[Editor] Improve Parameter<T> binding to backing properties

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/common/parameter/model/Parameter.kt

@@ -12,17 +12,31 @@ abstract class Parameter<T>(
    private val autocommit: Boolean = false,
    private val onCommit: (oldValue: T, newValue: T, submit: () -> Unit) -> Unit = { _, _, submit -> submit() }
 ) {
+   private var other: Property<T>? = null
+
    val keyProperty = ReadOnlyStringWrapper(key)
+
    val key by keyProperty
-
    val editableProperty: BooleanProperty = SimpleBooleanProperty(editable)
-   var editable by editableProperty
 
+   var editable by editableProperty
    val valueProperty: ObjectProperty<T> = SimpleObjectProperty(initialValue)
+
    var value by valueProperty
 
    fun commit() = onCommit(value, editorValueProperty.value, if (autocommit) NOOP else this::submit)
 
+   fun bindBidirectional(other: Property<T>) {
+      unbindBidirectional()
+      this.value = other.value
+      this.other = other.apply { bindBidirectional(valueProperty) }
+   }
+
+   fun unbindBidirectional() {
+      this.other?.unbindBidirectional(valueProperty)
+      this.other = null
+   }
+
    private fun submit() {
       value = editorValueProperty.value
    }
@@ -30,7 +44,17 @@ abstract class Parameter<T>(
    protected fun init() {
       if (autocommit) {
          editorValueProperty.bindBidirectional(valueProperty)
-         valueProperty.addListener { _, oldValue, newValue -> onCommit(oldValue, newValue, NOOP) }
+         valueProperty.addListener { _, oldValue, newValue ->
+
+            // Disclaimer:
+            // This ugly hack enforces the onCommit() listener to be fired, when
+            // `other` Property has been updated with current value.
+            // Without that hack, even if `other` is bidirectionally bound to `valueProperty`,
+            // it is updated right after the onCommit() listener, which is not very useful.
+            other?.value = newValue
+
+            onCommit(oldValue, newValue, NOOP)
+         }
       } else {
          editorValueProperty.value = value
          valueProperty.addListener { _, _, v -> editorValueProperty.value = v }

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/map/parameter/layer/ColorLayerParametersBinder.kt

@@ -9,10 +9,6 @@ import org.springframework.stereotype.Component
 
 @Component
 class ColorLayerParametersBinder : LayerParametersBinder<ColorLayer> {
-   private var red: IntegerParameter? = null
-   private var green: IntegerParameter? = null
-   private var blue: IntegerParameter? = null
-   private var alpha: IntegerParameter? = null
 
    override fun bind(
       layer: ColorLayer,
@@ -21,24 +17,15 @@ class ColorLayerParametersBinder : LayerParametersBinder<ColorLayer> {
       onCommit: () -> Unit
    ) {
       val red = IntegerParameter("red", 100, 0, 100, autocommit = true) { _, _, _ -> onCommit() }
-         .apply { valueProperty.bindBidirectional(layer.redProperty) }
-
       val green = IntegerParameter("green", 100, 0, 100, autocommit = true) { _, _, _ -> onCommit() }
-         .apply { valueProperty.bindBidirectional(layer.greenProperty) }
-
       val blue = IntegerParameter("blue", 100, 0, 100, autocommit = true) { _, _, _ -> onCommit() }
-         .apply { valueProperty.bindBidirectional(layer.blueProperty) }
-
       val alpha = IntegerParameter("alpha", 100, 0, 100, autocommit = true) { _, _, _ -> onCommit() }
-         .apply { valueProperty.bindBidirectional(layer.alphaProperty) }
+
+      red.bindBidirectional(layer.redProperty)
+      green.bindBidirectional(layer.greenProperty)
+      blue.bindBidirectional(layer.blueProperty)
+      alpha.bindBidirectional(layer.alphaProperty)
 
       parameters.addAll(red, green, blue, alpha)
    }
-
-   override fun unbind(layer: ColorLayer, parameters: ObservableList<Parameter<*>>) {
-      red?.valueProperty?.unbindBidirectional(layer.redProperty)
-      green?.valueProperty?.unbindBidirectional(layer.greenProperty)
-      blue?.valueProperty?.unbindBidirectional(layer.blueProperty)
-      alpha?.valueProperty?.unbindBidirectional(layer.alphaProperty)
-   }
 }

