRandomGenerator(223))
 
@@ -42,7 +44,7 @@ fun Application.module(context: Context = Global) {
     install(DefaultHeaders)
     install(CallLogging)
     install(ContentNegotiation) {
-        json(solidManager.visionManager.jsonFormat, ContentType.Application.Json)
+        json()
     }
     install(Routing) {
         get("/event") {
@@ -50,7 +52,11 @@ fun Application.module(context: Context = Global) {
             call.respond(event)
         }
         get("/geometry") {
-            call.respond(Model.buildGeometry())
+            call.respondText(
+                solidManager.visionManager.encodeToString(Model.buildGeometry()),
+                contentType = ContentType.Application.Json,
+                status = HttpStatusCode.OK
+            )
         }
         static("/") {
             resources()

visionforge-core/src/commonMain/kotlin/hep/dataforge/vision/Vision.kt

@@ -66,7 +66,7 @@ public interface Vision : Configurable, Described {
     /**
      * Update this vision using external meta. Children are not updated.
      */
-    public fun update(change: Vision)
+    public fun update(change: VisionChange)
 
     override val descriptor: NodeDescriptor?
 

visionforge-core/src/commonMain/kotlin/hep/dataforge/vision/VisionBase.kt

@@ -46,12 +46,13 @@ public open class VisionBase : Vision {
      * The config is initialized and assigned on-demand.
      * To avoid unnecessary allocations, one should access [getAllProperties] via [getProperty] instead.
      */
-    override val config: Config
+    override val config: Config by lazy {
-        get() = properties ?: Config().also { config ->
+        properties ?: Config().also { config ->
             properties = config.also {
                 it.onChange(this) { name, _, _ -> propertyChanged(name) }
             }
         }
+    }
 
     @Transient
     private val listeners = HashSet<PropertyListener>()
@@ -101,9 +102,9 @@ public open class VisionBase : Vision {
         properties = null
     }
 
-    override fun update(change: Vision) {
+    override fun update(change: VisionChange) {
-        if (change.properties != null) {
+        change.propertyChange[Name.EMPTY]?.let {
-            config.update(change.config)
+            config.update(it)
         }
     }
 

visionforge-core/src/commonMain/kotlin/hep/dataforge/vision/VisionChange.kt

@@ -0,0 +1,123 @@
+package hep.dataforge.vision
+
+import hep.dataforge.meta.*
+import hep.dataforge.names.Name
+import hep.dataforge.names.plus
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import kotlinx.serialization.*
+import kotlin.time.Duration
+
+/**
+ * An update for a [Vision] or a [VisionGroup]
+ */
+public class VisionChangeBuilder: VisionContainerBuilder<Vision> {
+    private val propertyChange = HashMap<Name, Config>()
+    private val childrenChange = HashMap<Name, Vision?>()
+
+    public fun isEmpty(): Boolean = propertyChange.isEmpty() && childrenChange.isEmpty()
+
+    public fun propertyChanged(visionName: Name, propertyName: Name, item: MetaItem<*>?) {
+        propertyChange.getOrPut(visionName) { Config() }.setItem(propertyName, item)
+    }
+
+    override fun set(name: Name, child: Vision?) {
+        childrenChange[name] = child
+    }
+
+    /**
+     * Isolate collected changes by creating detached copies of given visions
+     */
+    public fun isolate(manager: VisionManager): VisionChange = VisionChange(
+        propertyChange,
+        childrenChange.mapValues { it.value?.isolate(manager) }
+    )
+}
+
+private fun Vision.isolate(manager: VisionManager): Vision {
+    //TODO replace by efficient deep copy
+    val json = manager.encodeToJsonElement(this)
+    return manager.decodeFromJson(json)
+}
+
+@Serializable
+public data class VisionChange(
+    val propertyChange: Map<Name, @Serializable(MetaSerializer::class) Meta>,
+    val childrenChange: Map<Name, Vision?>) {
+    public fun isEmpty(): Boolean = propertyChange.isEmpty() && childrenChange.isEmpty()
+
+    /**
+     * A shortcut to the top level property dif
+     */
+    public val properties: Meta? get() = propertyChange[Name.EMPTY]
+}
+
+public inline fun VisionChange(manager: VisionManager, block: VisionChangeBuilder.() -> Unit): VisionChange =
+    VisionChangeBuilder().apply(block).isolate(manager)
+
+
+private fun CoroutineScope.collectChange(
+    name: Name,
+    source: Vision,
+    mutex: Mutex,
+    collector: ()->VisionChangeBuilder,
+) {
+    //Collect properties change
+    source.config.onChange(mutex) { propertyName, oldItem, newItem ->
+        if (oldItem != newItem) {
+            launch {
+                mutex.withLock {
+                    collector().propertyChanged(name, propertyName, newItem)
+                }
+            }
+        }
+    }
+
+    if (source is VisionGroup) {
+        //Subscribe for children changes
+        source.children.forEach { (token, child) ->
+            collectChange(name + token, child, mutex, collector)
+        }
+        //TODO update styles?
+
+        //Subscribe for structure change
+        if (source is MutableVisionGroup) {
+            source.onStructureChange(mutex) { token, before, after ->
+                before?.removeChangeListener(mutex)
+                (before as? MutableVisionGroup)?.removeStructureChangeListener(mutex)
+                if (after != null) {
+                    collectChange(name + token, after, mutex, collector)
+                }
+                collector()[name + token] = after
+            }
+        }
+    }
+}
+
+@DFExperimental
+public fun Vision.flowChanges(
+    manager: VisionManager,
+    collectionDuration: Duration,
+    scope: CoroutineScope = manager.context,
+): Flow<VisionChange> = flow {
+    val mutex = Mutex()
+
+    var collector = VisionChangeBuilder()
+    scope.collectChange(Name.EMPTY, this@flowChanges, mutex){collector}
+
+    while (true) {
+        //Wait for changes to accumulate
+        kotlinx.coroutines.delay(collectionDuration)
+        //Propagate updates only if something is changed
+        if (!collector.isEmpty()) {
+            //emit changes
+            emit(collector.isolate(manager))
+            //Reset the collector
+            collector = VisionChangeBuilder()
+        }
+    }
+}

