Mouse gestures

Hover

strip: show comment in tool tip
radar scope: show selection-to-mouse info
unpinned navpoints and elements on the radar scope: show short name, and frequency/channel if navaid
entry in navigator or ATC list: show a tool tip with true heading and distance from radar centre

Click

Left button:

on aircraft body, radar tag, strip or FPL: select
on radar background: deselect
on navpoint:

plain click: fill navigator filter and instruction navpoint fields
with SHIFT if selection contains a strip with a recognised route: add/remove enroute waypoint
with ALT: send "proceed direct" instruction through CPDLC to selected callsign ("request direct" if teaching)

on radio text chat message: recall dest./message in entry line

own message: recalls both
other: fill dest. and focus message field

on instruction panel button, with ALT: send instruction through CPDLC (or request if teaching)

Middle button:

on aircraft body, radar tag, strip or FPL: link to current selection if any and possible
with SHIFT on aircraft body, radar tag, strip or FPL (if selected and linked): unlink from rest of selection

Double-click

No modifiers:

on strip: open strip detail sheet
on aircraft body or radar tag: open linked strip if any
on rack, under strips: create new strip on rack
on loose strip bay background: create new strip in bay
on empty RWY box: start/reset separation timer
on rack tab or column title: edit/delete rack
on radar navpoint: pin/unpin label
on navigator entry: indicate point on radar screen
on notification: notification-dependant
on ATC callsign: raise text chat private channel
on ATC phone line icon: switch outgoing status

if "idle": place call
if outgoing or call in progress: hang up (drop line)
if incoming: answer call

With SHIFT:

on strip: indicate linked ACFT or XPDR identification
on ATC callsign: indicate position if known
on aircraft body: remove hdg/alt./FL/speed assignments
on radar tag: reset text box position
on radar background: add custom text label (annotate radar)
on custom text label: remove label

With ALT:

on strip, aircraft body or radar tag: open current/last CPDLC window for callsign

Click & drag

Left button:

radar scope background (if not locked) or loose strip bay: pan view
radar tag: move tag
aircraft body: vector/instruct (*)

without SHIFT: assign heading or instruct taxi if detected on ground
with SHIFT, dragging vertically: assign alt./FL
with SHIFT, dragging horizontally: assign speed

strip:

within/between racks, loose bays or runway boxes: rerack/reorder/reposition flight strip
drag loose strip with SHIFT: move and keep within bay, pushing edges as needed
drop on shelf: shelve strip, e.g. when releasing a contact
drop on ATC callsign, without ALT: send strip to ATC (handover)
drop on ATC callsign, with ALT if callsign connected to CPDLC: data authority transfer or handover instruction (as teacher: request handover)

Right button:

on radar scope

without SHIFT: quick heading and distance measuring tool + show ground elevation if available
with SHIFT as teacher: create new traffic

in tower view window when not following an aircraft (FlightGear input): look around

(*) Notes on click & drag vectoring:

with ALT (except taxi): send instruction through CPDLC (or request if teaching)
press right button while dragging to abort
in solo sessions if voice recognition turned off: action instructs callsign
as teacher: all actions take direct control of aircraft (no strip callsign look-up)