This is not that difficult. Two solutions,
1. Capture and save the screen after each event that changes it - yuck
2. Record events that result in changes to the display (user input, program
output etc.) Then when you get an update event, playback the events.
/fn
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of Mike
Davis
Sent: Friday, May 19, 2000 3:00 PM
To: Palm Developer Forum
Subject: Re: Screen Refresh Problem OS 3.5 Debug Rom on B/W
> At 09:12 PM 5/18/2000, Mike Davis wrote:
> >Is this problem of the screen not being refreshed (b/w debug rom),
> >when a form is popped up over a form that has WinDraw lines and
> >rectangles, etc., going to be fixed (or is it already), in the debug
> >ROMs?
>
> This is intentional. In low memory situations, dialogs sometimes can't
> allocated enough memory to store the portion of the screen they're
> drawn on top of. In this case, when the dialog is dismissed, the form
> has to do its own redrawing. The debug ROMs simulate this low memory
> condition to expose latent bugs in applications. In order to get your
> application to refresh properly on the debug ROMs (and on release ROMs
> when memory is low), all you need to do is to handle the
> frmUpdateEvent, and make it call FrmDrawForm, followed by any WinDraw
> lines and such, then return with handled = true. -- Peter Epstein Palm
> Inc. Developer
That is what another person said but here is the problem. Say an
application does something (draws some lines) based on user input,
then does something else, then does something else, and further say
that these "something elses" are not predictable, then a popup form
comes up. How is an application supposed to handle the FrmUpdateForm
without knowing what might have transpired before the popup? That
would mean having to keep a record of all possible drawing actions
that might have gone on before the popup. In the case of a simple
form, where these details are known in advance, this is not a
problem. But for other cases this is.
This looks like a considerable burden placed on the developer, to
compensate for small dynamic memory availible to the OS. I realize,
I guess, that there is no option. It looks like the Palm OS trying
to do too much without resources available.
Here is the situation. Say you have an application that offers the
users the ability to program, within the application. I mean an
application that allows the user to say write a program (within the
application) that will graph to the screen. In addition to the user
program that can draw, which is completely unknown to the
FrmUpdateForm event, you now require the application to keep track of
the user's program steps again. You have to do this because you
never know when a popup will come up over this graphing. So, to be
able to refresh you have to keep track of all graphing steps that
were performed.
How does anyone overcome this limitation in this case?
>
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