visionforge-core/src/commonMain/kotlin/hep/dataforge/vision/VisionGroupBase.kt

@@ -1,5 +1,6 @@
 package hep.dataforge.vision
 
+import hep.dataforge.meta.configure
 import hep.dataforge.names.*
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
@@ -95,6 +96,9 @@ public open class VisionGroupBase : VisionBase(), MutableVisionGroup {
         attachChild(NameToken("@static", index = child.hashCode().toString()), child)
     }
 
+    /**
+     * Create a vision group of the same type as this vision group. Do not attach it.
+     */
     protected open fun createGroup(): VisionGroupBase = VisionGroupBase()
 
     /**
@@ -158,22 +162,19 @@ public open class VisionGroupBase : VisionBase(), MutableVisionGroup {
         }
     }
 
-    override fun update(change: Vision) {
+    override fun update(change: VisionChange) {
-        if (change is VisionGroup) {
         //update stylesheet
-            val changeStyleSheet = change.styleSheet
+//            val changeStyleSheet = change.styleSheet
-            if (changeStyleSheet != null) {
+//            if (changeStyleSheet != null) {
-                styleSheet {
+//                styleSheet {
-                    update(changeStyleSheet)
+//                    update(changeStyleSheet)
-                }
+//                }
-            }
+//            }
-            change.children.forEach { (token, child) ->
+        change.propertyChange.forEach {(childName,configChange)->
-                when {
+            get(childName)?.configure(configChange)
-                    child is NullVision -> removeChild(token)
-                    children.containsKey(token) -> children[token]!!.update(child)
-                    else -> attachChild(token, child)
-                }
         }
+        change.childrenChange.forEach { (name, child) ->
+            set(name, child)
         }
         super.update(change)
     }

visionforge-core/src/commonMain/kotlin/hep/dataforge/vision/VisionManager.kt

@@ -25,7 +25,7 @@ public class VisionManager(meta: Meta) : AbstractPlugin(meta) {
             }
         }
 
