Add OliveProgram scriptless replacement

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

@@ -0,0 +1,43 @@
+package org.openrndr.extra.olive
+
+import org.openrndr.ApplicationBuilder
+import org.openrndr.Program
+import java.io.File
+import java.nio.file.Files
+import java.nio.file.Paths
+import kotlin.streams.toList
+
+open class OliveProgram(private val sourceLocation: String) : Program() {
+    val olive = extend(Olive<OliveProgram>(scriptMode = ScriptMode.OLIVE_PROGRAM)) {
+        script = sourceLocation
+    }
+}
+
+fun stackRootClassName(thread: Thread = Thread.currentThread(), sanitize: Boolean = true): String {
+    val root = Thread.currentThread().stackTrace.last()
+    val rootClass = root.className
+    return if (sanitize) rootClass.replace(Regex("Kt$"), "") else rootClass
+}
+
+fun ApplicationBuilder.oliveProgram(init: OliveProgram.() -> Unit): OliveProgram {
+    val rootClassName = stackRootClassName(sanitize = true)
+
+    var sourceLocation = "src/main/kotlin/$rootClassName.kt"
+    val candidateFile = File(sourceLocation)
+    if (!candidateFile.exists()) {
+        val otherCandidates = Files.walk(Paths.get("."))
+                .filter { Files.isRegularFile(it) && it.toString().endsWith("$rootClassName.kt") }.toList()
+        if (otherCandidates.size == 1) {
+            sourceLocation = otherCandidates.first().toString()
+        } else {
+            error("multiple source candidates found: $otherCandidates")
+        }
+    }
+    program = object : OliveProgram(sourceLocation) {
+        override fun setup() {
+            super.setup()
+            init()
+        }
+    }
+    return program as OliveProgram
+}