Hotkeys

pkg/hotkeys binds keys and joystick buttons the player presses in the simulator to an add-on’s actions, for example “answer the current checklist item” on Ctrl+Shift+C or a yoke button. It is built on SimConnect’s input groups: MapInputEventToClientEvent, SetInputGroupPriority, SetInputGroupState, RemoveInputEvent and ClearInputGroup, which the engine and the manager also expose directly.

h := hotkeys.New(0) // IDs from hotkeys.DefaultIDBase (0xB100)
h.Bind("checklistItem", "Ctrl+Shift+C", func() { crew.AnswerItem() })
h.SetBindings(loadedFromSettings) // the player's own bindings, by action name
h.Attach(client)                  // on every connect and reconnect
for msg := range client.Stream() {
    if h.Handle(msg) {
        continue
    }
    // …
}
save(h.Bindings()) // map[action]definition for the settings file

• A definition is SimConnect’s input string: keys joined with + ("Ctrl+Shift+C", "VK_F12"), or a joystick input ("joystick:0:button:5"). Which keys MSFS 2024 passes to SimConnect, and its joystick numbering, still need a live check.
• Bind before or after Attach. Binding a name again moves the action to the new input: the old one is removed and the new one mapped.
• Attach maps every binding on the connection, with the group at the highest priority and on. Call it again after a reconnect.
• Enable(false) turns the group off, so the keys reach the simulator as usual.
• Handle calls the action of a pressed input (outside the lock) and reports whether the message was one of its own.

IDs: the input group is the ID base and the actions’ client events are the base + 1 onwards, up to MaxActions (64). The default base, 0xB100, is clear of the traffic World’s 0xA000 range. Give another base to New to move it.