OpenEuphoria

Re: Help! GPF

• Posted by David Cuny <dcuny at LANSET.COM> Aug 04, 1999
• 403 views

I *think* I'm making a bit of progress on the GPF, but I'm not sure. Here's
what I know and suspect so far. The event names are approximate; I'm going
by memory.

Win32Lib is happily chugging along, processing Window events that are
associated with painting the controls - WM_ERASEBKGND and WM_COLORCNGSTATIC;
that sort of thing. Nothing unusual at all. Controls are popping up in the
window as they should.

Then one of the menu items gets a WM_PAINT event. Huh? I didn't think menu
items got paint events. Besides, the paint event should belong to the next
ordinal control, not a menu item. So this looks suspicious.

Win32Lib tries to let the menu item's default handler routine take care of
the WM_PAINT event, calling the stored default event handler. But I'm not
even sure that a menu item *has* a default event handler routine stored -
there's probably a zero for a value. Win32Lib never returns from the call to
the c_func() - I think this is where it goes off to la-la land.

The next event is a WM_CANCELSTATE event. This event is triggered when
Windows is about to take away focus from a window, and gives the application
or control a chance to gracefully drop the mouse if it's done a modal grab.
This is usually issued just before popping up a modal dialog box. This is
followed by a WM_LOSTFOCUS as the window loses focus, and at this point, I
think that Windows is putting up the dialog box displaying the GPF
information.

Focus returns to the window with a WM_GOTFOCUS, and from that point on, the
only event being processed is the WM_PAINT event, aimed at the same menu
item:

    WM_PAINT
    WM_PAINT
    WM_PAINT
    etc.

My guess is that, for some unknown reason, Win32Lib is somehow
mis-identifying the control that the handle is associated with, and pointing
to the menu item instead. I'm not sure how that could be happening, since it
just does a find() on a list of handles.

Why is this happening? I don't know. Maybe it has something to do with the
events taking place outside the WinMain loop; maybe I've done something
really stupid; maybe I'm entirely on the wrong track. Hopefully I'll have
better answers later.

-- David Cuny