-    private val jsonFormat: Json
+    public val jsonFormat: Json
         get() = Json(defaultJson) {
             serializersModule = this@VisionManager.serializersModule
         }

visionforge-core/src/commonMain/kotlin/hep/dataforge/vision/visionChange.kt

@@ -1,153 +0,0 @@
-package hep.dataforge.vision
-
-import hep.dataforge.meta.*
-import hep.dataforge.meta.descriptors.NodeDescriptor
-import hep.dataforge.names.Name
-import hep.dataforge.names.isEmpty
-import hep.dataforge.names.plus
-import hep.dataforge.vision.VisionManager.Companion.visionSerializer
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.flow
-import kotlinx.coroutines.launch
-import kotlinx.coroutines.sync.Mutex
-import kotlinx.coroutines.sync.withLock
-import kotlinx.serialization.*
-import kotlinx.serialization.descriptors.SerialDescriptor
-import kotlinx.serialization.encoding.Decoder
-import kotlinx.serialization.encoding.Encoder
-import kotlin.time.Duration
-
-
-public abstract class EmptyVision : Vision {
-
-    @Suppress("SetterBackingFieldAssignment", "UNUSED_PARAMETER")
-    override var parent: VisionGroup? = null
-        set(value) {
-            //do nothing
-        }
-
-    override val properties: Config? = null
-
-    override val allProperties: Laminate
-        get() = Laminate(Meta.EMPTY)
-
-    override fun getProperty(name: Name, inherit: Boolean): MetaItem<*>? = null
-
-    override fun propertyChanged(name: Name) {}
-
-    override fun onPropertyChange(owner: Any?, action: (Name) -> Unit) {}
-
-    override fun removeChangeListener(owner: Any?) {}
-
-    override fun update(change: Vision) {
-        error("Null vision should be removed, not updated")
-    }
-
-    override val config: Config get() = Config()
-    override val descriptor: NodeDescriptor? get() = null
-}
-
-/**
- * An empty vision existing only for Vision tree change representation. [NullVision] should not be used outside update logic.
- */
-@Serializable
-@SerialName("vision.null")
-public object NullVision : EmptyVision()
-
-/**
- * Serialization proxy is used to create immutable reference for a given vision
- */
-@Serializable(VisionSerializationProxy.Companion::class)
-private class VisionSerializationProxy(val ref: Vision) : EmptyVision() {
-    companion object : KSerializer<VisionSerializationProxy> {
-        override val descriptor: SerialDescriptor = visionSerializer.descriptor
-
-        @OptIn(ExperimentalSerializationApi::class)
-        override fun serialize(encoder: Encoder, value: VisionSerializationProxy) {
-            val serializer = encoder.serializersModule.getPolymorphic(Vision::class, value.ref)
-                ?: error("The polymorphic serializer is not provided for ")
-            serializer.serialize(encoder, value.ref)
-        }
-
-        override fun deserialize(decoder: Decoder): VisionSerializationProxy =
-            VisionSerializationProxy(visionSerializer.deserialize(decoder))
-    }
-}
-
-
-private fun MutableVisionGroup.getOrCreate(name: Name): Vision {
-    if (name.isEmpty()) return this
-    val existing = get(name)
-    return existing ?: VisionGroupBase().also { set(name, it) }
-}
-
-private fun CoroutineScope.collectChange(
-    name: Name,
-    source: Vision,
-    mutex: Mutex,
-    target: () -> MutableVisionGroup,
-) {
-    //Collect properties change
-    source.config.onChange(mutex){propertyName, oldItem, newItem->
-        if(oldItem!= newItem){
-            launch {
-                mutex.withLock {
-                    target().getOrCreate(name).setProperty(propertyName, newItem)
-                }
-            }
-        }
-    }
-//    source.onPropertyChange(mutex) { propertyName ->
-//        launch {
-//            mutex.withLock {
-//                target().getOrCreate(name).setProperty(propertyName, source.getProperty(propertyName,false))
-//            }
-//        }
-//    }
-
-    val targetVision: Vision =  target().getOrCreate(name)
-
-    if (source is VisionGroup) {
-        check(targetVision is MutableVisionGroup) { "Collector for a group should be a group" }
-        //Subscribe for children changes
-        source.children.forEach { (token, child) ->
-            collectChange(name + token, child, mutex, target)
-        }
-        //TODO update styles?
-
-        //Subscribe for structure change
-        if (source is MutableVisionGroup) {
-            source.onStructureChange(mutex) { token, before, after ->
-                before?.removeChangeListener(mutex)
-                (before as? MutableVisionGroup)?.removeStructureChangeListener(mutex)
-                if (after != null) {
-                    targetVision[token] = VisionSerializationProxy(after)
-                    collectChange(name + token, after, mutex, target)
-                } else {
-                    targetVision[token] = NullVision
-                }
-            }
-        }
-    }
-}
-
-@DFExperimental
-public fun Vision.flowChanges(scope: CoroutineScope, collectionDuration: Duration): Flow<Vision> = flow {
-    val mutex = Mutex()
-
-    var collector = VisionGroupBase()
-    scope.collectChange(Name.EMPTY, this@flowChanges, mutex) { collector }
-
-    while (true) {
-        //Wait for changes to accumulate
-        kotlinx.coroutines.delay(collectionDuration)
-        //Propagate updates only if something is changed
-        if (collector.children.isNotEmpty() || collector.properties?.isEmpty() != false) {
-            //emit changes
-            emit(collector)
-            //Reset the collector
-            collector = VisionGroupBase()
-        }
-    }
-}

