tcl-mac

[MACTCL] Coexisting with Tk's event loop

[Yves S. <yst...@uw...>]

Hi,

I am trying to get a Carbon window that I create and provide with an 
EventHandler to be sent some events in an embedded tcl application. In 
Win32, all events come through to the handler. On OSX, I am only getting 
activate events - mouse and keyboard events are siphoned off.

Is there a function I can call that prevents this from happening?

Thanks.

Yves

Re: [MACTCL] Coexisting with Tk's event loop

[Jim I. <ji...@ap...>]

Is this an embedded Tcl application, or are you also using Aqua Tk.  If the
former, you will have to do quite a bit of work to get this going.  Look at
the Aqua Tk sources to get started.  If you are also using Aqua Tk, then I
started to think about this when we were doing the Carbonization, but didn't
get all the way there.  The idea is in the code (which is the core of the Tk
event converter):

static int
ReceiveAndProcessEvent()
{
    TkMacOSXEvent       macEvent;
    MacEventStatus   eventStatus;
    int              err;
    char             buf [ 256 ];

    /*
     * This is a poll, since we have already counted the events coming
     * into this routine, and are guaranteed to have one waiting.
     */
     
    err=ReceiveNextEvent(0, NULL, kEventDurationNoWait,
            true, &macEvent.eventRef);
    if (err != noErr) {
        return err;
    } else {
        macEvent.eClass = GetEventClass(macEvent.eventRef);
        macEvent.eKind = GetEventKind(macEvent.eventRef);
        bzero(&eventStatus, sizeof(eventStatus));
        TkMacOSXProcessEvent(&macEvent,&eventStatus);
        if (!eventStatus.handledByTk) {
            if (!targetRef) {
                targetRef=GetEventDispatcherTarget();
            }
            
            err= SendEventToEventTarget(macEvent.eventRef,targetRef);
            if (err != noErr /* && err != eventNotHandledErr */) {
                fprintf(stderr,
                        "RCNE SendEventToEventTarget (%s) failed, %d\n",
                        CarbonEventToAscii(macEvent.eventRef,buf ),err);
            }
         }
         ReleaseEvent(macEvent.eventRef);
         return 0;
     }
}

So if any of the individual event handlers sets handledByTk to 0, it will
bet passed to the Event handler registered in the targetRef of the event.

It is  not wired up, however.  So, for instance try a patch like:

Index: tkMacOSXMouseEvent.c
===================================================================
RCS file: /cvsroot/tktoolkit/tk/macosx/Attic/tkMacOSXMouseEvent.c,v
retrieving revision 1.1.2.2
diff -p -r1.1.2.2 tkMacOSXMouseEvent.c
*** tkMacOSXMouseEvent.c        5 Feb 2002 02:25:17 -0000       1.1.2.2
--- tkMacOSXMouseEvent.c        22 May 2002 06:10:22 -0000
*************** TkMacOSXProcessMouseEvent(TkMacOSXEvent
*** 171,177 ****
  
      medPtr->windowPart= FindWindow(where, &medPtr->whichWin);
      window = TkMacOSXGetXWindow(medPtr->whichWin);
!        
      frontWindow = FrontWindow();
      medPtr->activeNonFloating = ActiveNonFloatingWindow();
  
--- 171,181 ----
  
      medPtr->windowPart= FindWindow(where, &medPtr->whichWin);
      window = TkMacOSXGetXWindow(medPtr->whichWin);
!     if (medPtr->whichWin != NULL && window == None) {
!         statusPtr->handledByTk = 0;
!         return 0;
!     }
!     
      frontWindow = FrontWindow();
      medPtr->activeNonFloating = ActiveNonFloatingWindow();
  

This will make all mouse events that are in a window that is NOT Tk's will
be dispatched to the Event handler for the window.  This is probably wrong,
I just hacked it in quickly tonight.  Probably better would be to check &
make sure the unrecognized window is the FRONT window.  This doesn't deal
with the other events, like Activate, Keystroke, Menu events when your
window is in the front.  Adding these behaviors is pretty straightforward,
but I have to think a bit more about when exactly to send the events to the
unrecognized window...

Jim

> Hi,
> 
> I am trying to get a Carbon window that I create and provide with an
> EventHandler to be sent some events in an embedded tcl application. In
> Win32, all events come through to the handler. On OSX, I am only getting
> activate events - mouse and keyboard events are siphoned off.
> 
> Is there a function I can call that prevents this from happening?
> 
> Thanks.
> 
> Yves
> 
> 
> _______________________________________________________________
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-- 
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Jim Ingham                              ji...@ap...
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