UI: Add Undo/Redo for volume change/mute via main fader

UI/volume-control.cpp

@@ -1,3 +1,4 @@
+#include "window-basic-main.hpp"
 #include "volume-control.hpp"
 #include "qt-wrappers.hpp"
 #include "obs-app.hpp"
@@ -63,13 +64,46 @@ void VolControl::VolumeMuted(bool muted)
 
 void VolControl::SetMuted(bool checked)
 {
+	bool prev = obs_source_muted(source);
 	obs_source_set_muted(source, checked);
+
+	auto undo_redo = [](const std::string &name, bool val) {
+		obs_source_t *source = obs_get_source_by_name(name.c_str());
+		obs_source_set_muted(source, val);
+		obs_source_release(source);
+	};
+
+	QString text =
+		QTStr(checked ? "Undo.Volume.Mute" : "Undo.Volume.Unmute");
+
+	const char *name = obs_source_get_name(source);
+	OBSBasic::Get()->undo_s.add_action(
+		text.arg(name),
+		std::bind(undo_redo, std::placeholders::_1, prev),
+		std::bind(undo_redo, std::placeholders::_1, checked), name,
+		name);
 }
 
 void VolControl::SliderChanged(int vol)
 {
+	float prev = obs_source_get_volume(source);
+
 	obs_fader_set_deflection(obs_fader, float(vol) / FADER_PRECISION);
 	updateText();
+
+	auto undo_redo = [](const std::string &name, float val) {
+		obs_source_t *source = obs_get_source_by_name(name.c_str());
+		obs_source_set_volume(source, val);
+		obs_source_release(source);
+	};
+
+	float val = obs_source_get_volume(source);
+	const char *name = obs_source_get_name(source);
+	OBSBasic::Get()->undo_s.add_action(
+		QTStr("Undo.Volume.Change").arg(name),
+		std::bind(undo_redo, std::placeholders::_1, prev),
+		std::bind(undo_redo, std::placeholders::_1, val), name, name,
+		true);
 }
 
 void VolControl::updateText()