There are two types of mouse gestures indicating button clicks:

button-down

button-up

When a mouse button is pressed or released, two gestures are sent. The first gesture indicates the specific button number, and if this gesture is not handled, the second has a button number set to f:

Because tuple literals fill unspecified slots with f, the last gesture can be written as T{ button-down }.

Gestures to indicate mouse motion, depending on whenever a button is held down or not:

motion

drag

Gestures to indicate that the mouse has crossed gadget boundaries:

mouse-enter

mouse-leave

A number of global variables are set after a mouse gesture is sent. These variables can be read to obtain additional information about the gesture.

hand-gadget

hand-world

hand-loc

hand-buttons

hand-clicked

hand-click-loc

hand-click#

There are some utility words for working with click locations:

hand-rel ( gadget -- loc )

hand-click-rel ( gadget -- loc )

drag-loc ( -- loc )

Mouse scroll wheel gesture:

mouse-scroll

Global variable set when a mouse scroll wheel gesture is sent:

scroll-direction