visionforge-core/src/jsMain/kotlin/hep/dataforge/vision/client/VisionClient.kt

@@ -3,6 +3,7 @@ package hep.dataforge.vision.client
 import hep.dataforge.context.*
 import hep.dataforge.meta.Meta
 import hep.dataforge.vision.Vision
+import hep.dataforge.vision.VisionChange
 import hep.dataforge.vision.VisionManager
 import hep.dataforge.vision.html.HtmlOutputScope
 import hep.dataforge.vision.html.HtmlOutputScope.Companion.OUTPUT_ENDPOINT_ATTRIBUTE
@@ -36,7 +37,8 @@ public class VisionClient : AbstractPlugin() {
 
     private fun getRenderers() = context.gather<ElementVisionRenderer>(ElementVisionRenderer.TYPE).values
 
-    public fun findRendererFor(vision: Vision): ElementVisionRenderer? = getRenderers().maxByOrNull { it.rateVision(vision) }
+    public fun findRendererFor(vision: Vision): ElementVisionRenderer? =
+        getRenderers().maxByOrNull { it.rateVision(vision) }
 
     /**
      * Fetch from server and render a vision, described in a given with [HtmlOutputScope.OUTPUT_CLASS] class.
@@ -71,8 +73,10 @@ public class VisionClient : AbstractPlugin() {
                             onmessage = { messageEvent ->
                                 val stringData: String? = messageEvent.data as? String
                                 if (stringData != null) {
-                                    val update = visionManager.decodeFromString(text)
+//                                    console.info("Received WS update: $stringData")
-                                    vision.update(update)
+                                    val dif = visionManager.jsonFormat
+                                        .decodeFromString(VisionChange.serializer(), stringData)
+                                    vision.update(dif)
                                 } else {
                                     console.error("WebSocket message data is not a string")
                                 }
@@ -121,7 +125,7 @@ public fun VisionClient.fetchVisionsInChildren(element: Element, requestUpdates:
 /**
  * Fetch visions from the server for all elements with [HtmlOutputScope.OUTPUT_CLASS] class in the document body
  */
-public fun VisionClient.fetchAndRenderAllVisions(requestUpdates: Boolean = true){
+public fun VisionClient.fetchAndRenderAllVisions(requestUpdates: Boolean = true) {
     val element = document.body ?: error("Document does not have a body")
     fetchVisionsInChildren(element, requestUpdates)
 }

visionforge-server/src/main/kotlin/hep/dataforge/vision/server/VisionServer.kt

@@ -8,6 +8,7 @@ import hep.dataforge.meta.long
 import hep.dataforge.names.Name
 import hep.dataforge.names.toName
 import hep.dataforge.vision.Vision
+import hep.dataforge.vision.VisionChange
 import hep.dataforge.vision.VisionManager
 import hep.dataforge.vision.flowChanges
 import hep.dataforge.vision.html.*
@@ -126,8 +127,8 @@ public class VisionServer internal constructor(
                         application.log.debug("Opened server socket for $name")
                         val vision: Vision = visions[name.toName()] ?: error("Plot with id='$name' not registered")
                         try {
-                            vision.flowChanges(this, updateInterval.milliseconds).collect { update ->
+                            vision.flowChanges(visionManager, updateInterval.milliseconds).collect { update ->
-                                val json = visionManager.encodeToString(update)
+                                val json = VisionManager.defaultJson.encodeToString(VisionChange.serializer(), update)
                                 outgoing.send(Frame.Text(json))
                             }
                         } catch (ex: Throwable) {
@@ -197,10 +198,11 @@ public fun Application.visionModule(context: Context, route: String = DEFAULT_PA
         }
     }
 
