48e05e26_QListView_Class__Action
[Keypress] Left Arrow [Action] 
If the current item is closed (+ icon) or has no children, make its parent item current and visible. If the current item is open (- icon) close it, i.e. hide its children. Exception: if the current item is the first item and is closed and the horizontal scrollbar is offset to the right the list view will be scrolled left.
QListView Class
Action