Restructure "src/" folder

Moving files from the "src/" folder into "src/legacy", "src/macro-core",
and "src/utils" was necessary as it was becoming a bit too cluttered.

src/utils/duration-control.hpp

@@ -0,0 +1,60 @@
+#pragma once
+#include <QWidget>
+#include <QDoubleSpinBox>
+#include <QComboBox>
+#include <QPushButton>
+#include <chrono>
+
+#include "obs-data.h"
+
+enum class DurationUnit {
+	SECONDS,
+	MINUTES,
+	HOURS,
+};
+
+class Duration {
+public:
+	void Save(obs_data_t *obj, const char *secondsName = "seconds",
+		  const char *unitName = "displayUnit");
+	void Load(obs_data_t *obj, const char *secondsName = "seconds",
+		  const char *unitName = "displayUnit");
+
+	bool DurationReached();
+	bool IsReset();
+	double TimeRemaining();
+	void SetTimeRemaining(double);
+	void Reset();
+	std::string ToString();
+
+	double seconds = 0.;
+	// only used for UI
+	DurationUnit displayUnit = DurationUnit::SECONDS;
+
+private:
+	std::chrono::high_resolution_clock::time_point _startTime;
+};
+
+class DurationSelection : public QWidget {
+	Q_OBJECT
+public:
+	DurationSelection(QWidget *parent = nullptr,
+			  bool showUnitSelection = true);
+	void SetValue(double value);
+	void SetUnit(DurationUnit u);
+	void SetDuration(Duration d);
+	QDoubleSpinBox *SpinBox() { return _duration; }
+
+private slots:
+	void _DurationChanged(double value);
+	void _UnitChanged(int idx);
+signals:
+	void DurationChanged(double value); // always reutrn value in seconds
+	void UnitChanged(DurationUnit u);
+
+private:
+	QDoubleSpinBox *_duration;
+	QComboBox *_unitSelection;
+
+	double _unitMultiplier;
+};