-    if(featureOrNull(CallLogging) == null){
+    if (featureOrNull(CallLogging) == null) {
         install(CallLogging)
     }
 
+    val visionManager = context.plugins.fetch(VisionManager)
 
     routing {
         route(route) {
@@ -210,8 +212,6 @@ public fun Application.visionModule(context: Context, route: String = DEFAULT_PA
         }
     }
 
-    val visionManager = context.plugins.fetch(VisionManager)
-
     return VisionServer(visionManager, this, route)
 }
 

visionforge-solid/src/commonMain/kotlin/hep/dataforge/vision/solid/Composite.kt

@@ -33,7 +33,7 @@ public class Composite(
         get() = null
 }
 
-public inline fun MutableVisionGroup.composite(
+public inline fun VisionContainerBuilder<Solid>.composite(
     type: CompositeType,
     name: String = "",
     builder: SolidGroup.() -> Unit
@@ -58,11 +58,11 @@ public inline fun MutableVisionGroup.composite(
     }
 }
 
-public inline fun MutableVisionGroup.union(name: String = "", builder: SolidGroup.() -> Unit): Composite =
+public inline fun VisionContainerBuilder<Solid>.union(name: String = "", builder: SolidGroup.() -> Unit): Composite =
     composite(CompositeType.UNION, name, builder = builder)
 
-public inline fun MutableVisionGroup.subtract(name: String = "", builder: SolidGroup.() -> Unit): Composite =
+public inline fun VisionContainerBuilder<Solid>.subtract(name: String = "", builder: SolidGroup.() -> Unit): Composite =
     composite(CompositeType.SUBTRACT, name, builder = builder)
 
-public inline fun MutableVisionGroup.intersect(name: String = "", builder: SolidGroup.() -> Unit): Composite =
+public inline fun VisionContainerBuilder<Solid>.intersect(name: String = "", builder: SolidGroup.() -> Unit): Composite =
     composite(CompositeType.INTERSECT, name, builder = builder)

visionforge-solid/src/commonMain/kotlin/hep/dataforge/vision/solid/SolidBase.kt

@@ -5,8 +5,8 @@ import hep.dataforge.meta.descriptors.NodeDescriptor
 import hep.dataforge.meta.float
 import hep.dataforge.meta.get
 import hep.dataforge.meta.node
-import hep.dataforge.vision.Vision
 import hep.dataforge.vision.VisionBase
+import hep.dataforge.vision.VisionChange
 import kotlinx.serialization.SerialName
 import kotlinx.serialization.Serializable
 
@@ -21,16 +21,20 @@ public open class SolidBase : VisionBase(), Solid {
 
     override var scale: Point3D? = null
 
-    override fun update(change: Vision) {
+    override fun update(change: VisionChange) {
-        fun Meta.toVector(default: Float = 0f) = Point3D(
+        updatePosition(change.properties)
-            this[Solid.X_KEY].float ?: default,
-            this[Solid.Y_KEY].float ?: default,
-            this[Solid.Z_KEY].float ?: default
-        )
-
-        change.properties[Solid.POSITION_KEY].node?.toVector()?.let { position = it }
-        change.properties[Solid.ROTATION].node?.toVector()?.let { rotation = it }
-        change.properties[Solid.SCALE_KEY].node?.toVector(1f)?.let { scale = it }
         super.update(change)
     }
 }
+
+internal fun Meta.toVector(default: Float = 0f) = Point3D(
+    this[Solid.X_KEY].float ?: default,
+    this[Solid.Y_KEY].float ?: default,
+    this[Solid.Z_KEY].float ?: default
+)
+
+internal fun Solid.updatePosition(meta: Meta?) {
+    meta[Solid.POSITION_KEY].node?.toVector()?.let { position = it }
+    meta[Solid.ROTATION].node?.toVector()?.let { rotation = it }
+    meta[Solid.SCALE_KEY].node?.toVector(1f)?.let { scale = it }
+}

visionforge-solid/src/commonMain/kotlin/hep/dataforge/vision/solid/SolidGroup.kt

@@ -38,7 +38,7 @@ public class SolidGroup : VisionGroupBase(), Solid, PrototypeHolder {
     /**
      * Create or edit prototype node as a group
      */
-    public fun prototypes(builder: MutableVisionGroup.() -> Unit): Unit {
+    public fun prototypes(builder: VisionContainerBuilder<Solid>.() -> Unit): Unit {
         (prototypes ?: Prototypes().also {
             prototypes = it
             it.parent = this
@@ -65,6 +65,10 @@ public class SolidGroup : VisionGroupBase(), Solid, PrototypeHolder {
 
     override fun createGroup(): SolidGroup = SolidGroup()
 
