Can Logitech G-Hub (script) listen to several events at the same time?

Question

I have a Lua script that works on Logitech G-Hub, and activates on the G4 key being pressed. It looks a bit like this:

function OnEvent(event, arg)
    if (event == "G_PRESSED" and arg == 4) then
        PressKey("s")
        Sleep(200)
        PressKey("lctrl")
        Sleep(300)
        ...
    end 
end

It goes on to do a lot more. Anyway, I need it to stop doing its whole thing once the G4 key is released. So something like:

function OnEvent(event, arg)
    if (event == "G_PRESSED" and arg == 4) then
        PressKey("s")
        if (event == "G_RELEASED" and arg == 4) then
            return
        end
        Sleep(200)
        if (event == "G_RELEASED" and arg == 4) then
            return
        end
        PressKey("lctrl")
        if (event == "G_RELEASED" and arg == 4) then
            return
        end
        Sleep(300)
        if (event == "G_RELEASED" and arg == 4) then
            return
        end
    end
end

Now obviously, this is not going to work. Just giving an example. I need some sort of event listener inside the first if statement checking if the G4 button has been pressed.

Is it possible to have the function immediately terminate once the button is released, such that future commands do not execute?

Answer 1

You can use polling of key/button statuses inside a long running script to exit it immediately.

First, bind "Forward" action to physical key G4.
"Forward" is the default action for mouse button 5, so Windows will see your G4 press as if it was mouse button 5 press.

Second, set the script:

local function ShoudExitNow()
   -- Exit when mouse button 5 is pressed
   return IsMouseButtonPressed(5)
end

local function InterruptableSleep(ms)
   local tm = GetRunningTime() + ms
   repeat
      -- Check exit condition every 10 ms
      -- A human is unable to press and release a key faster than 30 ms, so 10 ms is enough for polling
      Sleep(10)
      if ShoudExitNow() then return true end
   until GetRunningTime() >= tm
end

function OnEvent(event, arg)
    if event == "G_PRESSED" and arg == 4 then
        PressKey("s")
        if InterruptableSleep(200) then return end
        PressKey("lctrl")
        if InterruptableSleep(300) then return end
        ...
    end 
end