UI: Fix group sub-item selection bug

If a group's sub-item is selected in the list box and you select the
group via the preview, the sub-item would be deselected, but that
deselection would not be applied to the sub-item in the list box despite
being deselected.

UI/source-tree.cpp

@@ -119,6 +119,7 @@ void SourceTreeItem::DisconnectSignals()
 {
 	sceneRemoveSignal.Disconnect();
 	itemRemoveSignal.Disconnect();
+	deselectSignal.Disconnect();
 	visibleSignal.Disconnect();
 	renameSignal.Disconnect();
 	removeSignal.Disconnect();
@@ -163,6 +164,16 @@ void SourceTreeItem::ReconnectSignals()
 					Q_ARG(bool, visible));
 	};
 
+	auto itemDeselect = [] (void *data, calldata_t *cd)
+	{
+		SourceTreeItem *this_ = reinterpret_cast<SourceTreeItem*>(data);
+		obs_sceneitem_t *curItem =
+			(obs_sceneitem_t*)calldata_ptr(cd, "item");
+
+		if (curItem == this_->sceneitem)
+			QMetaObject::invokeMethod(this_, "Deselect");
+	};
+
 	auto reorderGroup = [] (void *data, calldata_t*)
 	{
 		SourceTreeItem *this_ = reinterpret_cast<SourceTreeItem*>(data);
@@ -185,6 +196,10 @@ void SourceTreeItem::ReconnectSignals()
 				this);
 	}
 
+	if (scene != GetCurrentScene())
+		deselectSignal.Connect(signal, "item_deselect", itemDeselect,
+				this);
+
 	/* --------------------------------------------------------- */
 
 	auto renamed = [] (void *data, calldata_t *cd)
@@ -432,6 +447,11 @@ void SourceTreeItem::ExpandClicked(bool checked)
 		tree->GetStm()->CollapseGroup(sceneitem);
 }
 
+void SourceTreeItem::Deselect()
+{
+	tree->SelectItem(sceneitem, false);
+}
+
 /* ========================================================================= */
 
 void SourceTreeModel::OBSFrontendEvent(enum obs_frontend_event event, void *ptr)

UI/source-tree.hpp

@@ -63,6 +63,7 @@ private:
 	OBSSignal sceneRemoveSignal;
 	OBSSignal itemRemoveSignal;
 	OBSSignal groupReorderSignal;
+	OBSSignal deselectSignal;
 	OBSSignal visibleSignal;
 	OBSSignal renameSignal;
 	OBSSignal removeSignal;
@@ -77,6 +78,8 @@ private slots:
 	void Renamed(const QString &name);
 
 	void ExpandClicked(bool checked);
+
+	void Deselect();
 };
 
 class SourceTreeModel : public QAbstractListModel {