Add Olive.reload and Reloadable class for reloadable state

orx-olive/src/main/kotlin/Reloadable.kt

@@ -0,0 +1,37 @@
+package org.openrndr.extra.olive
+
+import kotlin.reflect.KMutableProperty1
+import kotlin.reflect.KProperty1
+import kotlin.reflect.full.declaredMemberProperties
+import kotlin.reflect.jvm.jvmName
+
+private val store = mutableMapOf<String, Any>()
+
+/**
+ * A class with which persistent state can be reloaded from inside Olive scripts.
+ */
+open class Reloadable {
+    /**
+     * reload property values from store
+     */
+    @Suppress("UNCHECKED_CAST")
+    fun reload() {
+        val existing = store[this::class.jvmName]
+        if (existing != null) {
+            for (p in this::class.declaredMemberProperties) {
+                val e = existing::class.declaredMemberProperties.find { it.name == p.name }
+                if (e != null) {
+                    try {
+                        val value = (e as KProperty1<Any, Any?>).get(existing)
+                        val mp = (p as KMutableProperty1<Any, Any?>)
+                        mp.set(this, value as Any)
+                        println("reloaded property ${p.name} <- ${value}")
+                    } catch (e: Throwable) {
+                        println("error while reloading property ${p.name}: ${e.message}")
+                    }
+                }
+            }
+        }
+        store[this::class.jvmName] = this
+    }
+}