gdk:event-button-button (instance)

instance -- a gdk:event-button instance
button -- an unsigned integer for the button which was pressed

The accessor for the button slot of the gdk:event-button structure returns the button which was pressed or released, numbered from 1 to 5. Normally button 1 is the left mouse button, 2 is the middle button, and 3 is the right button. On 2-button mice, the middle button can often be simulated by pressing both mouse buttons together.