Refactor QueueUITask helper

lib/utils/temp-variable.cpp

@@ -734,12 +734,10 @@ TempVarSignalManager *TempVarSignalManager::Instance()
 void NotifyUIAboutTempVarChange(MacroSegment *segment)
 {
 	IncrementTempVarInUseGeneration();
-	QueueUITask(
-		[](void *segment) {
-			TempVarSignalManager::Instance()->SegmentTempVarsChanged(
-				(MacroSegment *)segment);
-		},
-		segment);
+	QueueUITask([segment]() {
+		TempVarSignalManager::Instance()->SegmentTempVarsChanged(
+			segment);
+	});
 }
 
 TempVarOutputMappingsWidget::TempVarOutputMappingsWidget(QWidget *parent)

lib/utils/ui-helpers.cpp

@@ -184,9 +184,9 @@ std::string GetThemeTypeName()
 #endif
 }
 
-void QueueUITask(void (*task)(void *param), void *param)
+void QueueUITaskRaw(void (*task)(void *param), void *param, bool wait)
 {
-	obs_queue_task(OBS_TASK_UI, task, param, false);
+	obs_queue_task(OBS_TASK_UI, task, param, wait);
 }
 
 bool IsCursorInWidgetArea(QWidget *widget)

lib/utils/ui-helpers.hpp

@@ -6,7 +6,10 @@
 #include <QIcon>
 #include <QString>
 
+#include <memory>
 #include <string>
+#include <type_traits>
+#include <utility>
 
 class QAbstractButton;
 class QComboBox;
@@ -38,7 +41,23 @@ EXPORT void DisplayTrayMessage(const QString &title, const QString &msg,
 EXPORT std::string GetThemeTypeName();
 EXPORT QWidget *GetSettingsWindow();
 
-EXPORT void QueueUITask(void (*task)(void *param), void *param);
+EXPORT void QueueUITaskRaw(void (*task)(void *param), void *param,
+			   bool wait = false);
+
+// Runs func on the main/UI thread; blocks if wait is true.
+template<typename F> void QueueUITask(F &&func, bool wait = false)
+{
+	using FnType = std::decay_t<F>;
+	auto *heapFunc = new FnType(std::forward<F>(func));
+
+	QueueUITaskRaw(
+		[](void *param) {
+			std::unique_ptr<FnType> fn(
+				static_cast<FnType *>(param));
+			(*fn)();
+		},
+		heapFunc, wait);
+}
 
 bool IsCursorInWidgetArea(QWidget *widget);