Re: Who is responsible for refreshing the UI?

A generic message pump that dispatches all messages and finishes
looks like the following:

MSG msg;
while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
    if (msg.message == WM_QUIT) {
        PostQuitMessage(msg.wParam); // resubmit WM_QUIT
        // Also need to abort your action here
        break;
    }
    TranslateMessage(&msg); // Only needed if you allow keyboard messages
    DispatchMessage(&msg);
}

You may want to filter out only certain messages, for example
if you only allow WM_PAINT, it'd be like:

while (PeekMessage(&msg, NULL, WM_PAINT, WM_PAINT, PM_REMOVE)) {
....

You can also chain multiple PeekMessage-s for processing
several messages or intervals:

while (PeekMessage(&msg, NULL, WM_PAINT, WM_PAINT, PM_REMOVE) ||
        PeekMessage(&msg, NULL, WM_KEYFIRST, WM_KEYLAST, PM_REMOVE)) {
....

The above message pump processes only WM_PAINT and
keyboard messages.

PeekMessage also has basic filters via flags in the last argument,
see the documentation for more details.

You should be concerned about reentrancy only if you use the
non-filtering generic message pump. If you filter the messages
you can construct your filter not to allow COM messages so
no nested COM calls would occur (IIRC all COM messages
are in the WM_USER space, but this is not documented).

Finally, if you have a window that needs full message processing,
you can filter by a window as well (that's the NULL second
parameter to PeekMessage - use your HWND there to filter the
messages for that window only).

I should note that since you don't know the client's accelerators,
you will necessarily fail to invoke them. If you want to allow
that, you need to accept an interface pointer from your client
and call it within the message loop to translate any accelerators
in your client.

Note WM_QUIT is never filtered out, regardless of your filters.

--
=====================================
Alexander Nickolov
Microsoft MVP [VC], MCSD
email: agnickolov@mvps.org
MVP VC FAQ: http://www.mvps.org/vcfaq
=====================================

"Bruce E. Stemplewski" <Bruce.Stemplewski@removenospamstempsoft.com> wrote
in message news:ofrag.1155$rT5.613@trndny04...