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/map/parameter/layer/ImageLayerParametersBinder.kt

@@ -3,7 +3,6 @@ package com.bartlomiejpluta.base.editor.map.parameter.layer
 import com.bartlomiejpluta.base.editor.common.parameter.model.GraphicAssetParameter
 import com.bartlomiejpluta.base.editor.common.parameter.model.IntegerParameter
 import com.bartlomiejpluta.base.editor.common.parameter.model.Parameter
-import com.bartlomiejpluta.base.editor.image.asset.ImageAsset
 import com.bartlomiejpluta.base.editor.map.model.layer.ImageLayer
 import com.bartlomiejpluta.base.editor.project.model.Project
 import javafx.collections.ObservableList
@@ -11,8 +10,6 @@ import org.springframework.stereotype.Component
 
 @Component
 class ImageLayerParametersBinder : LayerParametersBinder<ImageLayer> {
-   private var image: GraphicAssetParameter<ImageAsset>? = null
-   private var opacity: IntegerParameter? = null
 
    override fun bind(
       layer: ImageLayer,
@@ -20,20 +17,18 @@ class ImageLayerParametersBinder : LayerParametersBinder<ImageLayer> {
       project: Project,
       onCommit: () -> Unit
    ) {
-      image = GraphicAssetParameter("image", layer.imageAsset, true, project.images) { _, _, submit ->
+      val image = GraphicAssetParameter("image", layer.imageAsset, true, project.images) { _, _, submit ->
          onCommit()
          submit()
-      }.apply { valueProperty.bindBidirectional(layer.imageAssetProperty) }
+      }
 
-      opacity = IntegerParameter("opacity", 100, 0, 100, autocommit = true) { _, _, _ ->
+      val opacity = IntegerParameter("opacity", 100, 0, 100, autocommit = true) { _, _, _ ->
          onCommit()
-      }.apply { valueProperty.bindBidirectional(layer.opacityProperty) }
+      }
+
+      image.bindBidirectional(layer.imageAssetProperty)
+      opacity.bindBidirectional(layer.opacityProperty)
 
       parameters.addAll(image, opacity)
    }
-
-   override fun unbind(layer: ImageLayer, parameters: ObservableList<Parameter<*>>) {
-      image?.valueProperty?.unbindBidirectional(layer.imageAssetProperty)
-      opacity?.valueProperty?.unbindBidirectional(layer.opacityProperty)
-   }
 }

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/map/parameter/layer/LayerParametersBinder.kt

@@ -7,5 +7,4 @@ import javafx.collections.ObservableList
 
 interface LayerParametersBinder<T : Layer> {
    fun bind(layer: T, parameters: ObservableList<Parameter<*>>, project: Project, onCommit: () -> Unit)
-   fun unbind(layer: T, parameters: ObservableList<Parameter<*>>)
 }

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/map/view/editor/MapLayerParameters.kt

@@ -24,17 +24,21 @@ class MapLayerParameters : View() {
    private val parameters = observableListOf<Parameter<*>>()
 
    init {
-      editorStateVM.selectedLayerProperty.addListener { _, previousLayer, layer ->
+      editorStateVM.selectedLayerProperty.addListener { _, _, layer ->
-         when (previousLayer) {
+         parameters.forEach(Parameter<*>::unbindBidirectional)
-            is ColorLayer -> colorLayerParametersBinder.unbind(previousLayer, parameters)
-            is ImageLayer -> imageLayerParametersBinder.unbind(previousLayer, parameters)
-         }
-
          parameters.clear()
 
          when (layer) {
-            is ColorLayer -> colorLayerParametersBinder.bind(layer, parameters, projectContext.project!!) { fire(RedrawMapRequestEvent) }
+            is ColorLayer -> colorLayerParametersBinder.bind(layer, parameters, projectContext.project!!) {
-            is ImageLayer -> imageLayerParametersBinder.bind(layer, parameters, projectContext.project!!) { fire(RedrawMapRequestEvent) }
+               fire(
+                  RedrawMapRequestEvent
+               )
+            }
+            is ImageLayer -> imageLayerParametersBinder.bind(layer, parameters, projectContext.project!!) {
+               fire(
+                  RedrawMapRequestEvent
+               )
+            }
          }
       }
    }