+    override fun update(change: VisionChange) {
+        updatePosition(change.properties)
+        super.update(change)
+    }
 
     public companion object {
 //        val PROTOTYPES_KEY = NameToken("@prototypes")
@@ -82,13 +86,13 @@ public fun SolidGroup(block: SolidGroup.() -> Unit): SolidGroup {
 public tailrec fun PrototypeHolder.getPrototype(name: Name): Solid? =
     prototypes?.get(name) as? Solid ?: (parent as? PrototypeHolder)?.getPrototype(name)
 
-public fun MutableVisionGroup.group(name: Name = Name.EMPTY, action: SolidGroup.() -> Unit = {}): SolidGroup =
+public fun VisionContainerBuilder<Vision>.group(name: Name = Name.EMPTY, action: SolidGroup.() -> Unit = {}): SolidGroup =
     SolidGroup().apply(action).also { set(name, it) }
 
 /**
  * Define a group with given [name], attach it to this parent and return it.
  */
-public fun MutableVisionGroup.group(name: String, action: SolidGroup.() -> Unit = {}): SolidGroup =
+public fun VisionContainerBuilder<Vision>.group(name: String, action: SolidGroup.() -> Unit = {}): SolidGroup =
     SolidGroup().apply(action).also { set(name, it) }
 
 /**

visionforge-solid/src/commonTest/kotlin/hep/dataforge/vision/solid/VisionUpdateTest.kt

@@ -0,0 +1,74 @@
+package hep.dataforge.vision.solid
+
+import hep.dataforge.context.Global
+import hep.dataforge.meta.MetaItem
+import hep.dataforge.names.toName
+import hep.dataforge.vision.VisionChange
+import hep.dataforge.vision.get
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+class VisionUpdateTest {
+    val solidManager = Global.plugins.fetch(SolidManager)
+    val visionManager = solidManager.visionManager
+
+    @Test
+    fun testVisionUpdate(){
+        val targetVision = SolidGroup {
+            box(200,200,200, name = "origin")
+        }
+        val dif = VisionChange(visionManager){
+            group("top") {
+                color(123)
+                box(100,100,100)
+            }
+            propertyChanged("top".toName(), SolidMaterial.MATERIAL_COLOR_KEY, MetaItem.of("red"))
+            propertyChanged("origin".toName(), SolidMaterial.MATERIAL_COLOR_KEY, MetaItem.of("red"))
+        }
+        targetVision.update(dif)
+        assertTrue { targetVision["top"] is SolidGroup }
+        assertEquals("red", (targetVision["origin"] as Solid).color) // Should work
+        assertEquals("#00007b", (targetVision["top"] as SolidGroup).color) // new item always takes precedence
+    }
+
+    @Test
+    fun testVisionChangeSerialization(){
+        val change = VisionChange(visionManager){
+            group("top") {
+                color(123)
+                box(100,100,100)
+            }
+            propertyChanged("top".toName(), SolidMaterial.MATERIAL_COLOR_KEY, MetaItem.of("red"))
+            propertyChanged("origin".toName(), SolidMaterial.MATERIAL_COLOR_KEY, MetaItem.of("red"))
+        }
+        val serialized = visionManager.jsonFormat.encodeToString(VisionChange.serializer(), change)
+        println(serialized)
+        val reconstructed = visionManager.jsonFormat.decodeFromString(VisionChange.serializer(), serialized)
+        assertEquals(change.propertyChange,reconstructed.propertyChange)
+    }
+
+    @Test
+    fun testDeserialization(){
+        val str = """
+            {
+                "propertyChange": {
+                    "layer[4]": {
+                        "material": {
+                            "color": 123
+                        }
+                    },
+                    "layer[2]": {
+                        "material": {
+                        }
+                    }
+                },
+                "childrenChange": {
+                }
+            }
+        """.trimIndent()
+
+        val reconstructed = visionManager.jsonFormat.decodeFromString(VisionChange.serializer(), str)
+    }
+
+}