[Gambas-user] Forward events from constructor

[Tobias Boege]

On Sun, 04 Oct 2015, Beno??t Minisini wrote:
> Le 04/10/2015 18:29, Tobias Boege a ?crit :
> > On Sat, 03 Oct 2015, Beno??t Minisini wrote:
> >>> Is there a limitation, about raising events from constructors, I don't know
> >>> of? Also note how, in the demonstration project, I can very well initiate
> >>> the validation procedure just after the constructor finished.
> >>>
> >>
> >> The logic behind that behaviour is that an object whose constructor is
> >> not finished should not be able to raise or catch events.
> >>
> >> Said differently, an object must be ready to deal with events.
> >>
> >
> > Uff, I didn't expect the answer to make this much sense...
> >
> 
> It's not technically necessary to do that, but it avoids a lot of 
> possible annoying bugs in your code.
> 

I understand. And by the way, that Timer trick works even in the following
form:

--8<--[ ValidateBox.class]--------------------------------------------------
  Private $frmControl As FValidateBox
  Private $hTimer As Timer

  Public Sub _new()
    $frmControl = New FValidateBox(Me) As "Control"

    $hTimer = New Timer As "FirstCheck"
    $hTimer.Delay = 1
    $hTimer.Start()
  End

  Public Sub FirstCheck_Timer()
    $hTimer.Stop()
    $frmControl.txtInput_Change() ' Trigger first validation
  End
--8<------------------------------------------------------------------------

The 1 millisecond timer delay is provocative enough that everyone who reads
the code will get that this is a hack and why it's there for. It is not as
self-explanatory as the GB.Post() API which we have in C, though.

Regards,
Tobi

-- 
"There's an old saying: Don't change anything... ever!" -- Mr. Monk