Add SceneItemSelection and SceneItemSelectionWidget

Allows selecting individual scene items if there are duplicate entries
for the same source.

src/headers/scene-item-selection.hpp

@@ -0,0 +1,59 @@
+#pragma once
+#include <QComboBox>
+#include <obs-data.h>
+
+#include "scene-selection.hpp"
+#include "utility.hpp"
+
+class SceneItemSelection {
+public:
+	void Save(obs_data_t *obj, const char *name = "sceneItem",
+		  const char *targetName = "sceneItemTarget",
+		  const char *idxName = "sceneItemIdx");
+	void Load(obs_data_t *obj, const char *name = "sceneItem",
+		  const char *targetName = "sceneItemTarget",
+		  const char *idxName = "sceneItemIdx");
+
+	enum class Target { ALL, ANY, INDIVIDUAL };
+	Target GetType() { return _target; }
+	std::vector<obs_scene_item *> GetSceneItems(SceneSelection &s);
+	std::string ToString();
+
+private:
+	OBSWeakSource _sceneItem;
+	Target _target = Target::ALL;
+	int _idx = 0;
+	friend class SceneItemSelectionWidget;
+};
+
+class SceneItemSelectionWidget : public QWidget {
+	Q_OBJECT
+
+public:
+	enum class AllSelectionType { ALL, ANY };
+	SceneItemSelectionWidget(
+		QWidget *parent, bool allSelection = true,
+		AllSelectionType allType = AllSelectionType::ALL);
+	void SetSceneItem(const SceneItemSelection &);
+	void SetScene(const SceneSelection &);
+	void SetShowAll(bool);
+	void SetShowAllSelectionType(AllSelectionType t);
+signals:
+	void SceneItemChanged(const SceneItemSelection &);
+
+private slots:
+	void SceneChanged(const SceneSelection &);
+	void SelectionChanged(const QString &name);
+	void IdxChanged(int);
+
+private:
+	void SetupIdxSelection(int);
+
+	QComboBox *_sceneItems;
+	QComboBox *_idx;
+
+	SceneSelection _scene;
+	OBSWeakSource _sceneItem;
+	bool _showAll = false;
+	AllSelectionType _allType = AllSelectionType::ALL;
+};