<font color="blue">TShiftState indicates the state of the Alt, Ctrl, and Shift keys and the mouse buttons.
type TShiftState = set of (ssShift, ssAlt, ssCtrl, ssLeft, ssRight, ssMiddle, ssDouble);
The TShiftState type is used by key-event and mouse-event handlers to determine the state of the Alt, Ctrl, and Shift keys and the state of the mouse buttons when the event occurs. It is a set of flags that indicate the following:
ssShift The Shift key is held down.
ssAlt The Alt key is held down.
ssCtrl The Ctrl key is held down.
ssLeft The left mouse button is held down.
ssRight The right mouse button is held down.
ssMiddle The middle mouse button is held down.
ssDouble The mouse was double-clicked.</span>