This topic is discussed at
http://www.palmos.com/dev/tech/docs/palmos35/topissues.html
(it's the eighth "Problem Symptom" on the list)
SDK 3.5 Reference also discusses this under frmUpdateEvent.
"JB Parrett" <[EMAIL PROTECTED]> wrote in message
news:22185@palm-dev-forum...
>
> on 8/24/00 9:41 AM, Kent Quander at [EMAIL PROTECTED] wrote:
>
> > Some time ago I ran into the issue where the screen is not restored
after a
> > popup alert goes away. This effects me since I do a lot of custom
drawing
> > on forms. It is particularly an issue on the Symbol units ... after the
> > scanMgr library is loaded, a fellow only has about 5K of dynamic memory
to
> > work with. (the SPT1700's seem to be the most restrictive in this
regard).
> > Anyway, I "solved" the problem by wrapping the FrmCustomAlert() routine
as
> > follows:
>
> If you are doing your own drawing, you must provide your own
frmUpdateEvent
> case in your form event handler. The default frmUpdateEvent (handled by
the
> OS if you don't) redraws the form - on later versions of the OS this means
> the form is erased first, then the title and bounds (if modal) are drawn,
> then the form objects are told to draw. If you are doing any drawing on
the
> form yourself (gadgets, etc.), you need to do the following in your event
> handler:
>
> case frmUpdateEvent:
> FrmDrawForm(FrmGetActiveForm());
> // Call your drawing routine here
> fHandled = true; // Override the default behavior
> break;
>
> Also, check the Save Behind box for dialogs (modal forms). The system will
> try to save the screen bits underneath the dialog/alert offscreen if
> possible (for restoration when the dialog/alert is erased), but if there
is
> not enough dynamic heap available to support this, an update event is
added
> to the event queue instead.
>
> For a complete discussion of the default system behavior for different
event
> types and form objects, see Knowledge Base article #1788 (User Interface).
>
> -JB
>
> ----------------------------------------------
> JB Parrett [EMAIL PROTECTED]
> Palm, Inc.
>
> We grow a lot faster than trees,
> so we miss a lot of stuff. - B. Andreas
>
>
>
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