Programming Standard Windows Application

esferatec

I am currently creating a serial data logger program. I am wondering whether I am correctly using the event loop. I have found various approaches in the documentation and am not sure which one is best.

ui.run(win):wait()

win:show()
repeat
    ui.update()
until not win.visible

win:show()
while win.visible do
     ui.update()

To clarify my thoughts: I have a main window with various controls, including a Combobox to select the serial port. As long as no port has been selected, the other controls should be disabled.

Until now, I have displayed the window with “ui.rin(win):wait()” and then deactivated all other controls in the script. Once a port has been selected, I enabled the other controls via the event "Combobox.onSelect()". That means I have to disable or enable controls in different events.

Then I found somethin with async:

ui.run(win)

async(function()
  while win.visible do

    if not isnil(win.PortCombobox.selected) then
      win.WM_DISABLE:enable()
    else
      win.WM_DISABLE:disable()
    end
    if not isnil(win.COM) then
      if win.COM.isopen then
        win.WM_START:disable()
      else
        win.WM_START:enable()
      end
    end
    
    sleep()
    ui.update()
  end
end)

waitall()

I define the conditions for disabling or enabling various controls in the async function. Now I just have to define it in one place.

Is this a good way to program an app?

Samir

It's a very good question.
In fact, you can use any paradigm you want to suit your needs.

You can manage the calls to ui.update() in a loop or in a Task, or use ui.run() that will create a Task to call ui.update() periodicaly.

Next LuaRT version, 2.1.0, will simplify this : when requiring the ui module, a new Task will be created in background to manage events, so you won't have to take care of this.

You will be able to access the ui Task using ui.task property to cancel it or to wait on it. You will be able to use waitall() too

The ui Task will be terminated once the main Window will be closed by the user (the main Window is the first Window created or any other one you want by setting the new property ui.mainWindow)

esferatec

Next LuaRT version, 2.1.0, will simplify this : when requiring the ui module, a new Task will be created in background to manage events, so you won't have to take care of this.

Couldn't that lead to problems if you require the “ui” in different files? Does it creates several Tasks?

Samir

No it will create one unique Task 😉