Requests: Add AddSceneItem

New request `AddSceneItem` which allows you to add a
source to a scene. Returns an itemId which can be used
to manipulate the item further if necessary.

src/WSRequestHandler.cpp

@@ -60,6 +60,7 @@ const QHash<QString, RpcMethodHandler> WSRequestHandler::messageMap {
 	{ "SetSceneItemProperties", &WSRequestHandler::SetSceneItemProperties },
 	{ "ResetSceneItem", &WSRequestHandler::ResetSceneItem },
 	{ "DeleteSceneItem", &WSRequestHandler::DeleteSceneItem },
+	{ "AddSceneItem", &WSRequestHandler::AddSceneItem },
 	{ "DuplicateSceneItem", &WSRequestHandler::DuplicateSceneItem },
 	{ "ReorderSceneItems", &WSRequestHandler::ReorderSceneItems },
 

src/WSRequestHandler.h

@@ -78,6 +78,7 @@ class WSRequestHandler {
 		RpcResponse ResetSceneItem(const RpcRequest&);
 		RpcResponse DuplicateSceneItem(const RpcRequest&);
 		RpcResponse DeleteSceneItem(const RpcRequest&);
+		RpcResponse AddSceneItem(const RpcRequest&);
 		RpcResponse ReorderSceneItems(const RpcRequest&);
 
 		RpcResponse GetStreamingStatus(const RpcRequest&);

src/WSRequestHandler_SceneItems.cpp

@@ -2,6 +2,18 @@
 
 #include "WSRequestHandler.h"
 
+struct AddSourceData {
+	obs_source_t *source;
+	obs_sceneitem_t *sceneItem;
+	bool setVisible;
+};
+
+void AddSourceHelper(void *_data, obs_scene_t *scene) {
+	auto *data = reinterpret_cast<AddSourceData*>(_data);
+	data->sceneItem = obs_scene_add(scene, data->source);
+	obs_sceneitem_set_visible(data->sceneItem, data->setVisible);
+}
+
 /**
 * Gets the scene specific properties of the specified source item.
 * Coordinates are relative to the item's parent (the scene or group it belongs to).
@@ -544,6 +556,59 @@ RpcResponse WSRequestHandler::DeleteSceneItem(const RpcRequest& request) {
 	return request.success();
 }
 
+/**
+ * Creates a scene item in a scene. In other words, this is how you add a source into a scene.
+ *
+ * @param {String} `sceneName` Name of the scene to create the scene item in
+ * @param {String} `sourceName` Name of the source to be added
+ * @param {boolean} `setVisible` Whether to make the sceneitem visible on creation or not. Default `true`
+ *
+ * @return {int} `itemId` Numerical ID of the created scene item
+ *
+ * @api requests
+ * @name AddSceneItem
+ * @category scene items
+ * @since unreleased
+ */
+RpcResponse WSRequestHandler::AddSceneItem(const RpcRequest& request) {
+	if (!request.hasField("sceneName") || !request.hasField("sourceName")) {
+		return request.failed("missing request parameters");
+	}
+
+	const char* sceneName = obs_data_get_string(request.parameters(), "sceneName");
+	OBSSourceAutoRelease sceneSource = obs_get_source_by_name(sceneName);
+	OBSScene scene = obs_scene_from_source(sceneSource);
+	if (!scene) {
+		return request.failed("requested scene is invalid or doesnt exist");
+	}
+
+	const char* sourceName = obs_data_get_string(request.parameters(), "sourceName");
+	OBSSourceAutoRelease source = obs_get_source_by_name(sourceName);
+	if (!source) {
+		return request.failed("requested source does not exist");
+	}
+	
+	if (source == sceneSource) {
+		return request.failed("you cannot add a scene as a sceneitem to itself");
+	}
+
+	AddSourceData data;
+	data.source = source;
+	data.setVisible = true;
+	if (request.hasField("setVisible")) {
+		data.setVisible = obs_data_get_bool(request.parameters(), "setVisible");
+	}
+
+	obs_enter_graphics();
+	obs_scene_atomic_update(scene, AddSourceHelper, &data);
+	obs_leave_graphics();
+
+	OBSDataAutoRelease responseData = obs_data_create();
+	obs_data_set_int(responseData, "itemID", obs_sceneitem_get_id(data.sceneItem));
+
+	return request.success(responseData);
+}
+
 /**
  * Duplicates a scene item.
  *