developer's mag
main page
article
part 1
part 2
part 3
part 4
part 5
part 6
part 7
part 8
3 - Testing For Keys
To check for these and other keys, you could use a simple message loop such as the following: S32 CWindow1::MsgHandler(MSG_TYPE type,CViewable *from,S32 data)
{
if ( MSG_KEY==type )
{
switch (data)
{
case K_JOG_UP:
// process key...
break;
case K_JOG_DOWN:
// process key...
break;
// and so forth for specific keys...
default:
// handle all other keys here
break;
}
return 1; // handled - prevents beeping
}
return CWindow::MsgHandler(type,from,data); // default message handler
}
Note there are two ways to end processing
of each key message. Returning 1 (true) tells
the parent routine the message has been processed
completely. Calling the default window message
handler CWindow::MsgHandler() lets ordinary
processing continue. For keys, this will
often result in a beep, which may or may
not be your preference.The column's sample program (both source and .SEB file) uses a message loop like this to display all key characters, as well as the special key values. With it, you can get a feel for the user interface options available.
Previous Section
Next Section