OpenEuphoria

RE: Re[2]: getSelf() doesn't work in onOpen

• Posted by Derek Parnell <ddparnell at bigpond.com> Apr 11, 2001
• 399 views

Okay, I assumed that only the main window was giving us trouble, but you
have correctly highlighted a more general bug.

Any place in which a user-defined event handler can be called, that is
itself called from a routine that was not invoked due a Windows message,
needs special handling for getSelf() to work.

Your fix only does part of the job. The proper way is to do this ...

     pushSelf(id)
     invokeHandler(id, ...)
     VOID = popSelf()

that is to say, if you use pushSelf() you also need to match it with a
popSelf() call.

Of course the simple way to fix this, even if it is overkill, is to embed
the push/pop in the invokeHandler() routine.

-----------
cheers,
Derek Parnell

> -----Original Message-----
> From: Thomas Parslow (PatRat) [mailto:patrat at rat-software.com]
> Sent: Thursday, 12 April 2001 8:52 AM
> To: EUforum
> Subject: Re[2]: getSelf() doesn't work in onOpen
>
>
>
>
> > you have found a bug.
> >
> > There are two workarounds.
> >
> > a) Instead of using onOpen[xx] use setHandler().
> >
> >    setHandler( mywin, w32HOpen, routine_id("mywin_open"))
> >
> > if you do this the parameters of the handler procedure must be...
> >   procedure mywin_open(integer self, integer event, sequence parms)
> >
> > and you don't have to call getSelf() as the 'self'
> parameter is supplied.
> >
> > b) Change win32lib.ew.
> >    Find the line ...
> >          mainWindow = id
> >    in the WinMain() procedure and insert after that ...
> >          pushSelf(id)
> >
> > Now getSelf() should work.
> >
> > The reason is that getSelf() was designed to be used by
> handlers that got
> > invoked as a response to a Windows message. But at the time
> of opening the
> > very first window, which is done in WinMain, there has been
> no Windows
> > messages yet so the internal stack of control ids is empty.
> The fix to
> > win32lib.ew just preloads the stack with the initial window's id.
> >
> > The setHandler() function doesn't use the internal id
> stack, so that's why
> > it works.
> >
> > ------
> > Derek Parnell
> > Melbourne, Australia
> > "To finish a job quickly, go slower."
>
> Hi,
> This didn't fix the problem, it was happening when I was opening
<snip>

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