1. One or more computer-storage media having computer-executable instructions embodied thereon that, when executed, perform a method for initiating an action upon detecting a drag-operation on a graphical user interface (GUI) rendered at a touchscreen display, the method comprising: detecting a user-initiated input directed to a top-level control button; determining whether the user-initiated input is a drag-operation or a tap-type operation; upon recognizing the user-initiated input as the drag-operation being applied in a first direction, invoking a first action upon the drag-operation crossing a first trigger boundary that is established in the first direction from the top-level control button; upon recognizing the user-initiated input as the drag-operation being applied in a second direction, invoking a second action upon the drag-operation crossing a second trigger boundary that is established in the second direction from the top-level control button, wherein the first and second trigger boundaries are hidden from the user of the touchscreen display; and rendering an indication of the first or second action at the GUI.