🚀 go-pugleaf

On Tue, 27 Mar 2001 19:07:40 -0800, Robert Penoyer
<rpenoyer@earthlink.net> wrote:

>I'm trying to learn to use waveInOpen. The fourth argument of this
>function, dwCallback, is an _address_ of a "fixed callback function, an
>event handle, or a handle of a window or thread."
>
>1. How do I determine the address of a function or event handle?

In C/C++ you just specify its name, with no parentheses or arguments.
You may have to cast it to the correct type, which may be DWORD for
a multi-function argument like that one. Yuck.

>2. What is a "fixed" function?

The term is a bit vague, but in practice it must be a standalone
C-style function or a static class member. Normal class members can't
be used as callbacks, since the "this" pointer isn't available to pass
to them.
>3. How do I get the handle of a window or thread?

The handle of a VCL-created windows is obtained with form->Handle.
Threads are normally specified by thread ID, so I'm not sure about
that one.

>4. How do I invoke the event that triggers an event callback? Such an
>event might be "buffer full."

Read up on events in the API help.

The callback mechanism is the easiest to use of these.