set_input_focus(+WindowSpec, +RevertTo, +Time)

Changes the input focus and the last-focus-change time. It has no effect if the specified Time is earlier than the current last-focus-change-time or later than the current X server time. It generates focus_in and focus_out events.

WindowSpec is one of:

A ProXL Window
The window that will acquire the input focus.
If the focus window should be dynamically taken to be the root window of whatever screen the pointer is on at each keyboard event.
If all keyboard arguments should be discarded until a new focus window is set.

RevertTo specifies which window that the input focus should revert to, if the current focus becomes not viewable. One of:

Time is a timestamp in milliseconds (from an event) or current_time.