Component based UI system

indigo/indigo-extras/src/main/scala/indigoextras/ui/component/Component.scala

@@ -0,0 +1,56 @@
+package indigoextras.ui.component
+
+import indigo.*
+import indigoextras.ui.datatypes.Bounds
+import indigoextras.ui.datatypes.Dimensions
+import indigoextras.ui.datatypes.UIContext
+
+/** A typeclass that confirms that some type `A` can be used as a `Component` provides the necessary operations for that
+  * type to act as a component.
+  */
+trait Component[A, ReferenceData]:
+
+  /** The position and size of the component
+    */
+  def bounds(reference: ReferenceData, model: A): Bounds
+
+  /** Update this componenets model.
+    */
+  def updateModel(
+      context: UIContext[ReferenceData],
+      model: A
+  ): GlobalEvent => Outcome[A]
+
+  /** Produce a renderable output for this component, based on the component's model.
+    */
+  def present(
+      context: UIContext[ReferenceData],
+      model: A
+  ): Outcome[Layer]
+
+  /** Used internally to instruct the component that the layout has changed in some way, and that it should
+    * reflow/refresh it's contents - whatever that means in the context of this component type.
+    */
+  def refresh(reference: ReferenceData, model: A, parentDimensions: Dimensions): A
+
+object Component:
+
+  given [ReferenceData]: Component[Unit, ReferenceData] =
+    new Component[Unit, ReferenceData]:
+      def bounds(reference: ReferenceData, model: Unit): Bounds =
+        Bounds.zero
+
+      def updateModel(
+          context: UIContext[ReferenceData],
+          model: Unit
+      ): GlobalEvent => Outcome[Unit] =
+        _ => Outcome(model)
+
+      def present(
+          context: UIContext[ReferenceData],
+          model: Unit
+      ): Outcome[Layer] =
+        Outcome(Layer.empty)
+
+      def refresh(reference: ReferenceData, model: Unit, parentDimensions: Dimensions): Unit =
+        ()