add STUDIO_MODE_TOGGLE, SCENE_PREV, and SCENE_NEXT

src/main/kotlin/net/eksb/obsdc/Op.kt

@@ -3,6 +3,12 @@ package net.eksb.obsdc
 enum class Op {
 	/** If in studio mode, transition between scenes. */
 	STUDIO_TRANSITION,
+	/** Enable/disable studio mode. */
+	STUDIO_MODE_TOGGLE,
+	/** Activate the previous scene. */
+	SCENE_PREV,
+	/** Activate the next scene. */
+	SCENE_NEXT,
 	/** Activate the first scene. */
 	SCENE_1,
 	/** Activate the second scene. */

src/main/kotlin/net/eksb/obsdc/OpRunner.kt

@@ -20,17 +20,43 @@ class OpRunner(private val obs:Obs) {
 
 	private val controller = obs.controller
 
+	/**
+	 * Run the specified [Op].
+	 */
 	fun run(op:Op) {
 		obs.submit { controller ->
 			when(op) {
-				Op.SCENE_1 -> scene { scenes -> scenes.firstOrNull() }
+				Op.SCENE_NEXT -> scene { scenes, current ->
-				Op.SCENE_2 -> scene { scenes -> scenes.asSequence().drop(1).firstOrNull() }
+					if (current != null) {
-				Op.SCENE_3 -> scene { scenes -> scenes.asSequence().drop(2).firstOrNull() }
+						scenes.asSequence()
+							.dropWhile { scene -> scene != current }
+							.drop(1)
+							.firstOrNull()
+							?: scenes.firstOrNull()
+					} else {
+						null
+					}
+				}
+				Op.SCENE_PREV -> scene { scenes, current ->
+					if (current != null) {
+						scenes.reversed().asSequence()
+							.dropWhile { scene -> scene != current }
+							.drop(1)
+							.firstOrNull()
+							?: scenes.lastOrNull()
+					} else {
+						null
+					}
+				}
+				Op.SCENE_1 -> scene { scenes, current -> scenes.firstOrNull() }
+				Op.SCENE_2 -> scene { scenes, current -> scenes.asSequence().drop(1).firstOrNull() }
+				Op.SCENE_3 -> scene { scenes, current -> scenes.asSequence().drop(2).firstOrNull() }
 				Op.STUDIO_TRANSITION -> {
 					controller.triggerStudioModeTransition { response ->
 						log.debug("studio transitioned: ${response.isSuccessful}")
 					}
 				}
+				Op.STUDIO_MODE_TOGGLE -> studioModeToggle()
 				Op.PAN_UP -> transform { old -> positionY(old.positionY - panAmount ) }
 				Op.PAN_DOWN -> transform { old -> positionY(old.positionY + panAmount ) }
 				Op.PAN_LEFT -> transform { old -> positionX(old.positionX - panAmount ) }
@@ -39,13 +65,32 @@ class OpRunner(private val obs:Obs) {
 		}
 	}
 
+	private fun studioModeToggle() {
+		controller.getStudioModeEnabled { response ->
+			if (response.isSuccessful) {
+				val enable = !response.studioModeEnabled
+				log.debug("toggle studio mode: ${!enable}")
+				controller.setStudioModeEnabled(enable) { response ->
+					log.debug("toggled studio mode: ${enable}")
+				}
+			}
+		}
+	}
+
 	/**
 	 * Select a scene from the scene list with the supplied [selector] and set the selected scene (if any)
 	 * as the current program scene.
+	 *
+	 * @param selector Lambda that takes as arguments the list of scenes and the current scene (or null if the current
+	 * scene is unknown), and returns the scene to select, or null to not change the scene.
 	 */
-	private fun scene(selector:(List<Scene>)->Scene?) {
+	private fun scene(selector:(List<Scene>,Scene?)->Scene?) {
+		controller.getCurrentProgramScene { response ->
+			val currentSceneName = response.currentProgramSceneName
 			controller.getSceneList { response ->
-			val scene = selector(response.scenes.sortedBy(Scene::getSceneIndex).reversed())
+				val scenes = response.scenes.sortedBy(Scene::getSceneIndex).reversed()
+				val currentScene = scenes.find { scene -> scene.sceneName == currentSceneName }
+				val scene = selector(response.scenes.sortedBy(Scene::getSceneIndex).reversed(), currentScene)
 				log.debug("select scene ${scene?.sceneName} index:${scene?.sceneIndex}")
 				if (scene != null) {
 					controller.setCurrentProgramScene(scene.sceneName) { response ->
@@ -54,6 +99,7 @@ class OpRunner(private val obs:Obs) {
 				}
 			}
 		}
+	}
 
 	/**
 	 * Generate a transform for the lowest non-locked item in the current program scene with the