[orx-parameters, orx-property-watchers, orx-file-watcher, orx-gui] Add @PathParameter, file watcher delegates and property delegates

orx-jvm/orx-file-watcher/src/main/kotlin/FileWatcherDelegate.kt

@@ -0,0 +1,38 @@
+import kotlinx.coroutines.yield
+import org.openrndr.Program
+import org.openrndr.events.Event
+import org.openrndr.extra.filewatcher.watchFile
+import org.openrndr.launch
+import java.io.File
+import kotlin.reflect.KProperty
+
+class FileWatcherDelegate<T>(
+    program: Program,
+    file: File,
+    valueChangedEvent: Event<T>? = null,
+    requestStopEvent: Event<Unit>? = null,
+    transducer: (File) -> T
+) {
+    val watchValue = watchFile(file, valueChangedEvent, requestStopEvent, transducer)
+    var value = watchValue()
+
+    init {
+        program.launch {
+            while (true) {
+                value = watchValue()
+                yield()
+            }
+        }
+    }
+
+    operator fun getValue(any: Any, property: KProperty<*>): T {
+        return value
+    }
+}
+
+fun <R> Program.watchingFile(
+    file: File,
+    valueChangedEvent: Event<R>? = null,
+    requestStopEvent: Event<Unit>? = null,
+    transducer: (File) -> R
+) = FileWatcherDelegate(this, file, valueChangedEvent, requestStopEvent, transducer)